tag:theconversation.com,2011:/id/topics/dinosaur-tracks-11474/articlesDinosaur tracks – The Conversation2021-10-21T04:44:45Ztag:theconversation.com,2011:article/1702752021-10-21T04:44:45Z2021-10-21T04:44:45ZAustralia’s oldest dinosaur was a peaceful vegetarian, not a fierce predator<figure><img src="https://images.theconversation.com/files/427667/original/file-20211021-17-1j3e1kf.png?ixlib=rb-1.1.0&rect=32%2C19%2C4249%2C2824&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Anthony Romilio</span>, <span class="license">Author provided</span></span></figcaption></figure><p>Ipswich, about 40 kilometres west of Brisbane, seems an unlikely place to find dinosaur fossils. Yet the area has produced the oldest evidence of dinosaurs in Australia.</p>
<p>A fresh look at these fossils now reveals they aren’t what they first seemed, and it’s prompting us to reconsider how the story of Australia’s dinosaurs began.</p>
<p>In research <a href="https://www.tandfonline.com/doi/full/10.1080/08912963.2021.1984447">published</a> today in Historical Biology, we reanalyse a sequence of 220-million-year-old tracks from the Ipswich Coal Measures, thought to have belonged to a carnivorous dinosaur. </p>
<p>We show they actually belonged to an early sauropodomorph — a distant relative of the plant-eating sauropods that roamed the planet much later, during the Jurassic and Cretaceous periods. This is the first time fossil evidence of early sauropodomorphs has been found in Australia. </p>
<h2>Subterranean dinosaur tracks</h2>
<p>The Ipswich area was once the principal source of coal for Queensland. Its suburbs including Ebbw Vale, New Chum and Swanbank were dotted with underground mines during the late 1800s and the first half of the twentieth century.</p>
<p>These mining operations involved the creation of deep shafts and tunnels, from which miners could access deposits of coal sandwiched between other layers of rock. Some tunnels would descend hundreds of metres below the surface.</p>
<p>The coal would be removed from the seam by hand, and pillars were left in its place to support the ceiling of the resulting underground “room”. It was difficult and dangerous work.</p>
<p>In 1964, miners working at the Rhondda colliery in New Chum made a startling discovery. As they removed the coal from a seam they were following 213 metres below the surface, a series of giant, three-toed tracks became exposed in the ceiling of the mine shaft. For the miners, it was as if a dinosaur had just walked over their heads.</p>
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<a href="https://images.theconversation.com/files/427699/original/file-20211021-16-1f6x0w5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/427699/original/file-20211021-16-1f6x0w5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/427699/original/file-20211021-16-1f6x0w5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=399&fit=crop&dpr=1 600w, https://images.theconversation.com/files/427699/original/file-20211021-16-1f6x0w5.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=399&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/427699/original/file-20211021-16-1f6x0w5.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=399&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/427699/original/file-20211021-16-1f6x0w5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=502&fit=crop&dpr=1 754w, https://images.theconversation.com/files/427699/original/file-20211021-16-1f6x0w5.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=502&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/427699/original/file-20211021-16-1f6x0w5.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=502&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">Fossilised plant remains found in association with the tracks provide a fascinating window into the world of Australia’s first dinosaurs. The highly diverse flora comprised a dense groundcover of ferns, cycad-like plants and horsetails that grew under a canopy of gingko, voltzialean conifers and seed-ferns (corystosperms), like this <em>Dicroidium dubium</em>.</span>
<span class="attribution"><span class="source">Steven Salisbury</span>, <span class="license">Author provided</span></span>
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<p>These tracks remain the oldest-known dinosaur fossils in the entire continent. They’d been made by a dinosaur walking across a layer of swampy vegetation, which would be extracted as coal 220 million years later. Buried under fine silt and mud, they’d been preserved as natural casts. </p>
<p>It had been assumed some type of predatory dinosaur made the tracks. The only problem was the footprints were reportedly about 40–46 centimetres long. This would suggest the track-maker was just under 2m high at the hips.</p>
<p>This isn’t necessarily large for a theropod such as <em>Allosaurus fragillis</em>, which was about this size. <em>Tyrannosaurus rex</em> was even bigger, with a hip height of about 3.2m. </p>
<p>But the tracks found in Ipswich were created during the Late Triassic about 220 million years ago — 65 million years before <em>Allosaurus</em> and 150 million years before <em>T. rex</em>. And fossil evidence from around the world indicates theropods of a larger size didn’t appear until the start of the Early Jurrasic Period, 200 million years ago. </p>
<p>Was something unusual afoot in Australia during the Late Triassic?</p>
<p>As part of a broader review of Australian dinosaur tracks, we decided to take a closer look at the Rhondda colliery tracks. The mine has long been closed, so the original tracks are no longer accessible, but archival photographs and a plaster cast are held at the Queensland Museum. </p>
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<h2>Dispelling the myth of the ‘Triassic terror’</h2>
<p>Using the photos and cast, we created a 3D digital model of the track to allow a more detailed comparison with other dinosaur tracks from around the world. </p>
<p>Our study revealed two important things. First, the footprints were not as big as initially reported. Excluding drag marks and other unrelated surface features, they are close to 32–34cm long (not 40–46cm as previously documented). </p>
<p>Second, the shape of the footprints and the sequence in which they were made is more consistent with early sauropodomorphs. Sauropodomorphs were the distant relatives of the lumbering sauropods of the Late Jurassic and subsequent Cretaceous Period. </p>
<p>The towering Triassic terror of the Ipswich Coal Measures was no more. In its place was a peaceful plant-eater.</p>
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<img alt="Australia's oldest dinosaur, reconstructed based on a fossilised tracks founnd in 220 million year old rocks from Ipswich." src="https://images.theconversation.com/files/427698/original/file-20211021-24-ztn4dr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/427698/original/file-20211021-24-ztn4dr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=195&fit=crop&dpr=1 600w, https://images.theconversation.com/files/427698/original/file-20211021-24-ztn4dr.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=195&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/427698/original/file-20211021-24-ztn4dr.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=195&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/427698/original/file-20211021-24-ztn4dr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=245&fit=crop&dpr=1 754w, https://images.theconversation.com/files/427698/original/file-20211021-24-ztn4dr.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=245&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/427698/original/file-20211021-24-ztn4dr.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=245&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">Hypothetical reconstruction of the Ipswich sauropodomorph dinosaur, alongside an 3D orthographic image of one of the fossilised tracks form the Rhondda colliery, with a 1.8m person for scale.</span>
<span class="attribution"><span class="source">Anthony Romilio</span></span>
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<p>The remains of early sauropodomorph dinosaurs have been found in Upper Triassic rocks, aged between 220 million and 200 million years, in continental Europe, Argentina, Brazil and South Africa.</p>
<p>And by the start of the Jurassic, 200 million years ago, they had achieved a near global distribution, with fossils in North America, China and Antarctica. This isn’t surprising, given the continents at the time were still connected in a single landmass called Pangaea. </p>
<p>Our new interpretation of the Rhondda colliery tracks shows early sauropodomorphs lived in Australia, too, and that Australia’s first dinosaurs were friendlier than we thought.</p>
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Read more:
<a href="https://theconversation.com/the-march-of-the-titanosaurs-the-snake-creek-tracksite-unveiled-161039">The march of the titanosaurs: the Snake Creek Tracksite unveiled</a>
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<img src="https://counter.theconversation.com/content/170275/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Steven W. Salisbury has received funding from the Australian Research Councile and National Science Foundation.</span></em></p><p class="fine-print"><em><span>Anthony Romilio has received funding from Australian Geographic.</span></em></p>The oldest fossil evidence for dinosaurs in Australia came as a surprise when it was dug out by coal miners working in Ipswich.Steven W. Salisbury, PhD; Senior Lecturer, School of Biological Sciences, The University of QueenslandAnthony Romilio, PhD, Independent Researcher, The University of QueenslandLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1610392021-06-17T05:51:37Z2021-06-17T05:51:37ZThe march of the titanosaurs: the Snake Creek Tracksite unveiled<p>Fossilised bones belonging to enormous long-necked sauropod dinosaurs have been known from western Queensland since the 1930s, when <em>Austrosaurus mckillopi</em> was <a href="https://theconversation.com/a-new-look-at-a-lost-dinosaur-dig-in-the-australian-outback-81606">discovered</a> on Clutha Station near Maxwelton. Since then, western Queensland has <a href="https://www.theguardian.com/science/2016/oct/20/new-species-of-giant-herbivorous-dinosaur-found-in-outback-australia">yielded</a> many more sauropod bones and skeletons, particularly in the past two decades.</p>
<p>But the footprints of these behemoths, which can reveal much about how they behaved in life, remained elusive until 2016 when we and our colleagues at the <a href="https://www.australianageofdinosaurs.com/">Australian Age of Dinosaurs Museum</a> were informed about sauropod tracks dating back some 95 million years at Karoola Station, northwest of Winton.</p>
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<a href="https://images.theconversation.com/files/401519/original/file-20210519-21-1hy9nl7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Harry Elliott, Bob Elliott, and Stephen Poropat at the Snake Creek Tracksite." src="https://images.theconversation.com/files/401519/original/file-20210519-21-1hy9nl7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/401519/original/file-20210519-21-1hy9nl7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/401519/original/file-20210519-21-1hy9nl7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/401519/original/file-20210519-21-1hy9nl7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/401519/original/file-20210519-21-1hy9nl7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/401519/original/file-20210519-21-1hy9nl7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/401519/original/file-20210519-21-1hy9nl7.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">Harry Elliott, Bob Elliott, and Stephen Poropat at the Snake Creek Tracksite on June 10th, 2016.</span>
<span class="attribution"><span class="source">Trish Sloan/AAOD</span></span>
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<p>The tracksite, which we named “Snake Creek”, comprises a layer of siltstone less than a metre thick, as wide as a basketball court and twice as long. Ninety-five million years ago, this was a silt flat situated between a billabong and a meandering river. We describe the footprints preserved at the Snake Creek Tracksite in a <a href="https://peerj.com/articles/11544">new paper</a>, published in <em>PeerJ</em>.</p>
<p>Over the course of more than two years, the tracksite was excavated and moved in its entirety to a purpose-built facility at the <a href="https://www.australianageofdinosaurs.com/page/1/australian-age-of-dinosaurs-the-museum">Australian Age of Dinosaurs (AAOD) Museum</a> in Winton, where it is now open to the public.</p>
<h2>A snapshot of a prehistoric menagerie</h2>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/401767/original/file-20210519-13-q9y2wi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Close up of the Snake Creek Tracksite" src="https://images.theconversation.com/files/401767/original/file-20210519-13-q9y2wi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/401767/original/file-20210519-13-q9y2wi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=1464&fit=crop&dpr=1 600w, https://images.theconversation.com/files/401767/original/file-20210519-13-q9y2wi.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=1464&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/401767/original/file-20210519-13-q9y2wi.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=1464&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/401767/original/file-20210519-13-q9y2wi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1840&fit=crop&dpr=1 754w, https://images.theconversation.com/files/401767/original/file-20210519-13-q9y2wi.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1840&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/401767/original/file-20210519-13-q9y2wi.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1840&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">Close up of the Snake Creek Tracksite showing the direction of the various animals. Several crocs and all of the small theropod and ornithopod dinosaurs moved from northeast to southwest (and, therefore, in the opposite direction to the sauropods). Other crocs crossed the tracksite perpendicular to the rest.</span>
