tag:theconversation.com,2011:/id/topics/fossils-932/articlesFossils – The Conversation2024-03-27T12:37:29Ztag:theconversation.com,2011:article/2232682024-03-27T12:37:29Z2024-03-27T12:37:29ZHorses lived in the Americas for millions of years – new research helps paleontologists understand the fossils we’ve found and those that are missing from the record<figure><img src="https://images.theconversation.com/files/574775/original/file-20240211-26-t88v8r.jpg?ixlib=rb-1.1.0&rect=63%2C121%2C4179%2C2650&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">People have collected fossil horses throughout North America for centuries.</span> <span class="attribution"><span class="source">Florida Museum/Mary Warrick</span></span></figcaption></figure><p>Many people assume that horses first came to the Americas when Spanish explorers brought them here about 500 years ago. In fact, recent research has <a href="https://theconversation.com/archaeology-and-genomics-together-with-indigenous-knowledge-revise-the-human-horse-story-in-the-american-west-202222">confirmed a European origin</a> for horses associated with humans in the American Southwest and Great Plains.</p>
<p>But those weren’t the first horses in North America. The family Equidae, which includes domesticated varieties of horses and donkeys along with zebras and their kin, is actually native to the Americas. The <a href="https://doi.org/10.1126/science.1105458">fossil record reveals</a> horse origins here more than 50 million years ago, as well as their extinction throughout the Americas during the last Ice Age about 10,000 years ago.</p>
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<a href="https://images.theconversation.com/files/584586/original/file-20240326-30-4szthv.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="family tree showing horse evolution diversifying over time" src="https://images.theconversation.com/files/584586/original/file-20240326-30-4szthv.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/584586/original/file-20240326-30-4szthv.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=741&fit=crop&dpr=1 600w, https://images.theconversation.com/files/584586/original/file-20240326-30-4szthv.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=741&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/584586/original/file-20240326-30-4szthv.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=741&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/584586/original/file-20240326-30-4szthv.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=932&fit=crop&dpr=1 754w, https://images.theconversation.com/files/584586/original/file-20240326-30-4szthv.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=932&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/584586/original/file-20240326-30-4szthv.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=932&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Phylogeny, geographic distribution, diet and body sizes of the family Equidae over the past 55 million years.</span>
<span class="attribution"><a class="source" href="https://doi.org/10.1126/science.1105458">From 'Fossil horses–evidence for evolution.' Science. MacFadden, 2005. Reprinted with permission from AAAS.</a></span>
</figcaption>
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<p>We are <a href="https://scholar.google.com/citations?user=xhm6ez4AAAAJ&hl=en&oi=ao">paleontologists</a> <a href="https://scholar.google.com/citations?user=oZ8oBigAAAAJ&hl=en&oi=ao">who focus our research</a> on various types of fossils, including ancient horses. <a href="https://doi.org/10.1017/pab.2023.35">Our most recent work</a> used computer statistics to analyze gaps in the fossil record to infer more about which horse species really did and didn’t live in one ancient habitat in Florida.</p>
<h2>Horses evolved as ecosystems changed</h2>
<p>People have collected fossil horses throughout North America for centuries. Because horse fossils are abundant and widespread across the continent, scientists often point to the <a href="https://www.cambridge.org/us/universitypress/subjects/earth-and-environmental-science/palaeontology-and-life-history/fossil-horses-systematics-paleobiology-and-evolution-family-equidae?format=PB">long span of the horse family</a> as evidence of long-term evolutionary change.</p>
<p>Paleontologists like us, who study extinct mammals, almost never find complete skeletons. Instead, we focus on durable fossil teeth, which help us understand ancient diets, and fossil limbs, which help clarify how these animals moved.</p>
<p>Horses are eating machines. In the wild today, they primarily feed on grasses that don’t provide much nutrition, and thus they need to consume large quantities to survive. The large teeth of modern horses and their ancestors are adapted primarily for grazing on gritty grasses. They replaced smaller teeth of more primitive horses adapted to <a href="https://doi.org/10.1016/S0031-0182(01)00359-5">browsing on soft leafy vegetation</a>.</p>
<p>We know what horses ate millions of years ago by studying distinctive microscopic scratches, pits and other wear patterns on their teeth that were created <a href="https://doi.org/10.1016/j.palaeo.2015.11.004">as the ancient horses chewed plant foods</a>. And analyses of carbon preserved in fossil teeth show that <a href="https://doi.org/10.1016/0031-0182(94)90099-X">coexisting horse species ate different plants</a>; some browsed on leaves from bushes and trees, some grazed on grasses, and yet others were mixed feeders.</p>
<p>The change in tooth shape tracks the change in dominant vegetation types in North America, from tropical forests that then gave way to the <a href="https://doi.org/10.1146/annurev-earth-040809-152402">great expansion of open prairie grasslands</a>. As the climate and flora changed over millions of years, horses shifted from being largely forest-dwelling browsers to largely open-country grazers. Their teeth and feeding patterns adapted to the environment.</p>
<p>Another adaptation is visible on horses’ feet. Modern horses have one hoofed toe on each foot. Many extinct fossil horses – the ancient ancestors of today’s horses – had three toes per foot. The single toe on each elongated foot is good for rapid and sustained running to evade predators and for long-distance seasonal migrations. The more ancient three-toed feet provided <a href="https://doi.org/10.1038/308179a0">stability on unstable or wet ground</a>. The adaptation from three toes to one was likely in response to changing habitats.</p>
<p>But even as the environment changed, one distinct species didn’t completely replace another overnight. The fossil record in North America documents periods millions of years ago when multiple horse species coexisted on the ancient landscapes. Species were of different sizes and had teeth equipped for munching different plants, so they weren’t competing directly for the same foods. Different habitats within these ancient ecosystems likely had some species more adapted to forests and others more adapted to grasslands.</p>
<h2>Understanding Florida’s fossil record</h2>
<p>Paleontologists have been collecting horse fossils in Florida for over 125 years. The Florida Museum of Natural History at the University of Florida, where we work, has more than 70,000 fossil horse specimens from more than a thousand locations across the state.</p>
<p>One of our more <a href="https://www.floridamuseum.ufl.edu/florida-vertebrate-fossils/sites/montbrook/">prolific fossil sites, Montbrook</a>, provides a glimpse of a 5.8 million-year-old ancient stream bed. It preserved more than 30 extinct mammals, including rhinos, elephants and carnivores, as well as hundreds of bones and teeth of fossil horses.</p>
<p>Although six horse species are known elsewhere in Florida, we have only found four so far at Montbrook. This smaller number of horse species perplexed us, <a href="https://doi.org/10.1017/pab.2023.35">so we decided to investigate</a>. Did the two “missing” horse species truly not live at Montbrook, or have scientists simply not discovered their fossil remains yet?</p>
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<a href="https://images.theconversation.com/files/584451/original/file-20240326-26-8hew8y.PNG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Representative fossil horse teeth of Florida" src="https://images.theconversation.com/files/584451/original/file-20240326-26-8hew8y.PNG?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/584451/original/file-20240326-26-8hew8y.PNG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=784&fit=crop&dpr=1 600w, https://images.theconversation.com/files/584451/original/file-20240326-26-8hew8y.PNG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=784&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/584451/original/file-20240326-26-8hew8y.PNG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=784&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/584451/original/file-20240326-26-8hew8y.PNG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=985&fit=crop&dpr=1 754w, https://images.theconversation.com/files/584451/original/file-20240326-26-8hew8y.PNG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=985&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/584451/original/file-20240326-26-8hew8y.PNG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=985&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Each of the six fossil horse species (A-F) found in Florida have distinct teeth. Scale bar = 1 centimeter.</span>
<span class="attribution"><a class="source" href="https://doi.org/10.1017/pab.2023.35">Killingsworth & MacFadden, Paleobiology, 2024</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-sa/4.0/">CC BY-NC-SA</a></span>
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<p>We designed a theoretical model that compares Montbrook, with only four horse species, to other fossil sites in Florida that contain all six. Using a statistical technique that scientists call “<a href="https://www.lancaster.ac.uk/stor-i-student-sites/jack-trainer/bootstrapping-in-statistics/">bootstrapping</a>,” our computer essentially simulated continued fossil collecting over time. We generated 1,000 theoretical fossil collection events based on the fossil species counts from the sites where all six are present, to predict the probability of collecting the species that are currently missing at Montbrook.</p>
<p>Results from our simulation show that the two missing horse species at Montbrook were absent for different reasons. One of the horses is likely to be truly absent; the other may still be discovered with further excavation.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/576220/original/file-20240216-26-vkk8pe.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="About a dozen people focused on digging in soil a few feet below the surface of surrounding landscape." src="https://images.theconversation.com/files/576220/original/file-20240216-26-vkk8pe.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/576220/original/file-20240216-26-vkk8pe.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=442&fit=crop&dpr=1 600w, https://images.theconversation.com/files/576220/original/file-20240216-26-vkk8pe.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=442&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/576220/original/file-20240216-26-vkk8pe.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=442&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/576220/original/file-20240216-26-vkk8pe.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=555&fit=crop&dpr=1 754w, https://images.theconversation.com/files/576220/original/file-20240216-26-vkk8pe.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=555&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/576220/original/file-20240216-26-vkk8pe.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=555&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">Excavations are ongoing at the Montbrook fossil site in Florida.</span>
<span class="attribution"><span class="source">Florida Museum/Jeff Gage</span></span>
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<h2>Probing ‘gaps’ in the fossil record</h2>
<p>Knowing a species is absent is just as important as knowing when one is present at a fossil site. Absences may be indicators of underlying ecological and biological drivers changing population dynamics. Coupled with other types of analyses, researchers can apply this kind of predictive modeling across many fossil species and ancient landscapes.</p>
<p>Ever since <a href="https://www.britannica.com/biography/Charles-Darwin/Evolution-by-natural-selection-the-London-years-1836-42">Charles Darwin proposed his theory of evolution</a>, scientists have known that the fossil record is incomplete, resulting in gaps in our knowledge of the ancient past and evolutionary change. Paleontologists are challenged to explain these gaps, including which species were or were not present at particular fossil sites.</p>
<p>Gaps can result from certain materials, such as teeth and shells, which are often more durable than porous bone, fossilizing better than others. Likewise, different chemical conditions during fossilization, and even the amount of time spent collecting fossils at a particular site, <a href="https://doi.org/10.1016/j.earscirev.2023.104537">can contribute to the lack of knowledge</a>.</p>
<p>Fortunately, fossil horse teeth preserve quite well and are commonly found. As new discoveries are made, such as those from our ongoing excavations in Florida, they’ll help clarify and narrow gaps in the fossil record.</p><img src="https://counter.theconversation.com/content/223268/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Bruce J. MacFadden receives funding from the US National Science Foundation. </span></em></p><p class="fine-print"><em><span>Stephanie Killingsworth does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Horse fossils are abundant and widespread across North America. Scientists often use their long history to illustrate how species evolve in response to a changing environment.Stephanie Killingsworth, Ph.D. Student in Geological Sciences, University of FloridaBruce J. MacFadden, Distinguished Professor and Director of Thompson Earth Systems Institute (TESI), University of FloridaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2252862024-03-11T13:10:38Z2024-03-11T13:10:38ZA brief guide to birdwatching in the age of dinosaurs<p>Have you ever wondered what it would be like travel back in time to the age of dinosaurs? If you stumble upon a time machine, remember to bring your binoculars. Birdwatching is a popular hobby today, with an around <a href="https://www.wwt.org.uk/news-and-stories/blog/get-into-birdwatching/#:%7E:text=Bird%20watching%20in%20the%20UK,that%20we%20look%20after%20them.">3 million participants</a> in the UK alone, and in our modern world there are a staggering <a href="https://www.publish.csiro.au/pc/pdf/PCv27_BR4">11,000 species</a> of birds to spot. </p>
<p>Despite the popularity of their modern-day descendants, we often forget about ancient birds because of their more famous dinosaur cousins.</p>
<p>Birds are actually <a href="https://www.nhm.ac.uk/discover/how-dinosaurs-evolved-into-birds.html">a type of dinosaur</a>. They are closely related to smaller, agile meat-eating dinosaurs such as the <em>Velociraptor</em>. Ancient birds came in a variety of forms, from ones with teeth and claws to species barely distinguishable from farmyard <a href="https://www.nature.com/articles/d41586-020-00766-2">chickens</a>. </p>
<p>So, if you were to point your binoculars over the heads of <em>Triceratops</em> and <em><a href="https://theconversation.com/five-things-you-probably-have-wrong-about-the-t-rex-220011">Tyrannosaurus rex</a></em>, what could you spot? Here is a quick introduction to six of the most interesting ancient bird species. </p>
<h2><em>Archaeopteryx</em></h2>
<p><em>Archaeopteryx</em> is <a href="https://www.nhm.ac.uk/discover/dino-directory/archaeopteryx.html">the iconic “dino-bird”</a> from the Jurassic period. The discovery of <em>Archaeopteryx</em> fossils in Germany over 150 years ago provided scientists with the first clues about the link between dinosaurs and modern birds. </p>
<p>At first glance, the skeleton of <em>Archaeopteryx</em> is just like any other meat-eating dinosaur – sharp teeth, clawed hands and a long bony tail. Surrounding the skeleton of specimens such as the <a href="https://www.museumfuernaturkunde.berlin/en/about/news/archaeopteryx-named-fossil-year">Berlin <em>Archaeopteryx</em></a> (discovered between <a href="https://artsandculture.google.com/story/archaeopteryx-lithographica-%E2%80%93-the-berlin-specimen-museum-fuer-naturkunde-berlin/1AVxj85ySOZ4JQ?hl=en">1874 and 1876</a>) however, are imprints of feathers which form a pair of distinctly bird-like wings.</p>
<figure class="align-center ">
<img alt="3D rendering of black bird-like dinosaur flying through the sky" src="https://images.theconversation.com/files/580391/original/file-20240307-21-8fm1ve.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/580391/original/file-20240307-21-8fm1ve.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=338&fit=crop&dpr=1 600w, https://images.theconversation.com/files/580391/original/file-20240307-21-8fm1ve.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=338&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/580391/original/file-20240307-21-8fm1ve.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=338&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/580391/original/file-20240307-21-8fm1ve.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/580391/original/file-20240307-21-8fm1ve.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/580391/original/file-20240307-21-8fm1ve.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=424&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption"><em>Archaeopteryx</em> looked half way between a dinosaur and a modern bird.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-illustration/archaeopteryx-birdlike-dinosaur-flying-through-sky-1722734977">Dotted Yeti/Shutterstock</a></span>
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<p>But for many years, palaeontologists debated whether <em>Archaeopteryx</em> could have used these wings to fly. Scientists now think it is likely that <em>Archaeopteryx</em> could have flown, but only <a href="https://www.nature.com/articles/s41467-018-03296-8">in short bursts </a>, like a pheasant. Recent technological advances have given us our first insights into dinosaur colour and studies of fossilised, pigmented cells have shown that <em>Archaeopteryx</em> had <a href="https://www.nature.com/articles/s41598-020-65336-y">matt black</a> wing feathers.</p>
<h2><em>Confuciusornis</em></h2>
<p>This crow-sized bird had a beak like that of modern-day birds, but still had large, <a href="https://digitallibrary.amnh.org/items/fc74de43-ec0e-497f-a199-7f89b6b658b9">dinosaur-like claws</a> on its hands. It is thought that they lived in flocks, large numbers of which were killed by ash or gas in <a href="https://www.nature.com/articles/ncomms4151">volcanic eruptions</a> and preserved as fossils. Known from over <a href="https://www.researchgate.net/publication/326059155_A_taxonomical_revision_of_the_Confuciusornithiformes_Aves_Pygostylia">1,000 fossil specimens</a> from China, <em>Confuciusornis</em> is one of the most common fossil bird species.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/580395/original/file-20240307-30-nefob5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Outline of dinosaur clearly preserved in rock" src="https://images.theconversation.com/files/580395/original/file-20240307-30-nefob5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/580395/original/file-20240307-30-nefob5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/580395/original/file-20240307-30-nefob5.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/580395/original/file-20240307-30-nefob5.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/580395/original/file-20240307-30-nefob5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/580395/original/file-20240307-30-nefob5.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/580395/original/file-20240307-30-nefob5.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption"><em>Confuciusornis sanctus</em> fossil, encased in rock.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/dinosaur-fossil-confuciusornis-sanctus-rock-1232355214">Chawalit Chankhantha/Shutterstock</a></span>
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<p>Some of these birds had a <a href="https://royalsocietypublishing.org/doi/full/10.1098/rsbl.2008.0409?casa_token=dLetzDz5OIUAAAAA%3AKUyu-cMBlflBhPXtC6xu-PxSc6wFebScqXzE3LBa33EmqsrzLISDWi08ToliVPfTfyuuDI_psxm7fBY">pair of tail feathers</a> longer than their body, while others lacked these long feathers and would have looked comparatively stumpy. Scientists think these long-tailed birds were the males of the species and those with <a href="https://www.nature.com/articles/ncomms2377">short tails were females</a>. Like modern peacocks and peahens, the males probably used their extravagant tail feathers to woo the females.</p>
<h2><em>Falcatakely</em></h2>
<p>Discovered in 2020, <em><a href="https://www.nature.com/articles/s41586-020-2945-x">Falcatakely</a></em>, from Madagascar, would have resembled a small, buck-toothed toucan. Its oversized, banana-shaped bill only had teeth <a href="https://www.nature.com/articles/d41586-020-03260-x">at the very tip</a>. Although we don’t know what this buck-toothed bird would have eaten, its close relatives ate a <a href="https://www.biorxiv.org/content/10.1101/2023.07.18.549506v2.abstract">variety of food</a>, including fruit, fish and even larger prey. </p>
<p>Scientists think that birds such as <em>Falcatakely</em> could fly the same day they <a href="https://www.science.org/doi/full/10.1126/science.1100000">hatched from their egg</a>, unlike birds today which spend their first weeks or months helpless in the nest.</p>
<h2><em>Hesperornis</em></h2>
<p>One of the weirdest birds from the age of dinosaurs, <em>Hesperornis</em> would have looked something like a six-foot-tall penguin with a beak full of <a href="https://link.springer.com/article/10.1186/s12862-016-0753-6#Sec27">sharp teeth</a>. Its <a href="https://www.mdpi.com/1424-2818/14/4/267">tiny arms</a> would have made T rex look like a weightlifter, so it definitely couldn’t have used them to fly. </p>
<figure class="align-center ">
<img alt="Illustration of bird with tiny wings perched on a rock" src="https://images.theconversation.com/files/580394/original/file-20240307-18-16mtuh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/580394/original/file-20240307-18-16mtuh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=375&fit=crop&dpr=1 600w, https://images.theconversation.com/files/580394/original/file-20240307-18-16mtuh.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=375&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/580394/original/file-20240307-18-16mtuh.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=375&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/580394/original/file-20240307-18-16mtuh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=471&fit=crop&dpr=1 754w, https://images.theconversation.com/files/580394/original/file-20240307-18-16mtuh.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=471&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/580394/original/file-20240307-18-16mtuh.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=471&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption"><em>Hesperornis</em> was an aquatic bird that lived at the time of the dinosaurs.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-illustration/hesperornis-aquatic-bird-that-lived-time-1118302547">Daniel Eskridge/Shutterstock</a></span>
</figcaption>
</figure>
<p>Instead, <em>Hesperornis</em> used its oversized <a href="https://www.sciencedirect.com/science/article/pii/S0031018217307149">feet to propel</a> itself through the water like a modern cormorant. Out of the water, <em>Hesperornis</em> walked <a href="https://www.sciencedirect.com/science/article/pii/S0031018217307149">awkwardly upright</a> and probably couldn’t travel far overland.</p>
<h2><em>Vegavis and Asteriornis</em></h2>
<p>Towards the end of the dinosaurs’ reign, the earliest groups of modern birds began to appear. The first of these birds to be discovered was <em><a href="https://www.nature.com/articles/nature03150">Vegavis</a></em> from Antarctica, which in the time of dinosaurs would have been <a href="https://www.sciencedirect.com/science/article/pii/S0031018201004527">covered in trees</a> rather than ice. </p>
<p>It was probably an ancestor of ducks and geese and one exceptional fossil of <em>Vegavis</em> even has a rare <a href="https://www.nature.com/articles/nature19852">preserved vocal organ</a>. Analysis of this fossil suggested that <em>Vegavis</em> couldn’t make a songbird melody but could have made simple noises such as goose-like honks.</p>
<p>Sixty-six million years ago, not long before the <a href="https://www.pnas.org/doi/abs/10.1073/pnas.2006087117">asteroid impact</a>, which caused the extinction of the non-bird dinosaurs, lived <em><a href="https://www.nature.com/articles/s41586-020-2096-0">Asteriornis</a></em>. This quail-sized bird from Belgium was an ancestor of modern ducks and chickens. Although it would have looked unremarkable compared to the <a href="https://www.cambridge.org/core/journals/netherlands-journal-of-geosciences/article/stratigraphic-ranges-of-mosasaurs-in-belgium-and-the-netherlands-late-cretaceous-and-cephalopodbased-correlations-with-north-america/2601C3D2DD398B92DFEDA122E82F9991">giant swimming lizards</a> and <a href="https://www.nature.com/articles/s41586-022-05445-y">huge, toothed seagulls</a> it lived alongside, this may have been to its advantage.</p>
<p>Scientists think that the small size of birds such as <em>Asteriornis</em> helped them to survive the <a href="https://academic.oup.com/sysbio/article/67/1/1/3960267">mass extinction</a>. Because smaller animals need less food and take less time to reproduce, these humble birds were able to survive and evolve into the birds you can see through your binoculars today.</p><img src="https://counter.theconversation.com/content/225286/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Abi Crane does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>If you love learning about dinosaurs don’t let crowdpleasers like the T Rex distract you from the fascinating birdlife that once roamed the Earth.Abi Crane, Postgraduate Researcher in Palaeontology, University of SouthamptonLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2253592024-03-08T13:48:25Z2024-03-08T13:48:25ZMass extinction: our fossil study reveals which types of species are most at risk from climate change<figure><img src="https://images.theconversation.com/files/580670/original/file-20240308-16-uwcrn7.jpg?ixlib=rb-1.1.0&rect=70%2C35%2C3847%2C2572&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Animals in polar regions are at particular risk. </span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/strongest-gentoo-penguin-cute-funny-baby-1427288915">Andrew Mobbs/Shutterstock</a></span></figcaption></figure><p>Many experts believe we may soon face a <a href="https://theconversation.com/what-is-a-mass-extinction-and-are-we-in-one-now-122535">mass extinction</a> event, with a high proportion of Earth’s species dying out. Projections indicate <a href="https://www.cambridge.org/core/books/climate-change-2021-the-physical-science-basis/future-global-climate-scenariobased-projections-and-nearterm-information/309359EDDCFABB031C078AE20CEE04FD">the climate will continue to change for centuries to come</a>, and this is a <a href="https://www.ipbes.net/node/35274">significant threat to biodiversity</a> that has already had an impact on many species. </p>
<p>Despite the threat that climate change poses to biodiversity, we do not yet fully understand how it causes animals to go extinct. In our new paper, published in <a href="https://www.science.org/doi/10.1126/science.adj5763">Science</a>, we used the fossil record to make more precise estimates.</p>
<p>The geological rock record provides critical insight on past extinctions caused by a variety of climate change events. Fossils therefore offer a rare opportunity to understand the mechanisms of extinction and investigate how climate shifts have led to extinction in the past. Understanding why species went extinct under natural, pre-human conditions is paramount, since human-induced extinction drivers are accumulating over time. </p>
<p>By identifying which traits are linked to extinction, we can potentially use this knowledge to identify at-risk species to prioritise in conservation efforts.</p>
<p>In our latest research article, we analysed a data set comprising over 290,000 marine invertebrate fossils, covering the last 485 million years of Earth’s history. We looked directly for the traits most crucial for survival in the geologic past.</p>
<p>Previous studies have highlighted <a href="https://royalsocietypublishing.org/doi/full/10.1098/rspb.2021.1681">small body size</a> and <a href="https://www.pnas.org/doi/abs/10.1073/pnas.0701257104">limited geographic range size</a> (the spatial extent occupied by a species) as key predictors of extinction risk throughout geological history.</p>
<p>We reconstructed the climate for 81 geological stages across the Phanerozoic (the current geological era, starting 541 million years ago). And we used climate models to determine the range of temperatures that each species can endure. </p>
<p>These factors were then compared against geographic range size and body size to assess their relative importance. We then estimated an external factor that may impact risk of extinction: the magnitude of climate change experienced by each species.</p>
<p>We assessed how the intrinsic traits, such as temperature tolerance and body size, compared to climate change in affecting a species’ risk of extinction. Our study is the first to directly compare traits to external factors in determining what drives extinction. </p>
<p>Our findings revealed that species inhabiting climatic extremes, such as polar or equatorial regions, were particularly susceptible to extinction. Species with a narrow thermal tolerance of approximately less than 15°C faced a significantly higher risk of extinction. We also found that smaller-bodied species are more prone to extinction due to both climatic and other changes.</p>
<p>However, the most important predictor of extinction risk was geographic range size. Species with smaller ranges, occupying more geographically-confined areas, had a higher likelihood of extinction. </p>
<h2>Conservation is needed</h2>
<p>Alarmingly, our research has, for the first time, identified climate change as a significant predictor of extinction, alongside other species’ traits.</p>
<p>We observed that species subjected to local climate changes of 7°C or greater across geological stages were significantly more likely to face extinction. This suggests that surpassing this climate change threshold increases the likelihood of extinction for a species, regardless of its other traits.</p>
<p>That said, the research shows that there is a cumulative effect of these variables on extinction risk. This underscores the importance of considering a broad spectrum of factors when assessing vulnerability to extinction. </p>
<p>For instance, a species residing in polar regions, characterised by a small geographic range size and body size, and subjected to significant climate change, would face a higher extinction risk than what might be inferred if considering only its geographic range. This holistic approach reveals the interplay between various biological and environmental factors in determining species’ survival over geological timescales. </p>
<p>Our research underscores the urgent challenge climate change poses to global biodiversity. But it also emphasises the necessity for continued research.</p>
<p>Many uncertainties remain when it comes to extinction risk, particularly around why certain traits confer extinction resistance and how traits interact to effect extinction risk. This additional research is essential to fully leverage our study’s implications for conservation strategies. </p>
<p>Without immediate and targeted conservation efforts, informed by a deeper understanding, we risk moving toward a sixth mass extinction event. So our work provides a pivotal call to action. We should mitigate climate change, but also do more research to bolster our understanding of the impacts on vulnerable species.</p>
<hr>
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<img alt="Imagine weekly climate newsletter" src="https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<p><strong><em>Don’t have time to read about climate change as much as you’d like?</em></strong>
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<p class="fine-print"><em><span>Erin Saupe receives funding from the Leverhulme Prize and NERC grant NE/V011405/1. </span></em></p><p class="fine-print"><em><span>Cooper Malanoski does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>If the climate warms by more than 7 degrees, the likelihood of extinction for a species increases, regardless of its other traits.Erin Saupe, Associate Professor, Palaeobiology, University of OxfordCooper Malanoski, PhD Candidate in Geology, University of OxfordLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2197082024-03-07T13:30:42Z2024-03-07T13:30:42ZTitanosaurs were the biggest land animals Earth’s ever seen − these plant-powered dinos combined reptile and mammal traits<figure><img src="https://images.theconversation.com/files/578965/original/file-20240229-28-gycuea.jpg?ixlib=rb-1.1.0&rect=26%2C0%2C3000%2C1967&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A replica fossil of the titanosaur _Patagotitan_, one of the largest dinosaurs ever discovered. It would have weighed about 70 tons (63.5 metric tons.)</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/replica-of-one-of-the-largest-dinosaurs-ever-discovered-is-news-photo/504972828">Spencer Platt/Getty Images News via Getty Images</a></span></figcaption></figure><p>You’re probably familiar with classic sauropod dinosaurs – the four-legged herbivores famous for their long necks and tails. Animals such as <a href="https://www.ucpress.edu/book/9780520246232/the-sauropods"><em>Brachiosaurus</em>, <em>Apatosaurus</em> and <em>Diplodocus</em></a> have been standard fixtures in science museums since the 1800s.</p>
