tag:theconversation.com,2011:/us/topics/giant-birds-74635/articles
Giant birds – The Conversation
2023-01-04T05:23:48Z
tag:theconversation.com,2011:article/193346
2023-01-04T05:23:48Z
2023-01-04T05:23:48Z
Putting the bones of giant, extinct ‘thunderbirds’ under the microscope reveals how they grew
<figure><img src="https://images.theconversation.com/files/492562/original/file-20221031-24-5lt2a3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">An artist's reconstruction of the giant _Dromornis stirtoni_. </span> <span class="attribution"><span class="source">Peter Trusler ©</span></span></figcaption></figure><p>The largest flightless bird found anywhere in the world today is the ostrich. It stands about 2.7 metres tall and can weigh up to 150kg. But millions of years ago ostriches would have been dwarfed by several other flightless bird species. </p>
<p>One was <em>Dromornis stirtoni</em>, nicknamed the thunderbird. It lived in the late Miocene period of Australia, about 8 million years ago. Another, <em>Vorombe titan</em>, lived far more recently in Madagascar, off the coast of southern Africa. It is thought to have gone extinct in the 17th century after encountering humans. <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6170582">Fossil finds</a> suggest that both species stood about 3 metres tall and were more than double the mass of ostriches.</p>
<p>Today all that remains of these birds are their fossilised bones and, in the case of <em>Vorombe titan</em>, <a href="https://www.tandfonline.com/doi/pdf/10.1671/0272-4634%282007%2927%5B1%3AODOAES%5D2.0.CO%3B2?needAccess=true">a handful of eggs</a>. This means that scientists know very little about the birds’ biology; for instance, the physical differences between male and female <em>Dromornis stirtoni</em> were unclear – until now.</p>
<p>Recently, my colleagues Trevor Worthy and Warren Handley from Australia’s Flinders University and I investigated the microscopic structure of <em>Dromornis stirtoni’s</em> bones. This allowed us first to pinpoint the size differences between males and females. Then we assessed how quickly the giant birds grew and how this compared to other, later members of its lineage. </p>
<p>We found that <em>Dromornis stirtoni</em> grew far more slowly than the most recent “thunderbird” species, <em>Genyornis newtoni</em>, which in turn grew far more slowly than the emus it lived alongside about 40,000 years ago and which still exist today. Its slow growth made <em>Dromornis stirtoni</em> vulnerable to climatic shifts. </p>
<p>This is an important finding amid the current environmental degradation driven by climate change: it is clear that slow-growing animals will be the most vulnerable to extinction.</p>
<h2>Bones are key</h2>
<p>My involvement in this research stems from the work I have done on the bone histology and growth patterns of a number of extinct species. These include the aepyornithids, including <em>Vorombe titan</em> from Madagascar – the “<a href="https://academic.oup.com/biolinnean/article/130/2/268/5815707?login=false">elephant bird</a>” – and <a href="https://anatomypubs.onlinelibrary.wiley.com/doi/full/10.1002/ar.24282">several Mesozoic birds</a>, as well as their <a href="https://press.jhu.edu/books/title/3496/microstructure-dinosaur-bone">dinosaurian relatives</a>.</p>
<p>Despite being fossilised for millions of years, the microscopic structure of bone (histology) is preserved intact and gives us a unique glimpse at how the animal grew when it was alive. In some animals, growth rings (like tree rings) occur and, just like tree rings, they can give us an idea of the age of the animal, and also information about its health.</p>
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<figcaption><span class="caption">Professor Anusuya Chinsamy-Turan discusses her research.</span></figcaption>
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<p>By applying geometric morphology to <em>Dromornis stirtoni’s</em> bones, we were <a href="https://www.researchgate.net/publication/303839943_Sexual_dimorphism_in_the_late_Miocene_mihirung_Dromornis_stirtoni_Aves_Dromornithidae_from_the_Alcoota_Local_Fauna_of_central_Australia">able to ascertain</a> that females had an average body mass of about 441kg while males clocked in at on average 528kg.</p>