<span class="attribution"><span class="source">Stephen Poropat/AAOD</span></span>
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<p>The largest footprints at the Snake Creek Tracksite were made by sauropod dinosaurs. Sauropods walked on all fours, and the front and back feet left very different prints. </p>
<p>The front footprints are crescent-shaped, whereas the back feet are oval with a front taper. At least four individual sauropods walked across the tracksite in the same direction within a very narrow time frame. </p>
<p>The sauropod footprints appear to have been made when the tracksite was not underwater. They are surrounded by concentric ridges that imply brittle deformation of the silt, and many have blobs of siltstone in the middle (called “adhesion traces”) that show where sediment pooled after the animal lifted its foot. </p>
<p>One of the sauropod footprints had a surprise in store: a single three-toed footprint preserved within. This appears to have been made by a medium-sized, meat-eating theropod dinosaur, similar to Winton’s own <a href="https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0006190"><em>Australovenator wintonensis</em></a>, that crossed the tracksite before the sauropod when the silt was still fairly wet at depth.</p>
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Read more:
<a href="https://theconversation.com/introducing-australotitan-australias-largest-dinosaur-yet-spanned-the-length-of-2-buses-162177">Introducing Australotitan: Australia's largest dinosaur yet spanned the length of 2 buses</a>
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<img alt="Sauropod footprints at the Snake Creek Tracksite." src="https://images.theconversation.com/files/401536/original/file-20210519-15-i49y5q.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/401536/original/file-20210519-15-i49y5q.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=903&fit=crop&dpr=1 600w, https://images.theconversation.com/files/401536/original/file-20210519-15-i49y5q.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=903&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/401536/original/file-20210519-15-i49y5q.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=903&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/401536/original/file-20210519-15-i49y5q.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1135&fit=crop&dpr=1 754w, https://images.theconversation.com/files/401536/original/file-20210519-15-i49y5q.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1135&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/401536/original/file-20210519-15-i49y5q.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1135&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Sauropod footprints at the Snake Creek Tracksite. The front footprint (towards the top of the page) is crescent-shaped, whereas the back footprint is oval but tapered to the front and indented behind. The blob in the middle of the back footprint is a solidified mass of silt. Ridges encircle the footprints, which are also surrounded by footprints from smaller animals.</span>
<span class="attribution"><span class="source">Stephen Poropat/AAOD</span></span>
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<p>Most of the other footprints at the tracksite appear to have been made after the sauropod footprints, by animals buoyed up in water. Parallel to the sauropod tracks but running in the opposite direction are several trackways of small, three-toed footprints.</p>
<p>Initially, we thought all of these footprints were from small-bodied theropod and ornithopod dinosaurs, similar to those at the nearby <a href="https://network.qm.qld.gov.au/%7E/media/Documents/QM/About+Us/Publications/Memoirs+-+Nature/N21-2/n21-2_Thulborn-Wade-part1.pdf">Lark</a> <a href="https://network.qm.qld.gov.au/%7E/media/Documents/QM/About+Us/Publications/Memoirs+-+Nature/N21-2/n21-2_Thulborn-Wade-part2.pdf">Quarry</a> <a href="https://network.qm.qld.gov.au/%7E/media/Documents/QM/About+Us/Publications/Memoirs+-+Nature/N21-2/n21-2_Thulborn-Wade-part3.pdf">Conservation Park</a>. However, closer examination of the relative lengths of the toes and the width of the trackways revealed that some were not — at least four of the trackways were made by ancient relatives of modern crocodiles called crocodyliforms. </p>
<p>The absence of belly or tail drag marks, coupled with the scarcity of front footprints, means it is likely the crocodyliforms were <a href="https://www.facebook.com/watch/?v=1281668868697524">swimming in shallow water</a>, pushing off the bottom periodically with their back feet to propel themselves along.</p>
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Read more:
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<figure class="align-center ">
<img alt="Crocodyliform and theropod footprint." src="https://images.theconversation.com/files/401523/original/file-20210519-19-1nthch9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/401523/original/file-20210519-19-1nthch9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=399&fit=crop&dpr=1 600w, https://images.theconversation.com/files/401523/original/file-20210519-19-1nthch9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=399&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/401523/original/file-20210519-19-1nthch9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=399&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/401523/original/file-20210519-19-1nthch9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=501&fit=crop&dpr=1 754w, https://images.theconversation.com/files/401523/original/file-20210519-19-1nthch9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=501&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/401523/original/file-20210519-19-1nthch9.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">
<figcaption>
<span class="caption">A three-toed crocodyliform footprint (right) overprinting a three-toed small theropod dinosaur footprint (left).</span>
<span class="attribution"><span class="source">Stephen Poropat/AAOD</span></span>
</figcaption>
</figure>
<p>Other footprints at the Tracksite appear to be those of swimming turtles that touched down very rarely. Perhaps the most unusual traces are not footprints at all: they are horseshoe-shaped divots that appear to have been left by bottom-feeding lungfish.</p>
<figure class="align-center ">
<img alt="Possible lungfish feeding trace." src="https://images.theconversation.com/files/401525/original/file-20210519-13-uxiizh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/401525/original/file-20210519-13-uxiizh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=399&fit=crop&dpr=1 600w, https://images.theconversation.com/files/401525/original/file-20210519-13-uxiizh.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=399&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/401525/original/file-20210519-13-uxiizh.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=399&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/401525/original/file-20210519-13-uxiizh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=501&fit=crop&dpr=1 754w, https://images.theconversation.com/files/401525/original/file-20210519-13-uxiizh.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=501&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/401525/original/file-20210519-13-uxiizh.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">
<figcaption>
<span class="caption">Possible lungfish feeding trace.</span>
<span class="attribution"><span class="source">Stephen Poropat/AAOD</span></span>
</figcaption>
</figure>
<h2>Protecting the Tracksite</h2>
<p>Fossilised footprints require conservation if they are to be protected from weathering and erosion. They are often moulded with latex and cast in plaster or resin to create replicas for further study. </p>
<p>Much more rarely, fossilised footprints or trackways may be removed wholesale to a museum. The most notable example before now was the relocation of a relatively small section of a tracksite from the Paluxy River in Texas to the American Museum of Natural History in New York <a href="https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0093247">in the 1940s</a>.</p>
<p>In 2018, the Australian Age of Dinosaurs (AAOD) Museum <a href="https://d347awuzx0kdse.cloudfront.net/aaod/content-file/Saving%20Winton's%20sauropod%20trackway%20-%20FINAL.pdf?v=59d79f085d6937a919530f409a44947b3c53e28f">set out</a> to relocate and preserve the entire Snake Creek Tracksite, which was <a href="https://www.abc.net.au/news/2019-02-14/the-race-to-save-wintons-dinosaur-footprints/10578212?nw=0">at risk of erosion</a> from periodic flooding in Snake Creek.</p>
<p>Between April 2018 and November 2020 a small team of AAOD Museum staff and volunteers <a href="https://www.abc.net.au/news/2020-10-26/dinosaur-footprints-trackway-relocation-outback-queensland/12813234">systematically removed hundreds of tonnes of rock</a> from Karoola Station to the AAOD Museum.</p>
<figure class="align-center ">
<img alt="Anna Tzamouzaki, Christine Heller, and Judy Elliott" src="https://images.theconversation.com/files/401744/original/file-20210519-13-1ftw2u3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/401744/original/file-20210519-13-1ftw2u3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/401744/original/file-20210519-13-1ftw2u3.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/401744/original/file-20210519-13-1ftw2u3.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/401744/original/file-20210519-13-1ftw2u3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/401744/original/file-20210519-13-1ftw2u3.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/401744/original/file-20210519-13-1ftw2u3.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">Anna Tzamouzaki, Christine Heller, and Judy Elliott formed the core of the team that relocated the Snake Creek Tracksite. Each of these women spent more than a year on site, painstakingly removing sections of Tracksite piece by piece, loading them for transport, then reassembling them at the AAOD Museum.</span>
<span class="attribution"><span class="source">AAOD</span></span>
</figcaption>
</figure>
<p>In May 2021, the new home of the Snake Creek Tracksite was <a href="https://www.abc.net.au/news/2021-05-14/dinosaur-tourism-boom-outback-queensland/100131422">opened</a> to the public: a temperature-controlled, 885-square-metre building at the AAOD Museum in Winton, set up with the help of <a href="https://statements.qld.gov.au/statements/92059">funding from the Queensland Government</a>. The tracksite will now be accessible to future researchers, and offers a glimpse of a long-lost ecosystem in Australia’s deep past to any visitors to town.</p>
<figure class="align-center ">
<img alt="The March of the Titanosaurs building at the AAOD Museum." src="https://images.theconversation.com/files/401765/original/file-20210519-15-3q7p7i.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/401765/original/file-20210519-15-3q7p7i.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=338&fit=crop&dpr=1 600w, https://images.theconversation.com/files/401765/original/file-20210519-15-3q7p7i.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=338&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/401765/original/file-20210519-15-3q7p7i.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=338&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/401765/original/file-20210519-15-3q7p7i.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/401765/original/file-20210519-15-3q7p7i.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/401765/original/file-20210519-15-3q7p7i.jpeg?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">An inside view of the <em>March of the Titanosaurs</em> exhibition at the AAOD Museum.</span>
<span class="attribution"><span class="source">Steven Lippis/AAOD</span></span>
</figcaption>
</figure>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/a-new-look-at-a-lost-dinosaur-dig-in-the-australian-outback-81606">A new look at a lost dinosaur dig in the Australian outback</a>
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</em>
</p>
<hr>