<p>With their small brains and enormous bodies, these creatures have long been the poster children for <a href="https://www.scientificamerican.com/article/triumph-of-the-titans/">animals destined to go extinct</a>. But recent discoveries have completely rewritten the doomed sauropod narrative. </p>
<p><a href="https://scholar.google.com/citations?user=Dz3tM2YAAAAJ&hl=en">I study</a> a lesser known group of sauropod dinosaurs – the Titanosauria, or “titanic reptiles.” Instead of going extinct, <a href="https://doi.org/10.1007/978-3-030-95959-3_10">titanosaurs flourished</a> long after their more famous cousins vanished. Not only were they large and in charge on <a href="https://paleobiodb.org/navigator/">all seven continents</a>, they held their own amid the <a href="https://doi.org/10.1016/j.palaeo.2017.10.035">newly evolved duck-billed and horned dinosaurs</a>, until an <a href="https://doi.org/10.1126/science.aay2268">asteroid struck Earth</a> and ended the age of dinosaurs.</p>
<p>The secret to titanosaurs’ remarkable biological success may be how they merged the best of both reptile and mammal characteristics to form a unique way of life. </p>
<h2>Moving with the continents</h2>
<p>Titanosaurs <a href="https://doi.org/10.1111/j.1096-3642.2012.00853.x">originated by the Early Cretaceous Period</a>, nearly 126 million years ago, at a time when many of the <a href="https://deeptimemaps.com/map-lists-thumbnails/global-paleogeography-and-tectonics-in-deep-time/">Earth’s landmasses were much closer together</a> than they are today.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/HhkyXrWNoVA?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Starting about 200 million years ago, the supercontinent Pangea began to break apart and drift.</span></figcaption>
</figure>
<p>Over the next 75 million to 80 million years, the <a href="https://theconversation.com/how-earths-continents-became-twisted-and-contorted-over-millions-of-years-116168">continents slowly separated</a>, and titanosaurs drifted along with the changing formations, becoming distributed worldwide. </p>
<p>There were nearly <a href="https://doi.org/10.1007/978-3-030-95959-3_8">100 species of titanosaurs</a>, making up more than 30% of known sauropod dinosaurs. They varied greatly in size. From the largest known sauropods ever discovered, including <a href="https://doi.org/10.1080/08912960410001715132"><em>Argentinosaurus</em></a>, <a href="https://doi.org/10.1098/rspb.2017.1219"><em>Patagotitan</em></a> and <a href="https://doi.org/10.1590/S0001-37652007000300013"><em>Futalognkosaurus</em></a>, whose weight exceeded 60 tons (54.4 metric tons) and were bigger than a semitruck, to the smallest known sauropods, including <a href="https://doi.org/10.1016/j.cretres.2022.105389"><em>Rinconsaurus</em></a>, <a href="https://doi.org/10.1016/j.cretres.2014.12.012"><em>Saltasaurus</em></a> and <a href="https://doi.org/10.1073/pnas.1000781107"><em>Magyarosaurus</em></a>, which were around only 6 tons (5.4 metric tons) and about the size of an African elephant. </p>
<h2>Babies to titans</h2>
<p>Like many reptiles, titanosaurs began life comparatively tiny, hatching from <a href="https://doi.org/10.1038/24370">eggs no bigger than grapefruits</a>.</p>
<p>The <a href="https://doi.org/10.1038/24370">best data on titanosaur nests</a> and eggs comes from a site in Argentina called Auca Mahuevo, featuring 75 million-year-old exposed rocks. The site contains hundreds of fossilized nests containing thousands of eggs, some of which are so well preserved, scientists recovered <a href="https://doi.org/10.1666/05-150.1">skin impressions from ancient embryos</a>.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/579040/original/file-20240229-20-4s0o47.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Black and white microscopic image showing a bumpy pattern." src="https://images.theconversation.com/files/579040/original/file-20240229-20-4s0o47.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/579040/original/file-20240229-20-4s0o47.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=436&fit=crop&dpr=1 600w, https://images.theconversation.com/files/579040/original/file-20240229-20-4s0o47.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=436&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/579040/original/file-20240229-20-4s0o47.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=436&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/579040/original/file-20240229-20-4s0o47.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=548&fit=crop&dpr=1 754w, https://images.theconversation.com/files/579040/original/file-20240229-20-4s0o47.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=548&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/579040/original/file-20240229-20-4s0o47.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=548&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The fossilized skin of a titanosaur embryo discovered in Argentina.</span>
<span class="attribution"><span class="source">Courtesy of L. M. Chiappe, Natural History Museum of Los Angeles County</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>The sheer number of nests found together, in multiple geological layers, suggests titanosaurs <a href="https://doi.org/10.1016/j.palaeo.2013.05.031">returned to this site repeatedly</a> to lay their eggs. The nests are so closely spaced, it’s unlikely an adult titanosaur would have been able to move freely through the nesting ground. Titanosaurs likely had a hands-off parenting style, similar to many reptiles that lay numerous eggs and don’t spend much time tending the nest or taking care of hatchlings. </p>
<p><a href="https://doi.org/10.1126/science.aaf1509">A titanosaur hatchling</a> would have been roughly 1 foot (30 centimeters) tall, 3 feet (1 meter) long and 5-10 pounds (2.5-5 kg). Recent evidence from a site in Madagascar suggests these tiny titans were born ready to rumble.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/569145/original/file-20240112-19-8vmjcx.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="An illustration of a human standing next to five different sized 4-legged, long necked dinosaurs from an baby to towering individual." src="https://images.theconversation.com/files/569145/original/file-20240112-19-8vmjcx.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/569145/original/file-20240112-19-8vmjcx.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=259&fit=crop&dpr=1 600w, https://images.theconversation.com/files/569145/original/file-20240112-19-8vmjcx.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=259&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/569145/original/file-20240112-19-8vmjcx.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=259&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/569145/original/file-20240112-19-8vmjcx.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=325&fit=crop&dpr=1 754w, https://images.theconversation.com/files/569145/original/file-20240112-19-8vmjcx.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=325&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/569145/original/file-20240112-19-8vmjcx.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=325&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A titanosaur from Madagascar called <em>Rapetosaurus krausei</em> is known from fossils of tiny hatchlings, giant adults and a variety of in-between sizes.</span>
<span class="attribution"><span class="source">Jordan Mae Harris</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>Fossilized bones from the species <em>Rapetosaurus</em> suggest that by the time they would have been just knee high to a modern human, they were <a href="https://doi.org/10.1126/science.aaf1509">likely fending for themselves</a>. Microscopic details recorded deep within the bones indicate baby <em>Rapetosaurus</em> likely foraged independently for plants and moved much more nimbly than their lumbering adult relatives.</p>
<p>For the first century of dinosaur science, paleontologists imagined titanosaurs as giant, overgrown reptiles – and <a href="https://www.jstor.org/stable/2400208">used reptilian growth rates to predict their milestones</a>. In this slow-growth model, even the smallest titanosaurs would have taken nearly a century to reach their full size, meaning they would have been relatively small for a good chunk of their lives. New evidence suggests this growth pattern is unlikely.</p>
<p>Scientists like me <a href="https://www.ucpress.edu/book/9780520273528/bone-histology-of-fossil-tetrapods">study titanosaurs’ bones at high magnification</a> to better understand their growth. We look at the microscopic patterns of bone minerals as well as the density and architecture of the spaces that held blood vessels and cells. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/579902/original/file-20240305-24-l3albd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A microscopic image showing both horizontal wavy spaces and circular spaces against a solid background." src="https://images.theconversation.com/files/579902/original/file-20240305-24-l3albd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/579902/original/file-20240305-24-l3albd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=480&fit=crop&dpr=1 600w, https://images.theconversation.com/files/579902/original/file-20240305-24-l3albd.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=480&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/579902/original/file-20240305-24-l3albd.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=480&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/579902/original/file-20240305-24-l3albd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=603&fit=crop&dpr=1 754w, https://images.theconversation.com/files/579902/original/file-20240305-24-l3albd.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=603&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/579902/original/file-20240305-24-l3albd.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=603&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A thin slice of a juvenile titanosaur femur bone. The linear and circular structures are the spaces where a dense network of blood vessels supplied this fast-growing animal with plenty of nutrients.</span>
<span class="attribution"><span class="source">Kristi Curry Rogers</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>The more dense the blood supply is to a bone, the faster that animal grows. These signatures are also present in living animals and can accurately reflect <a href="https://doi.org/10.1201/9781351189590">growth rates, anomalies and even age</a>. </p>
<p>Bone data shows titanosaur growth rates were <a href="https://doi.org/10.1201/9781351189590">on par with mammals like whales</a> – much, much faster than any living reptile – meaning they would have reached their enormous adult sizes <a href="https://doi.org/10.1111/j.1469-185X.2010.00137.x">in just a few decades</a>. Scientists can’t know for sure how long titanosaurs lived, but based on large land animals living today, titanosaurs lived possibly 60 or more years. </p>
<h2>Fueled by plants</h2>
<p>The rapid growth rates of sauropods was partly due to their body temperatures. By studying the chemistry of fossilized teeth <a href="https://doi.org/10.1038/ncomms9296">and eggshells</a>, scientists have determined titanosaurs had body temperatures <a href="https://doi.org/10.1126/science.1206196">ranging from about 95 to 100.5 degrees Fahrenheit</a> (35 to 38 degrees Celsius). That’s higher than that of crocodiles and alligators, about the same as modern mammals and a bit lower than most birds, whose bodies can regularly get <a href="https://doi.org/10.1016/0300-9629(91)90122-S">as warm as 104 F (40 C)</a>.</p>
<p>Titanosaurs’ rapid growth rates were also powered by their prodigious appetites for plants. Microscopic patterns of scratches, wear and pits on their teeth indicate titanosaurs in Argentina fed on a diverse diet rich in grit, suggesting they were <a href="https://doi.org/10.1371/journal.pone.0151661">dining on plants found lower to the ground</a>, where sediment would be more commonly found.</p>
<p>In India, chunks of fossilized feces, <a href="https://theconversation.com/ancient-poop-offers-unusual-insight-into-animal-behaviour-197200">otherwise known as coprolites</a>, show titanosaurs there ingested everything from <a href="https://doi.org/10.1126/science.1118806">ground-level plants all the way up to the leaves and branches</a> of trees.</p>
<p>Like all dinosaurs, titanosaurs replaced their teeth throughout life. But data shows they replaced each tooth <a href="https://doi.org/10.1371/journal.pone.0069235">about every 20 days</a> for maximum efficiency, one of the highest tooth-replacement rates known for dinosaurs.</p>
<p>Had it not been for the <a href="https://doi.org/10.1126/science.1177265">asteroid impact 66 million years ago</a>, these long-lived, incredibly diverse and wildly successful animals probably would have kept on thriving, in places as distant as <a href="https://paleobiodb.org/navigator/">Madagascar, Romania, North America and even Antarctica</a>. Instead, titanosaurs were among the witnesses to – and victims of – the most recent mass extinction on Earth.</p><img src="https://counter.theconversation.com/content/219708/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Kristi Curry Rogers receives funding from the National Science Foundation and the David B. Jones Foundation. </span></em></p>Some of these giant vegetarians were as tall as a 3-story building. Microscopic analysis of their teeth, bones and eggshells reveals how they grew, what they ate and even their body temperature.Kristi Curry Rogers, Professor of Biology and Geology, Macalester CollegeLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2225122024-02-20T23:26:55Z2024-02-20T23:26:55ZA botanical Pompeii: we found spectacular Australian plant fossils from 30 million years ago<figure><img src="https://images.theconversation.com/files/576662/original/file-20240220-28-l9zg5j.jpg?ixlib=rb-1.1.0&rect=39%2C65%2C8544%2C5709&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Details of a silicified fern fossil.</span> <span class="attribution"><span class="source">Geoff Thompson/Queensland Museum</span></span></figcaption></figure><p>The Australian continent is now geologically stable. But volcanic rocks, lava flows and a contemporary landscape dotted with extinct volcanoes show this wasn’t always the case.</p>
<p>Between 40 and 20 million years ago – during the <a href="https://www.britannica.com/science/Tertiary-Period">Eocene to Miocene epochs</a> – there was widespread volcano activity across eastern Australia. In places such as western Victoria and the Atherton Tablelands in Queensland, it was even more recent.</p>
<p>Erupting volcanoes can have devastating consequences for human settlements, as we know from Pompeii in Italy, which was buried by ash when Mount Vesuvius erupted in 79 CE. But ash falls and lava flows can also entomb entire forests, or at least many of the plants within them. </p>
<p>Our studies of these rare and unique plant time capsules are revealing exquisitely preserved fossil floras and new insights into Australia’s botanical history. This new work is published <a href="https://authors.elsevier.com/a/1idT5,UYEnjl1W">in the journal Gondwana Research</a>.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/576661/original/file-20240220-16-fa264v.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A landscape with snow crested mountain in the background and ash layers covering plants next to a road" src="https://images.theconversation.com/files/576661/original/file-20240220-16-fa264v.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/576661/original/file-20240220-16-fa264v.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=399&fit=crop&dpr=1 600w, https://images.theconversation.com/files/576661/original/file-20240220-16-fa264v.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=399&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/576661/original/file-20240220-16-fa264v.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=399&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/576661/original/file-20240220-16-fa264v.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=501&fit=crop&dpr=1 754w, https://images.theconversation.com/files/576661/original/file-20240220-16-fa264v.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=501&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/576661/original/file-20240220-16-fa264v.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=501&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">This is what volcanoes can do to landscapes – super-heated gasses from the 2011–12 eruption of Puyehue-Cordon Caulle Volcano in Argentina killed the forest. After ten years, the forest has started to regrow.</span>
<span class="attribution"><span class="source">Andrew Rozefelds</span></span>
</figcaption>
</figure>
<h2>Remarkable preservation</h2>
<p>The most common volcanic rocks are basalts. The rich red soils derived from them are among the most fertile in Australia.</p>
<p>But the rocks in which fossils occur are buried under basalts or other volcanic rock, and are called silcretes – the name indicates their origins are from silica-rich groundwaters. Silica is the major constituent of sand, and familiar to most of us as quartz. </p>
<p>What makes the silcrete plant fossils so fascinating is the superfine preservation of plant material. This includes fine roots and root nodules, uncurling fern fronds and their underground stems, the soft outer bark of wood, feeding traces and <a href="https://www.amentsoc.org/insects/glossary/terms/frass/">frass</a> (powdery droppings) of insects, and even the delicate tissues and anatomy of fruits and seeds.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/576664/original/file-20240220-28-miohox.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Close-up of clearly visible fern leaves and fragments made up of amber coloured stone" src="https://images.theconversation.com/files/576664/original/file-20240220-28-miohox.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/576664/original/file-20240220-28-miohox.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/576664/original/file-20240220-28-miohox.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/576664/original/file-20240220-28-miohox.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/576664/original/file-20240220-28-miohox.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/576664/original/file-20240220-28-miohox.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/576664/original/file-20240220-28-miohox.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The foliage of a <em>Pteridium</em> fern, preserved in silcrete in exceptional detail.</span>
<span class="attribution"><span class="source">Geoff Thompson/Queensland Museum</span></span>
</figcaption>
</figure>
<p>For this fine preservation to occur, first there needs to be a rapid burial, like that from a volcanic eruption. Then, there has to be an abundant source of silica — a condition met when the volcanic rocks began to weather. </p>
<p>The process where silica infills and preserves plant structures is referred to as “<a href="https://en.wikipedia.org/wiki/Silicification">silicification</a>” or “permineralisation”. When plant material is buried, it provides acidic conditions that are ideal for this to happen. </p>
<p>And the process need not take millions of years. Overseas studies of plants <a href="https://doi.org/10.2110/palo.2012.p.12-064r">in hot springs</a> or undertaken <a href="https://doi.org/10.2110/palo.2012.p.12-064r">in the laboratory</a> have shown that some types of silica will quickly infiltrate wood and plant tissues.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/576663/original/file-20240220-24-49adlz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Close-up of a rocky amber and white material with bubble-like shapes within" src="https://images.theconversation.com/files/576663/original/file-20240220-24-49adlz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/576663/original/file-20240220-24-49adlz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/576663/original/file-20240220-24-49adlz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/576663/original/file-20240220-24-49adlz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/576663/original/file-20240220-24-49adlz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/576663/original/file-20240220-24-49adlz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/576663/original/file-20240220-24-49adlz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">This is a cross-section of the stem (rhizome) of a silicified fern, showing its characteristic anatomy.</span>
<span class="attribution"><span class="source">Geoff Thompson/Queensland Museum</span></span>
</figcaption>
</figure>
<h2>Why are these plant fossils significant?</h2>
<p>Because of their rapid entombment by the volcanoes, we can be sure the plants were in situ (that is, their original location) and were actively growing. This means we can gain detailed information about the make-up of these past plant communities.</p>
<p>In other areas where plant fossils might accumulate – such as river deltas – we can never be sure how far the bits of plants were carried, and whether they were from different types of vegetation.</p>
<p>Silicification not only preserves plants, but also leaf litter on the forest floor and even the underlying soil containing roots and root nodules. The fossil plants that are preserved at different sites varies, indicating the presence of distinct plant communities. </p>
<p>The abundance of seeds and fruits at one site near Capella, in central Queensland, even indicated to us that the local volcanic eruptions are likely to have occurred in summer or early autumn during the fruiting season.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/576665/original/file-20240220-26-49adlz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A detailed folded shape of a seed encased in orange-amber rock" src="https://images.theconversation.com/files/576665/original/file-20240220-26-49adlz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/576665/original/file-20240220-26-49adlz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/576665/original/file-20240220-26-49adlz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/576665/original/file-20240220-26-49adlz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/576665/original/file-20240220-26-49adlz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/576665/original/file-20240220-26-49adlz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/576665/original/file-20240220-26-49adlz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">This cross-section of a silicified native grape seed shows its complex internal structure which is typical of the seeds of this family.</span>
<span class="attribution"><span class="source">Geoff Thompson/Queensland Museum</span></span>
</figcaption>
</figure>
<p>The extraordinary preservation of these fossils allows us to compare them with modern plants. In turn, this means we can accurately identify them.</p>
<p>The ferns include fronds and underground stems (rhizomes) of the familiar bracken fern (<em>Pteridium</em>). We have also found the distinctive seeds and lianas of the grape family (Vitaceae), along with evidence of insect damage in the wood. Two sites also had evidence of palms.</p>
<p>While there have been few previous studies on silcrete plants, we have revealed new insights into the history of the modern Australian flora.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/576667/original/file-20240220-18-ycxe50.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Close-up of a bright green pointy leaved fern with sun shining from behind it" src="https://images.theconversation.com/files/576667/original/file-20240220-18-ycxe50.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/576667/original/file-20240220-18-ycxe50.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=398&fit=crop&dpr=1 600w, https://images.theconversation.com/files/576667/original/file-20240220-18-ycxe50.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=398&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/576667/original/file-20240220-18-ycxe50.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=398&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/576667/original/file-20240220-18-ycxe50.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=501&fit=crop&dpr=1 754w, https://images.theconversation.com/files/576667/original/file-20240220-18-ycxe50.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=501&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/576667/original/file-20240220-18-ycxe50.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=501&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A modern bracken fern found in Queensland – the clear successor of the ferns found in the silcrete rocks.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/fern-north-queensland-rainforest-australia-2400181713">AustralianCamera/Shutterstock</a></span>
</figcaption>
</figure>
<h2>Volcanoes shaped plant communities</h2>
<p>Volcanic activity both destroys and modifies existing plant communities. It also provides new substrates for plants to colonise.</p>
<p>Several sites contained ferns – this may be because they are among the first living plants to colonise new volcanic terrains via their tiny wind-borne spores. For instance, <a href="https://doi.org/10.2307/2937282">it has been documented</a> that bracken ferns were pioneer plants of the barren cone of the <a href="https://theconversation.com/krakatoa-is-still-active-and-we-are-not-ready-for-the-tsunamis-another-eruption-would-generate-147250">famous Krakatoa volcano</a> after its eruption in 1883.</p>
<p>But the diversity of seeds and fruits at another site suggests that an existing forest was buried by volcanic activity. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/576668/original/file-20240220-30-2d7f7g.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A star shaped impression embedded in an orange-amber rock" src="https://images.theconversation.com/files/576668/original/file-20240220-30-2d7f7g.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/576668/original/file-20240220-30-2d7f7g.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/576668/original/file-20240220-30-2d7f7g.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/576668/original/file-20240220-30-2d7f7g.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/576668/original/file-20240220-30-2d7f7g.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/576668/original/file-20240220-30-2d7f7g.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/576668/original/file-20240220-30-2d7f7g.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">This star-shaped fruit, seen in cross section here, is currently being studied and is likely to be a species new to science.</span>
<span class="attribution"><span class="source">Geoff Thompson/Queensland Museum</span></span>
</figcaption>
</figure>
<p>Researchers have suggested that the key factors responsible for the evolution of the Australian fauna and flora during the Cenozoic period (the last 66 million years) were predominantly climate and environmental change. It happened, in part, due to the movement of the Australian continental plate northwards.</p>
<p>But the broad-scale volcano activity that occurred in eastern Australia during the Cenozoic has rarely been invoked as a key driver of such changes. </p>
<p>So remarkably preserved, the silcrete plant fossils are now providing startling new insights into the history of some groups of Australian plants and the vegetation types in which they grew. </p>
<hr>
<p><em>The author would like to acknowledge co-author Raymond Carpenter from the University of Adelaide who contributed to this article.</em></p><img src="https://counter.theconversation.com/content/222512/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Andrew Rozefelds receives funding from the Herman Slade Foundation and Churchill Trust, Australia.</span></em></p>Millions of years ago, widespread volcano eruptions in eastern Australia buried entire forests. Today, these time capsules reveal stunningly fossilised plants.Andrew Rozefelds, Adjunct Assoc Professor Central Queensland University and Principal Curator Geosciences Queensland Museum, CQUniversity AustraliaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2235012024-02-16T15:54:58Z2024-02-16T15:54:58ZModern palaeontology keeps unmasking fossil forgeries – and a new study has uncovered the latest fake<figure><img src="https://images.theconversation.com/files/575570/original/file-20240214-17-sfwnu2.png?ixlib=rb-1.1.0&rect=0%2C8%2C1478%2C814&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The Tridentinosaurus counterfeit </span> <span class="attribution"><span class="source">Valentina Rossi</span>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span></figcaption></figure><p>Fake fossils are among us, passing almost undetected under the eye of experts all over the world. This is a serious problem – counterfeited specimens can mislead palaeontologists into studying an ancient past that never existed. </p>
<p>In <a href="https://doi.org/10.1111/pala.12690">a new study</a>, my colleagues and I reveal a surprising truth about a fossil celebrated for decades as one of the best preserved fossils from the Alps. </p>
<p>The <em>Tridentinosaurus antiquus</em> was a small lizard-like reptile that lived during the <a href="https://www.britannica.com/science/Permian-Period">Permian period</a> (299-252 million years ago), where the Alps are today. Discovered in 1931, the specimen was prized for what scientists thought were carbonised traces of the skin visible on the surface of the rock. Generations of palaeontologists thought the fossil was genuine, perhaps the oldest animal mummy ever discovered. This is partly because the type of preservation was rare. </p>
<p>The fossil has been reported in books and <a href="https://www.app.pan.pl/article/item/app20100087.html">articles</a> but has never been studied in detail with modern techniques. Experts were unsure about which group of reptiles the fossil belonged to. Our study was hoping to resolve this and other long-running debates among scientists. </p>
<p>But our team discovered that the skin is actually fake. What was thought to be well-preserved carbonised skin was just a carved lizard-shaped body impression covered in black paint. </p>
<p>The fossil is not a complete fake, however. The bones of the hind limbs, in particular the femurs, seem genuine. We also found some tiny, bony scales (called osteoderms, like the scales of crocodiles) preserved on what perhaps was the back of the animal.</p>
<p>It was with our preliminary investigation using <a href="https://news.utexas.edu/2019/06/10/new-photography-technique-brings-hidden-history-of-fossils-to-light/">ultraviolet photography</a> that we revealed that the dark coloured body outline and all these bones and scales had been treated with some sort of coating material. Coating fossils with varnishes or lacquers used to be normal practice over the past couple of centuries – and is sometimes still necessary to <a href="https://www.nhm.ac.uk/discover/fossil-preparation.html">preserve fossil</a> specimens in museum cabinets and exhibits.</p>
<p>We were hoping that, beneath the coating layer, the original soft tissues would still be in good condition. But chemical techniques found the material actually matched a kind of <a href="https://www.webexhibits.org/pigments/indiv/overview/boneblack.html">black paint</a> made from animal bones, meaning the skin was indeed totally forged.</p>
<p>Sadly, this means we will never know what the original fossil really looked like. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/575569/original/file-20240214-30-qoatq3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Two side by side images of ancient reptile" src="https://images.theconversation.com/files/575569/original/file-20240214-30-qoatq3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/575569/original/file-20240214-30-qoatq3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=563&fit=crop&dpr=1 600w, https://images.theconversation.com/files/575569/original/file-20240214-30-qoatq3.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=563&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/575569/original/file-20240214-30-qoatq3.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=563&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/575569/original/file-20240214-30-qoatq3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=707&fit=crop&dpr=1 754w, https://images.theconversation.com/files/575569/original/file-20240214-30-qoatq3.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=707&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/575569/original/file-20240214-30-qoatq3.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=707&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A photo of the specimen next to a UV image showing there isn’t soft tissue beneath the black covering layer.</span>
<span class="attribution"><span class="source">Valentia Rossi</span>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span>
</figcaption>
</figure>