<p>Next, we wanted to understand the species’ growth rates. For this, <a href="https://anatomypubs.onlinelibrary.wiley.com/doi/10.1002/ar.25047">we studied</a> the microscopic structure of <em>Dromornis</em> long bones belonging to small hatchlings, subadults and adults. </p>
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Read more:
<a href="https://theconversation.com/fossil-find-reveals-giant-prehistoric-thunder-birds-were-riddled-with-bone-disease-173745">Fossil find reveals giant prehistoric 'thunder birds' were riddled with bone disease</a>
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<p>We found that the young individuals experienced rapid growth but that this was followed by a period of arrested growth. In the largest individual at least 15 growth marks were present, suggesting that they needed at least 15 growth cycles (years) to reach adult body size. </p>
<p>We proposed that, as <a href="https://www.sciencedirect.com/science/article/pii/S0944200620301197">in modern kangaroos</a>, the periods of arrested growth most likely corresponded to the hot, dry summer months when they were likely experiencing thermal stress and needed to put their energy into dealing with that rather than into growth.</p>
<h2>Growth patterns</h2>
<p>This was an interesting finding, but we knew that it would have greater value if we could compare it to growth patterns in similar species, and in extant species.</p>
<p>So we looked at the bone microstructure of the most recent member of the “thunderbird” lineage – another giant flightless bird <a href="https://www.mdpi.com/1424-2818/13/5/219">called</a> <em>Genyornis newtoni</em>. It went extinct only about 40,000 years ago.</p>
<p>Our results showed that <em>Genyornis</em>, which was about 2.5 metres tall and probably weighed about 240kg, grew much more quickly than <em>Dromornis</em>. It reached adult body size on average in about one to two years, although it occasionally needed as many as four years. </p>
<p>We propose that this overall fast growth trajectory is likely to have helped <em>Genyornis</em> adapt to the unstable, turbulent times in the Pleistocene (from around 2.5 million years ago to about 12,000 years ago), when the aridification of Australia intensified. Instead of taking so long to grow up they would have been able to reach adult size more quickly and reproduce sooner.</p>
<p>But this relatively rapid growth trajectory was not enough to protect <em>Genyornis</em> from another threat: humans. Humans arrived on the Australian continent <a href="https://academic.oup.com/edited-volume/35424/chapter-abstract/303182141?redirectedFrom=fulltext&login=true;%20https://www.nature.com/articles/ncomms10511">about 55,000 years ago</a>. By 49,000 years ago, they had reached the Flinders Ranges, well within view of Lake Callabonna, where they would have encountered both <em>Genyornis</em> and emus.</p>
<p>Emus are about six times smaller than <em>Genyornis</em>, and have faster growth rates without any interruptions in their growth. In addition, they lay many more eggs during each breeding season. There is <a href="https://www.nature.com/articles/ncomms10496">strong evidence</a> that <em>Genyornis</em> eggs were collected and eaten by Indigenous people. <em>Genyornis</em> simply couldn’t lay enough eggs and its offspring simply didn’t grow fast enough to keep up with this pressure on their species; they were eventually driven to extinction by about 40,000 years ago. </p>
<h2>Recouping numbers</h2>
<p>Emus, of course, still exist. We propose that the rapid growth and reproductive strategy of emus allowed them to recoup their numbers at a faster rate after hard times, which allowed them to survive until today.</p><img src="https://counter.theconversation.com/content/193346/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>This research was funded by the Australian Research Council, ARC Discovery Project grant number, DP 180101913 to T. Worthy, L. Arnold, and A. Chinsamy-Turan and the National Research Foundation, South Africa, grant number, 117716 to A. Chinsamy</span></em></p>
The findings have repercussions today: it is clear that slow-growing animals will be the most vulnerable to extinction amid shifting climates.