<img src="https://counter.theconversation.com/content/161039/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Stephen Poropat works for the Australian Age of Dinosaurs Museum of Natural History, and a substantial portion of his research on the Snake Creek Tracksite was conducted while he was working for Swinburne University of Technology.</span></em></p><p class="fine-print"><em><span>Adele Pentland is affiliated with the Australian Age of Dinosaurs Natural History Museum. She has benefited from funding awarded to Stephen Poropat in 2017 by the Paleontological Society (Arthur James Boucot Research Grant).</span></em></p>A spectacular series of fossilised footprints from sauropod dinosaurs and other ancient animals opens a window onto life in northeast Australia 95 million years ago.Stephen Poropat, Adjunct Researcher, Swinburne University of TechnologyAdele Pentland, PhD candidate, Swinburne University of TechnologyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1409312020-06-18T20:07:51Z2020-06-18T20:07:51ZDinosaur footprints show predators as big as ‘T. rex’ stomped across Australia 160 million years ago<figure><img src="https://images.theconversation.com/files/342636/original/file-20200618-41230-1cwn8h7.png?ixlib=rb-1.1.0&rect=784%2C0%2C3005%2C1994&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Shutterstock/Author provided</span></span></figcaption></figure><p>Perhaps the most iconic dinosaur is <em>Tyrannosaurus rex</em>, a massive predator that lived in what is now North America. We have now <a href="https://www.tandfonline.com/doi/abs/10.1080/08912963.2020.1772252?journalCode=ghbi20">discovered</a> that carnivorous dinosaurs of a similar size existed in ancient Australia as well.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/342585/original/file-20200618-41221-oc80o.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/342585/original/file-20200618-41221-oc80o.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/342585/original/file-20200618-41221-oc80o.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=287&fit=crop&dpr=1 600w, https://images.theconversation.com/files/342585/original/file-20200618-41221-oc80o.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=287&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/342585/original/file-20200618-41221-oc80o.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=287&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/342585/original/file-20200618-41221-oc80o.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=361&fit=crop&dpr=1 754w, https://images.theconversation.com/files/342585/original/file-20200618-41221-oc80o.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=361&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/342585/original/file-20200618-41221-oc80o.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=361&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 giant dinosaurs of Queensland were slightly smaller than the largest known T. rex (shown in silhouette).</span>
<span class="attribution"><span class="source">Anthony Romilio</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<h2>Following the footprints</h2>
<p>We learned about these carnivores by studying fossils that were discovered up to 90 years ago. Coal miners came across them while digging in the Walloon Coal Measures at Rosewood, near Ipswich and Oakey, north of Toowoomba, Queensland.</p>
<p>The fossils are not bones. They are fossilised footprints, the only form of fossils that record the movements of animals and preserve details of their behaviour and environments they preferred.</p>
<p>While searching through records of fossil footprints in Australia, we came across an archival photograph from the 1930s showing a dinosaur footprint inside a coal mine. While these mines have long since closed, the picture led us to investigate fossil footprints collected at that time and stored in museums, and other footprints like them. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/342587/original/file-20200618-41213-143dirz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/342587/original/file-20200618-41213-143dirz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/342587/original/file-20200618-41213-143dirz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=390&fit=crop&dpr=1 600w, https://images.theconversation.com/files/342587/original/file-20200618-41213-143dirz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=390&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/342587/original/file-20200618-41213-143dirz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=390&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/342587/original/file-20200618-41213-143dirz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=490&fit=crop&dpr=1 754w, https://images.theconversation.com/files/342587/original/file-20200618-41213-143dirz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=490&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/342587/original/file-20200618-41213-143dirz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=490&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 miner measures footprints found in Rosewood coal mine circa 1966.</span>
<span class="attribution"><span class="source">Queensland Museum</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<h2>Older than <em>T. rex</em></h2>
<p>The specimens we found suggest the richly forested and swampy environment of southern Queensland in the Jurassic Period was home to several types of meat-eating dinosaurs. The smallest would have been the size of an emu, while the largest would have been just under 3 metres tall, almost as large and as imposing as a <em>T. rex</em>. </p>
<p>The footprint of this large dinosaur is almost 80cm long – roughly the distance from the centre of your body to the tip of your outstretched arm. The fossilised track is approximately 160 million years old, 90 million years older than the oldest known <em>T. rex</em> fossils. </p>
<p>This suggests the print belongs to a different predatory dinosaur. While similar to <em>T. rex</em> in size and dietary preference, these massive ancient Australian trackmakers may have been slimmer and more elongated in appearance than the North American dinosaur icon.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/342590/original/file-20200618-41209-14xpdx2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/342590/original/file-20200618-41209-14xpdx2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/342590/original/file-20200618-41209-14xpdx2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=357&fit=crop&dpr=1 600w, https://images.theconversation.com/files/342590/original/file-20200618-41209-14xpdx2.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=357&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/342590/original/file-20200618-41209-14xpdx2.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=357&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/342590/original/file-20200618-41209-14xpdx2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=449&fit=crop&dpr=1 754w, https://images.theconversation.com/files/342590/original/file-20200618-41209-14xpdx2.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=449&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/342590/original/file-20200618-41209-14xpdx2.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=449&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 photograph and a false-colour image showing the depth of one of the footprints.</span>
<span class="attribution"><span class="source">Anthony Romilio</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<h2>Fast runners, formidable predators</h2>
<p>As well as individual footprints, we found evidence of trackways where multiple footprints made by the same animal are preserved. Based on what we know about how two-legged animals move, we can use the trackways to figure out how the dinosaurs travelled through their environment.</p>
<p>Several of the larger dinosaurs seem to have been moving at a walking pace, as the lengths of their steps are shorter than the estimated lengths of their legs. However, two trackways had the very large step sizes that are typical of animals on the run. </p>
<p>The step distance suggests these large dinosaurs were moving at speeds of up to 35 kilometres per hour. For comparison, the average human can sprint at around 24 kilometres per hour. </p>
<p>These speeds mean the ancient track-makers would have been formidable predators. Unfortunately, no trackway was preserved for the largest track-maker.</p>
<h2>Lucky conditions</h2>
<p>Not all kinds of ground are equally suited to preserving tracks for fossilisation. What appears to have happened in southern Queensland is the dinosaurs stepped onto mats of swamp plant material that was then overlaid with sand, which results in sandstone filled footprints in a bed of coal. The miners were able to easily remove the softer coal from beneath the sandstone, and to their surprise found these ancient footprints.</p>
<p>If not for the mining of coal and the keen eyes of the 20th century miners who spotted unusual features in the rock, we might never have known about these tracks. It is likely that more hidden treasures are still buried beneath our feet.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/mysteries-of-prehistoric-australia-a-tough-place-to-hunt-dinosaurs-and-megafauna-4030">Mysteries of prehistoric Australia: a tough place to hunt dinosaurs and megafauna</a>
</strong>
</em>
</p>
<hr>
<h2>Filling in the gaps in ancient Australia</h2>
<p>Our discovery fills a gap in the slowly growing record of Australian dinosaurs. While large dinosaur tracks have been documented in various Australian states, so far most belong to plant-eaters. They include tracks of long-necked sauropods similar to <em>Brontosaurus</em>, and ornithopods similar as <em>Muttaburrasaurus</em>, the skeleton of which can be seen on display at the Queensland Museum. </p>
<p>Evidence for meat-eating dinosaurs also exists, but so far the fossil record indicated much smaller animals, ranging from the size of chickens to a little bit smaller than <em>Allosaurus</em>. </p>
<p>Our discovery of the footprints of a huge carnivore adds an important top-level predator to the Australian dinosaur-scape.</p><img src="https://counter.theconversation.com/content/140931/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Steven W. Salisbury has received funding from the Australian Research Council and the National Science Foundation.</span></em></p><p class="fine-print"><em><span>Anthony Romilio 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>Photos from Queensland coal mines helped researchers discover a missing top predator in the ancient Australian food chain.Anthony Romilio, PhD, Independent Researcher, The University of QueenslandSteven W. Salisbury, PhD; Senior Lecturer, School of Biological Sciences, The University of QueenslandLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1302152020-01-30T06:47:23Z2020-01-30T06:47:23ZFossil footprints show how life endured amid volcanic eruptions 183 million years ago<figure><img src="https://images.theconversation.com/files/310848/original/file-20200120-69559-9qh8iw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Reconstruction of the ancient environment at the Highlands trace fossil site about 183 million years ago. </span> <span class="attribution"><span class="source">Artwork by Akhil Rampersadh. Heterodontosaurid silhouette is courtesy of Viktor Radermacher.</span></span></figcaption></figure><p>Fossil footprints provide a special source of scientific evidence. They reveal how animals walked and how large they were. In some cases where there are no body fossils like bones, trace fossils such as footprints or trackways may be the only evidence that animals were present in an ancient environment. </p>
<p>In <a href="https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0226847">our new publication</a>, using techniques that have been honed by ichnologists – those who study trace fossils – we examined the trackways of land-dwelling vertebrates in what is today a farm in the centre of South Africa. These fossil trackways are preserved in sandstones within a thick pile of basaltic lava flows. They offer rare insights about ancient life in a stressful, hostile environment some 183 million years ago in the Early Jurassic.</p>
<p>This <a href="http://stratigraphy.org/index.php/ics-chart-timescale">geological epoch</a> is probably best known in the public imagination as the dawn of the age of the dinosaurs. Towards the end of the Early Jurassic, a <a href="https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0226847">major geological event devastated life</a>, especially in the oceans.</p>
<p>This mass extinction event was caused by, among other things, the degassing of the extensive lava flows that poured out during volcanic eruptions in the southern part of the <a href="https://www.livescience.com/37285-gondwana.html">supercontinent Gondwana</a>. These volcanic eruptions changed the chemistry of the ancient atmosphere and oceans at the time.</p>
<p>But in between the voluminous volcanic eruptions, the environment and life in it occasionally recovered. It was during these intermittent periods that the movement of animals across the land surface could be captured as the fossil trackways we study today. </p>
<p>These ancient footprints are important because they tell us about the type of Early Jurassic animal life, and because the tracks bring together different earth science disciplines that can help us visualise what the ancient world looked like.</p>
<h2>Reconstructing a landscape</h2>
<p>There was more to our research than just reconstructing what individual animal species were and how they moved. We also had to reconstruct the ancient environment in which these animals lived. For this we had to incorporate existing findings from different academic disciplines.</p>
<p>Geologists, including stratigraphers, volcanologists, geochronologists and sedimentologists, as well as palaeontologists, palaeobotanists and others, were all involved in studying these rocks before us. They gathered evidence about the properties of the sedimentary rocks that host the tracks; the plant fossils associated with these rocks; and the age, composition and structure of the ancient lava flows that entombed the track-bearing sediment surface.</p>
<p>Drawing from this existing research and our own work, our collective observations show that when vast sheets of lava flowed across the landscape, the environment turned into a land of fire. But during the quieter periods life returned to normal: streams ran, the sun shone, plants grew and the animals, among them dinosaurs, grazed and hunted. </p>
<p>What emerges is a picture not just of devastation wrought by volcanic eruptions, but one of a functioning ecosystem that endured despite environmental threats.</p>