<p>The circumstances behind this forgery are unknown, but we know that it took place before 1959 – the date of the official scientific description of the fossil. However, this discovery is a reminder of how important it is to report such specimens and combat fossil forgeries.</p>
<h2>The history of fossil forgeries</h2>
<p>The history of fossil forgery goes as far back as the dawn of palaeontology itself, with early reports dating back to the late <a href="https://www.rendicontisocietageologicaitaliana.it/297/article-4143/the-fossil-merchant-from-verona-the-first-written-testimony-of-paleontological-forgery-in-italy.html">18th and 19th centuries</a>. </p>
<p>This was mainly driven by the lucrative market of selling fossil specimens to private collectors and museums. For instance, an <a href="https://www.nhm.ac.uk/discover/dino-directory/archaeopteryx.html#:%7E:text=Archaeopteryx%20was%20a%20small%2C%20bird,it%20might%20be%20an%20angel">original specimen of _Archeopteryx</a>_ (an avian dinosaur) was <a href="https://link.springer.com/chapter/10.1007/978-3-031-14084-6_5#DOI">sold</a> for the current equivalent of £85,000 back in the early 1860s. Some people forged fossils for scientific and <a href="https://theconversation.com/solving-the-piltdown-man-crime-how-we-worked-out-there-was-only-one-forger-63615">social recognition</a>, too. </p>
<p>Famous examples span a range of fossil types, from the <a href="https://theconversation.com/a-new-twist-to-whodunnit-in-sciences-famous-piltdown-man-hoax-64470">Piltdown man</a> (1912), an elaborate fraud involving the construction of a hominid from an amalgamation of human and ape bones, to <em><a href="https://www.nature.com/articles/35069145">Archaeoraptor</a></em> (1990), a chimaera (a fossil reconstructed with elements coming from more than a single species or genus of animal) formed by different dinosaurs’ skeleton parts to form a new specimen that was initially <a href="https://www.science.org/doi/10.1126/science.290.5500.2224a">reported</a> in National Geographic magazine as genuine in 1999. </p>
<p>Other examples include cases of partial skulls of extinct mammals that were completed with bones <a href="https://evolutionnews.org/2023/06/fossil-friday-the-oldest-cheetah-was-yet-another-fraud/">made of plastic</a>. Sometimes a mixture of cement, resins, rock fragments and dust is used for this kind of forgery. Forgers can also use dark brown or black paint to change the appearance of poorly preserved specimens that otherwise would not be of interest to researchers or collectors. </p>
<p>This happened in the case of <a href="https://www.mapress.com/pe/article/view/palaeoentomology.2.5.15"><em>Mongolarachne chaoyangensis</em></a>, a supposedly giant spider found in China. It turned out to be a poorly preserved crayfish after palaeontologists took a closer look the same year the first paper about it was published in 2019.</p>
<p>Scientists have discovered that natural history museums around the world have counterfeit specimens in their collections. While new technology is helping to study fossil <a href="https://www.amnh.org/research/paleontology/collections/fossil-invertebrate-collection/trilobite-website/the-trilobite-files/fake-trilobites"><em>trilobites</em></a>, a kind of ancient marine invertebrates in more detail, it is also showing that many specimens are fake.</p>
<p>The same is happening with animal and plant remains fossilised in amber
(fossil <a href="https://onlinelibrary.wiley.com/doi/abs/10.1111/j.2151-6952.1994.tb01023.x?casa_token=o7kmo8NJM5UAAAAA:F2aabeMdF0gT5SafKrpJxpoyGqfiNahJNGkBUFQHB7XjKZThJOeWlFVHpkMMVbF_QqS18U3u2ITjKFI">tree resin</a>), acquired in historical times and only <a href="https://royalsocietypublishing.org/doi/10.1098/rsbl.2023.0059">recently analysed in detail</a> with modern techniques. </p>
<p>The market for fake fossils is a huge problem today. This is particularly the case in countries with less regulation. The fossil trade <a href="https://www.lyellcollection.org/doi/10.1144/SP485.1">in Morocco alone</a> is worth US$40 million (£32 million) a year and supplies fossil shows all over the world. </p>
<p>Meanwhile, colonialism stifled local expertise in <a href="https://royalsocietypublishing.org/doi/10.1098/rsos.210898">South America</a> – and as a result a high number of studies on fossils from the region are based on specimens illegally transferred to collections in other countries, particularly in Germany and Japan. </p>
<p>We need governments around the world to introduce <a href="https://link.springer.com/article/10.1007/s12371-021-00595-3">rigorous laws</a> to protect our world’s palaeontological and geological heritage.</p>
<p>The case of <em>Tridentinosaurus antiquus</em> is a cautionary tale. We believe our research can inform practices of conservation of fossils that are not appropriate any longer, such as painting over fossils, and in turn outline more ethical actions to take when a fossil is discovered. </p>
<p>For instance, the state of a fossil at the moment of discovery should be recorded in detail – along with information about when and where it was found and how it was prepared and conserved. Embellishments should be avoided. </p>
<p>We might not be able to put an end to the making of fake fossils, but we are here and ready to unmask them and protect our marvellous fossil heritage.</p><img src="https://counter.theconversation.com/content/223501/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Valentina Rossi is currently affiliated with the University College Cork. She receives funding from the Promotion of Educational
Policies, University and Research Department of the Autonomous Province of Bolzano — South Tyrol within the research project ‘Living with the supervolcano - How Athesian eruptions destroyed and preserved 15 million years of Permian life’ (nr. 11/34; CUP H32F20000010003) awarded to Prof. Evelyn Kustatscher (Museum of Nature South Tyrol, Bolzano, Italy).</span></em></p>A lizard fossil that was thought to be the best preserved ever has turned out to have fake skin.Valentina Rossi, Postdoctoral researcher, Palaeontology, University College CorkLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2193972024-02-06T21:38:09Z2024-02-06T21:38:09ZA 380-million-year old predatory fish from Central Australia is finally named after decades of digging<figure><img src="https://images.theconversation.com/files/568893/original/file-20240111-21-jl663h.jpg?ixlib=rb-1.1.0&rect=609%2C0%2C2039%2C1138&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Harajicadectes cruises through the ancient rivers of central Australia ~385 million years ago.</span> <span class="attribution"><span class="source">Brian Choo</span></span></figcaption></figure><p>More than 380 million years ago, a sleek, air-breathing predatory fish patrolled the rivers of central Australia. Today, the sediments of those rivers are outcrops of red sandstone in the remote outback.</p>
<p>Our new paper, published in the <a href="https://www.tandfonline.com/doi/full/10.1080/02724634.2023.2285000">Journal of Vertebrate Paleontology</a>,
describes the fossils of this fish, which we have named <em>Harajicadectes zhumini</em>. </p>
<p>Known from at least 17 fossil specimens, <em>Harajicadectes</em> is the first reasonably complete bony fish found from Devonian rocks in central Australia. It has also proven to be a most unusual animal.</p>
<h2>Meet the biter</h2>
<p>The name means “Min Zhu’s Harajica-biter”, after the location where its fossils were found, its presumed predatory habits, and in honour of eminent Chinese palaeontologist <a href="http://english.ivpp.cas.cn/people/members/202305/t20230530_331150.html">Min Zhu</a>, who has made many contributions to <a href="https://theconversation.com/a-kung-fu-kick-led-researchers-to-the-worlds-oldest-complete-fish-fossils-heres-what-they-found-190749">early vertebrate research</a>. </p>
<p><em>Harajicadectes</em> was a fish in the <a href="https://en.wikipedia.org/wiki/Tetrapodomorpha">Tetrapodomorpha</a> group. This group had strongly built paired fins and usually only a single pair of external nostrils.</p>
<p>Tetrapodomorph fish from the Devonian period (359–419 million years ago) have long been of great interest to science. They include the forerunners of modern tetrapods – animals with backbones and limbs such as amphibians, reptiles, birds and mammals.</p>
<p>For example, recent fossil discoveries show fingers and toes arose <a href="https://www.nature.com/articles/s41586-020-2100-8">in this group</a>. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/when-fish-gave-us-the-finger-this-ancient-four-limbed-fish-reveals-the-origins-of-the-human-hand-129072">When fish gave us the finger: this ancient four-limbed fish reveals the origins of the human hand</a>
</strong>
</em>
</p>
<hr>
<p>Devonian fossil sites in <a href="https://www.youtube.com/watch?v=LnHVPgvrn2M">northwestern</a> and <a href="https://australian.museum/learn/australia-over-time/fossils/sites/canowindra/">eastern</a> Australia have produced many spectacular discoveries of early tetrapodomorphs.</p>
<p>But until our discovery, the poorly sampled interior of the continent had only offered tantalising fossil fragments. </p>
<h2>A long road to discovery</h2>
<p>Our species description is the culmination of 50 years of tireless exploration and research. </p>
<p>Palaeontologist Gavin Young from the Australian National University made the initial discoveries in 1973 while exploring the Middle-Late Devonian Harajica Sandstone on Luritja/Arrernte country, more than 150 kilometres west of Alice Springs (Mparntwe).</p>
<p>Packed within red sandstone blocks on a remote hilltop were hundreds of fossil fishes. The vast majority of them were small <em>Bothriolepis</em> – a type of widespread prehistoric fish known as a <a href="https://en.wikipedia.org/wiki/Placodermi">placoderm</a>, covered in box-like armour.</p>
<p>Scattered among them were fragments of other fishes. These included <a href="https://bioone.org/journals/Acta-Palaeontologica-Polonica/volume-54/issue-4/app.2008.0057/A-New-Genus-of-Lungfish-from-the-Givetian-Middle-Devonian/10.4202/app.2008.0057.full">a lungfish known as <em>Harajicadipterus youngi</em></a>, named in honour of Gavin Young and his years of work on material from Harajica.</p>
<p>There were also spines from acanthodians (small, vaguely shark-like fish), the plates of phyllolepids (extremely flat placoderms) and, most intriguingly, jaw fragments of a previously unknown tetrapodomorph. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/565947/original/file-20231215-21-3lshgi.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/565947/original/file-20231215-21-3lshgi.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/565947/original/file-20231215-21-3lshgi.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/565947/original/file-20231215-21-3lshgi.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/565947/original/file-20231215-21-3lshgi.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/565947/original/file-20231215-21-3lshgi.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/565947/original/file-20231215-21-3lshgi.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/565947/original/file-20231215-21-3lshgi.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The moment of discovery when we found a complete fossil of <em>Harajicadectes</em> in 2016. Flinders University palaeontologists John Long (centre), Brian Choo (right) and Alice Clement (left) with ANU palaeontologist Gavin Young (top left).</span>
<span class="attribution"><span class="source">Author provided</span></span>
</figcaption>
</figure>
<p>Many more partial specimens of this Harajica tetrapodomorph were collected in 1991, including some by the late palaeontologist <a href="https://www.smh.com.au/national/the-man-who-found-4000-fish-fossils-in-a-nsw-country-town-20231205-p5ep2m.html">Alex Ritchie</a>.</p>
<p>There were early attempts at figuring out the species, but this proved troublesome. Then, our Flinders University expedition to the site in 2016 yielded the first almost complete fossil of this animal.</p>
<p>This beautiful specimen demonstrated that all the isolated bits and pieces collected over the years belonged to a single new type of fish. It is now in the collections of the Museum and Art Gallery of the Northern Territory, serving as the <a href="https://museum.wa.gov.au/explore/blogs/museumcollections/what-type-specimen">type specimen</a> of <em>Harajicadectes</em>.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/567575/original/file-20240102-21-i0b5nl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A sandstone image of a fish shape along with two graphics showing it in more detail" src="https://images.theconversation.com/files/567575/original/file-20240102-21-i0b5nl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/567575/original/file-20240102-21-i0b5nl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=448&fit=crop&dpr=1 600w, https://images.theconversation.com/files/567575/original/file-20240102-21-i0b5nl.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=448&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/567575/original/file-20240102-21-i0b5nl.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=448&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/567575/original/file-20240102-21-i0b5nl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=563&fit=crop&dpr=1 754w, https://images.theconversation.com/files/567575/original/file-20240102-21-i0b5nl.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=563&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/567575/original/file-20240102-21-i0b5nl.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=563&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The type specimen of <em>Harajicadectes</em> discovered in 2016.</span>
<span class="attribution"><span class="source">Author provided</span></span>
</figcaption>
</figure>
<h2>A strange apex predator</h2>
<p>Up to 40 centimetres long, <em>Harajicadectes</em> is the biggest fish found in the Harajica rocks. Likely the top predator of those ancient rivers, its big mouth was lined with closely-packed sharp teeth alongside larger, widely spaced triangular fangs.</p>
<p>It seems to have combined anatomical traits from different tetrapodomorph lineages via convergent evolution (when different creatures evolve similar features independently). An example of this are the patterns of bones in its skull and scales. Exactly where it sits among its closest relatives is difficult to resolve. </p>
<figure class="align-left zoomable">
<a href="https://images.theconversation.com/files/569190/original/file-20240114-27-x8x87i.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A large fish seen on the bottom of the sea with two smaller armoured fish underneath it" src="https://images.theconversation.com/files/569190/original/file-20240114-27-x8x87i.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/569190/original/file-20240114-27-x8x87i.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=781&fit=crop&dpr=1 600w, https://images.theconversation.com/files/569190/original/file-20240114-27-x8x87i.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=781&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/569190/original/file-20240114-27-x8x87i.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=781&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/569190/original/file-20240114-27-x8x87i.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=981&fit=crop&dpr=1 754w, https://images.theconversation.com/files/569190/original/file-20240114-27-x8x87i.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=981&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/569190/original/file-20240114-27-x8x87i.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=981&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Artist’s reconstruction of <em>Harajicadectes</em> menacing a pair of armoured <em>Bothriolepis</em>.</span>
<span class="attribution"><span class="source">Artist: Brian Choo</span></span>
</figcaption>
</figure>
<p>The most striking and perhaps most important features are the two huge openings on the top of the skull called spiracles. These typically only appear as minute slits in most early bony fishes.</p>
<p>Similar giant spiracles also appear in <a href="https://en.wikipedia.org/wiki/Gogonasus"><em>Gogonasus</em></a>, a marine tetrapodomorph from the famous Late Devonian Gogo Formation of Western Australia. (It doesn’t appear to be an immediate relative of <em>Harajicadectes</em>.)</p>
<p>They are also seen in the unrelated <a href="https://onlinelibrary.wiley.com/doi/am-pdf/10.1002/spp2.1243"><em>Pickeringius</em></a>, an early ray-finned fish that was also at Gogo.</p>
<h2>The earliest air-breathers?</h2>
<p>Other Devonian animals that sported such spiracles were the famous elpistostegalians – freshwater tetrapodomorphs from the Northern Hemisphere such as <a href="https://en.wikipedia.org/wiki/Elpistostege"><em>Elpistostege</em></a> and <a href="https://en.wikipedia.org/wiki/Tiktaalik"><em>Tiktaalik</em></a>.</p>
<p>These animals were extremely close to the ancestry of limbed vertebrates. So, enlarged spiracles seem to have arisen independently in at least four separate lineages of Devonian fishes.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/567607/original/file-20240102-21-evllkl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/567607/original/file-20240102-21-evllkl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/567607/original/file-20240102-21-evllkl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=628&fit=crop&dpr=1 600w, https://images.theconversation.com/files/567607/original/file-20240102-21-evllkl.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=628&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/567607/original/file-20240102-21-evllkl.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=628&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/567607/original/file-20240102-21-evllkl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=789&fit=crop&dpr=1 754w, https://images.theconversation.com/files/567607/original/file-20240102-21-evllkl.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=789&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/567607/original/file-20240102-21-evllkl.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=789&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The skull of <em>Harajicadectes</em> seen from above, showing the enormous spiracles.</span>
<span class="attribution"><span class="source">Author provided</span></span>
</figcaption>
</figure>
<p>The only living fishes with similar structures are bichirs, African ray-finned fishes that live in shallow floodplains and estuaries. It was recently confirmed <a href="https://theconversation.com/now-listen-air-breathing-fish-gave-humans-the-ability-to-hear-21324">they draw surface air through their spiracles</a> to aid survival in oxygen-poor waters.</p>
<p>That these structures appeared roughly simultaneously in four Devonian lineages provides a fossil “signal” for scientists attempting to reconstruct atmospheric conditions in the distant past.</p>
<p>It could help us uncover the evolution of air breathing in backboned animals.</p><img src="https://counter.theconversation.com/content/219397/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Brian Choo receives funding from the Australian Research Council and is employed by Flinders University.</span></em></p><p class="fine-print"><em><span>Alice Clement receives funding from the Australian Research Council and is employed by Flinders University.</span></em></p><p class="fine-print"><em><span>John Long receives funding from The Australian Research Council.</span></em></p>For decades, the sandstone in central Australia yielded tantalising segments of some sort of fossil fish. Now, we have finally pieced together a complete picture of this remarkable species.Brian Choo, Postdoctoral fellow in vertebrate palaeontology, Flinders UniversityAlice Clement, Research Associate in the College of Science and Engineering, Flinders UniversityJohn Long, Strategic Professor in Palaeontology, Flinders UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2226322024-02-06T06:13:31Z2024-02-06T06:13:31ZNewly identified prehistoric pterosaur will help us understand evolution of flying reptiles<figure><img src="https://images.theconversation.com/files/573093/original/file-20240202-19-jahq7z.jpg?ixlib=rb-1.1.0&rect=0%2C13%2C2246%2C1232&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">An artist's impression of the new pterosaur species, Cheoptera </span> <span class="attribution"><span class="source">Mark Witton/Natural History Museum</span>, <span class="license">Author provided</span></span></figcaption></figure><p>When dinosaurs roamed the land, the skies above their heads were filled with a variety of soaring reptiles, which swept through the air on <a href="https://www.scientificamerican.com/article/pterosaurs-were-monsters-of-the-mesozoic-skies/">slender, membranous wings</a>. These animals, pterosaurs, were not dinosaurs but their <a href="https://www.nhm.ac.uk/discover/watch-a-pterosaur-fly.html">evolutionary cousins</a>. </p>
<p><a href="https://www.tandfonline.com/doi/full/10.1080/02724634.2023.2298741">We’ve just announced</a> the discovery of a new species of pterosaur nearly 15 years after a fossil was found on the Isle of Skye. It is one of the most complete pterosaur fossils to be found in the UK since palaeontologist <a href="https://www.nhm.ac.uk/discover/mary-anning-unsung-hero.html">Mary Anning</a> unearthed <a href="https://www.geolsoc.org.uk/Library-and-Information-Services/Collection-Highlights/Mary-Anning-and-the-Geological-Society/pterosaurs-coprolites-and-sepia/dimorphodon-macronyx">the first</a> from the Dorset coast in 1828. </p>
<p>Pterosaurs were the first backboned animals to achieve powered flight (<a href="https://www.sciencedirect.com/science/article/pii/S0960982216314610">insects got there</a> first). Pterosaur fossils are known worldwide but their remains are rare in comparison to those of their land and water-based relatives. This is due to the <a href="https://theconversation.com/pterosaurs-should-%20have-been-too-big-to-fly-so-how-did-they-manage-it-60892">fragile nature of their skeletons</a>, which are composed of thin-walled, hollow bones.</p>
<p>Pterosaur fossils are often incomplete, <a href="https://www.amnh.org/exhibitions/pterosaurs-flight-in-the-age-of-dinosaurs/why-are-pterosaur-fossils-rare">crushed and distorted</a>. A sparse pterosaur record has been harvested from the Jurassic period (200-145 million years ago) and <a href="https://www.nhm.ac.uk/discover/the-cretaceous-period.html#:%7E:text=When%20was%20the%20Cretaceous%20Period,Cenozoic%20Era%2C%20our%20current%20era.">Cretaceous period</a> (145-66 million years ago) rocks of the UK since Anning’s discoveries. </p>
<p>But most of these are limited to a few isolated bones <a href="https://www.southampton.ac.uk/oes/news/2013/03/20_new_pterosaur_from_isle_of_wight.page">such as <em>Vectidraco</em></a>, a toothless pterosaur whose fossilised remains were found on the Isle of Wight in 2008 by five-year-old Daisy Morris. </p>
<p>This is where <a href="https://www.scottishtours.co.uk/scotland/isle-of-skye/">the Isle of Skye</a> comes in. Although Skye is most famous for the ancient volcanic landscapes of the <a href="https://www.isleofskye.com/skye-guide/skye-places/the-cuillin">Cuillin Hills</a> mountain range, there are <a href="https://www.isleofskye.com/skye-guide/history/jurassic-skye#:%7E:text=The%20Isle%20of%20Skye%20holds,mainly%20contained%20in%20local%20knowledge.">Jurassic-aged rocks</a> around the margins of the island. </p>
<p>Over the past 50 years teams of geologists and palaeontologists have been gradually uncovering <a href="https://www.cambridge.org/core/journals/earth-and-environmental-science-transactions-of-royal-society-of-edinburgh/article/diverse-vertebrate-assemblage-of-the-kilmaluag-formation-bathonian-middle-jurassic-of-skye-scotland/B8DD4D46839FA83FA2E57437BDEBF2B8">more of Skye’s ancient</a> past. This work has accelerated thanks to the new imaging techniques, mainly CT scanning, which <a href="https://www.theguardian.com/science/2016/mar/30/getting-under-a-fossils-skin-how-ct-scans-have-changed-palaeontology-dinosaur-lizard">make it easier</a> to study these fossils. </p>
<p>Our new pterosaur was found in 2006 by a team of researchers including Paul Barrett in a loose boulder lying on the beach at <a href="https://canmore.org.uk/site/138335/cladach-a-ghlinne">Cladach a’Glinne</a>, on the edge of a remote bay overshadowed by the Cuillins. </p>
<p>At first sight, the new skeleton was an underwhelming smear of thin, broken, black bone set in a hard, dark-grey mudstone. But, even then, these thin bones suggested that the find would turn out to be interesting.</p>
<p>It took <a href="https://www.nhm.ac.uk/our-science/departments-and-staff/staff-directory/lu-allington-jones.html">Lu Allington-Jones</a>, one of the Natural History Museum’s fossil technicians, nearly two years to prepare our discovery for study. The rocks from Skye are extremely hard, and the fossil bones are delicate. </p>
<p>Although Lu’s work allowed us to study some of the bones, others remained encased in rock as they were too dainty to remove or expose further.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/573095/original/file-20240202-21-y3x46f.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/573095/original/file-20240202-21-y3x46f.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/573095/original/file-20240202-21-y3x46f.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=469&fit=crop&dpr=1 600w, https://images.theconversation.com/files/573095/original/file-20240202-21-y3x46f.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=469&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/573095/original/file-20240202-21-y3x46f.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=469&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/573095/original/file-20240202-21-y3x46f.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=589&fit=crop&dpr=1 754w, https://images.theconversation.com/files/573095/original/file-20240202-21-y3x46f.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=589&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/573095/original/file-20240202-21-y3x46f.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=589&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Skeleton of the new pterosaur <em>Ceoptera evansae</em> from the Isle of Skye.</span>
<span class="attribution"><span class="source">The Trustees of the Natural History Museum</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>Once this work was complete, the specimen lay dormant in the museum’s collections for about nine years. But then we decided to examine the fossil using the <a href="https://www.bristol.ac.uk/earthsciences/research/palaeobiology/facilities/xtm-facility/">university’s CT scanner</a>. </p>
<p>Using this equipment, similar to that used in a hospital for diagnosing broken bones, with many months of careful imaging we were able to reveal almost the entire animal in three dimensions. </p>
<p>After comparing it with other pterosaur fossils from around the world, we realised that we were dealing with something new and we called it <em>Ceoptera evansae</em> (from the Gaelic name for Skye, Eilean a’ Cheò, Isle of Mist, and honouring <a href="https://profiles.ucl.ac.uk/9226-susan-evans">Professor Susan Evans</a> who has worked extensively in the area). </p>
<p>This pterosaur species is important because of the quality of preservation and its age. It is one of only a <a href="https://epub.ub.uni-muenchen.de/12007/1/zitteliana_2008_b28_05.pdf">handful of pterosaur skeletons</a> from the <a href="https://www.nationalgeographic.com/science/article/jurassic">Middle Jurassic period</a>, approximately 167 million years ago. </p>
<p>At this time pterosaurs were undergoing colossal anatomical changes from early small-bodied, long-tailed pterosaurs such as <em><a href="https://www.britannica.com/animal/Dimorphodon">Dimorphodon</a></em> (roughly the size of a raven) to later pterosaurs like <em><a href="https://www.britannica.com/animal/Pteranodon">Pteranodon</a></em> which had a wingspan similar to that of a small airplane. </p>
<p>The lack of good pterosaur specimens from this time interval has hindered scientists’ attempts to understand how pterosaurs evolved from these earlier forms to those that dominated the skies later in Earth’s history. <em>Ceoptera</em> helps to fill this a gap. </p>
<p>For 15 years scientists have studied <a href="https://www.smithsonianmag.com/science-%20nature/darwinopterus-a-transitional-pterosaur-55145586/">transitional pterosaurs</a> that show a mix of features seen in the
earlier, tailed forms and their later, giant relatives. <em>Ceoptera</em> is one of these transitional forms (called a <a href="https://www.smithsonianmag.com/science-nature/darwinopterus-a-transitional-pterosaur-55145586/">Darwinopteran</a>), one of the first members of this group known from Europe, and is the second-oldest darwinopteran worldwide. </p>
<p>This makes <em>Ceoptera</em> crucial in understanding the pace of pterosaur evolution, and it has pushed back the appearance of more advanced pterosaurs to the Early Jurassic period, about 10 million years earlier than previously thought. It brings us one step closer to understanding where and when the more advanced pterosaurs evolved. </p>
<p><em>Ceoptera</em>‘s discovery shows how palaeontologists are making new discoveries all the time, even in places like the UK - one of the most heavily surveyed places worldwide. It also shows how new technology can is helping to unearth the mysteries of Earth’s ancient past. </p>
<hr>
<figure class="align-left ">
<img alt="" src="https://images.theconversation.com/files/536131/original/file-20230706-17-460x2d.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/536131/original/file-20230706-17-460x2d.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/536131/original/file-20230706-17-460x2d.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/536131/original/file-20230706-17-460x2d.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/536131/original/file-20230706-17-460x2d.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/536131/original/file-20230706-17-460x2d.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/536131/original/file-20230706-17-460x2d.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption"></span>
</figcaption>
</figure>
<p><em>Looking for something good? Cut through the noise with a carefully curated selection of the latest releases, live events and exhibitions, straight to your inbox every fortnight, on Fridays. <a href="https://theconversation.com/uk/newsletters/something-good-156">Sign up here</a>.</em></p>
<hr><img src="https://counter.theconversation.com/content/222632/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Paul Barrett is affiliated with The Linnean Society (Trustee).</span></em></p><p class="fine-print"><em><span>Elizabeth Martin-Silverstone does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>The Isle of Skye has a rich palaeontological heritage, so perhaps it’s no surprise scientists made an important discovery there.Elizabeth Martin-Silverstone, Research Assistant in Palaeontology, University of BristolPaul Barrett, Individual Merit Researcher, Natural History MuseumLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2168532024-02-05T13:30:30Z2024-02-05T13:30:30ZStudying lake deposits in Idaho could give scientists insight into ancient traces of life on Mars<figure><img src="https://images.theconversation.com/files/568753/original/file-20240110-30-i5trcc.JPG?ixlib=rb-1.1.0&rect=23%2C398%2C3128%2C1343&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Scientists have been studying the Clarkia site for nearly five decades.</span> <span class="attribution"><span class="source">Robert Patalano</span></span></figcaption></figure><p>Does life exist elsewhere in the universe? If so, how do scientists search for and identify it? Finding life beyond Earth is extremely difficult, partly because other planets are so far away and partly because we are not sure what to look for.</p>
<p>Yet, astrobiologists have learned a lot about <a href="https://science.nasa.gov/astrobiology/">how to find life</a> in extraterrestrial environments, mainly by studying how and when the early Earth became livable.</p>
<p>While research teams at NASA are <a href="https://mars.nasa.gov/mars2020/mission/overview/">directly combing</a> the surface of Mars for signs of life, our <a href="https://news.bryant.edu/there-life-red-planet-faculty-earns-funding-explore-theory-earth">interdisciplinary research group</a> is <a href="https://news.bryant.edu/mars-mind-bryant-students-earn-funding-nasa-ri-space-grant-consortium">using a site here on Earth</a> to approximate ancient environmental conditions on Mars. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/568752/original/file-20240110-18-1v7yda.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A rock face with several blocky layers of rock, in different stripes of color. The top layers are a darker clay, while the bottom layers are a lighter volcanic ash." src="https://images.theconversation.com/files/568752/original/file-20240110-18-1v7yda.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/568752/original/file-20240110-18-1v7yda.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/568752/original/file-20240110-18-1v7yda.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/568752/original/file-20240110-18-1v7yda.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/568752/original/file-20240110-18-1v7yda.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/568752/original/file-20240110-18-1v7yda.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/568752/original/file-20240110-18-1v7yda.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A close-up view of the Clarkia site where you can see lacustrine clay and volcanic ash layers. This site represents Mars in our work.</span>