<h2>A new ichnospecies</h2>
<p>Our research also unearthed a new species of dinosaur footprint. The best-preserved trackways at the Highlands farm site were made by dinosaurs – both meat-eating ones which walked on two legs, as well as plant-eating ones which walked on four legs. Less well-preserved trackways are more difficult to interpret. But those we studied appear to have been potentially made by <a href="https://nasmus.co.za/palaeontology/">synapsids</a>, a group of reptiles that are considered to be the ancestors of mammals. The synapsids have <a href="https://theconversation.com/why-south-africas-karoo-is-a-palaeontological-wonderland-43045">a rich skeletal record</a> in South Africa. </p>
<p>To identify the trackmakers, we carefully compared the morphology of the tracks – for example the shape, size and angles between the toe impressions – to other known tracks around the world. Some had characteristics common in footprints made by theropods, a group of carnivorous dinosaurs. But some showed features known only in tracks of ornithischians, a group of herbivorous dinosaurs. </p>
<p>We then closely compared our observations to those previously reported, and were able to come up with a list of diagnostic features that define the new ichnospecies. We named it after a French priest and trace fossil expert, Dr Paul Ellenberger, who is considered <a href="https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0226847">the father of vertebrate ichnology</a> in southern Africa. </p>
<h2>Significance of the South African fossil heritage</h2>
<p>South Africa is a global epicentre for palaeontology. <a href="https://theconversation.com/five-reasons-why-2018-was-a-big-year-for-palaeontology-106725">Discoveries</a> made in the country have showcased some of the first animals to walk on land, some of the first mammals, the first turtles, early dinosaurs, and hominids. </p>
<p>But the country’s famous fossils only truly help us understand the history of life on Earth if their geological and palaeoenvironmental contexts are also described. Placed in their ancient environmental setting, these Early Jurassic trackways show that some animal life was resilient even as the environment changed and was hit by catastrophic events.</p><img src="https://counter.theconversation.com/content/130215/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Emese M Bordy receives funding from the Centre of Excellence in Palaeosciences (COE-PAL National Research Foundation-DST), the National Research Foundation of South Africa and the University of Cape Town.</span></em></p>These trackways offer rare insights about ancient life in a stressful, hostile environment during the Early Jurassic.Emese M Bordy, Associate Professor in Geological Sciences, University of Cape TownLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/860042017-10-25T18:31:46Z2017-10-25T18:31:46ZMeet the giant dinosaur that roamed southern Africa 200 million years ago<figure><img src="https://images.theconversation.com/files/191793/original/file-20171025-25544-htfgc5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Kayentapus ambrokholohali footprints belong to an animal of about 26 feet long, dwarfing all the life around it.</span> <span class="attribution"><span class="source">Theropod image adapted by Lara Sciscio, with permission, from an illustration by Scott Hartman</span></span></figcaption></figure><p>Globally at around 200 million years ago, in what’s known as the Early Jurassic, small and agile two-legged carnivorous dinosaurs called <a href="http://www.ucmp.berkeley.edu/diapsids/saurischia/theropoda.html">theropods</a> roamed the ancient landscapes. In southern Africa, we know of their existence from their rare body fossils but also, importantly, from their fossil footprints.</p>
<p>Now our team’s new discovery, <a href="http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0185941">published in <em>PLOS ONE</em></a>, unexpectedly reveals that very large carnivorous dinosaurs with an estimated body length of between 8 to 9 meters (or 26 feet) – that’s a <a href="https://www.convertunits.com/from/feet/to/story">two-story building</a> or two adult rhinos nose to tail – lived in southern Africa too. </p>
<figure class="align-left zoomable">
<a href="https://images.theconversation.com/files/191351/original/file-20171023-1689-2ow4d6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/191351/original/file-20171023-1689-2ow4d6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/191351/original/file-20171023-1689-2ow4d6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=771&fit=crop&dpr=1 600w, https://images.theconversation.com/files/191351/original/file-20171023-1689-2ow4d6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=771&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/191351/original/file-20171023-1689-2ow4d6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=771&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/191351/original/file-20171023-1689-2ow4d6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=969&fit=crop&dpr=1 754w, https://images.theconversation.com/files/191351/original/file-20171023-1689-2ow4d6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=969&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/191351/original/file-20171023-1689-2ow4d6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=969&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Miengah Abrahams, a PhD student from the University of Cape Town, lying next to the dinosaur’s tracks. She is 1.6m tall.</span>
<span class="attribution"><span class="source">Lara Sciscio</span></span>
</figcaption>
</figure>
<p>Evidence for this massive beast comes from a set of three-toed, 57cm long and 50cm wide footprints recently found in western Lesotho. This is a first for Africa. It places a huge carnivorous dinosaur in what was then the southern part of the <a href="https://www.livescience.com/37285-gondwana.html">supercontinent Gondwana</a> during Early Jurassic times.</p>
<p>Until this discovery, theropod dinosaurs were thought to be considerably smaller, at three to five metres in body length, during the Early Jurassic. </p>
<p>There has only been one other report of large carnivorous dinosaurs occurring as early as 200 million years ago. This also came from fossil footprint evidence in Poland’s <a href="https://www.researchgate.net/publication/244483002_Slady_wielkich_teropodow_z_wczesnojurajskich_osadow_Gor_Swietokrzyskich_in_Polish_with_English_abstract">Holy Cross Mountains</a>. Such giants are rare. The iconic and enormous (about 12 metres long) <em>Tyrannosaurus</em>, for instance, only emerged around 128 million years later during the <a href="https://animals.howstuffworks.com/dinosaurs/late-cretaceous-period.htm">Late Cretaceous</a>. </p>
<p>The dimensions of the trackmaker with the 57cm long feet, although slightly smaller, come close to those of the well-known and younger Late Cretaceous theropod dinosaurs such as <em>Tyrannosaurus rex</em> or the similarly huge North African <em>Spinosaurus</em>.</p>
<p>The unanticipated footprint size of this Lesotho giant considerably expands the body size range of theropods in the Early Jurassic. Now the hunt is on to track down more theropod footprints – and perhaps even their body fossils.</p>
<h2>Lesotho’s giant carnivore</h2>
<p>Our <a href="http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0185941">team of scientists</a> from South Africa’s University of Cape Town, the University of Manchester in the UK, <a href="http://www.fundaciondinopolis.org/">Fundación Conjunto Paleontológico de Teruel-Dinópolis</a> in Spain, and Brazil’s Universidade de São Paulo discovered the 200 million year old megatheropod trackway during recent fieldwork in Lesotho. </p>
<p>The footprints were found on a small dirt road approximately 2km from the National University of Lesotho at Roma (Maseru District) in the western part of the country. They are on a palaeosurface, an ancient land surface that has been preserved in time.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/191391/original/file-20171023-1717-heeaf0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/191391/original/file-20171023-1717-heeaf0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/191391/original/file-20171023-1717-heeaf0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=699&fit=crop&dpr=1 600w, https://images.theconversation.com/files/191391/original/file-20171023-1717-heeaf0.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=699&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/191391/original/file-20171023-1717-heeaf0.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=699&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/191391/original/file-20171023-1717-heeaf0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=879&fit=crop&dpr=1 754w, https://images.theconversation.com/files/191391/original/file-20171023-1717-heeaf0.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=879&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/191391/original/file-20171023-1717-heeaf0.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=879&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Once the dinosaur’s tracks had been identified and cleaned of rock debris, the team photographed and took silicon rubber impressions of them.</span>
<span class="attribution"><span class="source">Lara Sciscio</span></span>
</figcaption>
</figure>
<p>The ancient surface is also covered in the footprints of other theropod dinosaurs. Even their footprint impressions are relatively large (30-40cm long) for the time period. </p>
<p>The 57 cm long Lesotho footprints have been named <em>Kayentapus ambrokholohali</em>. The trackmaker falls into an informal grouping of very large dinosaurs, called “megatheropods”, with footprints exceeding 50 cm in length and calculated hip heights greater than 2 m. </p>
<p>The new species name <em>ambrokholohali</em> was given to identify this particular footprint. It was derived in honour of Emeritus Professor David Ambrose, a now retired professor and Head Research Fellow at National University of Lesotho, for his detailed recording of the trace fossil heritage within Roma. </p>
<p>We were following in Ambrose’s footsteps, trying to relocate one of his documented sites, when we discovered the freshly exposed megatheropod footprints.</p>
<p>The latter part of the name, <em>kholohali</em>, is derived from two Sesotho words: “kholo”, meaning big, large or great and “hali”, meaning much or very. This was to describe its unexpectedly large size. </p>
<h2>Size matters</h2>
<p>The main bipedal predators during the Mesozoic (the “Dinosaur Era”) were large theropod dinosaurs. They included the <em>Allosaurus</em> (from the late Jurassic) and <em>Tyrannosaurus</em> (Upper Cretaceous). But early in the Mesozoic, theropod dinosaurs were usually relatively small (3–5 m body length). Truly large forms of theropods only started making their appearance around 100 million years later, within the Late Jurassic and Early Cretaceous.</p>
<p>In light of this, the new discovery of these impressively large tracks expands the range of body size for theropods in the Early Jurassic at the very onset of their diversification. But, why were these theropods so much larger than anything else around at the time? An answer could lie in the timing of their evolution. </p>
<p>The megatheropod tracks appear after the end-Triassic <a href="https://www.britannica.com/science/end-Triassic-extinction">mass extinction event</a>. This mass extinction event was the result of a biotic crisis that significantly affected animals both on land and sea. The biotic crisis allowed for the main competitors of theropod dinosaurs to be completely eradicated. Killing off the competition, coupled with changes in ecosystem composition, probably gave theropod dinosaurs “free reign” to dominate the Early Jurassic landscape and resources. </p>
<p>Another possible driver for larger theropod body size was the increased size of the herbivorous dinosaurs – like the <a href="https://www.theguardian.com/science/2015/nov/10/south-african-scientists-new-dinosaur-species-fossils-sauropod-highland-giant-karoo">Highland Giant sauropodomorph</a> – within the same ancient landscape. </p>
<p>It’s most likely that both factors lead to theropods in southern Africa being able to evolve into numerous forms and increase in abundance. But these are questions we can’t answer conclusively.</p>
<h2>Giant footprints, but still no fossils</h2>
<p>The body fossil evidence for theropod dinosaurs in southern Africa is slim. Luckily the footprints they left behind are not. By studying these and other tracks as well as the bone fossil record, scientists are able to tentatively link footprints to potential trackmakers. </p>
<p>To date, we have no body fossil material to match the <em>K. ambrokholohali</em>‘s footprints. Hopefully we’ll soon discover more unusual footprints and, from there, body fossils that will help add to our understanding of the complex ancient world.</p><img src="https://counter.theconversation.com/content/86004/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Lara Sciscio and her colleagues received funding for this work from the National Research Foundation of South Africa
Competitive Programme for Rated Researches (NRF Grant number 93544 Bordy) and the Department of Science and Technology-National Research Foundation Centre of Excellence in Palaeosciences. The work was also supported by the ARAID (<a href="https://www.araid.es/">https://www.araid.es/</a>)</span></em></p>Until this discovery, theropod dinosaurs were thought to be considerably smaller, at three to five metres in body length, during the Early Jurassic.Lara Sciscio, Postdoctoral Research Fellow in Geological Sciences, University of Cape TownLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/813232017-08-07T20:09:40Z2017-08-07T20:09:40ZWhen dinosaurs walked the Earth they moved like modern birds<figure><img src="https://images.theconversation.com/files/180828/original/file-20170803-9082-hoofvc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">How the mighty dinosaurs would have walked millions of years ago.</span> <span class="attribution"><a class="source" href="https://www.flickr.com/photos/hoyd/32176906413/">Flickr/Ørjan Hoyd Vøllestad</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span></figcaption></figure><p>We know that dinosaurs ruled the Earth many millions ago, but how they walked has been a mystery.</p>
<p>Our new research shows that the movement of some dinosaurs has a lot in common with some of today’s ground-dwelling birds. We looked at <a href="https://www.britannica.com/animal/theropod">theropod</a> dinosaurs, which were typically bipedal (two-legged), walking on their hind legs like <em>Tyrannosaurus rex</em>.</p>
<p>In our study, <a href="http://rsif.royalsocietypublishing.org/content/14/132/20170276">published in the Journal of the Royal Society Interface</a>, we took measurements of 211-million-year-old theropod footprints from a quarry at Culpeper in Virginia, in the United States, and compared them to similar measurements for locomotion in humans and 11 species of ground-dwelling bird such as the quail, emu and Australian bush turkey.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/book-review-flying-dinosaurs-how-fearsome-reptiles-became-birds-30704">Book review: Flying Dinosaurs – How fearsome reptiles became birds</a>
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<p>This is the first time that locomotion in the three groups of bipeds has been compared on a level playing field. In particular, we focused on a parameter called step width, which measures how widely spaced the left and right feet are during locomotion.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/180997/original/file-20170804-27473-1th32xr.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/180997/original/file-20170804-27473-1th32xr.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/180997/original/file-20170804-27473-1th32xr.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=800&fit=crop&dpr=1 600w, https://images.theconversation.com/files/180997/original/file-20170804-27473-1th32xr.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=800&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/180997/original/file-20170804-27473-1th32xr.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=800&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/180997/original/file-20170804-27473-1th32xr.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1005&fit=crop&dpr=1 754w, https://images.theconversation.com/files/180997/original/file-20170804-27473-1th32xr.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1005&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/180997/original/file-20170804-27473-1th32xr.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1005&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 footprints of a human, living bird and extinct dinosaur.</span>
<span class="attribution"><span class="source">Christofer Clemente and Peter Bishop</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>We compared measurements of step width against the speed of the animal, measured directly for the modern species, or by using stride length as a proxy for the extinct theropods. </p>
<h2>From walking to running</h2>
<p>In all three groups, step width decreased with increasing speed. In other words, as the animal moved faster, the left and right feet were placed closer towards the body midline, and at the fastest speeds of locomotion, the feet could even cross over the midline. </p>
<p>So this told us that the extinct theropods that made the footprints were at least following the same general principle seen in modern bipeds.</p>
<p>Interestingly, however, the way in which step width decreased with increasing speed was different between the three groups. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/180998/original/file-20170804-27452-180tlh1.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/180998/original/file-20170804-27452-180tlh1.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/180998/original/file-20170804-27452-180tlh1.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=876&fit=crop&dpr=1 600w, https://images.theconversation.com/files/180998/original/file-20170804-27452-180tlh1.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=876&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/180998/original/file-20170804-27452-180tlh1.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=876&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/180998/original/file-20170804-27452-180tlh1.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1101&fit=crop&dpr=1 754w, https://images.theconversation.com/files/180998/original/file-20170804-27452-180tlh1.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1101&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/180998/original/file-20170804-27452-180tlh1.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1101&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Note the sudden change in the way humans move when they speed up compared to living birds and extinct dinosaur.</span>
<span class="attribution"><span class="source">Christofer Clemente and Peter Bishop</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>In humans, step width shows an abrupt, precipitous decrease at the transition from walking to running. In other words, as soon as we start running we suddenly bring our feet much closer towards the body midline. </p>
<p>But in both the modern birds and the extinct theropods, no such abrupt change was observed. Instead, the step width decreased gradually with increasing speed.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/FwcHSrc0oYs?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">T. rex may have looked like this quail when it moved.</span></figcaption>
</figure>
<p>This pattern of similarity and contrast suggests that the extinct theropods were moving more like modern birds than humans. </p>
<p>Furthermore, a gradual or continuous change with speed has been previously observed for many other measurements of locomotion in birds, such as stride length and step frequency.</p>
<p>Birds therefore have what is called a “continuous locomotor repertoire” – that is, walking and running are not distinct gaits (as they are in humans), but instead they transition seamlessly from one to the other.</p>
<p>The extinct theropods that made the footprints were probably also using a similarly continuous locomotor behaviour.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/180830/original/file-20170803-23530-1qiofsh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/180830/original/file-20170803-23530-1qiofsh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/180830/original/file-20170803-23530-1qiofsh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=324&fit=crop&dpr=1 600w, https://images.theconversation.com/files/180830/original/file-20170803-23530-1qiofsh.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=324&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/180830/original/file-20170803-23530-1qiofsh.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=324&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/180830/original/file-20170803-23530-1qiofsh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=408&fit=crop&dpr=1 754w, https://images.theconversation.com/files/180830/original/file-20170803-23530-1qiofsh.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=408&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/180830/original/file-20170803-23530-1qiofsh.jpg?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>
<figcaption>
<span class="caption">The dinosaur tracks at Dinosaur Ridge in Colorado, in teh United Sates, are typical of the dinosaur footprints found today.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Dinosaur_Ridge_tracks.JPG">Mediawiki/Footwarrior</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<h2>A better understanding</h2>
<p>This research changes our thinking about theropod movement, in three main ways. </p>
<p>First, using a continuous locomotor behaviour could have been beneficial to theropods by allowing them to run just that bit faster while maintaining stability, thus reducing bone and muscle stresses. </p>
<p>Second, the unique locomotor behaviour that characterises modern birds today may actually have been inherited in part from their theropod ancestors, showing more similarities between birds and dinosaurs than previously recognised.</p>
<p>And third, this study helps to paint a better picture of what extinct theropods were like as living animals. We now know that side-to-side limb movements were important for theropod dinosaur locomotion to increase stability while walking, and that theropods did not simply use human-like walking and running gaits.</p>
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<em>
<strong>
Read more:
<a href="https://theconversation.com/meet-savannasaurus-australias-newest-titanosaur-67383">Meet Savannasaurus, Australia's newest titanosaur</a>
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</em>
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<p>This locomotory gait found in dinosaurs and birds may also be important for improving visual acuity by increasing head stability, particularly in the vertical direction.</p>
<p>This is important if we wish to create biomechanical models of theropod locomotion, <a href="http://www.bbc.com/news/science-environment-40632751">such as one of <em>T. rex</em></a>, to address questions such as maximum speed capabilities or endurance.</p>
<p>It’s also important if we want to make sure that these types of dinosaurs are portrayed accurately in film, animation, computer simulations and other forms of popular culture.</p><img src="https://counter.theconversation.com/content/81323/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Christofer Clemente receives funding from an ARC DECRA Fellowship (DE120101503)</span></em></p><p class="fine-print"><em><span>Peter Bishop received funding from the Australian Government (Research Training Stipend) and the International Society of Biomechanics (Matching Dissertation Grant). </span></em></p>The footprints of dinosaurs can tell a lot about how they moved about many millions of years ago.Christofer Clemente, Lecturer in Animal Ecophysiology, University of the Sunshine CoastPeter Bishop, Postdoctoral research fellow, Griffith UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/773452017-05-16T00:14:18Z2017-05-16T00:14:18ZIt’s time to celebrate Africa’s forgotten fossil hunters<figure><img src="https://images.theconversation.com/files/168887/original/file-20170511-32618-bewdt0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Local people at Tendaguru (Tanzania) excavation site in 1909 with Giraffatitan fossils.</span> <span class="attribution"><a class="source" href="http://www.welt.de/wissenschaft/article3586616/Urzeitliches-Knochenpuzzle-aus-Deutsch-Ostafrika.html">Wikimedia Commons/Public domain</a></span></figcaption></figure><p>There are few things more exciting for a professional palaeontologist than discovering fossil remains. In early 2017 I found a beautifully preserved skeleton sticking out of the ground in South Africa’s Karoo region. It was the vertebral column of a big herbivorous animal called <a href="http://www.ucmp.berkeley.edu/anapsids/pareiasauria.html">pareiasaur</a>. </p>
<p>The individual vertebral arches were accompanied by the animal’s two hip blades. Fragments of its forelimbs and some parts of its cranium were also visible. All this suggested that I’d found a skeleton nearly 2 meters long, the rest of it hidden below the ground. These 275 million years old fossils had no deformities and were easy to identify. I realised that even someone with no training in palaeontology would have easily find such eroding bones and recognised them as some giant creature’s remains.</p>
<p>This got me thinking about Africa’s earliest fossil seekers, whose identities are largely unknown. Who were they, and how did their discoveries influence our thinking about evolution? How many of their ideas were dismissed or written out of history after the arrival of colonialism and western fossil hunters on the continent? </p>
<p>It’s important to honour these people and their fossil finds, which are examples of both cultural and palaeontological heritage.</p>
<h2>Historical fossil hunting in Africa</h2>
<p>For many, the history of fossil bone discovery in Africa can’t be separated from famous European-led expeditions. Many of these happened during the 19th and 20th centuries and generated breathless headlines around the world. </p>
<p>There was the German expedition at Tendaguru (Tanzania), which yielded the extraordinary skeletons of some of the <a href="https://www.amazon.com/African-Dinosaurs-Unearthed-Tendaguru-Expeditions/dp/0253342147">biggest dinosaurs ever found</a>. American and European palaeontologists also mounted several trips to the <a href="https://link.springer.com/chapter/10.1007/978-0-387-73896-3_9">Fayum depression</a> in Egypt because it was home to mammals of all sorts and sizes some 35 million years ago.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/168366/original/file-20170508-20745-17ek8mu.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/168366/original/file-20170508-20745-17ek8mu.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/168366/original/file-20170508-20745-17ek8mu.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/168366/original/file-20170508-20745-17ek8mu.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/168366/original/file-20170508-20745-17ek8mu.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/168366/original/file-20170508-20745-17ek8mu.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/168366/original/file-20170508-20745-17ek8mu.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/168366/original/file-20170508-20745-17ek8mu.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">This perfectly preserved backbone actually belongs to a long extinct reptile called pareiasaur.</span>