<span class="attribution"><span class="source">Taylor Vahey</span></span>
</figcaption>
</figure>
<p>Contained within northern Idaho’s <a href="https://doi.org/10.1130/G48901.1">Clarkia Middle Miocene Fossil Site</a> are sediments that preserve some of Earth’s most diverse biological marker molecules, or <a href="https://doi.org/10.1016/j.epsl.2008.07.012">biomarkers</a>. These are remains of past life that offer glimpses into Earth’s history.</p>
<h2>An ancient lake</h2>
<p>About 16 million years ago, a lava flow in what would one day become Clarkia, Idaho, dammed a local drainage system and created a deep lake in a <a href="https://archive.org/details/latecenozoichist0000unse/page/424/mode/2up">narrow, steep-sided valley</a>. Although the lake has since dried up, weathering, erosion and <a href="https://www.facebook.com/p/Fossil-Bowl-100063724775941/">human activity</a> have exposed sediments of the former lake bed.</p>
<p>For nearly five decades, research teams like ours – being led by <a href="https://www.radcliffe.harvard.edu/people/hong-yang">Dr. Hong Yang</a> and <a href="https://www.bryant.edu/academics/faculty/leng-qin">Dr. Qin Leng</a> – have used <a href="https://doi.org/10.7717/peerj.4880">fossil remains</a> and <a href="https://doi.org/10.1016/0146-6380(95)80001-8">biogeochemistry</a> to reconstruct past environments of the Clarkia Miocene Lake region. </p>
<p>The lake’s depth created the <a href="https://www.jstor.org/stable/1303276">perfect conditions</a> for protecting microbial, plant and animal remains that fell to the lake’s bottom. In fact, the sediments are so well preserved that some of the fossilized leaves still show their autumn colors from when they sank into the water millions of years ago.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/568751/original/file-20240110-15-2y3q3p.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A reddish brown long, thin leaf shown embedded on a piece of smooth sediment." src="https://images.theconversation.com/files/568751/original/file-20240110-15-2y3q3p.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/568751/original/file-20240110-15-2y3q3p.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/568751/original/file-20240110-15-2y3q3p.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/568751/original/file-20240110-15-2y3q3p.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/568751/original/file-20240110-15-2y3q3p.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/568751/original/file-20240110-15-2y3q3p.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/568751/original/file-20240110-15-2y3q3p.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A fossil magnolia leaf showing fall (reddish) colors. This leaf likely fell off a tree in the fall once the trees paused photosynthesis for the winter and sank to the bottom of the lake, where it was buried. The leaf retained its fall coloring for 16 million years, though once being dug up and exposed to air, it quickly oxidized and lost its color.</span>
<span class="attribution"><span class="source">Robert Patalano</span></span>
</figcaption>
</figure>
<p>Today, ancient lake beds on Earth are becoming <a href="https://doi.org/10.1146/annurev-earth-053018-060332">important settings</a> for learning about habitable environments on other planets. </p>
<h2>Biological marker molecules</h2>
<p>Clarkia’s lake sediments <a href="https://doi.org/10.1016/0146-6380(94)90045-0">contain a suite</a> of ancient biomarkers. These compounds, or classes of compounds, can reveal how organisms and their <a href="https://doi.org/10.1016/j.quascirev.2011.07.009">environments functioned</a> in the past.</p>
<p>Since the discovery of the <a href="https://www.idahogeology.org/pub/Information_Circulars/IC-33.pdf">Clarkia fossil site in 1972</a>, multiple research teams have used various <a href="https://doi.org/10.1016/S0146-6380(02)00212-7">cutting-edge technologies to analyze</a> different biomarkers. </p>
<p>Some of those found at Clarkia <a href="https://doi.org/10.1073/pnas.90.6.2246">include lignin</a>, which is the structural support tissue of plants, <a href="https://doi.org/10.1016/S0146-6380(00)00107-8">lipids like fats and waxes</a>, and possibly <a href="https://doi.org/10.1038/344656a0">DNA and amino acids</a>.</p>
<p>Understanding the origins, history and environmental factors that have allowed these biosignatures to stay so well preserved at Clarkia may also allow our team to predict the potential of organic matter preservation in ancient lake deposits on Mars.</p>
<h2>Studying life signatures on Mars</h2>
<p>In 2021, the <a href="https://mars.nasa.gov/mars2020/">Mars Perseverance Rover</a> landed on top of lake deposits in Mars’ <a href="https://doi.org/10.1126/science.abl4051">Jezero Crater</a>. Jezero is a meteorite impact crater believed to have once been flooded with water and home to an ancient river delta. Microbial life may have lived in Jezero’s crater lake, and their biomarkers might be found in lake bed sediments today. Perseverance has been drilling into the crater’s surface to collect samples that could contain ancient signs of life, with the intent of <a href="https://mars.nasa.gov/msr/#Facts">returning the samples to Earth in 2033</a>.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/547616/original/file-20230911-26-nc2bk5.jpg?ixlib=rb-1.1.0&rect=14%2C7%2C4977%2C2799&q=45&auto=format&w=1000&fit=clip"><img alt="An artist's rendition of the Perseverence rover, made of metal with six small wheels, a camera and a robotic arm." src="https://images.theconversation.com/files/547616/original/file-20230911-26-nc2bk5.jpg?ixlib=rb-1.1.0&rect=14%2C7%2C4977%2C2799&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/547616/original/file-20230911-26-nc2bk5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=338&fit=crop&dpr=1 600w, https://images.theconversation.com/files/547616/original/file-20230911-26-nc2bk5.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=338&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/547616/original/file-20230911-26-nc2bk5.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=338&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/547616/original/file-20230911-26-nc2bk5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/547616/original/file-20230911-26-nc2bk5.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/547616/original/file-20230911-26-nc2bk5.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=424&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The Perseverance Rover is collecting samples to learn more about Mars’ environment.</span>
<span class="attribution"><a class="source" href="https://newsroom.ap.org/detail/MarsLanding/c835b14b3e6645d7a0cd46558745752b/photo?Query=mars%20rover&mediaType=photo&sortBy=&dateRange=Anytime&totalCount=530&currentItemNo=11&vs=true">NASA/JPL-Caltech via AP</a></span>
</figcaption>
</figure>
<p>Clarkia has many similarities to the Jezero Crater. Both Clarkia and Jezero Crater have ancient <a href="https://doi.org/10.1006/icar.2000.6530">lake deposits</a> derived from silica-rich, <a href="https://doi.org/10.1029/2017JE005478">basaltic rock</a> that formed under <a href="https://doi.org/10.1016/j.gloplacha.2022.103737">a climate with</a> higher temperatures, high humidity and a carbon dioxide-rich atmosphere. </p>
<p>At Clarkia, these conditions preserved microbial biomarkers in the ancient lake. Similar settings could have <a href="https://doi.org/10.1029/2012JE004115">formed lakes</a> on the surface of Mars. </p>
<p>The samples <a href="https://mars.nasa.gov/mars-rock-samples/#23">Perseverance is collecting</a> contain the geologic and climate history of the Jezero Crater landing site and may even contain preserved biomarkers of ancient life.</p>
<p>While Perseverance continues its mission, our group is <a href="https://agu.confex.com/agu/fm23/meetingapp.cgi/Paper/1367388">establishing criteria</a> for biomolecular authentication. That means we are developing ways to figure out whether ancient biomarkers from Earth, and hopefully Mars, are true echoes of life – rather than recent contamination or molecules from nonliving sources.</p>
<p>To do so, we are studying biomarkers from Clarkia’s fossil leaves and sediments and developing laboratory experiments using <a href="https://spaceresourcetech.com/collections/regolith-simulants">Martian simulants</a>. This material simulates the chemical and physical properties of Jezero Crater’s lake sediments.</p>
<p>By deciphering the sources, history and preservation of biomarkers connected with Clarkia’s ancient lake deposits, we hope to develop new strategies for studying the Perseverance Rover samples once they are back on Earth.</p><img src="https://counter.theconversation.com/content/216853/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Robert Patalano receives funding from the NASA Rhode Island Space Grant Program. </span></em></p>While NASA rovers on the surface of Mars look for hints of life, researchers back on Earth are studying ‘echoes of life’ from ancient basins – hoping that the two sites might be similar.Robert Patalano, Lecturer of Biological and Biomedical Sciences, Bryant UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2219312024-01-31T00:40:50Z2024-01-31T00:40:50ZA 365-million-year-old fish with an extreme underbite showcases vertebrate diversity<figure><img src="https://images.theconversation.com/files/572031/original/file-20240129-25-h41utn.jpg?ixlib=rb-1.1.0&rect=0%2C40%2C3000%2C2465&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Artist reconstruction of Alienacanthus malkowskii, a 365-million-year-old placoderm fish from Poland and Morocco.</span> <span class="attribution"><span class="source">(Beat Scheffold & Christian Klug)</span>, <span class="license">Author provided</span></span></figcaption></figure><iframe style="width: 100%; height: 100px; border: none; position: relative; z-index: 1;" allowtransparency="" allow="clipboard-read; clipboard-write" src="https://narrations.ad-auris.com/widget/the-conversation-canada/a-365-million-year-old-fish-with-an-extreme-underbite-showcases-vertebrate-diversity" width="100%" height="400"></iframe>
<p>Vertebrates are defined as all animals that possess a vertebral column, or backbone. Most living vertebrates also possess jaws, teeth and paired fins or limbs.</p>
<p>Fossils of the earliest vertebrates help us understand not only how these features originated, but also how they evolved and diversified over time. </p>
<p>Our study, <a href="https://dx.doi.org/10.1098/rsos.231747">published in <em>Royal Society Open Science</em></a>, examines 365-million-year-old fossils of a fish with the world’s longest underbite, called <em>Alienacanthus malkowskii</em>. These fossils demonstrate the diversity of jawed vertebrates early on during their evolution.</p>
<p><em>Alienacanthus</em> is a member of an extinct group of fish called <a href="https://ucmp.berkeley.edu/vertebrates/basalfish/placodermi.html">placoderms</a>, which are some of the first jawed vertebrates. They are armoured fish of various shapes and sizes and are essential to understanding the evolution of vertebrates and their features, particularly jaws and teeth.</p>
<p>Together, placoderm jaws and teeth hold evidence of feeding strategies and diets, giving us insights into what and how some of our fishy ancestors ate. </p>
<h2>From spine to jaw</h2>
<p>In 1957, Polish paleontologist Julian Kulczycki <a href="https://www.app.pan.pl/article/item/app02-285.html">described fossil fishes</a> from the Polish Holy Cross mountains. Among these finds were two partially broken long thin bones which he thought were some weird-looking fin spines from a fish. The odd shape of the so-called spines gave the animal its name, <em>Alienacanthus</em>. </p>
<p>In the late 1990s to early 2000s, members of our research team came across some Moroccan specimens in the collections of the Muséum national d’Histoire naturelle in Paris that included the same bony elements. The team later encountered more specimens from Poland and Morocco, which we identified as belonging to a placoderm.</p>
<p><em>Alienacanthus</em> had a massive, rounded head with a pointy snout and large eyes. What Kulczycki had identified as spines turned out to be the lower jaws, which extended way past the closing of the mouth, unlike the upper jaws. The teeth were sharp, slightly curved towards the back to trap live prey, and the teeth continued past the closing of the mouth. </p>
<p>Unlike in other placoderms, the upper jaws of <em>Alienacanthus</em> were capable of a slight movement independently of the skull, helping to accommodate the lower jaw.</p>
<h2>Most extreme case</h2>
<p>The extended lower jaw of <em>Alienacanthus</em>, twice as long as the skull, is unique among placoderms and extremely rare in other living and fossil groups. In most animals, jaw protrusion is seen in the upper jaw, like in the <a href="https://www.britannica.com/animal/swordfish-fish">swordfish</a>, or both upper and lower jaws like <a href="https://theconversation.com/how-climate-change-killed-the-dinosaurs-underwater-cousins-55803">ichthyosaurs</a> or <a href="https://nationalzoo.si.edu/animals/gharial">gharials</a>. </p>
<p>Among living species, only a tiny fish called the <a href="https://www.britannica.com/animal/halfbeak">halfbeak</a> shows an elongated lower jaw. The halfbeak measures just five to 10 cm in length, while <em>Alienacanthus</em>’ head and jaws alone reach 80 cm. The relative length of the lower jaw is also 20 per cent greater than in the halfbeak.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/572030/original/file-20240129-29-wk61fi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="a small fish with an elongated lower jaw" src="https://images.theconversation.com/files/572030/original/file-20240129-29-wk61fi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/572030/original/file-20240129-29-wk61fi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/572030/original/file-20240129-29-wk61fi.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/572030/original/file-20240129-29-wk61fi.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/572030/original/file-20240129-29-wk61fi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/572030/original/file-20240129-29-wk61fi.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/572030/original/file-20240129-29-wk61fi.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Of currently living species, only the halfbeak shows an elongated lower jaw.</span>
<span class="attribution"><span class="source">(Shutterstock)</span></span>
</figcaption>
</figure>
<p><em>Alienacanthus</em> also holds the title of the oldest case of lower jaw elongation. The previous record belonged to the 310-million-year-old shark <a href="https://archive.org/details/newsharkoffamily161zang/page/n9/mode/2up"><em>Ornithoprion</em></a>. </p>
<h2>The Age of fishes</h2>
<p><em>Alienacanthus</em> and relatives lived during <a href="https://www.britannica.com/science/Devonian-Period">the Devonian period</a> (358 to 419 million years ago), also referred to by paleontologists as the <a href="https://eartharchives.org/articles/when-monsters-ruled-the-water-the-age-of-fishes/index.html">Age of fishes</a>. During this time, a variety of fish groups ruled the oceans, including <a href="https://www.nhm.ac.uk/discover/shark-evolution-a-450-million-year-timeline.html">sharks</a>, <a href="https://theconversation.com/its-less-than-2cm-long-but-this-400-million-year-old-fossil-fish-changes-our-view-of-vertebrate-evolution-96419">bony fishes</a>, <a href="https://eartharchives.org/articles/ostracoderms-armored-fishes-without-jaws/index.html">jawless fishes</a> and placoderms, which together illustrated a wide range of body, head and jaw shapes. </p>
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Read more:
<a href="https://theconversation.com/ancient-fishes-kept-their-young-in-a-nursery-65400">Ancient fishes kept their young in a nursery</a>
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</em>
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<p><em>Alienacanthus</em> stretches that diversity to the limit with such a unique look. Fifteen million years after this animal’s occurrence, placoderms met their demise. </p>
<p>The evolution of more complex jaws allowed for a wider range of feeding and hunting methods. The oldest placoderms favoured a <a href="https://doi.org/10.1098/rsbl.2006.0569">fast-closing mouth</a> for catching prey. But some placoderms started <a href="https://doi.org/10.1111/j.1096-3642.1980.tb01932.x">feeding on durophagous animals, with hard shells and exoskeletons</a>, and others may have been <a href="https://doi.org/10.1098/rsos.200272">filter-feeders</a>. </p>
<p><em>Alienacanthus</em> used its sharp teeth to catch and trap live prey, possibly using its elongated jaw to confuse or injure its future meal, as seen in swordfish and some ichthyosaurs. </p>
<h2>Learning more</h2>
<p>The further back in time we go, the more our planet’s continents looked different. During the Late Devonian period, when <em>Alienacanthus</em> lived, Poland was situated on the northeastern coast and Morocco on the southern coast of a vast ocean. The presence of the same species on both ends shows that migration occurred in that ocean at that time, despite sea level fluctuation. </p>
<p><em>Alienacanthus</em> comprises just one of numerous recent finds in Poland and Morocco from the Late Devonian period. Such discoveries illustrate the remaining high potential for deposits of this age to reveal critical insights about early vertebrates.</p><img src="https://counter.theconversation.com/content/221931/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Melina Jobbins received funding from the Swiss National Science Foundation. </span></em></p><p class="fine-print"><em><span>Christian Klug receives funding from the Swiss National Science Foundation SNSF (grant nr. 200020_184894).</span></em></p><p class="fine-print"><em><span>Martin Rücklin received funding from Dutch Research Council (NWO).</span></em></p>What paleontologists had believed to be spiny fins turned out to be elongated jaws. New examination of fossils that were 365 million years old revealed a fish with a remarkable lower jaw.Melina Jobbins, Researcher, Evolutionary Biology, University of ZurichChristian Klug, Professor, Curator of the Palaentological Museum, University of ZurichMartin Rücklin, Research group leader, Naturalis Biodiversity Center and Senior researcher, Instituut Biologie Leiden, Leiden UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2181282024-01-15T19:04:45Z2024-01-15T19:04:45Z565-million-years-old, some of the oldest UK fossils are eerily similar to famous Australian ones<figure><img src="https://images.theconversation.com/files/562350/original/file-20231129-28-ulz8qc.jpg?ixlib=rb-1.1.0&rect=2%2C4%2C1531%2C1016&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Ediacaran life as imagined by scientists in the 1980s.</span> <span class="attribution"><a class="source" href="https://en.m.wikipedia.org/wiki/File:Life_in_the_Ediacaran_sea.jpg">Ryan Somma/Wikimedia</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span></figcaption></figure><p>Some half a billion years ago, life on Earth went through a huge transformation. In what is called <a href="https://www.annualreviews.org/doi/10.1146/annurev.earth.33.092203.122519">the Ediacaran period</a>, after billions of years of single-celled organisms, large multicellular organisms emerged in the fossil record.</p>
<p>These traces of the oldest complex ecosystems have been found in only a handful of locations around the world. The fossils were made by soft-bodied creatures covered by sand, creating impressions of their squashed remains imprinted into rock.</p>
<p>Evidence of these creatures was first found in the <a href="https://ediacarafoundation.org/visit/">Ediacara Hills</a>, in South Australia’s Flinders Ranges. The discovery was pivotal in defining the <a href="https://www.idunn.no/doi/10.1080/00241160500409223">Ediacaran period</a>: a time in Earth’s past characterised by a specific layer of rock which symbolises a significant change in history.</p>
<p>What was happening elsewhere at this time? <a href="https://www.nature.com/articles/268624a0">Similar-looking fossils</a> have been found in a disused quarry in a farmer’s field at Llangynog in Wales, but until now their precise age was unknown. </p>
<p>In a <a href="https://dx.doi.org/10.1144/jgs2023-081">new study published in Journal of the Geological Society</a>, we have dated these Welsh remnants of ancient marine life. Now, we can confirm they were near contemporaries of the famous South Australian fossils. </p>
<h2>A bookmark for rocks</h2>
<p>How do geologists figure out the age of fossils? Understanding the age of fossils is extremely useful for correlation and understanding how biological communities evolved.</p>
<p>Luckily, at least for us today, an environmental catastrophe loomed in the shallow sea where these Welsh organisms lived. </p>
<p><a href="https://theconversation.com/volcano-eruptions-are-notoriously-hard-to-forecast-a-new-method-using-lasers-could-be-the-key-207031">Volcanic explosions</a> threw mineral particles over the surrounding landscape and polluted the atmosphere with toxic gases.</p>
<p>The billowing red hot clouds created ash layers. These ash layers contain mineral grains that are <a href="https://www.britannica.com/science/isotope">isotopically</a> datable, acting like miniature stopwatches that record the time elapsed since they crystallised in a volcano. Hence, volcanic ash acts much like a bookmark in a sequence of rocks, tracking the moment of eruption.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/568992/original/file-20240112-19-9fua7r.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Illustration of a conic volcano in the distance spewing out an ash cloud" src="https://images.theconversation.com/files/568992/original/file-20240112-19-9fua7r.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/568992/original/file-20240112-19-9fua7r.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/568992/original/file-20240112-19-9fua7r.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/568992/original/file-20240112-19-9fua7r.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/568992/original/file-20240112-19-9fua7r.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/568992/original/file-20240112-19-9fua7r.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/568992/original/file-20240112-19-9fua7r.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Volcanic eruptions produce layers of ash that can be used as ‘bookmarks’ in the geological record.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-illustration/volcano-errupting-volcanic-erruption-3d-illustration-2213727917">CGS Graphics</a></span>
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<h2>A clock for rocks</h2>
<p>A clock tick-tocks every second, but how do we measure time when each tick takes a million years? We use a <a href="https://www.gsoc.org/news/2020/12/07/zircon">mineral called zircon</a>. </p>
<p>Trapped within zircon is some uranium that undergoes nuclear decay to lead over millions of years. Scientists know the rate at which this change occurs, so by analysing the composition of the crystal we can use the zircon as a geological clock.</p>
<p>The more precisely we measure the amount of uranium and lead, the more precise the clock. By carefully <a href="https://www.boisestate.edu/earth-isotope/labshare/id-tims-instructional-videos/">dissolving, heating and analysing zircon</a>, we have dated the rocks in Wales to 565 million years (plus or minus 0.1%). That is a precise death certificate for the fossils.</p>
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<strong>
Read more:
<a href="https://theconversation.com/scientists-cant-agree-on-when-the-first-animals-evolved-our-research-hopes-to-end-the-debate-212076">Scientists can't agree on when the first animals evolved – our research hopes to end the debate</a>
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<h2>It’s life, but not as we know it</h2>
<p>Evidence from Ediacaran fossils implies that after four billion years of oceans containing single-celled microbes, suddenly – in geological terms at least – the seas teemed with new complex life. <a href="https://eos.org/features/hunting-rare-fossils-of-the-ediacaran">Ediacaran life is odd</a>, with strange soft-bodied forms whose interaction with the environment is unclear. </p>
<p>Were the creatures stationary, or did they move around and eat each other? In some ways these creatures would be strangely familiar, yet in another way, bizarre. </p>
<p>Some appeared fern-like, others like cabbages, and yet others were similar to modern <a href="https://www.britannica.com/animal/sea-pen">sea pens</a>, resembling fat, old-fashioned writing quills.</p>
<p>Nevertheless, fossils from this time preserve the earliest evidence for large-scale multicellular organisms, <a href="https://www.australianenvironmentaleducation.com.au/education-resources/life-in-the-ediacaran/">including the first animals</a>.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/568974/original/file-20240111-17-he84nu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Green hills stretching to the horizon with clouds above and a few sheep in the foreground" src="https://images.theconversation.com/files/568974/original/file-20240111-17-he84nu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/568974/original/file-20240111-17-he84nu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=338&fit=crop&dpr=1 600w, https://images.theconversation.com/files/568974/original/file-20240111-17-he84nu.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=338&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/568974/original/file-20240111-17-he84nu.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=338&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/568974/original/file-20240111-17-he84nu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/568974/original/file-20240111-17-he84nu.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/568974/original/file-20240111-17-he84nu.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=424&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The rolling countryside of mid-south Wales – hidden away in these hills is evidence of ancient life.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/rolling-agricultural-hills-mid-wales-landscape-2095266949">Parkerspics</a></span>
</figcaption>
</figure>
<h2>A tropical paradise?</h2>
<p>Half a billion years ago, Wales was not green and sheep covered and looked much more like a barren volcanic island. The Llangynog fossils are fascinating because they record a shallow marine ecosystem. </p>
<p>In contrast, other famous fossil sites like <a href="https://www.bgs.ac.uk/news/560-million-year-old-fossil-is-first-animal-predator/">Charnwood Forest in the United Kingdom</a> and <a href="https://whc.unesco.org/en/list/1497/">Mistaken Point, Canada</a> record deep-marine conditions.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/565985/original/file-20231215-15-xkahqn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A circular impression on a grey rock with a 20mm scale in the corner" src="https://images.theconversation.com/files/565985/original/file-20231215-15-xkahqn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/565985/original/file-20231215-15-xkahqn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=503&fit=crop&dpr=1 600w, https://images.theconversation.com/files/565985/original/file-20231215-15-xkahqn.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=503&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/565985/original/file-20231215-15-xkahqn.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=503&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/565985/original/file-20231215-15-xkahqn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=632&fit=crop&dpr=1 754w, https://images.theconversation.com/files/565985/original/file-20231215-15-xkahqn.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=632&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/565985/original/file-20231215-15-xkahqn.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=632&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption"><em>Aspidella</em>, one of the weird and wonderful fossils of Llangynog, Wales.</span>
<span class="attribution"><span class="source">Anthony Clarke</span></span>
</figcaption>
</figure>
<p>In the shallow waters of the chain of tropical volcanic islands that’s now Wales, a creature called <em>Aspidella terranovica</em> felt the warmth of sunlight and the sway of the tides 565 million years ago. This fossil is rare and valuable because it shows evidence of movement.</p>
<p>Alongside <em>Aspidella</em>, other disc-like organisms are preserved; these could represent the anchor for fern-shaped filter feeders.</p>
<p>Hidden away in an unassuming quarry in Wales are the remnants of a diverse shallow marine ecosystem containing some of Britain’s oldest fossils, which we have proved have cousins of a similar age in Australia. This time in Earth’s history was just after a <a href="https://theconversation.com/how-snowball-earth-volcanoes-altered-oceans-to-help-kickstart-animal-life-53280">global glaciation</a> so severe and widespread that some researchers consider the entire planet froze into a “snowball”. </p>
<p>The Ediacaran fossils show this thaw-out heralded evolutionary change, demonstrating a profound link between our planet’s geological processes and its biological cargo.</p>
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Read more:
<a href="https://theconversation.com/friday-essay-the-silence-of-ediacara-the-shadow-of-uranium-72058">Friday essay: the silence of Ediacara, the shadow of uranium</a>
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<img src="https://counter.theconversation.com/content/218128/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Chris Kirkland receives funding from the Australian Research Council and various state government organisations within Australia.</span></em></p><p class="fine-print"><em><span>Anthony Clarke receives funding from the Australian Research Council.</span></em></p>Fossil traces of the oldest complex ecosystems are found in precious few locations worldwide, including Australia. Newly dated fossils from Wales now join the ranks.Chris Kirkland, Professor of Geochronology, Curtin UniversityAnthony Clarke, PhD Student in Applied Geology, Curtin UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2193042024-01-10T19:13:07Z2024-01-10T19:13:07ZGiant ‘kings of apes’ once roamed southern China. We solved the mystery of their extinction<figure><img src="https://images.theconversation.com/files/563807/original/file-20231206-15-lq4hvc.jpg?ixlib=rb-1.1.0&rect=4%2C9%2C3241%2C2087&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Artist's impression of a group of Gigantopithecus blacki in a forest in southern China.</span> <span class="attribution"><span class="source">Garcia/Joannes-Boyau (Southern Cross University)</span></span></figcaption></figure><p>Giant creatures are usually associated with dinosaurs, woolly mammoths or mystical beasts. But if you go back though the human lineage you’ll find a very distant relative that stood three metres tall and weighed around 250 kilograms. This was <em>Gigantopithecus blacki</em>, the mightiest of all the primates and one of the biggest unresolved mysteries in palaeontology.</p>
<p>Despite surviving for nearly two million years in what is now the Guangxi Zhuang Autonomous Region of southern China, the entire species is represented in the fossil record only by a few thousand teeth and four jawbones. Nothing from the neck down. </p>
<p>Added to that is its mysterious disappearance from the fossil record at a time when other primates were flourishing. Where did the giants go and what brought them down?</p>
<p>Since 2015, a team of Chinese, Australian and US scientists <a href="https://www.wheregiantsroamed.com/">has been chasing</a> this mighty beast in <a href="https://education.nationalgeographic.org/resource/karst/">the distinctive terrains</a> of southern China. Our findings <a href="https://www.nature.com/articles/s41586-023-06900-0">are published in Nature today</a> and reveal a story of seasonality, stress and vulnerability.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/566488/original/file-20231219-23-d6iweb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A series of flat-topped tall cliffs covered in greenery set against a blue sky" src="https://images.theconversation.com/files/566488/original/file-20231219-23-d6iweb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/566488/original/file-20231219-23-d6iweb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=226&fit=crop&dpr=1 600w, https://images.theconversation.com/files/566488/original/file-20231219-23-d6iweb.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=226&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/566488/original/file-20231219-23-d6iweb.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=226&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/566488/original/file-20231219-23-d6iweb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=284&fit=crop&dpr=1 754w, https://images.theconversation.com/files/566488/original/file-20231219-23-d6iweb.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=284&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/566488/original/file-20231219-23-d6iweb.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=284&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A karst landscape panorama in southern China.</span>
<span class="attribution"><span class="source">Renaud Joannes-Boyau</span></span>
</figcaption>
</figure>
<h2>Finding the window of extinction</h2>
<p>Extensive exploration and excavations in hundreds of caves over a five-year period has been narrowed down into evidence from 22 caves in two regions of Guangxi: Chongzuo, near the Vietnamese border, and Bubing Basin, close to Nanning. Eleven of these caves contain evidence of <em>G. blacki</em> and the other eleven – of a similar age range – do not. </p>