<span class="attribution"><span class="source">Julien Benoit</span></span>
</figcaption>
</figure>
<p>These expeditions captured the public’s imagination. But the archaeological record reveals that fossils were discovered and collected <a href="http://press.princeton.edu/titles/9435.html">well before such trips</a>, by amateurs who used them in, for instance, religious rituals.</p>
<p>In her book about fossil discoveries in classical Antiquity, “<a href="http://press.princeton.edu/titles/9435.html">The First Fossil Hunters</a>”, Adrienne Mayor mentions that gigantic bones were found in Morocco as early as 300 to 400 B.C. She suspects they were fossilised elephants.</p>
<p>One of the most famous ancient fossil discoveries in Africa involved a giant tooth. Christian theologian and philosopher Saint Augustin, the bishop of what is today Algeria, found it near Utica (Tunisia) in the fourth century A.D. It proved to be a <a href="http://sp.lyellcollection.org/content/310/1/67.abstract">fossilised elephant molar</a>.</p>
<p>Saint Augustin’s discovery isn’t the oldest example of fossil collection in Africa, though. That title goes to the ancient Egyptians who collected and gathered millions of years old mammalian fossil bones and packed them in linen, likely as a <a href="https://books.google.co.za/books?id=9TwhfvU08UcC&source=gbs_book_other_versions">form of worship to Set</a>. These fossil collectors lived 3000 years ago. There’s also evidence of fossilised shark teeth that were collected and pierced to be worn as pendants in ancient Egypt, some <a href="https://books.google.co.za/books?id=9TwhfvU08UcC&source=gbs_book_other_versions">6500 years</a> ago. </p>
<h2>The search for the first fossil collectors</h2>
<p>It’s possible that fossils were recognised in Africa even earlier than this. In Congo, a site dating back 21 000 years has yielded the tooth of a fossil elephant that went extinct millions of years earlier. This <a href="https://books.google.co.za/books?id=9TwhfvU08UcC&source=gbs_book_other_versions">suggests</a> that someone stumbled upon this large fossil tooth and brought it back home, perhaps as a curio.</p>
<p>In addition, an undated Khoisan rock art site in Lesotho appears to represent <a href="http://www.tandfonline.com/doi/pdf/10.1080/10420940591008971">dinosaur footprints</a>. Fossil tracks dating back more than 200 million years ago are not uncommon in this region, and are often well exposed – lying close to the surface of the earth – so it makes sense that ancient residents would have seen and documented them. The Khoisan could well have been the first people to find fossils in Southern Africa. </p>
<p>Though this hypothesis is still <a href="http://www.davidpublishing.com/davidpublishing/Upfile/10/18/2013/2013101882378185.pdf">hotly debated</a>, these drawings are accompanied by cave paintings which suggest the Khoisan interpreted these footprints as belonging to a race of <a href="http://www.tandfonline.com/doi/pdf/10.1080/10420940591008971">giant, flightless birds</a>. Today, most scientists consider birds to be dinosaurs’ closest living relatives. This would imply that Khoisans ancestors had a remarkable sense of scientific reconstruction, even though no framework for evolution had yet been described.</p>
<h2>Before Darwin</h2>
<p>The Khoisan weren’t the only people in Africa thinking way ahead of the Darwinian curve. A number of Muslim scholars from the Middle East and North Africa made very explicit, <a href="https://www.thevintagenews.com/2016/08/27/priority-first-theory-evolution-600-years-older-darwin/">farsighted statements centuries before Darwin</a>.</p>
<p>For example, a Tunisian scholar named Ibn Khaldun, stated as early as 1377 that “the higher stage of man is reached from the world of the monkeys, in which both sagacity and perception are found.” He was probably inspired by his predecessor, the Persian Ibn Miskawayh (932-1030), who stated in the Brethren of Purity that “Animalilty […] finally reaches the frontier of humanity with the Ape which is just a degree below Man in the <a href="http://pu.edu.pk/images/journal/uoc/PDF-FILES/%2811%29%20Dr.%20Sultan%20Shah_86_2.pdf">scale of evolution”</a>.</p>
<p>It’s very likely that Darwin didn’t know about these ancient discoveries and medieval authors since they are not mentioned in any of his biographies or works. But the very fact that they exist illustrates Africa’s formidable potential to influence and develop palaeontological research. </p>
<p>The challenge now is to build upon this heritage and raise awareness about these long-forgotten discoveries and theorists. This is an important way to motivate a new generation of African fossil researchers.</p><img src="https://counter.theconversation.com/content/77345/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Julien Benoit receives funding from The Claude Leon Foundation; PAST and its Scatterlings projects; the National Research Foundation of South Africa; and the DST-NRF Centre of Excellence in Palaeosciences (CoE in Palaeosciences). </span></em></p>Africa has one of the world’s richest fossil records, and evidence suggests that amateurs collected really important fossils long before professionals arrived on the scene.Julien Benoit, Postdoc in Vertebrate Palaeontology, University of the WitwatersrandLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/690672016-11-24T12:03:24Z2016-11-24T12:03:24ZFossil footprints give glimpse of how ancient climate change drove the rise of reptiles<figure><img src="https://images.theconversation.com/files/146607/original/image-20161118-19371-u719n3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Sphenacodon.</span> <span class="attribution"><a class="source" href="https://en.wikipedia.org/wiki/Sphenacodon#/media/File:Sphenacodon2.jpg">Wikimedia Commons</a></span></figcaption></figure><p>After lying largely forgotten in a museum for decades, a set of fossilised footprints have revealed a new glimpse of the world when reptiles began taking over from amphibians as the dominant land animals. Using cutting-edge technology, we have been able to identify the creatures that probably made the footprints <a href="https://peerj.com/articles/2718/">over 300m years ago.</a> This gives us a snapshot of what was happening as reptiles started diversifying and began the process that would see them become the dominant form of vertebrate life on land.</p>
<p><a href="https://en.wikipedia.org/wiki/Birmingham">Birmingham</a> used to be covered in lush tropical rainforest. This city in the British Midlands is today known as an ethnically-diverse melting pot of industry and innovation, famous for canals, heavy metal, Balti curry and friendly people with distinctive accents. But 310m years ago – long before the dinosaurs or the first mammals – the area was dominated by primitive plants like horsetails and club mosses, which grew into <a href="https://en.wikipedia.org/wiki/Lepidodendron">towering 30 metre tall trees</a>.</p>
<p>A great diversity of early amphibians, insects, arachnids and other invertebrates lived among the lush vegetation. As the plants died, their remains formed thick layers of peat that over time were compressed to form <a href="http://www.palaeontologyonline.com/articles/2011/fossil-focus-coal-swamps/">rich deposits of coal that today underlie many parts of Britain</a>. These coal deposits would later power the industrial revolution that would make Birmingham a world leader in manufacturing.</p>
<p>But towards the end of the Carboniferous period (299m years ago), the world began to change. The global climate became increasingly dry and the rainforests of Europe began to contract and vanish. This rainforest collapse is believed to have caused a mass extinction among plants, while many groups of amphibians disappeared and were <a href="http://palaeo.gly.bris.ac.uk/macro/Carb.html">replaced by early groups of reptiles</a>. </p>
<p>A collection of fossil footprints from Birmingham provides a unique window into this changing world. A schoolteacher, Walter Henry Hardaker, discovered the footprints in the early 20th century in a quarry in the Hamstead area in the northwest of the city. Since Hardaker’s work, they have lain largely ignored in the collections of the <a href="http://www.birmingham.ac.uk/facilities/lapworth-museum/index.aspx">Lapworth Museum of Geology</a> at the University of Birmingham – until our research team decided to restudy them as part of a research project funded by the <a href="http://www.palass.org/">Palaeontological Association</a>.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/146610/original/image-20161118-19345-c4pzo8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/146610/original/image-20161118-19345-c4pzo8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=465&fit=crop&dpr=1 600w, https://images.theconversation.com/files/146610/original/image-20161118-19345-c4pzo8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=465&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/146610/original/image-20161118-19345-c4pzo8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=465&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/146610/original/image-20161118-19345-c4pzo8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=584&fit=crop&dpr=1 754w, https://images.theconversation.com/files/146610/original/image-20161118-19345-c4pzo8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=584&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/146610/original/image-20161118-19345-c4pzo8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=584&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Amphibian tracks.</span>
<span class="attribution"><span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>The footprints are preserved on about 20 red sandstone slabs, and provide a remarkable window into life in Birmingham at the end of the Carboniferous period. They formed as animals walked over muddy areas next to river channels, and were preserved by a covering of sand in a subsequent flood. Trackways show how the animals that lived there moved and skittered across the floodplain. Exquisite details of the environment are preserved, including raindrops and mudcracks that formed during drier intervals. </p>
<p>Our team, led by Birmingham Palaeobiology & Palaeoenvironments undergraduate student <a href="http://www.birmingham.ac.uk/schools/gees/news/2015/20Oct15-luke-meade-footprints-study.aspx">Luke Meade</a>, used cutting-edge photogrammetric technology to study the footprints. Each trackway was photographed from numerous different angles, and special software was then used to turn these photos into high-resolution 3D models. <a href="https://zenodo.org/record/154382#.WDLWcGSDyOE">These models are freely available to download</a>, and can be used for educational purposes.</p>
<p>Colour-coding the models allowed us to produce topographic maps of each specimen that illustrate them in three dimensions. By comparing these models to Carboniferous tracks from other parts of the world, we were able to identify the types of animals that probably made the tracks. </p>
<h2>Amphibian decline</h2>
<p>Most common were amphibians, ranging from a few centimetres up to a metre or more in length. Alongside these amphibians lived two other vertebrate groups. Rare tracks show that large <a href="http://www.ucmp.berkeley.edu/synapsids/pelycosaurs.html">pelycosaurs</a> were present, probably superficially resembling modern day Komodo dragons. Pelycosaurs were part of the great evolutionary lineage that would eventually lead to mammals, including humans.</p>
<p>Smaller tracks document early representatives of another great branch of the vertebrate evolutionary tree, the sauropsid reptiles, which were small and lizard-like. These would ultimately diversify into <a href="http://www.evolution.berkeley.edu/evolibrary/search/imagedetail.php?id=265&topic_id=&keywords=">everything from dinosaurs to lizards, turtles and birds</a>.</p>
<p>This snapshot of geological time captures an important evolutionary moment. Although amphibians were still abundant, their dependence on moist environments and bodies of water for spawning may have put them at a <a href="http://www.bbc.co.uk/news/science-environment-11870322">disadvantage compared to the rapidly diversifying reptiles as the climate became increasingly arid</a>. Lying at the centre of a famously soggy island, the bustling city of Birmingham may today seem a far cry from this past world. But the rocks on which it sits surely still hold many untold secrets about daily life more than 300m years ago.</p><img src="https://counter.theconversation.com/content/69067/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Richard Butler receives funding from the Palaeontological Association. </span></em></p><p class="fine-print"><em><span>Andrew Jones 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>A set of fossils that lay forgotten in a museum are revealing new secrets about Britain’s prehistoric wildlife.Richard Butler, Senior research fellow, University of BirminghamAndrew Jones, PhD Candidate, University of BirminghamLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/529112016-01-08T13:12:14Z2016-01-08T13:12:14ZMysterious footprint fossils point to dancing dinosaur mating ritual<figure><img src="https://images.theconversation.com/files/107659/original/image-20160108-3334-gdk2gs.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Tyrannosaurus tango</span> <span class="attribution"><span class="source">Xing Lida and Yujiang Han</span></span></figcaption></figure><p>Studying dinosaurs is a lot like being a detective. Just as Sherlock Holmes was noted for his ability to interpret the behaviour of victims or criminals using footprints, palaeontologists have a similar practice when looking for evidence of dinosaur behaviour known as ichnology.</p>