<p>Our team applied several dating techniques to sediments from the caves: <a href="https://www.thoughtco.com/luminescence-dating-cosmic-method-171538">luminescence dating</a> of feldspars (a common rock-forming mineral), <a href="https://en.wikipedia.org/wiki/Electron_spin_resonance_dating">electron spin resonance dating</a> of quartz, and <a href="https://www.britannica.com/science/dating-geochronology/Uranium-series-disequilibrium-dating">uranium series dating</a> of stalagmites and similar deposits, as well as fossils. Altogether we ended up with a staggering 157 radiometric ages.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/566487/original/file-20231219-25-qvs2tg.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A dark cave with light walls, with several people in hard hats looking through the sediment" src="https://images.theconversation.com/files/566487/original/file-20231219-25-qvs2tg.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/566487/original/file-20231219-25-qvs2tg.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/566487/original/file-20231219-25-qvs2tg.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/566487/original/file-20231219-25-qvs2tg.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/566487/original/file-20231219-25-qvs2tg.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/566487/original/file-20231219-25-qvs2tg.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/566487/original/file-20231219-25-qvs2tg.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Excavations in Ma Feng Cave in Guangxi Zhuang Autonomous Region of southern China.</span>
<span class="attribution"><span class="source">Kira Westaway</span></span>
</figcaption>
</figure>
<p>We used these data sets to establish exactly when <em>G. blacki</em> dropped out of the fossil record, to define a “window of extinction”. This window allowed us to target a period of time to look closely at the environmental changes.</p>
<p>Next, we looked at eight sources of environmental and behavioural evidence, including ancient pollen grains, other animal bones and micro details in the sediments.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/567028/original/file-20231221-15-f2uwk9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A close up of a dark faced ape with dark ginger hair, black eyes and a round muzzle" src="https://images.theconversation.com/files/567028/original/file-20231221-15-f2uwk9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/567028/original/file-20231221-15-f2uwk9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=679&fit=crop&dpr=1 600w, https://images.theconversation.com/files/567028/original/file-20231221-15-f2uwk9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=679&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/567028/original/file-20231221-15-f2uwk9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=679&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/567028/original/file-20231221-15-f2uwk9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=853&fit=crop&dpr=1 754w, https://images.theconversation.com/files/567028/original/file-20231221-15-f2uwk9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=853&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/567028/original/file-20231221-15-f2uwk9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=853&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The closest primate relative of <em>G. blacki</em> is the critically endangered orangutan.</span>
<span class="attribution"><a class="source" href="https://unsplash.com/photos/brown-monkey-on-green-grass-during-daytime-Sn9t1C7AhXQ">Bob Brewer/Unsplash</a></span>
</figcaption>
</figure>
<p>Furthermore, we gained a wealth of information from <em>G. blacki</em> teeth themselves – from <a href="https://en.wikipedia.org/wiki/Isotopic_signature">isotopic signatures</a>, trace elements and the wear patterns on the surface of the teeth. This evidence can indicate diet, migration patterns, habitat preferences, diversity of food sources and stress. </p>
<p>This data represents the largest collection of well-dated evidence for the giant ape and for the first time is supported by well-documented environmental and behavioural changes. It reveals the rise and fall of <em>G. blacki</em> in comparison to its closest primate relative – the orangutans. </p>
<h2>Stronger seasons</h2>
<p>Surprisingly, <em>G. blacki</em> went extinct between 295,000 and 215,000 years ago, much more recently than previously assumed. Before this time, <em>G. blacki</em> flourished in a rich and diverse forest. </p>
<p>But between 600,000 and 300,000 years ago the environment became more variable. An increase in the strength of the seasons caused a change in the structure of the forest plant communities. By 200,000 years ago, the forests started to deteriorate.</p>
<figure class="align-left zoomable">
<a href="https://images.theconversation.com/files/566490/original/file-20231219-15-qvs2tg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/566490/original/file-20231219-15-qvs2tg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/566490/original/file-20231219-15-qvs2tg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=731&fit=crop&dpr=1 600w, https://images.theconversation.com/files/566490/original/file-20231219-15-qvs2tg.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=731&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/566490/original/file-20231219-15-qvs2tg.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=731&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/566490/original/file-20231219-15-qvs2tg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=919&fit=crop&dpr=1 754w, https://images.theconversation.com/files/566490/original/file-20231219-15-qvs2tg.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=919&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/566490/original/file-20231219-15-qvs2tg.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=919&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Differences in trace elements such as barium, strontium and calcium mapped across the inside of <em>G. blacki</em> and orangutan teeth. At earlier sites, clear banding in both species’ teeth suggests diverse food sources and a flourishing population. Diffuse or no banding in later <em>G. blacki</em> suggests less diverse food sources and chronic stress. The orangutan tooth suggests a less stressed population than <em>G. blacki</em> at this time.</span>
<span class="attribution"><span class="source">Nature</span></span>
</figcaption>
</figure>
<p>Despite being a close relative of <em>G. blacki</em>, orangutans were able to adapt their size, behaviour and habitat preferences to accommodate to these forest changes. Their fossils display a flexible and balanced diet with very little stress during this period.</p>
<p>But <em>G. blacki</em> made the fatal mistake of relying on a less nutritious back-up food like twigs and bark when their favourite food sources such as fruit-bearing plants were unavailable. This meant the diversity of the giant apes’ food decreased and their less mobile body size compared to the more agile orangutans restricted their geographic range for foraging. </p>
<p>Surprisingly, <em>G. blacki</em> also increased in body size over this period, which further contributed to food source problems and caused immense chronic stress to the species. This stress can be seen in the trace element mapping of their teeth, providing an insight into a species on the brink of extinction.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/566489/original/file-20231219-23-1rpdyk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A graph showing more arboreal plants and fewer ferns before the window of extinction, and a more even spread of plants afterward" src="https://images.theconversation.com/files/566489/original/file-20231219-23-1rpdyk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/566489/original/file-20231219-23-1rpdyk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=187&fit=crop&dpr=1 600w, https://images.theconversation.com/files/566489/original/file-20231219-23-1rpdyk.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=187&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/566489/original/file-20231219-23-1rpdyk.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=187&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/566489/original/file-20231219-23-1rpdyk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=235&fit=crop&dpr=1 754w, https://images.theconversation.com/files/566489/original/file-20231219-23-1rpdyk.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=235&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/566489/original/file-20231219-23-1rpdyk.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=235&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Pollen records from caves in the region showing the change in plant communities over time.</span>
<span class="attribution"><span class="source">Nature</span></span>
</figcaption>
</figure>
<h2>Failure to adapt</h2>
<p>As a direct consequence, <em>G. blacki</em> numbers dwindled as the species was placed under increasing environmental stress.</p>
<p>It would seem that by having such specific food and habitat preferences, <em>G. blacki</em> was vulnerable to environmental and habitat changes. Its size and choice of food hampered its adaptation compared to more agile and mobile species like orangutans.</p>
<p>The story of <em>G. blacki</em> is a lesson in extinction – how some species are more equipped to survive change and others are more vulnerable. This is a lesson we must take on board with the looming threat of a sixth mass extinction event. </p>
<p>Trying to understand past extinctions is a good starting point to understand primate resilience. It may offer clues to the fate of other large animals, both in the past and in the future.</p>
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Read more:
<a href="https://theconversation.com/what-is-a-mass-extinction-and-are-we-in-one-now-122535">What is a 'mass extinction' and are we in one now?</a>
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<img src="https://counter.theconversation.com/content/219304/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Kira Westaway receives funding from The Australian Research Council</span></em></p><p class="fine-print"><em><span>Marian Bailey receives funding from the Australian Government RTP Stipend. </span></em></p><p class="fine-print"><em><span>Renaud Joannes-Boyau receives funding from the Australian Research Council. </span></em></p><p class="fine-print"><em><span>Simon Haberle receives funding from the Australian Research Council.</span></em></p><p class="fine-print"><em><span>Yingqi Zhang receives funding from Chinese Academy of Sciences and The Australian Research Council. </span></em></p>What happened to the three-metre tall apes that once lived alongside orangutans? A new study suggests they were too slow to adapt to a changing world.Kira Westaway, Associate Professor, School of Natural Sciences, Macquarie UniversityMarian Bailey, PhD Candidate, Geoarchaeology, Southern Cross UniversityRenaud Joannes-Boyau, Associate Professor, Southern Cross UniversitySimon Haberle, Professor, Australian National UniversityYingqi Zhang, Research professor in palaeontology, Chinese Academy of SciencesLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2188332024-01-04T10:27:36Z2024-01-04T10:27:36ZAfricans discovered dinosaur fossils long before the term ‘palaeontology’ existed<p>Credit for discovering the first dinosaur bones usually goes to British gentlemen for their finds between the 17th and 19th centuries in England. <a href="http://www.oum.ox.ac.uk/learning/htmls/plot.htm">Robert Plot</a>, an English natural history scholar, was the first of these to <a href="https://www.amnh.org/explore/videos/dinosaurs-and-fossils/who-discovered-the-first-dinosaur-fossils?utm_source=twitter&utm_medium=social&utm_campaign=share-from-amnh-org">describe</a> a dinosaur bone, in his 1676 book The Natural History of Oxfordshire. Over the next two centuries dinosaur palaeontology would be dominated by numerous British natural scientists. </p>
<p>But <a href="https://www.lyellcollection.org/doi/10.1144/SP543-2022-236">our study</a> shows that the history of palaeontology can be traced back much further into the past. We present evidence that the first dinosaur bone may have been discovered in Africa as early as 500 years before Plot’s.</p>
<p>We’re a team of scientists who study fossils in South Africa. Peering through the published and unpublished archaeological, historical and palaeontological literature, we discovered that there has been interest in fossils in Africa for as long as there have been people on the continent. </p>
<p>This is not a surprise. Humankind originated in Africa: <em>Homo sapiens</em> has existed for at least <a href="https://www.nature.com/articles/nature22336">300,000 years</a>. And the continent has a great diversity of rock outcrops, such as the Kem Kem beds in Morocco, the Fayum depression in Egypt, the Rift Valley in <a href="https://theconversation.com/the-maasai-legend-behind-ancient-hominin-footprints-in-tanzania-119373">east Africa</a> and the Karoo in southern Africa, containing fossils that have always been accessible to our ancestors. </p>
<p>So it wasn’t just likely that African people discovered fossils first. It was inevitable.</p>
<p>More often than not, the first dinosaur fossils supposedly discovered by scientists were actually brought to their attention by local guides. Examples are the discovery of the gigantic dinosaurs <a href="https://kids.britannica.com/students/article/Jobaria/390687"><em>Jobaria</em></a> by the Tuaregs in Niger and <a href="https://www.inaturalist.org/taxa/542624-Giraffatitan"><em>Giraffatitan</em></a> by the Mwera in Tanzania.</p>
<p>Our paper reviews what’s known about African indigenous knowledge of fossils. We list fossils that appear to have long been known at various African sites, and discuss how they might have been used and interpreted by African communities before the science of palaeontology came to be.</p>
<h2>Bolahla rock shelter in Lesotho</h2>
<p>One of the highlights of our paper is the archaeological site of Bolahla, a Later Stone Age rock shelter in Lesotho. Various dating techniques indicate that the site was occupied by the Khoesan and Basotho people from the 12th to 18th centuries (1100 to 1700 AD). The shelter itself is surrounded by hills made of consolidated sediments that were deposited under a harsh Sahara-like desert some 180 million to 200 million years ago, when the first dinosaurs roamed the Earth. </p>
<p>This part of Lesotho is particularly well known for delivering the species <em>Massospondylus carinatus</em>, a 4 to 6 metre, long-necked and small-headed dinosaur. Fossilised bones of <em>Massospondylus</em> are abundant in the area and were already so when the site was occupied by people in the Middle Ages. </p>
<p>In 1990, <a href="https://www.jstor.org/stable/3889171">archaeologists</a> working at Bolahla discovered that a finger bone of <em>Massospondylus</em>, a fossil phalanx, had been transported to the cave. There are no fossil skeletons sticking out the walls of the cave, so the only chance that this phalanx ended up there was that someone in the distant past picked it up and carried it to the cave. Perhaps this person did so out of simple curiosity, or to turn it into a pendant or toy, or to use it for traditional healing rituals. </p>
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Read more:
<a href="https://theconversation.com/dinosaur-tracksite-in-lesotho-how-a-wrong-turn-led-to-an-exciting-find-208963">Dinosaur tracksite in Lesotho: how a wrong turn led to an exciting find</a>
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<p>After heavy rains, it is not unusual that the people in the area discover the bones of extinct species that have been washed out of their mother-rock. They usually identify them as belonging to a dragon-like monster that devours people or even whole houses. In Lesotho, the Basotho call the monster “Kholumolumo”, while in South Africa’s bordering Eastern Cape province, the Xhosa refer to it as “<a href="https://chosindabazomhlaba.com/2022/03/29/ukufika-kwamacikilishe-angamagongqongqo/">Amagongqongqo</a>”.</p>
<p>The exact date when the phalanx was collected and transported is unfortunately lost to time. Given the current knowledge, it could have been at any time of occupation of the shelter from the 12th to 18th centuries. This leaves open the possibility that this dinosaur bone could have been collected up to 500 years prior to Robert Plot’s find.</p>
<h2>Early knowledge of extinct creatures</h2>
<p>Most people knew about fossils well before the scientific era, for as far back as collective societal memories can go. In Algeria, for example, people referred to some dinosaur footprints as belonging to the legendary “<a href="https://www.tandfonline.com/doi/abs/10.1080/10420940109380182">Roc bird</a>”. In North America, cave paintings depicting dinosaur footprints were painted by the <a href="https://www.tandfonline.com/doi/abs/10.1080/10420940109380182">Anasazi people</a> between AD 1000 and 1200. Indigenous Australians identified dinosaur footprints as belonging to a legendary “<a href="https://www.tandfonline.com/doi/abs/10.1080/10420940109380182">Emu-man</a>”. To the south, the notorious conquistador Hernan Cortes was given the fossil femur of a Mastodon by the <a href="https://books.google.co.za/books/about/Fossil_Legends_of_the_First_Americans.html?id=CMsgQQkmFqQC&redir_esc=y">Aztecs</a> in 1519. In Asia, Hindu people refer to ammonites (coiled fossil-sea-shells) as “<a href="https://theconversation.com/shaligrams-the-sacred-fossils-that-have-been-worshipped-by-hindus-and-buddhists-for-over-2-000-years-are-becoming-rarer-because-of-climate-change-209311">Shaligrams</a>” and have been worshipping them for more than 2,000 years. </p>
<h2>Claiming credit</h2>
<p>The fact that people in Africa have long known about fossils is evident from folklore and the archaeological record, but we still have much to learn about it. For instance, unlike the people in Europe, the Americas and Asia, indigenous African palaeontologists seem to have seldom used fossils for traditional medicine. We are still unsure whether this is a genuinely unique cultural trait shared by most African cultures or if it is due to our admittedly still incomplete knowledge. </p>
<p>Also, some rather prominent fossil sites, such as the Moroccan Kem Kem beds and South African Unesco <a href="https://www.maropeng.co.za/content/page/introduction-to-your-visit-to-the-cradle-of-humankind-world-heritage-site">Cradle of Humankind</a> caves, have still not provided robust evidence for indigenous knowledge. This is unfortunate, as fossil-related traditions could help bridge the gap between local communities and palaeontologists, which in turn could contribute <a href="https://theconversation.com/graffiti-threatens-precious-evidence-of-ancient-life-on-south-africas-coast-157777">preserving</a> important heritage sites.</p>
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Read more:
<a href="https://theconversation.com/rock-stars-how-a-group-of-scientists-in-south-africa-rescued-a-rare-500kg-chunk-of-human-history-192508">Rock stars: how a group of scientists in South Africa rescued a rare 500kg chunk of human history</a>
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<p>By exploring indigenous palaeontology in Africa, our team is putting together pieces of a forgotten past that gives credit back to local communities. We hope it will inspire a new generation of local palaeoscientists to walk in the footsteps of these first African fossil hunters.</p><img src="https://counter.theconversation.com/content/218833/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Julien Benoit receives funding from the DSI-NRF African Origins Platform program and GENUS (DSI-NRF Centre of Excellence in Palaeosciences) </span></em></p><p class="fine-print"><em><span>Cameron Penn-Clarke receives funding from GENUS (DSI-NRF Centre of Excellence in Palaeosciences).</span></em></p><p class="fine-print"><em><span>Charles Helm does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Some time between 1100 and 1700 AD, a Massospondylus bone was discovered and carried to a rock shelter in Lesotho.Julien Benoit, Senior Researcher in Vertebrate Palaeontology, University of the WitwatersrandCameron Penn-Clarke, Senior Researcher, University of the WitwatersrandCharles Helm, Research Associate, African Centre for Coastal Palaeoscience, Nelson Mandela UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2165482023-12-26T08:48:13Z2023-12-26T08:48:13ZUnusual ancient elephant tracks had our team of fossil experts stumped – how we solved the mystery<figure><img src="https://images.theconversation.com/files/559289/original/file-20231114-17-wm62rc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Elephants communicate underground by generating seismic waves. </span> <span class="attribution"><span class="source">Anadolu Agency</span></span></figcaption></figure><p>Over the past 15 years, through our scientific study of tracks and traces, we have identified more than 350 <a href="https://doi.org/10.1016/j.quascirev.2019.07.039">fossil vertebrate tracksites</a> from South Africa’s Cape south coast. Most are found in cemented sand dunes, called aeolianites, and all are from the <a href="https://www.britannica.com/science/Pleistocene-Epoch">Pleistocene Epoch</a>, ranging in age from about 35,000 to 400,000 years. </p>
<p>During that time we have honed our identification skills and have become used to finding and interpreting tracksites – a field called ichnology. And yet, every once in a while, we encounter something we immediately realise is so novel that it has been found nowhere else on Earth.</p>
<p>Such a moment of unexpected discovery happened in 2019 along the coastline of the De Hoop Nature Reserve, about 200km east of Cape Town. Less than two metres away from a cluster of fossil elephant tracks was a round feature, 57cm in diameter, containing concentric ring features. Another layer was exposed about 7cm below this surface. It contained at least 14 parallel groove features. Where the grooves approached the rings, they made a slight curve towards them. The two findings, we hypothesised, were connected with each other and appeared to have a common origin.</p>
<p>Elephants are the largest, heaviest land animals. They leave large, deep, easily recognisable tracks. We’ve documented 35 fossilised elephant track sites in our study area, as well as the <a href="https://doi.org/10.1017/qua.2021.32">first evidence</a> of fossilised elephant trunk-drag impressions. </p>
<p>Elephants, like another group of massive land creatures, dinosaurs, can be viewed as geological engineers that create minor earth-moving forces on the ground they walk(ed) on. This can be related also to a remarkable ability that elephants possess: communicating by generating seismic waves. These are a form of energy that can travel under the surface of the Earth.</p>
<p>The feature we found in 2019 seemed to reflect just such a phenomenon: an elephant triggering waves that rippled outwards. After additional investigation and a thorough search for alternative explanations, we could report in a <a href="https://www.sciencedirect.com/science/article/pii/S0016787823000792">recently published study</a> that we believe we’ve found the world’s first trace fossil signature of seismic, underground communication between elephants. </p>
<h2>Elephant seismicity</h2>
<p>Since the 1980s, an ever-increasing body of literature has documented “elephant seismicity” and <a href="https://doi.org/10.1007/BF00300007">seismic communication through infrasound</a>. The lower threshold of human hearing is 20Hz; below that, low frequency sounds are known as infrasound. Elephant “rumbles”, originating in the larynx and transmitted into the ground through the limbs, fall within the infrasonic range. </p>
<p>Infrasound at high amplitude (it would seem very loud to us if at a slightly higher frequency) can travel further than high frequency sounds, <a href="https://doi.org/10.1016/j.cub.2018.03.062">over distances as great as 6km</a>. Elephants have an advantage here. Lighter creatures cannot <a href="https://doi.org/10.1152/physiol.00008.2007">generate low-frequency sound waves through vocalisation</a>. It is thought that long-distance seismic communication can allow elephant groups to interact over substantial distances, and it has <a href="https://doi.org/10.1016/j.cub.2018.03.062">been shown</a> that sandy terrain allows the communication to travel furthest.</p>
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Read more:
<a href="https://theconversation.com/fossil-tracks-and-trunk-marks-reveal-signs-of-ancient-elephants-on-south-africas-coast-164306">Fossil tracks and trunk marks reveal signs of ancient elephants on South Africa's coast</a>
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<p>Continuing the elephant-dinosaur analogy, we considered the multitude of publications on dinosaur tracks. We are aware of only a single example that exhibits possible concentric rings within a track, from Korea, and none that involve parallel grooves. This suggests something unique about elephants that generates concentric rings within tracks and leads to the associated groove features. Elephant rumbling provides a plausible explanation.</p>
<p>In our scenario at De Hoop Nature Reserve, we postulate that vibrations from rumbling travelled down the elephant limb and created the concentric ring features. They are reminiscent of some of the patterns that become evident when <a href="https://www.youtube.com/watch?v=tFAcYruShow">sprinkling sand onto a vibrating surface</a>. The surface on which the concentric rings appear must have been just below the dune surface at the time. The parallel grooves would then represent a trace fossil signature of subsurface communication. We’re not yet sure how old the trace fossil is; we’ve sent samples for testing.</p>
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<figcaption><span class="caption">A video showing sand vibrating when it’s exposed to sound.</span></figcaption>
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<h2>Rumblings in rock art</h2>
<p>Elephant seismicity is a relatively new field of study for scientists. However, those who have lived close to elephants won’t be surprised at the idea of the animals communicating through vibration. Indeed, vibrations from elephant rumblings can sometimes be felt (rather than heard) by the astute observer. And it appears that this knowledge is not just recent. </p>
<p>The rock art experts on our team have identified and interpreted rock art that suggests the indigenous San people appreciated and celebrated this knowledge in southern Africa thousands of years ago. Elephants were of profound importance to the San and were prominently featured in <a href="https://www.archaeology.org.za/sites/default/files/attachments/publications/2019/09/02/ds_2018_december.pdf">their works of art</a>. Several rock art sites appear to contain paintings of elephants in relation to sound or vibration.</p>
<p>For example, at the Monte Cristo site in the Cederberg the artist has painted 31 elephants, in several groups. They are in a realistic arrangement. Fine red lines surround each elephant; zigzag lines touch the abdomen, groin, throat, trunk, and specifically the feet. Many zigzag lines link the elephant to the ground. The finest lines are closest to the elephants, and every elephant is connected to this set of lines. These are in turn connected to broader lines surrounding the elephant group, which radiate out and away from the elephants as concentric rings. </p>
<p>This is interpreted as the San artist’s probable illustration of seismic communication between elephants. The feeling of shaking and vibration, which the San call <em>thara n|om</em>, is vital to the San healing dances, including the <a href="https://www.archaeology.org.za/sites/default/files/attachments/publications/2019/09/02/ds_2018_december.pdf">elephant song and elephant dance</a>. Lines of energy, called <em>n|om</em>, are regarded as a vibrant life-giving force that animates all living beings and is the source of <a href="https://www.spiritualityandpractice.com/book-reviews/view/28011/way-of-the-bushman">all inspired energy</a>.</p>
<p>We believe that an understanding of elephant seismicity requires the integration of three bodies of knowledge: research on extant elephant populations, ancestral knowledge (often manifested in rock art) and the trace fossil record. </p>
<p>That elephant seismic communication might leave a trace fossil record has never been reported before, or even postulated. Our findings may have the potential to stimulate multi-disciplinary research into this field. This could include a dedicated search for sub-surface patterns in the sand in the vicinity of modern rumbling elephants.</p><img src="https://counter.theconversation.com/content/216548/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Charles Helm does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Elephants can be viewed as geological engineers that create minor tectonic forces on the substrate they walk on.Charles Helm, Research Associate, African Centre for Coastal Palaeoscience, Nelson Mandela UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2199612023-12-20T00:06:41Z2023-12-20T00:06:41Z19-million-year-old fossil jaw bone hints the biggest whales first evolved somewhere unexpected<figure><img src="https://images.theconversation.com/files/566527/original/file-20231219-15-u7qnu9.jpg?ixlib=rb-1.1.0&rect=68%2C0%2C1773%2C1279&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The baleen whale fossil at Museums Victoria Research Institute.</span> <span class="attribution"><span class="source">Eugene Hyland, Museums Victoria</span></span></figcaption></figure><p>Baleen whales are the titans of the ocean, the largest animals to have ever lived. The record holder is the blue whale (<em>Balaenoptera musculus</em>), which can reach <a href="https://www.worldwildlife.org/stories/meet-the-biggest-animal-in-the-world">lengths of up to 30 metres</a>. That’s longer than a basketball court.</p>
<p>However, throughout their evolutionary history, most baleen whales <a href="https://www.science.org/content/article/why-whales-grew-such-monster-sizes">were relatively much smaller</a>, around five metres in length. While still big compared to most animals, for a baleen whale that’s quite small.</p>
<p>However, new fossil discoveries from the Southern Hemisphere are beginning to disrupt this story. The latest is an unassuming fossil from the banks of the Murray River in South Australia.</p>
<p>Roughly 19 million years old, this fossil is the tip of the lower jaws (or “chin”) of a baleen whale estimated to be around nine metres in length, which makes it the new record holder from its time. This find has been published today in the journal <a href="https://doi.org/10.1098/rspb.2023.2177">Proceedings of the Royal Society B: Biological Sciences</a>.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/566189/original/file-20231218-23-ajfj29.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Illustration of a whale with a piece of yellow bone superimposed on its lower jaw" src="https://images.theconversation.com/files/566189/original/file-20231218-23-ajfj29.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/566189/original/file-20231218-23-ajfj29.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=338&fit=crop&dpr=1 600w, https://images.theconversation.com/files/566189/original/file-20231218-23-ajfj29.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=338&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/566189/original/file-20231218-23-ajfj29.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=338&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/566189/original/file-20231218-23-ajfj29.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/566189/original/file-20231218-23-ajfj29.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/566189/original/file-20231218-23-ajfj29.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=424&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">The roughly 19-million-year-old fossil ‘chin’ bone superimposed on a Murray River whale illustration.</span>
<span class="attribution"><span class="source">Art by Ruairidh Duncan</span></span>
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<h2>What are baleen whales?</h2>
<p>Most mammals have teeth in their mouth. Baleen whales are a strange exception. While <a href="https://theconversation.com/ancient-whales-had-more-bite-than-todays-gentle-giants-82907">their ancestors had teeth</a>, today’s baleen whales instead have baleen – a large rack of fine, hair-like keratin used to filter out small krill from the water.</p>
<p>This structure enabled baleen whales to feed efficiently on <a href="https://www.scientificamerican.com/article/why-are-blue-whales-so-gigantic/">enormous shoals of tiny zooplankton</a> in productive parts of the ocean, which facilitated the evolution of larger and larger body sizes. </p>
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<a href="https://images.theconversation.com/files/566194/original/file-20231218-21-bvvl3z.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Illustration of a large dark humpback whale with its mouth open, showing off what looks like a solid filter at the top of its mouth" src="https://images.theconversation.com/files/566194/original/file-20231218-21-bvvl3z.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/566194/original/file-20231218-21-bvvl3z.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=325&fit=crop&dpr=1 600w, https://images.theconversation.com/files/566194/original/file-20231218-21-bvvl3z.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=325&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/566194/original/file-20231218-21-bvvl3z.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=325&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/566194/original/file-20231218-21-bvvl3z.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=408&fit=crop&dpr=1 754w, https://images.theconversation.com/files/566194/original/file-20231218-21-bvvl3z.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=408&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/566194/original/file-20231218-21-bvvl3z.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=408&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">The bristle-like baleen, as shown on a humpback whale.</span>
<span class="attribution"><span class="source">Art by Ruairidh Duncan</span></span>
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<h2>The ‘missing years’ of whale evolution</h2>
<p>Various groups of <a href="https://www.telegraph.co.uk/news/2023/08/02/whale-heaviest-animal-ever-lived-perucetus-colossus/">toothed whales</a> terrorised the ocean for millions of years, including some that were the <a href="https://theconversation.com/ancient-ancestors-of-modern-baleen-whales-were-toothy-not-so-gentle-giants-96338">ancestors of the toothless baleen whales</a>. Yet at some time between 23 and 18 million years ago these ancient “toothed baleen whales” went extinct.</p>
<p>We aren’t exactly sure when, as fossil whales from this episode in Earth’s history <a href="https://museumsvictoria.com.au/media-releases/mystery-of-whale-fossil-dark-age-solved-in-new-palaeontology-research/">are exceedingly rare</a>. What we do know is immediately after this gap in the whale fossil record, only the relatively small, toothless ancestors of baleen whales remained. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/566198/original/file-20231218-25-dshb8.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A dark silhouette of a whale next to a smaller figure of a whale and even smaller human figure" src="https://images.theconversation.com/files/566198/original/file-20231218-25-dshb8.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/566198/original/file-20231218-25-dshb8.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=338&fit=crop&dpr=1 600w, https://images.theconversation.com/files/566198/original/file-20231218-25-dshb8.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=338&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/566198/original/file-20231218-25-dshb8.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=338&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/566198/original/file-20231218-25-dshb8.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/566198/original/file-20231218-25-dshb8.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/566198/original/file-20231218-25-dshb8.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=424&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The newly described extinct Murray River whale (9 metres) next to a fin whale (26 metres) and a human diver (2 metres).</span>
<span class="attribution"><span class="source">Art by Ruairidh Duncan, graphic by Rob French</span></span>
</figcaption>
</figure>
<p>Scientists previously thought baleen whales kept to relatively small proportions until the ice ages (which began from about 3–2.5 million years ago). But the majority of research on trends in the evolutionary history of whales is based on the reasonably well-explored fossil record from the Northern Hemisphere – a notable bias that likely shaped these theories.</p>
<p>Crucially, new fossil finds from the Southern Hemisphere are starting to show us that at least down south, whales got bigger much earlier than previous theories suggest.</p>
<h2>An unexpected find</h2>
<p>More than 100 years ago, palaeontologist Francis Cudmore found the very tips of a large pair of fossil whale jaws eroding out of the banks of the Murray River in South Australia. These 19-million-year-old fossils made their way to Museums Victoria and remained unrecognised in the collection until they were rediscovered in a drawer by one of the authors, Erich Fitzgerald.</p>
<p>Using equations derived from measurements of modern-day baleen whales, we predicted the whale this fossilised “chin” came from was approximately nine metres long. The previous record holder from this early period of whale evolution was only six metres long.</p>
<p>Together with <a href="https://www.nationalgeographic.co.uk/animals/2019/05/fossil-of-85-foot-blue-whale-is-largest-ever-discovered">other fossils</a> from Peru in South America, this suggests larger baleen whales may have emerged much earlier in their evolutionary history and the large body size of whales evolved gradually over many more millions of years than previous research suggested.</p>
<figure class="align-left zoomable">
<a href="https://images.theconversation.com/files/566195/original/file-20231218-30-l3q7vz.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="An artist's reconstruction of the extinct whale, showing where the fossil is located, and a map of Australia showing the location it was found" src="https://images.theconversation.com/files/566195/original/file-20231218-30-l3q7vz.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/566195/original/file-20231218-30-l3q7vz.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=449&fit=crop&dpr=1 600w, https://images.theconversation.com/files/566195/original/file-20231218-30-l3q7vz.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=449&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/566195/original/file-20231218-30-l3q7vz.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=449&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/566195/original/file-20231218-30-l3q7vz.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=564&fit=crop&dpr=1 754w, https://images.theconversation.com/files/566195/original/file-20231218-30-l3q7vz.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=564&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/566195/original/file-20231218-30-l3q7vz.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=564&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The fossilised baleen whale ‘chin’ was found along the banks of the Murray River in South Australia.</span>
<span class="attribution"><span class="source">Art by Ruairidh Duncan, photo by Eugene Hyland</span></span>
</figcaption>
</figure>
<h2>The Southern Hemisphere as the cradle of gigantic whale evolution</h2>
<p>The large whale fossils from Australasia and South America seem to suggest that for most of the evolutionary history of baleen whales, whenever a large baleen whale shows up in the fossil record, it is in the Southern Hemisphere.</p>
<p>Strikingly, this pattern persists despite the fact the Southern Hemisphere contains less than 20% of the known fossil record of baleen whales. While this is an unexpectedly strong signal from our research, it doesn’t come as a complete surprise when we consider living baleen whales.</p>
<p>Today, the temperate seas of the Southern Hemisphere are connected by the chilly Southern Ocean, which surrounds Antarctica and is <a href="https://niwa.co.nz/productivity-of-the-southern-ocean-antarctica">extremely productive</a>, supporting the greatest biomass of marine megafauna on Earth.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/566197/original/file-20231218-19-6xezc.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A graph, showing that baleen whales in the Southern Hemisphere were larger than Northern Hemisphere whales throughout most of the last 23 million years" src="https://images.theconversation.com/files/566197/original/file-20231218-19-6xezc.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/566197/original/file-20231218-19-6xezc.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=437&fit=crop&dpr=1 600w, https://images.theconversation.com/files/566197/original/file-20231218-19-6xezc.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=437&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/566197/original/file-20231218-19-6xezc.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=437&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/566197/original/file-20231218-19-6xezc.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=549&fit=crop&dpr=1 754w, https://images.theconversation.com/files/566197/original/file-20231218-19-6xezc.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=549&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/566197/original/file-20231218-19-6xezc.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=549&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Fossils from the Southern Hemisphere, including the Murray River whale fossil, are demonstrating that whales may have evolved large body sizes first in the Southern Hemisphere.</span>
<span class="attribution"><span class="source">Art by Ruairidh Duncan</span></span>
</figcaption>
</figure>
<p>Around the time baleen whales started evolving from big to gigantic, the strength of the Antarctic Circumpolar Current was intensifying, eventually leading to the present day powerhouse Southern Ocean. </p>
<p>Today, baleen whales are ecosystem engineers, their huge bodies consuming tremendous amounts of energy. <a href="https://oceanservice.noaa.gov/facts/whale-fall.html">Upon death</a>, these whales provide an abundance of nutrients to deep-sea ecosystems.</p>
<p>As we learn more about the evolutionary history of whales, such as when and where their large size evolved, we can begin to understand just how ancient their role in the ocean ecosystem may have been and how it could shift in tune with global climate change.</p>
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Read more:
<a href="https://theconversation.com/the-true-origins-of-the-worlds-smallest-and-weirdest-whale-208279">The true origins of the world's smallest and weirdest whale</a>
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<img src="https://counter.theconversation.com/content/219961/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>James Patrick Rule currently receives funding from an Engineering and Physical Sciences Research Council UKRI Fellowship, and previously received funding from an Australian Research Council Discovery Project.</span></em></p><p class="fine-print"><em><span>Erich Fitzgerald received funding from an Australian Research Council Linkage Project that supported part of this research.</span></em></p>A newly described fossil from South Australia is making waves in our understanding of where and when whales evolved titanic body sizes.James Patrick Rule, Research Affiliate, Monash UniversityErich Fitzgerald, Senior Curator, Vertebrate Palaeontology, Museums Victoria Research InstituteLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2200112023-12-19T16:53:46Z2023-12-19T16:53:46ZFive things you probably have wrong about the T rex<figure><img src="https://images.theconversation.com/files/566317/original/file-20231218-17-rt6kdx.jpg?ixlib=rb-1.1.0&rect=36%2C12%2C8142%2C5444&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/adventurous-young-boy-imitating-dinosaur-toy-2124861329">Jacob Lund/Shutterstock</a></span></figcaption></figure><p>An icon from the age of dinosaurs, <em>Tyrannosaurus rex</em> has featured in everything from blockbuster movies to the shape of chicken nuggets. As a creature to be feared for its bone-crushing bite or ridiculed for its inability to give a high five, T rex has captured the imagination of children and adults alike. </p>
<p>One skeleton broke records in 2020 when it sold at auction for <a href="https://www.science.org/content/article/stan-t-rex-sells-record-32-million-auction">US$32 million</a> (£25 million). But how well do you really know T rex? Here is the truth behind five common misconceptions about this dinosaur.</p>
<h2>Myth: T rex had bad eyesight</h2>
<p>Scientists think that T rex had excellent vision, despite what Jurassic Park might have you believe. The <a href="https://www.nature.com/articles/s42003-022-03706-0">grapefruit-sized eyes</a> of T rex could have distinguished objects with up to five times more precision than those of a falcon and <a href="https://www.tandfonline.com/doi/pdf/10.1671/0272-4634(2006)26%5B321%3ABVITD%5D2.0.CO%3B2">13 times better</a> than a human. </p>
<p>They also had <a href="https://www.uv.es/pe/2000_1/retinal/text.pdf">superior colour vision</a>. Like birds and crocodiles, T rex could distinguish more colours of the rainbow than humans and see ultraviolet light. Although it makes for good dramatic tension in fiction, standing still would not hide you from a hungry T rex. </p>
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<h2>Myth: Chickens are the direct descendants of T rex</h2>
<p>This myth has its origins in truth. All birds, including chickens, are not only descendants of dinosaurs but <a href="https://evolution-outreach.biomedcentral.com/articles/10.1007/s12052-009-0133-4">are themselves dinosaurs</a>. Birds belong to a lineage of dinosaurs closely related to the raptors (including <em>Velociraptor</em>). </p>
<p>Early birds, such as <a href="https://www.nhm.ac.uk/discover/dino-directory/archaeopteryx.html"><em>Archaeopteryx</em></a>, had wings like modern birds but teeth and long tails like their ancestors. These ancient birds first appeared <a href="https://www.nature.com/articles/nature12168">in the Jurassic period</a>, millions of years before T rex evolved. </p>
<p>Scientists have identified an ancestor of modern ducks and chickens as the quail-sized <a href="https://www.nature.com/articles/s41586-020-2096-0"><em>Asteriornis</em></a>, nicknamed the <a href="https://www.cam.ac.uk/stories/wonderchicken">wonderchicken</a> by scientists. It was still living at the time of T rex. A handful of these humble bird species <a href="https://www.sciencedirect.com/science/article/pii/S0960982218305347">survived the mass extinction</a> that killed their dinosaur relatives and evolved into all the birds we know today.</p>
<p>T rex, rather than being the grandparent of the modern chicken, is more like an oversized cousin to all birds.</p>
<h2>Myth: T rex had tiny, useless arms</h2>
<p>Muscle reconstructions show that T rex arms <a href="https://www.researchgate.net/profile/Kenneth-Carpenter-2/publication/314895700_Looking_again_at_the_forelimbs_of_Tyrannosaurus_rex/links/58c70de0aca27232ac8297b6/Looking-again-at-the-forelimbs-of-Tyrannosaurus-rex.pdf">were strong</a> for their size and had a reasonable range of motion. It is likely they were used in a range of behaviour. </p>
<p>The <a href="https://www.eaapublishing.org/journals/index.php/biosis/article/view/60">most plausible suggestions</a> scientists have come up with so far include slashing and holding onto prey and use in communicating between T rex individuals.</p>
<p>T rex actually <a href="https://link.springer.com/article/10.1007/BF03043773">couldn’t twist its arms</a> to make its hands face palm downward, as is commonly depicted. To improve the accuracy of your next T rex impression, face your palms towards each other, as if clapping. </p>
<p>At around one metre long, T rex arms are larger than human arms but still small compared with their 13-metre long bodies. Small arms are common among larger theropods (two-legged, predatory dinosaurs) and have <a href="https://www.sciencedirect.com/science/article/pii/S0960982222008600">evolved several times</a> in this group. Other dinosaurs in this group had even smaller arms. </p>
<p>The eight-metre long <a href="https://www.nhm.ac.uk/discover/dino-directory/carnotaurus.html"><em>Carnotaurus</em></a>, a horned predator from South America, had <a href="https://www.sciencedirect.com/science/article/abs/pii/S0024408298901935">stubby arms</a> less than 50 centimetres long. </p>
<h2>Myth: T rex lived alongside <em>Stegosaurus</em></h2>
<p>The age of dinosaurs was probably longer than you think. T rex lived at the end of the Cretaceous period, just before the dinosaur-killing <a href="https://www.pnas.org/doi/abs/10.1073/pnas.2006087117">asteroid strike</a> 66 million years ago. <a href="https://www.nhm.ac.uk/discover/dino-directory/stegosaurus.html"><em>Stegosaurus</em></a>, and other popular Jurassic dinosaurs such as <a href="https://www.nhm.ac.uk/discover/dino-directory/diplodocus.html"><em>Diplodocus</em></a>, lived around 150 million years ago. </p>
<p>T rex lived closer to the modern day than to the time of <em>Stegosaurus</em>. By the time T rex walked the Earth, <em>Stegosaurus</em> were already fossils beneath their feet.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/566315/original/file-20231218-21-hst1i7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Kids food dinosaur shapes on a plate" src="https://images.theconversation.com/files/566315/original/file-20231218-21-hst1i7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/566315/original/file-20231218-21-hst1i7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=403&fit=crop&dpr=1 600w, https://images.theconversation.com/files/566315/original/file-20231218-21-hst1i7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=403&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/566315/original/file-20231218-21-hst1i7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=403&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/566315/original/file-20231218-21-hst1i7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=506&fit=crop&dpr=1 754w, https://images.theconversation.com/files/566315/original/file-20231218-21-hst1i7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=506&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/566315/original/file-20231218-21-hst1i7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=506&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">The T rex lived long after stegosaurus went extinct.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/kids-food-dinosaur-shaped-chicken-fish-1427323466">Erhan Inga/Shutterstock</a></span>
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<h2>Myth: T rex was scaly and grey or green</h2>
<p>The idea that T rex might have had feathers is contentious, even among palaeontologists. There is evidence of feathers in many dinosaur species, leading some scientists to conclude that feathers were <a href="https://www.science.org/doi/full/10.1126/science.1235463">widespread among dinosaurs</a>. <a href="https://www.nature.com/articles/nature10906"><em>Yutyrannus</em></a>, a nine-metre long relative of T rex, was found preserved with a coat of fuzzy feathers. </p>
<p>So does this mean T rex was also fluffy? Not so fast. Some scientists think that a full feather coat would leave the giant, warm-blooded T rex at risk of overheating. </p>
<p>This thinking is supported by <a href="https://royalsocietypublishing.org/doi/full/10.1098/rsbl.2017.0092">preserved patches of skin</a> found from many parts of the body that appear to be scaled. Although we don’t know for certain either way, the real T rex was probably something between fully scaly and fully fuzzy. </p>
<p>The science of dinosaur colour is one of the most <a href="https://www.annualreviews.org/doi/abs/10.1146/annurev-earth-073019-045641">exciting developments</a> in recent palaeontology. Scientists have been able to determine the colours and patterns of some exceptionally well preserved dinosaurs by studying fossilised pigement-containing capsules within cells in feathers and scales. </p>
<p>Although no one has worked out what colour T rex was yet, we now know that dinosaurs came in a range of colours, including <a href="https://www.science.org/doi/full/10.1126/science.1186290">red</a> and <a href="https://www.science.org/doi/10.1126/science.1213780">iridescent black</a>, and patterns <a href="https://www.nature.com/articles/nature08740">such as stripes</a>.</p><img src="https://counter.theconversation.com/content/220011/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Abi Crane does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Impress your niece or nephew with these T rex facts.Abi Crane, Postgraduate Researcher, University of SouthamptonLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2152782023-11-16T14:27:49Z2023-11-16T14:27:49ZJurassic Park: why we’re still struggling to realise it 30 years on<figure><img src="https://images.theconversation.com/files/556310/original/file-20231027-26-umzgc5.jpg?ixlib=rb-1.1.0&rect=29%2C5%2C3964%2C2658&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/human-hand-compare-real-dinosaur-footprint-1205774944">Rattana/Shutterstock</a></span></figcaption></figure><p>Jurassic Park is arguably the ultimate Hollywood blockbuster. Aside from the appeal of human-chomping dinosaurs, tense action sequences and ground-breaking cinematography, its release in 1993 was a movies-meet-science milestone.</p>
<p>As global audiences were soaking up the gory action, the premise of the movie - extracting DNA from fossil insects preserved in amber to resurrect dinosaurs - was given the credibility of publication by several <a href="https://www.nature.com/articles/363536a0">high-profile studies</a> on <a href="https://www.science.org/doi/10.1126/science.1411508">fossil amber</a>. The authors recovered ancient DNA from amber, and even <a href="https://www.science.org/doi/10.1126/science.7538699">revived</a> amber-hosted bacteria. The world seemed primed for a real-life Jurassic Park. </p>
<p>But since then, the science has taken many twists and turns. An increasing number of palaeontologists are reporting evidence of DNA and proteins, which also give genetic information, in fossils. These chemical traces could provide unprecedented insights into ancient life and evolution. But such reports are the source of ongoing debate and controversy among scientists. Our <a href="https://www.nature.com/articles/s41559-023-02177-8">recent study</a>, published in the journal Nature Ecology and Evolution, offers new insight.</p>
<h2>Ancient DNA</h2>
<p>DNA yields the most detailed information, compared to other molecules, on how closely species are related. However, DNA is extremely fragile and <a href="https://www.nature.com/articles/362709a0">decays rapidly</a> after an organism dies. </p>
<p>That said, DNA can sometimes survive in polar climates, because the freezing temperatures slow down decay. Geologically young DNA (thousands of years old) therefore has the potential to resurrect extinct animals from the last ice age through to the recent past. </p>
<p>Commercial companies such as <a href="https://reviverestore.org/pleistocene-patreon/">Pleistocene Park</a>, <a href="https://colossal.com/de-extinction/">Colossal</a> and <a href="https://reviverestore.org/projects/woolly-mammoth/">Revive & Restore</a> are working on projects to bring back the woolly mammoth and passenger pigeon. </p>
<p>There is a long time gap between these mammoths and dinosaurs, which went extinct 66 million years ago. There is some evidence, though, that genetic material may survive in fossils even on these timescales. </p>
<p>For example, fossil chromosomes – fragments of DNA smaller than a cell – have been <a href="https://www.science.org/doi/10.1126/science.1249884">found in plants</a> up to <a href="https://www.sciencedirect.com/science/article/abs/pii/S0034666720302694">180 million years old</a> and a 75 million-year-old <a href="https://doi.org/10.1093/nsr/nwz206">dinosaur</a>.</p>
<p>Scientists have yet to find evidence, however, that actual DNA can survive for tens of millions of years. </p>
<h2>Ancient proteins</h2>
<p>Proteins also code information (in the form of <a href="https://www.britannica.com/science/amino-acid/Standard-amino-acids">amino acid sequences</a>) that can shed light on the evolutionary links among species. </p>
<p>Scientists believe that proteins can survive for longer than DNA. Indeed, researchers have found many examples of fossilised proteins, most notably intact amino acid sequences of collagen (a protein found in connective tissues), but these are at most a few million years old.</p>
<p>Scientists don’t expect large protein fragments <a href="https://doi.org/10.1042/BIO02403012">to survive</a> for as long as these smaller ones. So the scientific community was electrified in 2007 by the report of <a href="https://www.science.org/doi/10.1126/science.1137614">68 million-year-old collagen fragments</a> in a <em>Tyrannosaurus rex</em> bone.</p>
<p>Controversy soon followed though as <a href="https://royalsocietypublishing.org/doi/10.1098/rspb.2017.0544">concerns mounted</a> about the <a href="https://www.science.org/doi/10.1126/science.1155006">team’s methodology</a>, such as the potential for contamination and the lack of rigorous controls and independent verification. </p>
<p>Similar debate surrounds more recent reports of degraded proteins and <a href="https://www.nature.com/articles/ncomms8352">collagen fibres</a> in fossils as old as <a href="https://www.nature.com/articles/ncomms14220">130 million years</a>. </p>
<h2>A way forward</h2>
<p>These studies highlight the difficulties of working with fossils, especially using analytical methods that may not be appropriate to use on ancient tissues. The evidence for survival of fossil protein remnants, however, has proved compelling. </p>
<p>These studies are also stimulating other researchers to explore new methods and analytical approaches that might be better suited for use with fossils. </p>
<p>Our <a href="https://doi.org/10.1038/s41559-023-02177-8">new study</a> explores one such approach, using a focused beam of light plus X-rays to irradiate samples of ancient feathers. These techniques reveal which chemical bonds are present, providing information on the structure of proteins. In turn, this helps us to detect traces of proteins in fossil feathers. </p>
<p>Our analyses of the 125 million-year-old feathered dinosaur <em>Sinornithosaurus</em> revealed abundant corrugated protein structures, consistent with a protein called beta-keratin, which is common in modern feathers. Spiral protein structures (indicative of another protein called alpha-keratin) were present only in small amounts. </p>
<p>When we simulated the process of fossilisation in laboratory experiments, we found that corrugated protein structures unravel and form spiral structures when heated. </p>
<p>These findings suggest that ancient feathers were remarkably similar in chemistry to modern-day feathers. It also suggests that spiral protein structures in fossils are probably artefacts of the fossilisation process. </p>
<p>But ultimately, our findings suggest traces of proteins do survive for hundreds of millions of years.</p>
<h2>Real-life Jurassic Park – science fact or fiction?</h2>
<p>Palaeontologists today can test fossils for evidence of ancient molecules using an arsenal of techniques that were not available 30 years ago. This has allowed us to identify fragments of molecules in fossil animals that are tens to hundreds of millions of years old.</p>
<p>Scientists have discovered haemoglobin, a protein in red blood cells, in 50-million-year-old insects, and melanin pigments in the ink sacs of 200-million-year-old squid. </p>
<p>Ultimately though, we need intact DNA to resurrect species. So although scientists have made a lot of progress, the prospect remains in the realm of science fiction. All data from fossils and experiments to date suggests that DNA is simply unlikely to survive for tens of millions of years. </p>
<p>Even if scientists did find DNA fragments in dinosaur fossils, these would probably be very short. Short fragments of DNA are unlikely to give us useful information about a species. And we don’t yet have the technology to validate such rare DNA fragments as original rather than random combinations of amino acids, generated during fossilisation. </p>
<p>Better lab protocols and fossilisation experiments are helping us to make more accurate interpretations of fossils. This is paving the way for more rigorous studies of ancient molecules. </p>
<p>In the future, these studies may challenge what we think we know about how long molecules can survive, and may even reshape our understanding of the evolution of life on Earth.</p><img src="https://counter.theconversation.com/content/215278/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Tiffany Shea Slater receives funding from the European Research Council and the Irish Research Council. </span></em></p><p class="fine-print"><em><span>Maria McNamara receives funding from the European Research Council and Science Foundation Ireland. </span></em></p>New laboratory experiments add analytical rigour to the search for ancient biomoleculesTiffany Shea Slater, Postdoctoral Researcher, Palaeobiology, University College CorkMaria McNamara, Professor, Palaeobiology, University College CorkLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2145722023-10-03T00:14:40Z2023-10-03T00:14:40ZHoles in baby dinosaur bones show how football-sized hatchlings grew to 3-tonne teens<figure><img src="https://images.theconversation.com/files/551328/original/file-20231002-25-pmkx02.jpg?ixlib=rb-1.1.0&rect=71%2C862%2C3242%2C2128&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-illustration/maiasaura-dinosaurs-cross-swamp-3d-illustration-2316905179">Shutterstock</a></span></figcaption></figure><p>Despite their public image as torpid, lumbering creatures, many dinosaurs were <a href="https://doi.org/10.1111/brv.12822">evidently warm-blooded, highly active animals</a>, capable of prolonged and strenuous aerobic exercise. </p>
<p>In new research, my colleagues and I determined how much energy minibus-sized dinosaurs called Maiasaura used while growing to adulthood. </p>
<p>Our results, <a href="https://doi.org/10.1017/pab.2023.24">published</a> in the journal Paleobiology, show Maiasaura was capable of taking in huge amounts of energy and nutrients and using them for rapid growth and levels of activity comparable to those of modern mammals.</p>
<h2>How bones heal and grow</h2>
<p>Living an active lifestyle can leave traces in the skeleton. Locomotion and weight-bearing activity cause stresses and strains that result in microfractures in the bones. If these tiny cracks build up, the outcome can be a catastrophic fracture.</p>
<p>Fortunately, the leg bones of dinosaurs – like those of birds, mammals and varanid lizards such as the Komodo dragon – <a href="https://doi.org/10.1242/jeb.00514">repair themselves</a> in a process known as bone remodelling. </p>
<p>This occurs by blood capillaries growing through old bone, which is dissolved and replaced by new bone. Under the microscope, the new bone can be seen as column-like structures called “secondary osteons”.</p>
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Read more:
<a href="https://theconversation.com/how-smart-were-our-ancestors-turns-out-the-answer-isnt-in-brain-size-but-blood-flow-130387">How smart were our ancestors? Turns out the answer isn't in brain size, but blood flow</a>
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<p>Many palaeontologists have looked for and found these secondary osteons in dinosaur bones as evidence for the bone remodelling that is characteristic of warm-blooded animals. </p>
<p>However, little attention has been given to the bones of juvenile dinosaurs, in which primary bone is being laid down in a process called bone modelling. </p>
<p>The main impediment to this research is the shortage of collections of bones from a single dinosaur species at different stages of growth. </p>
<h2>‘Good mother reptile’</h2>
<p>Possibly the best growth series of dinosaur bones in the world comes from the fossil beds of the Two Medicine Formation in the US state of Montana. </p>
<p>Fossils from this formation have yielded much information about the eggs, hatchlings and early lives of a dinosaur named Maiasaura (meaning “good mother reptile”). </p>
<p>This herbivorous hadrosaur apparently tended her eggs and <a href="https://iknowdino.com/maiasaura-episode-37/">raised her offspring</a> for more than a year after hatching. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/551329/original/file-20231002-23-va3j3t.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="An illustration showing a mother Maiasaura with one of her young." src="https://images.theconversation.com/files/551329/original/file-20231002-23-va3j3t.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/551329/original/file-20231002-23-va3j3t.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=288&fit=crop&dpr=1 600w, https://images.theconversation.com/files/551329/original/file-20231002-23-va3j3t.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=288&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/551329/original/file-20231002-23-va3j3t.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=288&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/551329/original/file-20231002-23-va3j3t.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=362&fit=crop&dpr=1 754w, https://images.theconversation.com/files/551329/original/file-20231002-23-va3j3t.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=362&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/551329/original/file-20231002-23-va3j3t.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=362&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">Maiasaura tended their eggs and raised offspring for more than a year after they hatched.</span>
<span class="attribution"><a class="source" href="https://www.deviantart.com/ntamura/art/Maiasaura-mother-and-son-80065377">N. Tamura</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span>
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<p>Young Maiasaura grew <a href="https://doi.org/10.1017/pab.2015.19">astonishingly fast</a>, reaching 200-400 kilograms by their second year, and over 3,000kg by their teens. </p>
<p>In comparison, cold-blooded saltwater crocodiles today weigh only about 6kg at the age of two, and reach adulthood at between ten and 16 years old, when females weigh about 34kg and males about 115kg.</p>
<p>Such high growth rates in Maiasaura involved rapid lengthening and thickening of their long bones, and the process doubtlessly required much oxygen and nutrients from the blood. </p>