<p>This is the study of the traces living organisms leave behind including bones, footprints and even bite marks on leaves. Indeed, Sherlock Holmes’ creator, Sir Arthur Conan Doyle, was <a href="https://books.google.co.uk/books?id=kji6fde5g-gC&pg=SL26-PA1&lpg=SL26-PA1&dq=conan+doyle+dinosaur+footprint+beckles&source=bl&ots=g1gpnVvSkW&sig=j6w-TmfTXyZv0z3C5NECPSS2vKs&hl=en&sa=X&ved=0ahUKEwiQz8-RmZrKAhWIVhoKHfkNDrIQ6AEIIDAA#v=onepage&q=conan%20doyle%20dinosaur%20footprint%20beckles&f=false">very well aware</a> of the traces of dinosaur footprints that had been discovered in the rocks of the Weald near his home in south-east England.</p>
<p>Now researchers in the US have discovered some very unusual trace fossils they believe could also be footprints. Although it is far from certain, these markings may provide the first clue as to whether dinosaurs performed dance-like mating rituals similar to those of living birds.</p>
<h2>Scratching the surface</h2>
<p>The team from the University of Colorado Denver <a href="http://www.nature.com/articles/srep18952">have unearthed</a> some truly extraordinary trace fossils on the bedding surfaces of sedimentary rocks of Cretaceous age in Colorado. The bedding surfaces have revealed an irregular array of large scoop-shaped depressions up to 2m in diameter and adjacent hummocks. Many of the scoops also display clear and unequivocal elongate scratch marks.</p>
<p>Given the geological ages of these rocks, the only large, powerful ground-dwelling creatures likely to be able to make such structures would have been dinosaurs. These curious sedimentary structures are not simply a one-off isolated discovery that can be explained as just a weird bit of geology, but have been found in clusters at a number of discrete sites across Colorado. Each site has a rather similar, comparatively dense, cluster of these scoop-like structures.</p>
<p>At first sight it would be perfectly reasonable to consider that such structures were the remnants of ancient dinosaur nests. Dinosaur nest sites, including eggs, shell fragments and even nestling dinosaur remains are comparatively well known. They <a href="http://www.nature.com/nature/journal/v378/n6559/abs/378774a0.html">have been reported</a> from a range of Cretaceous aged sites that have been found in North America, South America and Asia.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/107660/original/image-20160108-3345-mjbkwx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/107660/original/image-20160108-3345-mjbkwx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=419&fit=crop&dpr=1 600w, https://images.theconversation.com/files/107660/original/image-20160108-3345-mjbkwx.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=419&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/107660/original/image-20160108-3345-mjbkwx.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=419&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/107660/original/image-20160108-3345-mjbkwx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=527&fit=crop&dpr=1 754w, https://images.theconversation.com/files/107660/original/image-20160108-3345-mjbkwx.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=527&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/107660/original/image-20160108-3345-mjbkwx.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=527&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Dinosaur detectives.</span>
<span class="attribution"><span class="source">M. Lockley</span></span>
</figcaption>
</figure>
<p>But these “scoops and hummocks” differ in their detailed structure when compared to definitive dinosaur nests. Dinosaur nests <a href="http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=4428272&fileId=S0016756800011547">tend to be</a> circular, rather flat-bottomed, usually have traces of egg shell and are typically surrounded by a rim-like perimeter wall.</p>
<p>In fact, these new and distinctive structures show no evidence of what appear to be conventional dinosaur nest structure or scattered egg shell fragments. They are elongate, concave depressions with sediment clearly heaped to one side. In many instances, they display scrape marks that appear to have been made by dragging claws.</p>
<p>These structures are most comparable to the “leks” produced by living ground-nesting birds. Leks are effectively display arenas in which <a href="https://theconversation.com/five-lessons-in-seduction-from-the-males-of-the-animal-kingdom-52118">male birds</a> perform a courtship ritual that can include dancing, showing off their feathers and making calls to attract the attention of nearby females.</p>
<p>The researchers suggest the geological structures were originally created by theropods, the group of dinosaurs most closely <a href="https://theconversation.com/six-amazing-dinosaur-discoveries-that-changed-the-world-51367">related to living birds</a> and which includes <em>Tyrannosaurus Rex</em>. <a href="http://www-hsc.usc.edu/%7Ecmchuong/2014Birdorig.pdf">Theropods may well</a> have been very like modern birds in their behaviour and made the scrapes as part of the production of a display arena for courtship. However, it seems likely that if these marks were leks they would have been next to actual breeding/nesting sites, but so far no trace of nests has been discovered.</p>
<h2>Tracking down Cinderella</h2>
<p>The frustrating thing about ichnology is that while the tracks and traces left by living creatures can be matched to observations of their actual behaviour, this is rarely the case when it comes to the fossilised traces of dinosaurs. Trying to tie the identity of fossilised tracks to the original track-maker has been a persistent problem for palaeontologists. It’s rather like the hunt for Cinderella: they have to look for animals that lived at the exact time the tracks were formed, with feet bones the right size and shape to precisely fit the shoe of the fossilised footprint.</p>
<p>Fossilised tracks and traces used to be <a href="http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=4423968&fileId=S0016756800010050">rather disparaged</a> by palaeontologists because the difficulties surrounding the identity of the actual track-maker seemed more or less insurmountable. However, the past few decades has seen a growing appreciation of the information that can be gleaned from such tracks and traces.</p>
<p>This includes the local environmental conditions when the tracks were made, the texture of the sediments that the creature was walking upon, and the details of foot placement, stride length and stride pattern. These can reveal a surprising amount of information about the way the track-maker walked, its posture and even the likely speed at which it was moving – very reminiscent of the skills demonstrated by Conan Doyle’s heroic sleuth.</p>
<p>Just a few years ago the question of bird-dinosaur affinities was also a topic that was very hotly disputed. The discovery of <a href="http://www-hsc.usc.edu/%7Ecmchuong/2014Birdorig.pdf">feathered theropods</a> in the 1990s finally proved that theropod dinosaurs were ancestral to living birds. Although we can’t yet be sure, the new research suggests some dinosaurs may have been not just anatomically similar to birds but also have shared some mating behaviours. This gives rise to the amusing possibility of a dancing <em>T. Rex</em> trying to impress his potential mate.</p><img src="https://counter.theconversation.com/content/52911/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>David Norman 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>Researchers believe newly uncovered fossils suggest some dinosaurs had similar courtship practices to modern birds. But can ancient footprints really reveal so much?David Norman, Reader in Paleobiology, Curator of Palaeontology, Sedgwick Museum of Earth Sciences, University of CambridgeLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/289712014-07-14T20:11:20Z2014-07-14T20:11:20ZNo dinosaur stampede at Lark Quarry – so what really happened?<figure><img src="https://images.theconversation.com/files/53484/original/c4rb66wr-1404958640.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Dinosaur footprints at the Lark Quarry site.</span> <span class="attribution"><span class="source">Steven Salisbury</span></span></figcaption></figure><p>Everyone loves a good dinosaur story and they don’t come much better than the dramatic dinosaur stampede found in Queensland’s outback. But did a stampede really happen?</p>
<p>In the late 1970s at <a href="http://www.dinosaurtrackways.com.au/">Lark Quarry</a>, about 110km southwest of Winton, central-west Queensland, half a hillside was removed to reveal a surface of rock pitted with thousands of three-toed dinosaur tracks.</p>
<p>There was a series of large tracks heading off to the southwest and thousands of smaller ones, most of which are directed to the northwest.</p>
<p>The original interpretation that was <a href="http://www.qm.qld.gov.au/About+Us/Publications/Memoirs+of+the+Queensland+Museum/MQM+Vol+21#.U8Mx242Syrw">published in 1984</a> proposed that the set of large tracks were made a large-bodied carnivorous <a href="http://dinosaurs.about.com/od/typesofdinosaurs/a/bigtheropods.htm">theropod</a> dinosaur, perhaps something akin to the mighty <em>Tyrannosaurus</em>. The smaller tracks were thought to belong to small-bodied coelurosaurian theropods and herbivorous ornithopods. </p>
<p>It was estimated that there were more than 150 of the smaller dinosaurs. Given that nearly all their tracks are aligned in the same direction, and that some of them were imprinted into the larger tracks, it was proposed there must have been a stampede, most likely triggered by the approach of the large meat-eating theropod. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/jRWFXr60kUk?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">The stampede theory makes for a good story. But did it really happen that way?</span></figcaption>
</figure>
<h2>Stampede story a popular attraction</h2>
<p>This is a great story, and it definitely helped bring Lark Quarry to life. Stephen Spielberg liked it so much it became the inspiration behind <a href="http://www.youtube.com/watch?v=nM-RPO10aPY">one of the scenes</a> in his 1993 film <a href="http://www.imdb.com/title/tt0107290/">Jurassic Park</a>.</p>
<p>Tourists love it as well, with many going out of their way to visit Lark Quarry and have the story told to them by professional guides.</p>
<p>The state and federal governments liked it too. Approximately $A3.2 million was put into the construction of purpose-built building to protect the site, and in 2004 it was given National Heritage Listing and renamed the <a href="http://www.environment.gov.au/node/19647">Dinosaur Stampede National Monument</a>. </p>
<p>But did a dinosaur stampede really happen at Lark Quarry?</p>
<h2>The greatest story ever told … was just a story</h2>
<p>Around 2010, we began to look more closely the large Lark Quarry dinosaur tracks. When various proportions of the outlines that had been published in 1984 were compared alongside other dinosaur tracks, they appeared to belong to a plant-eating <a href="http://dinosaurs.about.com/od/typesofdinosaurs/a/ornithopods.htm">ornithopod</a> rather than a theropod.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/53678/original/8thykhn4-1405295313.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/53678/original/8thykhn4-1405295313.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/53678/original/8thykhn4-1405295313.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=457&fit=crop&dpr=1 600w, https://images.theconversation.com/files/53678/original/8thykhn4-1405295313.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=457&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/53678/original/8thykhn4-1405295313.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=457&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/53678/original/8thykhn4-1405295313.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=575&fit=crop&dpr=1 754w, https://images.theconversation.com/files/53678/original/8thykhn4-1405295313.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=575&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/53678/original/8thykhn4-1405295313.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=575&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Anthony Romilio re-examines the footprints at Lark Quarry.</span>
<span class="attribution"><span class="source">Steven Salisbury</span></span>
</figcaption>
</figure>
<p>Could it be that the large Lark Quarry trackmaker wasn’t a theropod?</p>