<p>The shafts of long bones of the leg, such as the femur (thigh bone) and tibia (shin bone), are supplied with blood by the principal nutrient artery, which enters the bone through a hole (called a foramen) that is visible on the surface.</p>
<h2>How to measure blood flow from bones</h2>
<p>A decade ago, I wondered whether the size of the foramen could be an indirect measurement of the rate of blood flow to a bone. </p>
<p>This turned out to be true, and since then the “foramen technique” has been <a href="https://doi.org/10.1098/rspb.2011.0968">used on fossils</a> to estimate blood flow rate and hence how much energy and nutrients were used in the bones of adult dinosaurs.</p>
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<img alt="Three photos of a fossilised bone, with a small round discolouration circled." src="https://images.theconversation.com/files/551330/original/file-20231002-15-y0rv8n.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/551330/original/file-20231002-15-y0rv8n.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=385&fit=crop&dpr=1 600w, https://images.theconversation.com/files/551330/original/file-20231002-15-y0rv8n.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=385&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/551330/original/file-20231002-15-y0rv8n.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=385&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/551330/original/file-20231002-15-y0rv8n.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=484&fit=crop&dpr=1 754w, https://images.theconversation.com/files/551330/original/file-20231002-15-y0rv8n.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=484&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/551330/original/file-20231002-15-y0rv8n.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=484&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">A fossilised Maiasaura shin bone, showing the foramen – the hole which allows an artery to supply blood to the bone.</span>
<span class="attribution"><span class="source">Photos by Heath Caldwell of a specimen in the Museum of the Rockies.</span>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
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<p>To apply the foramen technique to the fast-growing juvenile Maiasaura, I teamed up with Heath Caldwell, a student at Montana State University, who searched for the tiny foramina among the fossil collection at the Museum of the Rockies in Bozeman, Montana. </p>
<p>Holly Woodward of Oklahoma State University had previously determined the ages of the animals when they died. Qiaohui Hu at Adelaide University used the best techniques for measuring foramen size and relating it to nutrient artery size. </p>
<h2>Rapid growth doesn’t come cheap</h2>
<p>Our work produced clear results. Blood flow rates calculated from foramen size were similar in one-year-old dinosaurs weighing between 189kg and 455kg and in six- to 11-year-old adults weighing between 1,680kg and 3,200kg. </p>
<p>In other words, a one-year-old had about four times as much blood flowing to each gram of its shinbone as a full-grown adult did. The flow rate per gram in the femur of a two kilogram hatchling Maiasaura was 15 times higher than that of the adults. </p>
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Read more:
<a href="https://theconversation.com/hot-fuss-is-warm-blooded-dinosaur-theory-right-or-wrong-8174">Hot fuss: is warm-blooded dinosaur theory right or wrong?</a>
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<p>These differences reveal how much more energy and nutrients it took to build bones in the early rapid growth stages of a Maiasaura’s life than it did to maintain the bones in adulthood. </p>
<p>The size of the foramen in adults was also comparable to those in mammals alive today, and much larger than in most modern reptiles. These findings support the view that dinosaurs were not cold-blooded and sluggish, but warm-blooded, very active, fast-growing animals that dominated the Mesozoic landscape.</p><img src="https://counter.theconversation.com/content/214572/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Roger S. Seymour receives funding from The Australian Research Council.</span></em></p>Small holes in baby dinosaur bones add to the growing mass of evidence that the ancient creatures were warm-blooded and highly active.Roger S. Seymour, Professor Emeritus of Physiology, University of AdelaideLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2138182023-09-22T13:11:26Z2023-09-22T13:11:26ZSouth African hominin fossils were sent into space and scientists are enraged<p><em>When a Virgin Galactic commercial flight soared into space on 8 September 2023, there were two Virgin Galactic pilots, an instructor and three passengers on board – as well as two fossils of ancient prehuman relatives from South Africa. Timothy Nash, a businessman, carried a clavicle belonging to Australopithecus sediba and the thumb bone of a Homo naledi specimen. The fossils’ brief journey – the VSS Unity’s flight lasted just an hour – was organised by palaeontologist Lee Berger, who led the team that discovered and described Homo naledi in 2015. Berger was granted an export permit in July by the South African Heritage Resources Agency (SAHRA) to take the fossils from the country to the US launch site for VSS Unity. <a href="https://www.sahra.org.za/about/">SAHRA is a</a> “national administrative body responsible for the protection of South Africa’s cultural heritage”.</em></p>
<p><em>The event has <a href="https://www.nature.com/articles/d41586-023-02882-1">drawn the ire</a> of scores of human evolution researchers from South Africa and beyond. Some have <a href="https://www.researchprofessionalnews.com/rr-news-africa-south-2023-9-scientists-slam-pr-stunt-that-sent-hominin-fossils-into-space/">labelled it</a> “unethical” and a “publicity stunt”. Berger issued <a href="https://twitter.com/LeeRberger/status/1706277191762231582">a brief statement</a> on X (formerly Twitter) on 25 September addressing the situation. And SAHRA, in <a href="https://www.nature.com/articles/d41586-023-02882-1">a statement</a> quoted by Nature, said it was “satisfied that the promotional benefit derived was appropriately weighted against the inherent risk of travel of this nature”.</em></p>
<p><em>The Conversation Africa asked Dipuo Winnie Kgotleng, <a href="https://www.uj.ac.za/faculties/humanities/research/research-centres/palaeo-research-institute/">director of the Palaeo-Research Institute</a> at the University of Johannesburg, and Robyn Pickering, co-director of the <a href="https://www.heriuct.co.za/">Human Evolution Research Institute</a> at the University of Cape Town, why the space flight created such unhappiness.</em></p>
<h2>Why are scientists so angry about the fossils being sent to space?</h2>
<p>There are a number of reasons. </p>
<p>One is the threat to South African heritage. According to the <a href="https://sahris.sahra.org.za/sites/default/files/website/articledocs/Archaeology%20Permit%20Policy_April2016_Approved.pdf">SAHRA permitting policy</a>, fossils of this nature are only allowed to travel for scientific purposes and should be securely packed to prevent damage. The fossils travelled in space in a sealed tube – and were then kept in an individual’s pocket as he floated freely.</p>
<p>There is no scientific reason for allowing these fossils to travel to space. No new knowledge has been generated and no community, either local or international, has been engaged on this science. </p>
<p>Also, doses of radiation which these specimens were exposed to during this trip could have potentially permanently altered the fossil microstructure, affecting any data which might be required in the future. </p>
<p>A second issue is that the <em>A. sediba</em> clavicle is a type specimen: it is the original physical example of the species and, if such a specimen is lost or destroyed, it is gone forever.</p>
<p>Finally, this event demonstrated the unequal power relations at play in accessing this invaluable heritage. Some local communities – like the people of Taung, where a 2.8 million year old child’s skull <a href="https://humanorigins.si.edu/evidence/human-fossils/fossils/taung-child">nicknamed the Taung Child</a> was discovered in 1924 – have <a href="https://sundayworld.co.za/news/locals-want-taung-skull-returned-home/">requested access</a> to fossil specimens that originated from their areas. In the case of the Taung Child, there have <a href="https://sundayworld.co.za/news/locals-want-taung-skull-returned-home/">reportedly been discussions</a> “over a long time” to have the skull returned by the university where it is stored.</p>
<p>So, is it only wealthy, famous rich white men who can have access to fossils? Poor communities do not have access to the same privileges?</p>
<h2>Professor Berger’s SAHRA application <a href="https://sahris.sahra.org.za/node/620113">called</a> the fossils’ space flight a ‘once in a lifetime opportunity to bring awareness to science, exploration, human origins and South Africa and its role in understanding Humankind’s shared African ancestry’.</h2>
<p>We completely disagree. Which community has been engaged in science awareness? Surely no South African or any African community has been engaged through this act?</p>
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Read more:
<a href="https://theconversation.com/science-and-race-in-south-africa-lessons-from-old-bones-in-boxes-179774">Science and race in South Africa: lessons from 'old bones in boxes'</a>
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<h2>Some have argued that the space flight echoes colonial attitudes to human remains. How so?</h2>
<p>This is an example of what we <a href="https://www.nature.com/articles/s41561-022-01010-4">call</a> <a href="https://link.springer.com/article/10.1023/A:1022374703178">neo-colonialism</a>. The <a href="https://jacana.co.za/product/darwins-hunch-science-race-and-the-search-for-human-origins/">science of human evolution has a long</a>, dark past of exploitation and extraction. The main perpetrators of this past were privileged white men, so this latest event feels familiar but is really not OK in 2023. </p>
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Read more:
<a href="https://theconversation.com/archaeology-is-changing-slowly-but-its-still-too-tied-up-in-colonial-practices-133243">Archaeology is changing, slowly. But it's still too tied up in colonial practices</a>
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<p>Our field is just beginning to grapple with its past, and we’ve made <a href="https://www.heriuct.co.za/news-content/celebrating-5-years-of-advancing-womxn">some progress</a> in the last decade. Something like this puts us right back into the olden days.</p>
<h2>So what happens next?</h2>
<p>Several professional bodies in various African regions have <a href="https://eaappinfo.wordpress.com/">issued statements</a> <a href="https://twitter.com/SASQUA1/status/1702245012472205761/photo/1">expressing</a> their unhappiness about the treatment of the fossils. </p>
<p>Various arms of the palaeoscience community, such as the <a href="https://www.facebook.com/photo?fbid=301773955808321&set=a.159433826709002">Association of Southern African Professional Archaeologists</a>, have directly asked SAHRA and the Cradle of Humankind Management Authority (which is responsible for preserving the world heritage site where the fossils were found) and the government to address us and the South African public more broadly. </p>
<p>We are also pushing for these organisations to reflect on this issue and to discuss changes to their permitting policy. We’re confident that the outrage we’ve demonstrated will guard against something like this happening again in the future.</p>
<p>September is Heritage Month in South Africa, a time when we are asked to come together as a country, to celebrate, learn about and explore our heritage as a way to build unity in a diverse society. Our common heritage, represented by the fossils, is a great tool for bringing us together as a country. Treating the same fossils in this way goes against this noble aim.</p>
<p><em>This article was updated on 27 September to add Professor Lee Berger’s <a href="https://twitter.com/LeeRberger/status/1706277191762231582">statement</a>.</em></p><img src="https://counter.theconversation.com/content/213818/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Dipuo Winnie Kgotleng has received funding from the Wenner-Gren foundation, National Heritage Council and National Research Foundation. </span></em></p><p class="fine-print"><em><span>Robyn Pickering receives funding from The University of Cape Town, the National Research Foundation (NRF) and the DSI Centre of Excellence in Palaeosciences/GENUS</span></em></p>Experts insist there is no scientific reason for allowing these fossils to travel to space.Dipuo Winnie Kgotleng, Director, University of JohannesburgRobyn Pickering, Senior lecturer, University of Cape TownLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2132692023-09-14T11:59:04Z2023-09-14T11:59:04ZPollen in pee: fossilised urine from a small African mammal helps us understand past environments<figure><img src="https://images.theconversation.com/files/547771/original/file-20230912-27-za8r9z.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The lessons pollen can teach us are not to be sneezed at.</span> <span class="attribution"><span class="source">Elisa Manzati</span></span></figcaption></figure><p>If you are allergic to pollen, you are likely to curse the existence of these microscopic particles. You’re not alone: <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4829390/#:%7E:text=Allergies%20on%20the%20Rise,people%20worldwide%20affected%20by%20asthma">up to 30%</a> of the world’s population suffers from hay fever, which is often driven by pollen allergies. Shifting global climates are likely to <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4829390/">push that figure even higher</a>.</p>
<p>However, pollen represents one of the most powerful tools to uncover the nature of past environmental change. </p>
<p>I am the head of the <a href="https://drlynnequick.com/nelson-mandela-palaeolab/">Palaeoecology Laboratory</a> at <a href="https://www.mandela.ac.za/">Nelson Mandela University</a> in South Africa. My research focuses on unravelling the secrets of ancient environments and ecosystems by examining fossil pollen grains. These tiny time capsules hold a wealth of information about the earth’s past. They help scientists to reconstruct ecosystems, track climate change and understand the evolution of plant life.</p>
<p>But it can be difficult to source pollen deposits in arid regions. That’s because such deposits are often found in large lakes, which are in short supply in southern Africa. That’s where an unlikely scientific ally enters the picture: the fossilised urine of a small mammal, the <a href="https://www.awf.org/wildlife-conservation/hyrax">rock hyrax</a> (South Africans call them “dassies”). </p>
<h2>Looking back</h2>
<p>Pollen grains are incredibly durable because they are made of an organic substance (called sporopollenin) that is very resistant to decay. Pollen is released into the air, often in large quantities, and can settle on surfaces like lakes, and become preserved in sediment deposits over thousands, or even millions, of years.</p>
<p>In the lab, we examine the pollen found in these deposits using a microscope. By identifying the different types of pollen grains found within the different layers (representing different time slices) we can reconstruct the area’s vegetation history. Plants grow under specific climatic conditions: for instance, desert plants can grow under low rainfall conditions whereas forest plants need high amounts of rainfall. So we can make inferences about the climate at the time that the pollen was incorporated into the deposit.</p>
<figure class="align-center ">
<img alt="A rather chubby small rodent with dark brown fur and protruding front teeth regards the photographer." src="https://images.theconversation.com/files/547484/original/file-20230911-23-arxq3p.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/547484/original/file-20230911-23-arxq3p.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/547484/original/file-20230911-23-arxq3p.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/547484/original/file-20230911-23-arxq3p.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/547484/original/file-20230911-23-arxq3p.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/547484/original/file-20230911-23-arxq3p.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/547484/original/file-20230911-23-arxq3p.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The fossilised urine of rock hyraxes helps in the study of pollen.</span>
<span class="attribution"><span class="source">Kiev Victor</span></span>
</figcaption>
</figure>
<p>As I’ve said, southern Africa’s arid climates mean there are very few large lakes in the region. This makes it a challenge to source deposits that adequately preserve pollen within them over long periods of time. That’s where <a href="https://www.sciencedirect.com/science/article/abs/pii/S0277379112003319">fossilised dassie urine</a> comes in. </p>
<p>These sticky deposits called “middens” accumulate in rock crevices in mountainous areas over thousands to tens of thousands of years and contain beautifully preserved pollen grains. As they also contain various other types of evidence (such as geochemical data) and can be accurately dated, they represent the most valuable archive of past climate data in southern Africa. The oldest middens we’ve worked with date back 50,000 years.</p>
<h2>Ancient sites</h2>
<p>The research my lab conducts, focusing on harnessing the power of the humble pollen grain and utilising unique archives such as hyrax middens, is strongly multidisciplinary. It draws together elements from botany, geography, geology, climatology and archaeology. </p>
<p>We are currently generating fossil pollen records from several sites within the Cape Fold Belt mountains of South Africa. For example, we have a midden sequence that covers the last 6,000 years from the Baviaanskloof in the Eastern Cape province. The fossil pollen from this sequence shows that there was a dramatic shift in vegetation about 3,300 years ago, driven by a large fire event and increased temperatures. We’re hoping to publish this research soon.</p>
<p>This information provides baselines of variability in natural systems and can help inform current conservation efforts within the Baviaanskloof, which is a biodiversity hotspot. </p>
<p><a href="https://www.africanpaleoscienceslab.org/fieldwork/capp">Another project</a> that we are involved in is centred on the archaeological excavation within South Africa’s southern Cape region at a site called Boomplaas Cave. By using the fossil pollen within hyrax middens found within the vicinity of Boomplaas Cave, we hope to provide the environmental context to the archaeological record which can help to decipher how early humans responded to climate change.</p>
<h2>And looking forward</h2>
<p>We are not only working within the realm of the past: as pollen is one of the main sources of allergies it is important to monitor the types and amounts of pollen currently present in the air we breathe. My lab is part of the <a href="https://pollencount.co.za/">South African Pollen Monitoring network</a> and we generate pollen data for the city of Gqeberha in the Eastern Cape province. </p>
<p>This initiative focuses on analysing pollen captured in the air across several different parts of South Africa and ensuring that this information is publicly available. This project is particularly important as, <a href="https://journals.co.za/doi/abs/10.10520/EJC21714">due to climate change</a>, pollen seasons are lengthening and <a href="https://www.immunology.theclinics.com/article/S0889-8561(20)30061-8/fulltext">allergenic pollen is increasing</a>.</p><img src="https://counter.theconversation.com/content/213269/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Lynne Quick receives funding from the National Research Foundation of South Africa: African Origins Platform and
GENUS: DSI-NRF Centre of Excellence in Palaeosciences
</span></em></p>Pollen can become preserved in sediment deposits over thousands, or even millions, of years.Lynne Quick, Senior Research Fellow, Nelson Mandela UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2132712023-09-13T14:00:06Z2023-09-13T14:00:06ZFlowering plants survived the dinosaur-killing asteroid – and may outlive us<figure><img src="https://images.theconversation.com/files/547777/original/file-20230912-15-mm7cp3.jpg?ixlib=rb-1.1.0&rect=53%2C44%2C5937%2C3943&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/pink-rose-flower-pastel-ink-creative-1336421165">Zamurovic Brothers/Shutterstock</a></span></figcaption></figure><p>If you looked up 66 million years ago you might have seen, for a split second, a bright light as a mountain-sized asteroid burned through the atmosphere and smashed into Earth. <a href="https://www.nature.com/articles/s41586-022-04446-1">It was springtime</a> and the literal end of an era, the <a href="https://www.usgs.gov/youth-and-education-in-science/mesozoic">Mesozoic</a>. </p>
<p>If you somehow survived the initial impact, you would have witnessed the devastation that followed. Raging firestorms, megatsunamis, and <a href="https://pubmed.ncbi.nlm.nih.gov/11539442/">a nuclear winter</a> lasting months to years. The 180-million-year reign of non-avian dinosaurs was over in the blink of an eye, as well as at least <a href="https://www.science.org/doi/abs/10.1126/science.215.4539.1501?casa_token=DrtWs804WZsAAAAA:4SB3Ih2f1Ffnvilw9c8jxUViVd3IvyUVQRQ9PHOIezMQ7O5K9fR3a_nTWZWVKDJ94uKgsCBUfMH7Kg">75% of the species</a> who shared the planet with them. </p>
<p>Following this event, known as the <a href="https://www.britannica.com/science/K-T-extinction">Cretaceous-Paleogene mass extinction</a> (K-Pg), a new dawn emerged for Earth. Ecosystems bounced back, but the life inhabiting them was different.</p>
<p>Many iconic pre-K-Pg species can only be seen in a museum. The formidable <em>Tyrannosaurus rex</em>, the <em>Velociraptor</em>, and the winged dragons of the <em>Quetzalcoatlus</em> genus could not survive the asteroid and are confined to deep history. But if you take a walk outside and smell the roses, you will be in the presence of ancient lineages that blossomed in the ashes of K-Pg. </p>
<hr>
<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/513999/original/file-20230307-18-3frmra.gif?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/513999/original/file-20230307-18-3frmra.gif?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/513999/original/file-20230307-18-3frmra.gif?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/513999/original/file-20230307-18-3frmra.gif?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/513999/original/file-20230307-18-3frmra.gif?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/513999/original/file-20230307-18-3frmra.gif?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/513999/original/file-20230307-18-3frmra.gif?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption"></span>
</figcaption>
</figure>
<p><em>Many people think of plants as nice-looking greens. Essential for clean air, yes, but simple organisms. A step change in research is shaking up the way scientists think about plants: they are far more complex and more like us than you might imagine. This blossoming field of science is too delightful to do it justice in one or two stories.</em>
<em><a href="https://theconversation.com/topics/plant-curious-137238?utm_source=TCUK&utm_medium=linkback&utm_campaign=PlantCurious2023&utm_content=InArticleTop">This article is part of a series, Plant Curious</a>, exploring scientific studies that challenge the way you view plantlife.</em></p>
<hr>
<p>Although the living species of roses are not the same ones that shared Earth with <em>Tyrannosaurus rex</em>, their lineage (family Rosaceae) <a href="https://www.nature.com/articles/s41467-020-17116-5">originated tens of millions of years</a> before the asteroid struck.</p>
<p>And the roses are an not unusual angiosperm (flowering plant) lineage in this regard. Fossils and genetic analysis suggest that the <a href="https://www.nature.com/articles/s41559-020-1241-3">vast majority of angiosperm families</a> originated before the asteroid. </p>
<p>Ancestors of the ornamental orchid, magnolia and passionflower families, grass and potato families, the medicinal daisy family, and the herbal mint family all shared Earth with the dinosaurs. In fact, the explosive evolution of angiosperms into the roughly 290,000 species today may have been facilitated by K-Pg. </p>
<p>Angiosperms seemed to have taken advantage of the fresh start, similar to the early members of our own lineage, <a href="https://www.cell.com/current-biology/pdf/S0960-9822(23)00767-4.pdf">the mammals</a>. </p>
<figure class="align-center ">
<img alt="Purple flower growing out of a crack in the pavement" src="https://images.theconversation.com/files/547779/original/file-20230912-35629-s73lh2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/547779/original/file-20230912-35629-s73lh2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/547779/original/file-20230912-35629-s73lh2.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/547779/original/file-20230912-35629-s73lh2.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/547779/original/file-20230912-35629-s73lh2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/547779/original/file-20230912-35629-s73lh2.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/547779/original/file-20230912-35629-s73lh2.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Flowers are surprisingly resilient.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/purple-flower-growing-on-crack-street-776381272">PopTika/Shutterstock</a></span>
</figcaption>
</figure>
<p>However, it’s not clear how they did it. Angiosperms, so fragile compared with dinosaurs, cannot fly or run to escape harsh conditions. They rely on sunlight for their existence, which was blotted out. </p>
<h2>What do we know?</h2>
<p>Fossils in different regions tell different versions of events. It is clear there was high angiosperm turnover (species loss and resurgence) <a href="https://www.science.org/doi/full/10.1126/science.abf1969?casa_token=s5xuTGC7SpAAAAAA%3AJHgkvkmunfwRZLpwfcoumaus-20jehSJ4vDnlJa8LRzFqco_pveiJVbdvHm1h2P3SXvHckDRN5ERuw">in the Amazon</a> when the asteroid hit, and a decline in plant-eating insects <a href="https://www.pnas.org/doi/10.1073/pnas.042492999#:%7E:text=The%20most%20specialized%20associations%2C%20which,associations%20regained%20their%20Cretaceous%20abundances">in North America</a> which suggests a loss of food plants. But other regions, <a href="https://www.sciencedirect.com/science/article/abs/pii/S0034666723001021?via%3Dihub">such as Patagonia</a>, show no pattern. </p>
<p>A study in 2015 analysing angiosperm fossils of 257 <a href="https://www.britannica.com/science/genus-taxon">genera</a> (families typically contain multiple genera) found K-Pg had <a href="https://nph.onlinelibrary.wiley.com/doi/full/10.1111/nph.13247">little effect</a> on extinction rates. But this result is difficult to generalise across the <a href="https://academic.oup.com/sysbio/article/71/2/301/6275244">13,000 angiosperm genera</a>. </p>
<p>My colleague Santiago Ramírez-Barahona, from the Universidad Nacional Autónoma de México, and I took a new approach to solving this confusion in a study we <a href="https://royalsocietypublishing.org/doi/10.1098/rsbl.2023.0314">recently published</a> in Biology Letters. We analysed large angiosperm family trees, which previous work mapped from mutations in DNA sequences from 33,000-73,000 species. </p>
<p>This way of tree-thinking has laid the groundwork for major insights about the evolution of life, since the first family tree was scribbled by Charles Darwin. </p>
<figure class="align-left zoomable">
<a href="https://images.theconversation.com/files/547814/original/file-20230912-25-6n0182.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Scribble of a diagram with handwritten notes to the sides and underneath" src="https://images.theconversation.com/files/547814/original/file-20230912-25-6n0182.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/547814/original/file-20230912-25-6n0182.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=978&fit=crop&dpr=1 600w, https://images.theconversation.com/files/547814/original/file-20230912-25-6n0182.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=978&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/547814/original/file-20230912-25-6n0182.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=978&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/547814/original/file-20230912-25-6n0182.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1229&fit=crop&dpr=1 754w, https://images.theconversation.com/files/547814/original/file-20230912-25-6n0182.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1229&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/547814/original/file-20230912-25-6n0182.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1229&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Charles Darwin’s first diagram of an evolutionary tree from 1837.</span>
</figcaption>
</figure>
<p>Although the family trees we analysed did not include extinct species, their shape contains clues about how extinction rates changed through time, through the way the branching rate ebbs and flows. </p>
<p>The extinction rate of a lineage, in this case angiosperms, can be estimated using mathematical models. The one we used compared ancestor age with estimates for how many species should be appearing in a family tree according to what we know about the evolution process. </p>
<p>It also compared the number of species in a family tree with estimates of how long it takes for a new species to evolve. This gives us a net diversification rate - how fast new species are appearing, adjusted for the number of species that have disappeared from the lineage. </p>
<p>The model generates time bands, such as a million years, to show how extinction rate varies through time. And the model allowed us to identify time periods that had high extinction rates. It can also suggest times in which major shifts in species creation and diversification have occurred as well as when there may have been a mass extinction event. It shows how well the DNA evidence supports these findings too. </p>
<p>We found that extinction rates seem to have been remarkably constant over the last 140-240 million years. This finding highlights how resilient angiosperms have been over hundreds of millions of years. </p>
<p>We cannot ignore the <a href="https://www.cambridge.org/core/journals/cambridge-prisms-extinction/article/endcretaceous-plant-extinction-heterogeneity-ecosystem-transformation-and-insights-for-the-future/D74EBD512E4261E4C28BB7AF024E80B9">fossil evidence</a> showing that many angiosperm species did disappear around K-Pg, with some locations hit harder than others. But, as our study seems to confirm, the lineages (families and orders) to which species belonged carried on undisturbed, creating life on Earth as we know it. </p>
<p>This is different to how non-avian dinosaurs fared, who disappeared in their entirety: their entire branch was pruned. </p>
<p>Scientists believe <a href="https://genome.cshlp.org/content/24/8/1334.short">angiosperm resilience</a> to the K-Pg mass extinction (why only leaves and branchlets of the angiosperm tree were pruned) may be explained by their ability to adapt. For example, their evolution of new seed-dispersal and pollination mechanisms. </p>
<p>They can also <a href="https://royalsocietypublishing.org/doi/10.1098/rspb.2017.0912">duplicate their entire genome</a> (all of the DNA instructions in an organism) which provides a second copy of every single gene on which selection can act, potentially leading to new forms and greater diversity.</p>
<p>The sixth mass extinction event <a href="https://www.science.org/doi/full/10.1126/sciadv.1400253">we currently face</a> may follow a similar trajectory. A worrying number of angiosperm species are already threatened with extinction, and their demise will probably lead to the end of life as we know it. </p>
<p>It’s true angiosperms may blossom again from a stock of diverse survivors - and they may outlive us.</p><img src="https://counter.theconversation.com/content/213271/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Jamie Thompson received PhD funding from Roger and Sue Whorrod (University of Bath alumni and philanthropists).</span></em></p>The fossil record tells conflicting stories about what happened to flowering plants after the asteroid.Jamie Thompson, Postdoctoral Evolutionary Biologist, University of BathLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2100842023-08-18T14:43:47Z2023-08-18T14:43:47ZWhy we think that some extinct giant flying reptiles cared for their young<figure><img src="https://images.theconversation.com/files/543063/original/file-20230816-28-82uhml.jpg?ixlib=rb-1.1.0&rect=9%2C0%2C6082%2C2931&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Pteranodon was a large-bodied pterosaur.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/pteranodon-flying-genus-pterosaur-lived-during-2133739385">YuRi Photolife / Shutterstock</a></span></figcaption></figure><p>Our understanding of animal behaviour depends on observation. Researchers can study how animals are born, grow and develop. We can gather evidence of how they interact with each other and their environment.</p>
<p>But how do we do this for extinct animals? <a href="https://royalsocietypublishing.org/doi/10.1098/rspb.2023.1102">In a recent scientific paper</a>,
palaeontologist <a href="https://www.ucc.ie/en/mariamcnamara/whoweare/zixiao/">Zixiao Yang</a> and colleagues compared the growth of small and giant pterosaurs. </p>