<p>If it was a large-bodied ornithopod, maybe something similar to <a href="http://www.qm.qld.gov.au/Find+out+about/Dinosaurs+and+Ancient+Life+of+Queensland/Dinosaurs/Eromanga+giants/Muttaburrasaurus#.U8McI42Syrw"><em>Muttaburrasaurus</em></a>, which we know inhabited this part of Queensland around the time the Lark Quarry tracks were made, would its approach have caused the smaller dinosaurs to stampede? </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/53726/original/bmj6dx6f-1405312314.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/53726/original/bmj6dx6f-1405312314.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/53726/original/bmj6dx6f-1405312314.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=558&fit=crop&dpr=1 600w, https://images.theconversation.com/files/53726/original/bmj6dx6f-1405312314.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=558&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/53726/original/bmj6dx6f-1405312314.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=558&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/53726/original/bmj6dx6f-1405312314.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=701&fit=crop&dpr=1 754w, https://images.theconversation.com/files/53726/original/bmj6dx6f-1405312314.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=701&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/53726/original/bmj6dx6f-1405312314.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=701&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Artistic rendering of the large Lark Quarry track-maker: a bipedal ornithopodan dinosaur, similar to but smaller than <em>Muttaburrasaurus langdoni</em>.</span>
<span class="attribution"><span class="source">Anthony Romilio</span></span>
</figcaption>
</figure>
<p>When we <a href="http://www.sciencedirect.com/science/article/pii/S0195667110001096">published our results</a> in 2011, many of our colleagues thought it was great; they’d also had doubts about the identity of the large track-maker.</p>
<h2>A stampede of dispute</h2>
<p>But others were aghast. Chief among these was Dr Tony Thulborn, formerly at the University of Queensland and lead author on the <a href="http://www.qm.qld.gov.au/About+Us/Publications/Memoirs+of+the+Queensland+Museum/MQM+Vol+21#.U8Mx242Syrw">original 1984 publication</a> in which the tracks had been described, and the stampede scenario first proposed.</p>
<p>In a <a href="http://www.tandfonline.com/doi/abs/10.1080/03115518.2013.748482#.U8MdWo2Syrw">response</a> that came out in 2013, he labelled our claims as “iconoclastic”. He considered the methods we had used to analyse the track outlines to be flawed, and that in obtaining our results we had in some way “fabricated” our data.</p>
<p>His main gripe seemed to be that we had altered the outlines of some of the tracks to suit the analytical method we chose to employ. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/53684/original/thmhx754-1405298769.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/53684/original/thmhx754-1405298769.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/53684/original/thmhx754-1405298769.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=240&fit=crop&dpr=1 600w, https://images.theconversation.com/files/53684/original/thmhx754-1405298769.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=240&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/53684/original/thmhx754-1405298769.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=240&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/53684/original/thmhx754-1405298769.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=301&fit=crop&dpr=1 754w, https://images.theconversation.com/files/53684/original/thmhx754-1405298769.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=301&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/53684/original/thmhx754-1405298769.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=301&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Analysing the footprints in 3D.</span>
<span class="attribution"><span class="source">Anthony Romilio</span></span>
</figcaption>
</figure>
<p>The analytical method we used required the use of complete track outlines. The outlines that had been published in 1984 had dotted portions to them where a definite outline was presumably hard to make out.</p>
<p>There were different versions of some outlines, and the dotted parts weren’t always in the same place. In subsequent publications by Thulborn and others, some of the track outlines had been filled with colour, while others had the dotted parts joined. After convincing ourselves that the 1984 outlines were good approximations of the tracks, we decided to join the dots. </p>
<p>What the ensuing controversy highlighted was just how problematic the construction of track outlines can be. The majority of dinosaur tracks are 3D structures, and any representation of them in 2D means that information relating to depth is lost or compressed.</p>
<p>Creating an outline therefore depends on how the investigator interprets the track, making them highly subjective. This was clearly the case with the large Lark Quarry tracks. Where some saw dots or clear, unbroken lines, others saw red.</p>
<p>Using digital photogrammetry, we were able to approach the problem in a far more objective way.</p>
<p>This technique involves taking a series of photographs and then stitching them together to create a 3D model. The results can easily be reproduced, and none of the 3D information relating to track depth is lost. If you consider an outline, it’s simply a matter of selecting a contour line around or within part of the track. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/53728/original/j97kg64n-1405312661.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/53728/original/j97kg64n-1405312661.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/53728/original/j97kg64n-1405312661.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=161&fit=crop&dpr=1 600w, https://images.theconversation.com/files/53728/original/j97kg64n-1405312661.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=161&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/53728/original/j97kg64n-1405312661.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=161&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/53728/original/j97kg64n-1405312661.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=203&fit=crop&dpr=1 754w, https://images.theconversation.com/files/53728/original/j97kg64n-1405312661.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=203&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/53728/original/j97kg64n-1405312661.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=203&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Tracks in time: A – One of the large Lark Quarry tracks as it appeared after excavation c. 1977; B – 3D digital relief from new study; C – outline of 3D relief from new study; D – outline published in 1984.</span>
<span class="attribution"><span class="source">A - Queensland Museum; B & C - Romilio and Salisbury (2014); D - Romilio and Salisbury (2014), adapted from Thulborn and Wade (1984)</span></span>
</figcaption>
</figure>
<p>The 3D photogrammetric analysis of the large tracks that we published this year in <a href="http://www.sciencedirect.com/science/article/pii/S0195667114001141">Cretaceous Research</a> shows them to be very different to how they were first portrayed in 1984. The dinosaur that made these tracks had broad feet with flat, rounded toes.</p>
<p>There is no evidence of separate pads beneath the toes or the heel, and there is no evidence of sharp claw impressions; characteristics that would normally be expected had they been made by a theropod.</p>
<p>Overall, they are a good match for tracks from Europe and Asia that are thought to have been made by large-bodied iguanodontian ornithopods, animals similar to <em>Muttaburrasaurus</em>. </p>
<h2>Something else revealed in the images</h2>
<p>The 3D images also showed something else. Most of the large tracks have raised margins around them. These “displacement rims” typically occur when the ground in which a track is made is saturated, but not covered in water.</p>
<p>This suggests that the large Lark Quarry track-maker walked across the site when the surface was wet, but probably not underwater.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/53730/original/vbnfc8zw-1405313017.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/53730/original/vbnfc8zw-1405313017.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/53730/original/vbnfc8zw-1405313017.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=768&fit=crop&dpr=1 600w, https://images.theconversation.com/files/53730/original/vbnfc8zw-1405313017.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=768&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/53730/original/vbnfc8zw-1405313017.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=768&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/53730/original/vbnfc8zw-1405313017.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=965&fit=crop&dpr=1 754w, https://images.theconversation.com/files/53730/original/vbnfc8zw-1405313017.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=965&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/53730/original/vbnfc8zw-1405313017.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=965&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">3D relief of one of the Lark Quarry ornithopod footprints, with arrows showing the position of drag marks incising the side of the footprint’s pressure bulge.</span>
<span class="attribution"><span class="source">Anthony Romilio</span></span>
</figcaption>
</figure>
<p>The displacement rims around some of the large tracks are disrupted by drag marks, probably caused by partially floating vegetation. These could only have been made when water covered the site some time after the large dinosaur traversed it.</p>
<p>Since both the large footprints and drag marks have small dinosaur tracks overprinting them, the dinosaurs that made the smaller tracks must have crossed the area much later. From research that <a href="http://www.bioone.org/doi/full/10.1080/02724634.2012.694591">we published in 2013</a> we also know that some of these smaller dinosaurs were running, some were wading and some were even swimming.</p>
<h2>No evidence of a stampede</h2>
<p>The timing between the formation of the larger tracks, the vegetation drag marks and the smaller tracks could be anywhere from hours to days.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/53725/original/wptgdz8h-1405311971.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/53725/original/wptgdz8h-1405311971.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/53725/original/wptgdz8h-1405311971.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=527&fit=crop&dpr=1 600w, https://images.theconversation.com/files/53725/original/wptgdz8h-1405311971.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=527&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/53725/original/wptgdz8h-1405311971.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=527&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/53725/original/wptgdz8h-1405311971.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=662&fit=crop&dpr=1 754w, https://images.theconversation.com/files/53725/original/wptgdz8h-1405311971.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=662&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/53725/original/wptgdz8h-1405311971.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=662&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 sequence of track-forming events at Lark Quarry as inferred in the new study. 1 - Progression of the large-bodied ornithopod during likely subaerial track surface conditions; 2 - the formation of drag marks by partially buoyed vegetation; 3 - the progression of at least some of the small-bodied ornithopod track-makers, some of which were swimming.</span>
<span class="attribution"><span class="source">Anthony Romilio</span></span>
</figcaption>
</figure>
<p>The most likely scenario that could account for the series of events that produced Lark Quarry is probably a gentle rise and fall in the water level of a river that flowed through the area approximately 93 million years ago.</p>
<p>During this time various dinosaurs and a few floating bits of vegetation crossed the site. Some point after all the tracks were formed the entire surface was probably exposed and allowed to harden, with another rise in water eventually burying it in layer of sand before any features in it weathered away.</p>
<p>We may never really know exactly what happened at Lark Quarry all those millions of years ago. But we can present interpretations of what we think happened based on the evidence at hand. </p>
<p>In the case of Lark Quarry, the evidence is written in stone. As scientists, we just need to learn how to read it, and the way we read the evidence can change as science progresses. If new techniques allow us to refine the way we see things, then our interpretations will likely change. That’s science. </p>
<p>What the scientific community and the public at large make of our reading of the evidence is something we can’t always control. But at some point, the dust, or in this case, mud, will eventually settle.</p><img src="https://counter.theconversation.com/content/28971/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Steven W. Salisbury receives funding from the Australian Research Council, the National Science Foundation, the National Geographic Society, the Australian Geographic Society, the Linnean Society of NSW, Isisford Shire Council, Longreach Regional Council, Winton Sire Council, Queensland Museum, The Western Australian Greens, The Wilderness Society and Land Rover Australia. </span></em></p><p class="fine-print"><em><span>Anthony Romilio 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>Everyone loves a good dinosaur story and they don’t come much better than the dramatic dinosaur stampede found in Queensland’s outback. But did a stampede really happen? In the late 1970s at Lark Quarry…Steven W. Salisbury, PhD; Senior Lecturer, School of Biological Sciences, The University of QueenslandAnthony Romilio, PhD; Research assistant, The University of QueenslandLicensed as Creative Commons – attribution, no derivatives.