<p>These were flying reptiles that were alive between about 228 million years ago and 66 million years ago – sharing the Earth with dinosaurs. Yang and colleagues wanted to understand what, if anything, was different about how the giant animals got so big.</p>
<figure class="align-center ">
<img alt="Pterosaur" src="https://images.theconversation.com/files/543263/original/file-20230817-23-q0f85v.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/543263/original/file-20230817-23-q0f85v.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=368&fit=crop&dpr=1 600w, https://images.theconversation.com/files/543263/original/file-20230817-23-q0f85v.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=368&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/543263/original/file-20230817-23-q0f85v.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=368&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/543263/original/file-20230817-23-q0f85v.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=462&fit=crop&dpr=1 754w, https://images.theconversation.com/files/543263/original/file-20230817-23-q0f85v.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=462&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/543263/original/file-20230817-23-q0f85v.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=462&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Model pterosaur, Dimorphodon macronyx (reconstruction). Photographed at the National Museum of Scotland.</span>
<span class="attribution"><a class="source" href="https://www.jasongilchrist.co.uk/Blog_386348.html">Jason Gilchrist</a></span>
</figcaption>
</figure>
<p>They looked at the limb bones, which are critical to locomotion: the forelimbs to flight, the hindlimbs to movement on the ground. With the smaller-bodied pterosaurs (the smallest in the study had a wingspan of 0.19–0.74 metres), they discovered that the limb bones that lay closest to the body – the “proximal” ones – grew more slowly relative to their total body size as the animals aged after hatching.</p>
<p>For large-bodied pterosaur species, such as <a href="https://www.britannica.com/animal/Pteranodon"><em>Pteranodon</em></a>, with a wingspan range of 3.91-6.37 metres, the limb bones that lay closest to the body grew faster than other elements of their skeleton after hatching.</p>
<figure class="align-center ">
<img alt="Limb bone growth allometry in pterosaurs of different sizes. The wings of small-bodied pterosaurs show limb bones that grew slowly with respect to the rest of the body, indicating that they were potentially good fliers soon after hatching. Large-bodied pterosaur species, however, were born with relatively small arms. Even though their wing bones grew quickly after hatching relative to the rest of the body, the young of these species likely could not fly as efficiently and therefore parental care may have been required." src="https://images.theconversation.com/files/543289/original/file-20230817-30641-1dr1ti.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/543289/original/file-20230817-30641-1dr1ti.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=348&fit=crop&dpr=1 600w, https://images.theconversation.com/files/543289/original/file-20230817-30641-1dr1ti.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=348&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/543289/original/file-20230817-30641-1dr1ti.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=348&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/543289/original/file-20230817-30641-1dr1ti.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=438&fit=crop&dpr=1 754w, https://images.theconversation.com/files/543289/original/file-20230817-30641-1dr1ti.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=438&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/543289/original/file-20230817-30641-1dr1ti.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=438&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Infographic showing different growth patterns in large and small pterosaurs.</span>
<span class="attribution"><span class="source">Yang Z, Jiang B, Benton MJ, Xu X, McNamara ME, Hone DWE.</span></span>
</figcaption>
</figure>
<p>In bird and mammal species alive today, this pattern is associated with particular developmental strategies. Present-day species showing a developmental pattern most similar to the smaller pterosaurs tend to <a href="https://web.stanford.edu/group/stanfordbirds/text/uessays/uPrecocial_and_Altricial.html">move around independently</a> from an early age.</p>
<p>While not necessarily lacking in parental care, such species tend to be less dependent on or demanding of their parents. By contrast, living species showing the developmental pattern seen in the larger <em>Pteranodon</em> tend to have young that are not capable of independent movement. In these animals, intensive parental care – including feeding the young – is the norm.</p>
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<em>
<strong>
Read more:
<a href="https://theconversation.com/dinosaur-egg-bonanza-gives-vital-clues-about-prehistoric-parenting-121401">Dinosaur egg bonanza gives vital clues about prehistoric parenting</a>
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</em>
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<h2>Wing development</h2>
<p>Using data from fossils, Yang and colleagues used computers to model the body measurements of different pterosaur species as they grew.</p>
<p><em>Pteranodon</em>‘s wing aspect ratio (the wing length relative to wing area) increased as the species grew, allowing it to develop a long, narrow wing, associated with soaring in modern birds. The smaller pterosaurs, however, showed a consistent or decreasing wing aspect ratio during growth, allowing more manoeuvrability.</p>
<p>These developmental differences between larger and smaller species of pterosaur indicate that <em>Pteranodon</em>’s relatively greater proximal limb growth shortly after hatching, along with – perhaps – enhanced parental care, may have helped it reach a large adult size. Pterosaurs as a group encompassed the largest flying animals of all time. <em><a href="https://link.springer.com/article/10.1007/s00114-002-0307-1">Hatzegopteryx thambema</a></em> may have been the biggest, with a wingspan of up to 12 metres. But all pterosaurs started small.</p>
<p>Pterosaur hatchlings’ size was limited by ultimately the size of their eggs, which was constrained by the size of the pelvic opening of female pterosaurs, and by the <a href="https://www.cell.com/current-biology/fulltext/S0960-9822(14)00525-9">soft eggshell produced by pterosaurs</a>. Compared to hard-shelled bird eggs, soft eggs are weaker and cannot support larger sizes. To grow big, pterosaurs had to do most of their growing after they hatched.</p>
<h2>Parental care</h2>
<p>A key difference between the small and large species may have been parental care. This may have released large pterosaurs from growth and size constraints. An extended maturation period where parents protected their young and fed them may have allowed a bending of developmental physics, resulting in a larger body size, a lighter skeleton and more robust joints. In contrast, small pterosaur species by the nature of their slower proximal limb growth may have been locked into maturity at smaller sizes.</p>
<p>It’s also possible that baby pterosaurs from larger species with parental care were not capable of flight, whereas smaller species were <a href="https://www.nature.com/articles/s41598-021-92499-z">flight-ready upon hatching</a>.</p>
<p>To grow to such a large body size, the giant pterosaurs also needed two things from their environment: space and updrafts. Big pterosaurs would principally have been soarers, meaning that they used updrafts to stay aloft and economised on energy by minimising flapping. Giant pterosaurs also needed a food supply to support their large size and fuel their metabolic requirements.</p>
<p>While competitors for food were likely in short supply for large adult pterosaurs, youngsters – being smaller – would be more likely to overlap in terms of food sources and habitats with smaller pterosaur species. Young giant pterosaurs probably <a href="https://tetzoo.com/blog/2021/7/21/baby-pterosaurs-were-excellent-fliers-and-occupied-different-niches-from-their-parents">did not compete for food with adult pterosaurs of the same species</a>.</p>
<p>Predation on adult giant pterosaurs by other animals would have been limited. What dinosaurs (or other creatures) would have been big and hard enough to take on such an imposing sharp-beaked monster?</p>
<figure class="align-center ">
<img alt="Pteranodon longiceps being preyed on by a Cretoxyrhina shark." src="https://images.theconversation.com/files/543066/original/file-20230816-22-6737f1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/543066/original/file-20230816-22-6737f1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=386&fit=crop&dpr=1 600w, https://images.theconversation.com/files/543066/original/file-20230816-22-6737f1.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=386&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/543066/original/file-20230816-22-6737f1.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=386&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/543066/original/file-20230816-22-6737f1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=485&fit=crop&dpr=1 754w, https://images.theconversation.com/files/543066/original/file-20230816-22-6737f1.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=485&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/543066/original/file-20230816-22-6737f1.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=485&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">Large pterosaurs like Pteranodon probably had only a handful of predators, such as this large shark.</span>
<span class="attribution"><a class="source" href="https://www.markwitton.co.uk/">Mark Witton</a>, <span class="license">Author provided</span></span>
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<h2>Future fossils</h2>
<p>Incredible as it seems, we can infer the presence of parental care – and lack thereof – in long-dead species of flying reptile. The odds of a pterosaur being preserved in the act of unambiguous parental care seem incredibly slim. So evidence from fossils and understanding patterns from contemporary species are critical to our understanding.</p>
<p>At some point, someone will hopefully find juvenile giant pterosaurs, and their hatchlings, eggs and embryos. Otherwise, questions will remain regarding the development of baby pterosaurs.</p>
<p>These questions include: what was the nature of the parental care? Did parents keep eggs and young warm by sitting over them? Did they defend juveniles against predators, providing food for pterosaur babies? Did males and females share parental care equally? Did they care for young that were not their own?</p>
<p>To more fully re-imagine the early lives and parental behaviour of giant pterosaurs, we need more fossils. Let’s find them.</p><img src="https://counter.theconversation.com/content/210084/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Jason Gilchrist does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Reptiles don’t generally care for their offspring, but some pterosaurs may have bucked the trend.Jason Gilchrist, Lecturer in the School of Applied Sciences, Edinburgh Napier UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2111562023-08-14T15:06:14Z2023-08-14T15:06:14ZFossil footprint discoveries and what they tell us<figure><img src="https://images.theconversation.com/files/541937/original/file-20230809-26-9gcmy3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Photo by DeAgostini/Getty Images</span></span></figcaption></figure><p>Footprints on a sandy surface don’t usually last long: they’re washed away by water, wiped out by wind or covered over by new tracks. At certain sites in southern Africa, though, some traces of animals have lasted for many thousands or even millions of years – fleeting moments preserved in sand that turned to rock. </p>
<p>They tell scientists about the creatures that lived in ancient times, how they behaved and what their environment was like. Studying fossil footprints also adds to what the body fossil record reveals.</p>
<p>In these articles from our archive, scientists share some of their exciting fossil footprint finds.</p>
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<h2>Zebra crossing – with a difference</h2>
<p>Charles Helm studies the fossilised tracks, trails, burrows and excavations made by animals. He’s <a href="https://theconversation.com/new-discovery-fossilised-giant-zebra-tracks-found-in-south-africa-201687?notice=Article+has+been+updated">discovered</a> how, tens of thousands of years ago, a huge horse species roamed along South Africa’s Cape south coast. </p>
<p>These findings also revealed that these Giant Cape Zebras must have been a fairly regular sight on the landscape. An insight that body fossil records don’t provide.</p>
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Read more:
<a href="https://theconversation.com/new-discovery-fossilised-giant-zebra-tracks-found-in-south-africa-201687">New discovery: fossilised giant zebra tracks found in South Africa</a>
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<h2>Oldest human footprints</h2>
<p>Armed with specialist skills and world-class technology, Charles Helm also teamed up with geographer Andrew Carr to <a href="https://theconversation.com/worlds-oldest-homo-sapiens-footprint-identified-on-south-africas-cape-south-coast-205310?notice=Article+has+been+updated.">investigate</a> tracks along South Africa’s coast. That’s how they identified something truly remarkable: a footprint left by one of our human ancestors 153,000 years ago. So far, it’s the oldest footprint in the world attributed to our species, <em>Homo sapiens</em>
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<p>They explained how the finding also confirms that the Cape south coast was an area in which early modern humans survived, evolved and thrived, before spreading out of Africa to other continents.</p>
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Read more:
<a href="https://theconversation.com/worlds-oldest-homo-sapiens-footprint-identified-on-south-africas-cape-south-coast-205310">World's oldest _Homo sapiens_ footprint identified on South Africa's Cape south coast</a>
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<h2>Dinosaur behaviour insights</h2>
<p>Today, dinosaur fossils can be found in many parts of the world. South Africa and Lesotho’s main Karoo Basin, for example, contains many dinosaur fossils and dinosaur markings, like footprints.</p>
<p>Miengah Abrahams <a href="https://theconversation.com/footprints-take-science-a-step-closer-to-understanding-southern-africas-dinosaurs-185480?notice=Article+has+been+updated.">explains</a> that fossil footprints are a treasure chest of information. They can reveal what organism made the tracks, offer clues to their behaviour and even provide evidence about the conditions in which they lived. She outlines what’s been learnt from dinosaur tracks in the Karoo Basin. </p>
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Read more:
<a href="https://theconversation.com/footprints-take-science-a-step-closer-to-understanding-southern-africas-dinosaurs-185480">Footprints take science a step closer to understanding southern Africa's dinosaurs</a>
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<p>__</p>
<h2>An unexpected discovery</h2>
<p>In this <a href="https://theconversation.com/dinosaur-tracksite-in-lesotho-how-a-wrong-turn-led-to-an-exciting-find-208963?notice=Article+has+been+updated">article</a>, Miengah Abrahams tells the story of how she unexpectedly came across some new dinosaur footprints in Lesotho. For a geologist studying dinosaur tracksites this wasn’t a massive surprise, but it was the first time a dinosaur from the ornithischian group – a four-footed, plant-eating, “bird-hipped” community – had been documented in the Roma Valley, an area rich in fossil footprints.</p>
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Read more:
<a href="https://theconversation.com/dinosaur-tracksite-in-lesotho-how-a-wrong-turn-led-to-an-exciting-find-208963">Dinosaur tracksite in Lesotho: how a wrong turn led to an exciting find</a>
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<img src="https://counter.theconversation.com/content/211156/count.gif" alt="The Conversation" width="1" height="1" />
Some footprints last thousands or even millions of years, preserved in sand that turned to rock.Natasha Joseph, Commissioning EditorMoina Spooner, Assistant EditorLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2089632023-08-03T14:39:56Z2023-08-03T14:39:56ZDinosaur tracksite in Lesotho: how a wrong turn led to an exciting find<figure><img src="https://images.theconversation.com/files/539023/original/file-20230724-14014-ctdnz7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">An artistic impression of the various dinosaur species that once roamed the Roma Valley.</span> <span class="attribution"><span class="source">Akhil Rampersadh</span></span></figcaption></figure><p>I am a poor navigator. This is not an easy thing for a field geologist to admit. We need to be able to find our planned area of interest in good time and make our way back to our potentially hidden and distant vehicles at the end of the day. It’s especially true that I am a poor navigator when I need to use nondescript bushes, the distant hill shape, and the odd fallen boulder as reference points. </p>
<p>So it was no surprise when I led my MSc student Loyce Mpangala and our PhD candidate field assistant Akhil Rampersadh astray in Lesotho’s Roma Valley. We were walking back to our car after looking at a <a href="https://theconversation.com/meet-the-giant-dinosaur-that-roamed-southern-africa-200-million-years-ago-86004">dinosaur tracksite</a> that I’d visited before. The tracksite, which is marked on Google Maps as an attraction, was on the other side of a sparsely populated hill with numerous informal walkways, overlooking the National University of Lesotho.</p>
<p>Walking along the wrong (I didn’t know it then) footpath, I spotted a dinosaur footprint I hadn’t seen before. Once you’ve worked on dinosaur tracks for seven years and visited the same site a few times you get to know their shape and their personality. And this one was different. The first footprint I spotted superficially resembled others on the hill: three-toed, longer-than-wide with claw marks; but it was far away from the known site we had just visited. </p>
<p>After taking a few more steps, we spotted some more footprints. These had distinct shapes we had not yet seen in the Roma area: short, wide footprints with rounded, stubby toes. When we looked more closely, they were sometimes paired with star-shaped handprints. These footprints were made by herbivorous ornithischian dinosaurs and it is the <a href="https://www.tandfonline.com/doi/full/10.1080/08912963.2023.2221306">first time</a> their distinct shape has been documented in the Roma Valley, which is rich in fossil footprints. It adds to scientists’ knowledge of the extensive trace fossil diversity of the local dinosaur community during the <a href="https://www.britannica.com/science/Jurassic-Period">Early Jurassic</a> period about 200 million years ago. </p>
<p>I guess sometimes – and I cannot overemphasise how rarely – the wrong turn can lead you to the right place. </p>
<h2>New, old and very old</h2>
<p>The tracksite was new to our dino-tracking team from South Africa’s University of Cape Town. But it was not a new discovery. It is known as the Mokhosi site and was reported in 2003 by David Ambrose, a tracking enthusiast and mathematics professor at the National University of Lesotho. He noted that a number of large three-toed prints were preserved, with more likely to be beneath the recent sand covering. </p>
<p>Our extensive uncovering (a glamorous way for saying sweeping) of the 18 metre by 2 metre tracksite showed that more fossil evidence had indeed been captured in the rock. We documented 35 footprints; most were part of trackways, heading in all directions. </p>
<p>The footprints were all three-toed and fell into two main shape groupings – those that were longer-than-wide, with slender toes and sharp claw marks, and those that were wider-than-long, with robust, rounded toes. The latter were occasionally associated with smaller and shallow handprints, in front and slightly to the outer side of their corresponding footprints. </p>
<p>The <a href="https://theconversation.com/footprints-take-science-a-step-closer-to-understanding-southern-africas-dinosaurs-185480">first group of tracks</a> (longer-than-wide) are a type commonly preserved in southern Africa and can be attributed to carnivorous theropod dinosaurs. The theropod tracks at Mokhosi reach a maximum length of about 40cm, meaning that these meat-eating travellers would have had a hip height of about 2 metres, towering over humans.</p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/footprints-take-science-a-step-closer-to-understanding-southern-africas-dinosaurs-185480">Footprints take science a step closer to understanding southern Africa's dinosaurs</a>
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<p>The second group of hand- and footprints preserve characteristics consistent with herbivorous ornithischian dinosaur trackmakers. Our excitement rose as we carefully dusted these tracks: globally, ornithischian footprints are rarer than theropods during the Early Jurassic. </p>
<p>This marks the first time these distinct quadrupedal ornithischian footprints have been found in the Roma Valley. It’s remarkable, given that a high number of tracksites (14) have been identified and studied in the area.</p>
<h2>Waiting to be found again</h2>
<p>When we walked back to our car after a long day, we took a moment to stare back at the wonderful site we’d stumbled across. We knew that the future rains and winds would once again hide the Mokhosi tracksite, leaving only small clues to the keen eye of what lies beneath the sand. </p>
<p>We wish the same excitement to the next passerby who unveils this little wonder. </p>
<p>To help you, I’d like to note that the nearby bush is “bushier than the surrounding ones”, that the hill gradient “changes ever so slightly above the track-bearing sandstone”, and that the nearby boulders are completely “nondescript”.</p><img src="https://counter.theconversation.com/content/208963/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>The research component of this project was supported from the following research grants obtained by MA: DSI-NRF Centre of Excellence Genus (grant number 86073); NRF Thuthuka (grant number 138151); UCT Research Development Grants 2020 – 2021. AR is a recipient of postgraduate funding from the DST-NRF Centre of Excellence in Palaeoscience (Genus). LM is a recipient of postgraduate funding from the DST-NRF Centre of Excellence in Palaeoscience (Genus) and Palaeontological Scientific Trust (PAST), Johannesburg, South Africa; DSI-NRF Centre of Excellence in Palaeoscience.</span></em></p>Fossilised tracks of a group of plant-eating dinosaurs have been found in Lesotho’s Roma Valley for the first time.Miengah Abrahams, Lecturer, University of Cape TownLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2099192023-07-30T11:15:37Z2023-07-30T11:15:37ZMeet the gigantic extinct reptile that weighed as much as an adult black rhino<figure><img src="https://images.theconversation.com/files/539200/original/file-20230725-29-xonj5i.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Three 3D views of _Bradysaurus baini_ specimen (FMNH UC 1533). Scale bar equals 50 cm. [Published in Van den Brandt et al. 2023](https://www.tandfonline.com/doi/full/10.1080/08912963.2023.2175211?journalCode=ghbi20)</span> <span class="attribution"><span class="source">Credit: Fabio Manucci and Marco Romano</span></span></figcaption></figure><p>Around 262 million years ago, during the <a href="https://www.tandfonline.com/doi/abs/10.1080/14772019.2022.2035440">middle Permian Period</a>, a new family of reptiles emerged. Pareiasaurs – meaning “cheek lizards”, a reference to the flat flanges of bone that make up their cheeks – had skulls covered in bony growths and bumps, and bony plates on their bodies.</p>
<p>They were among the first large terrestrial animals to evolve and did so rapidly, quickly becoming some of the most abundant plant-eating animals worldwide. At least <a href="https://www.frontiersin.org/articles/10.3389/fevo.2021.758802/full">21 separate species evolved</a> before all pareiasaurs were wiped out about 252 million years ago during the <a href="https://doi.org/10.25131/sajg.123.0009">Permian-Triassic extinction event</a>.</p>
<p>From the 1830s onward, pareiasaur fossils began to be found in various parts of the world. One large, abundant species, <em>Bradysaurus</em>, from the middle Permian Period, was found in South Africa and <a href="https://royalsocietypublishing.org/doi/10.1098/rstb.1892.0008">scientifically described</a> in 1892. <a href="https://www.frontiersin.org/articles/10.3389/fevo.2021.692035/full"><em>Scutosaurus</em></a>, from the late Permian Period of Russia, was described in 1922.</p>
<p>Thanks to more than 150 years of research, we know that several pareiasaurs were big animals, reaching lengths of up to 3 metres. Their bones reveal that they were thick and stocky. They stood low to the ground, with a primitive sprawling posture. But no accurate studies of their likely body mass exist. </p>
<p>Body mass plays a central role in understanding an organism’s general physiology, ecology, metabolism, diet and movement.</p>
<p>In our <a href="https://www.tandfonline.com/doi/abs/10.1080/08912963.2023.2175211?journalCode=ghbi20">new study</a>, we set out to fill this knowledge gap for <em>Bradysaurus</em>, having done so for <em>Scutosaurus</em> in <a href="https://www.frontiersin.org/articles/10.3389/fevo.2021.692035/full">another piece of work</a>. We used a new method for calculating body mass that allowed us to calculate the <em>Bradysaurus</em> had a likely overall average body mass of 1,022kg. </p>
<p>For the Russian <em>Scutosaurus</em>, <a href="https://www.frontiersin.org/articles/10.3389/fevo.2021.692035/full">we found</a> an average body mass of 1,160kg. That means both of these pareiasaurs, from different hemispheres and living in different times, weighed in at about the mass of a large adult black rhino or a large domestic bull.</p>
<p><em>Bradysaurus</em> is the oldest pareiasaur that has been reliably dated. It was one of the earliest huge plant-eating tetrapods (four-legged creatures) to appear in the development of life on Earth, along with other large pareiasaur species like <em>Scutosaurus</em>. By obtaining accurate body mass estimates for these animals, we can better understand the evolution of the said body mass, which was built around a long intestinal track inside a huge fermentation chamber – just what the animals needed to break down high volumes of poor quality vegetation.</p>
<h2>A new method</h2>
<p>Typically, the body masses of extinct tetrapods are estimated using mathematical formulas that relate the circumferences of the thigh bone (the femur) and the upper arm bone (the humerus) to body mass. </p>
<p>These formulas were derived from large sets of measurements of the limb bones of modern animals whose masses can be measured directly. </p>
<p>But, as palaeontologist Marco Romano has <a href="https://www.idunn.no/doi/full/10.1111/let.12207">detailed</a> in <a href="https://www.tandfonline.com/doi/abs/10.1080/08912963.2019.1640219">several studies</a>, using these <a href="https://www.frontiersin.org/articles/10.3389/fevo.2021.692035/full">formulas</a> tends to <a href="https://www.tandfonline.com/doi/abs/10.1080/08912963.2023.2175211?journalCode=ghbi20">result</a> in hugely inflated overestimates of body mass when they are applied to extinct reptiles. These animals often had a sprawling posture and, as a result, thickened bones. Modern mammals have upright postures and relatively slender limb bones. </p>
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<strong>
Read more:
<a href="https://theconversation.com/technology-and-planning-help-museums-manage-outdated-exhibitions-143852">Technology and planning help museums manage outdated exhibitions</a>
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</p>
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<p>We used a new volumetric method to determine a more realistic mass estimate. First, 3D models of skeletons were made using photogrammetry. Nearly 200 photographs were taken around each skeleton, then digitally combined in specialist software to create accurate 3D models of the bones. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/539201/original/file-20230725-25-kjdcs1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/539201/original/file-20230725-25-kjdcs1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=646&fit=crop&dpr=1 600w, https://images.theconversation.com/files/539201/original/file-20230725-25-kjdcs1.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=646&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/539201/original/file-20230725-25-kjdcs1.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=646&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/539201/original/file-20230725-25-kjdcs1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=811&fit=crop&dpr=1 754w, https://images.theconversation.com/files/539201/original/file-20230725-25-kjdcs1.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=811&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/539201/original/file-20230725-25-kjdcs1.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=811&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Artistic <em>in vivo</em> reconstruction of <em>Bradysaurus baini</em> specimen (FMNH UC 1533) based on the 3D ‘average’ model sculpted around the specimen, in five views. Scale bar equals 50 cm. Published in Van den Brandt et al. 2023.</span>
<span class="attribution"><span class="source">Credit: Fabio Manucci and Marco Romano</span></span>
</figcaption>
</figure>
<p>Next, palaeoartist Fabio Manucci used other specialist software to model soft tissue, muscles and guts around the bones, creating three reconstructions of possible volumes (“slim”, “average”, “fat”) for each skeleton by adding three different amounts of soft tissue.</p>
<p>The average density of both extinct and living vertebrate animals is very close to the density of water (1kg per litre). The denser bones and tissues are balanced out by empty spaces such as <a href="https://anatomypubs.onlinelibrary.wiley.com/doi/full/10.1002/ar.24574">air in the lungs and guts</a>. Extinct pareiasaurs were probably a bit more dense because of their very thick bones and plated, bony body armour.</p>
<p>To determine a range of masses, we applied three different densities for living tissues (0.99kg, 1kg and 1.15kg/litre) to each of our slim, average and fat volumes to calculate possible body masses.</p>
<p>The estimates we obtained differed from those obtained using two popular existing formulas based on modern mammals and non-avian reptiles’ limb bone measurements. For <em>Bradysaurus</em>, the two formulas exceeded our volumetric estimates by up to 375%, suggesting a mass of close to 4 tonnes. For <em>Scutosaurus</em>, the figure was up to 235% higher than our results. </p>
<p>These high mass estimates seem highly unlikely. If they were accurate, the density of the animal’s tissues would have been greater than sandstone or concrete.</p>
<h2>Body size in herbivores</h2>
<p>Now that we have what we believe is an accurate estimate of two pareiasaur species’ body mass, what does it tell us?</p>
<p>The fossil record suggests a rapid increase in body size between the time when their (likely small) ancestors diverged from other early reptiles and the first appearance of <em>Bradysaurus</em> in the fossil record about 262 million years ago.</p>
<p><em>Bradysaurus’s</em> large size is best explained by a negative relationship between food digestibility and body mass. In ecology, this is known as the <a href="https://academic.oup.com/biolinnean/article/115/1/173/2440439?login=false">Jarman-Bell</a> principle. It predicts the evolution of large body size in herbivores that ingest copious, low-quality plant material. Plants are hard to digest, and a plant-based diet typically results in a large body size – herbivores are typically substantially heavier than other dietary groups in living animals. </p>
<p>Alternatively, or maybe in conjunction with the evolution of herbivory, the large body size of <em>Bradysaurus</em> may also have evolved as protection from co-existing predators. Pareiasaurian body armour and their large cheek flanges also suggest adaptations developed as protection from common predators, which would be especially useful for these slow moving, stocky herbivores.</p><img src="https://counter.theconversation.com/content/209919/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Marc Johan Van den Brandt receives funding from the University of the Witwatersrand, GENUS (DSI-NRF Centre of Excellence in Palaeosciences, UID 86073), and the Millenium Trust.</span></em></p><p class="fine-print"><em><span>Kenneth D. Angielczyk receives funding from the U.S. National Science Foundation and the Field Museum of Natural History. </span></em></p><p class="fine-print"><em><span>Marco Romano does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Large pareiasaurs are among the earliest huge plant-eating tetrapods to appear in the history of the development of life on Earth.Marc Johan Van den Brandt, Postdoctoral Research Fellow at the Evolutionary Studies Institute (ESI), University of the Witwatersrand, Johannesburg., University of the WitwatersrandKenneth D. Angielczyk, Lecturer, University of ChicagoMarco Romano, Professor of Paleontology, Sapienza University of RomeLicensed as Creative Commons – attribution, no derivatives.