Anusuya Chinsamy-Turan, Professor, Biological Sciences Department, University of Cape Town
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/173745
2021-12-14T19:10:56Z
2021-12-14T19:10:56Z
Fossil find reveals giant prehistoric ‘thunder birds’ were riddled with bone disease
<figure><img src="https://images.theconversation.com/files/437472/original/file-20211214-17-1onlc9e.jpg?ixlib=rb-1.1.0&rect=31%2C7%2C5251%2C3493&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Phoebe McInerney/@phoebyornis</span>, <span class="license">Author provided</span></span></figcaption></figure><p>Until around 45,000 years ago, Australia was home to <em><a href="https://theconversation.com/a-case-of-mistaken-identity-for-australias-extinct-big-bird-52856">Genyornis newtoni</a></em>, a fearsomely huge bird weighing roughly 230kg – almost six times as much as an emu – and standing 2 metres tall.</p>
<p>This giant, from a unique group of Australian flightless birds called the <a href="https://theconversation.com/new-research-reveals-the-origin-of-australias-extinct-flightless-giants-the-mihirung-birds-85394">dromornithids</a> or “thunder birds”, was among the largest birds that have ever lived. And then, along with many of Australia’s other “megafaunal” species, it disappeared, for reasons that still remain debated.</p>
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Read more:
<a href="https://theconversation.com/new-research-reveals-the-origin-of-australias-extinct-flightless-giants-the-mihirung-birds-85394">New research reveals the origin of Australia’s extinct flightless giants, the mihirung birds</a>
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<p>Fossils of <em>Genyornis</em> are mainly found at the famous South Australian fossil site of Lake Callabonna, which was first studied in 1893. This exceptional site preserves hundreds of megafaunal fossils, in the same location and in many cases the same exact body position in which they died after becoming stuck in the muddy lake bed.</p>
<p>New research, published in the journal <a href="https://doi.org/10.1002/spp2.1415">Papers in Palaeontology</a>, shows that getting stuck in the mud was not the birds’ only concern. Bone infections also seem to have been common in this population – highlighting the challenges these birds were facing as their species began to die out.</p>
<h2>The sickness</h2>
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<a href="https://images.theconversation.com/files/437476/original/file-20211214-19-10d9f7y.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/437476/original/file-20211214-19-10d9f7y.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/437476/original/file-20211214-19-10d9f7y.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=733&fit=crop&dpr=1 600w, https://images.theconversation.com/files/437476/original/file-20211214-19-10d9f7y.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=733&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/437476/original/file-20211214-19-10d9f7y.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=733&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/437476/original/file-20211214-19-10d9f7y.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=921&fit=crop&dpr=1 754w, https://images.theconversation.com/files/437476/original/file-20211214-19-10d9f7y.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=921&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/437476/original/file-20211214-19-10d9f7y.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=921&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">Infection on the sternum or chest plate with images of the internal structures associated with the infection.</span>
<span class="attribution"><span class="source">Credit: PL McInerney</span></span>
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<p>As we worked on the fossils in the Flinders University’s palaeontology lab, we noticed several of the bones just didn’t look quite right. They showed unusual distortions, cavities, and a “frothy” surface texture – all clear signs of abnormal bone infections.</p>
<p>We next looked inside the affected bones with the help of CT scans, which confirmed they had suffered abnormal development, distortion and destruction of their internal structure. Investigation into the type of illness that could cause such pathologies led to their diagnosis as osteomyelitis.</p>
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<a href="https://images.theconversation.com/files/437475/original/file-20211214-17-ver0sp.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/437475/original/file-20211214-17-ver0sp.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/437475/original/file-20211214-17-ver0sp.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=642&fit=crop&dpr=1 600w, https://images.theconversation.com/files/437475/original/file-20211214-17-ver0sp.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=642&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/437475/original/file-20211214-17-ver0sp.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=642&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/437475/original/file-20211214-17-ver0sp.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=806&fit=crop&dpr=1 754w, https://images.theconversation.com/files/437475/original/file-20211214-17-ver0sp.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=806&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/437475/original/file-20211214-17-ver0sp.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=806&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">Infection on the leg of <em>Genyornis newtoni</em> and a life reconstruction of the injured bird.</span>
<span class="attribution"><span class="source">Credit: PL McInerney</span></span>
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<p>Osteomyelitis is a chronic bacterial infection of bone tissue, which can be caused either by trauma that lets microbes directly enter bone tissue, or via transmission from infected soft tissues nearby. It can cause serious damage.</p>
<p>Of the 34 partial skeletons of <em>Genyornis</em>, four showed signs of bone infections. But the real number is likely higher, because we couldn’t assess all bones from all 34 individuals.</p>
<p>With the chest, leg and foot regions afflicted, individuals would have suffered pain and restricted mobility. As a result, finding enough water and food around the muddy lake beds of Lake Callabonna would have become an arduous task.</p>
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Read more:
<a href="https://theconversation.com/a-case-of-mistaken-identity-for-australias-extinct-big-bird-52856">A case of mistaken identity for Australia's extinct big bird</a>
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<h2>Disease and drought</h2>
<p>These birds seem to have suffered an unusually high rate of bone disease, compared with today’s birds. This suggests the disease was not random, but instead was associated with a particular environmental cause – but what?</p>
<p>One way to help answer this question is to date the fossils accurately, and then to compare their plight with what we know was happening to the environment at Lake Callabonna at the time.</p>
<p>Calculating the age of these intriguing fossils is not necessarily straightforward because, like many of Australia’s extinct megafauna, they are too old for the classic radiocarbon dating method to work.</p>
<p>So we used an alternative dating technique called <a href="https://www.nature.com/articles/s43586-021-00068-5?proof=t">single-grain optically stimulated luminescence</a>, which reveals when sand grains in the surrounding lake sediments were deposited. This provides a useful estimate of when the birds became mired in the mud.</p>
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<a href="https://images.theconversation.com/files/437483/original/file-20211214-23-1pyf0ic.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/437483/original/file-20211214-23-1pyf0ic.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/437483/original/file-20211214-23-1pyf0ic.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=730&fit=crop&dpr=1 600w, https://images.theconversation.com/files/437483/original/file-20211214-23-1pyf0ic.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=730&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/437483/original/file-20211214-23-1pyf0ic.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=730&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/437483/original/file-20211214-23-1pyf0ic.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=917&fit=crop&dpr=1 754w, https://images.theconversation.com/files/437483/original/file-20211214-23-1pyf0ic.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=917&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/437483/original/file-20211214-23-1pyf0ic.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=917&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">The dating of the Lake Callabonna sediments.</span>
<span class="attribution"><span class="source">Photos supplied by Lee Arnold</span></span>
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<p>As this dating technique applies to sediments rather than bones, it can also be used to reveal the lake history. In particular, it can distinguish between times when the lake was full of water and was accumulating mud on the lake floor, and times when it was much drier and was accumulating wind-blown sands.</p>
<p>Our study revealed that the beleaguered <em>Genyornis</em> population met its demise getting stuck in sediments laid down between 54,200 and 50,400 years ago. Sediments dated from Lake Callabonna and nearby lake systems reveal that a protracted drought phase began around 50,000-46,000 years ago. After this time, the permanent and extensive water body was transformed into the dry lake bed seen today.</p>
<p>This suggests the birds’ fate was sealed once the lake began to dry up. The population became trapped in the freshly exposed lake floor muds as they searched for ever-diminishing water supplies.</p>
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<img alt="" src="https://images.theconversation.com/files/437484/original/file-20211214-13-74x2ws.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/437484/original/file-20211214-13-74x2ws.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=338&fit=crop&dpr=1 600w, https://images.theconversation.com/files/437484/original/file-20211214-13-74x2ws.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=338&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/437484/original/file-20211214-13-74x2ws.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=338&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/437484/original/file-20211214-13-74x2ws.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/437484/original/file-20211214-13-74x2ws.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/437484/original/file-20211214-13-74x2ws.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=424&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">Researchers excavating the Lake Callabonna salt lakes.</span>
<span class="attribution"><span class="source">Photo supplied by Phoebe McInerney</span></span>
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<h2>A role in their extinction?</h2>
<p>The rare preservation of <em>Genyornis</em> fossils at Lake Callabonna offers an extraordinary opportunity to investigate the impact of environmental change on this now-extinct population.</p>
<p>When resources are limited, as they would have been during these severe droughts, birds can initiate a stress response that helps them survive until the next time of plenty. But in the long term, this stress response directs resources away from the immune system, ultimately increasing the birds’ susceptibility to infection and disease.</p>
<p>Thus, it is perhaps no surprise the <em>Genyornis</em> bones bear the hallmarks of severe disease.</p>
<p>There is no conclusive evidence that <em>Genyornis</em> survived for long beyond this time. The drying-out of the lakes they called home may have ultimately sealed their extinction fate.</p><img src="https://counter.theconversation.com/content/173745/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Phoebe McInerney receives funding from Australian Government Research Training Program Scholarship. </span></em></p><p class="fine-print"><em><span>Lee Arnold receives funding from The Australian Research Council. </span></em></p><p class="fine-print"><em><span>Trevor H. Worthy receives funding from The Australian Research Council. </span></em></p>
Genyornis newtoni was one of the biggest birds ever to walk the earth. And new research shows its mysterious extinction may have come amid a bout of widespread bone disease as its lake home dried out.
Phoebe McInerney, PhD Candidate in Avian Palaeontology, Vertebrate Palaeontology Group, Flinders University
Lee Arnold, Associate Professor in Earth Sciences, Centre of Excellence for Australian Biodiversity and Heritage, University of Wollongong
Trevor H. Worthy, Associate Professor, Vertebrate Palaeontology Group, Flinders University
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/121437
2019-08-06T23:13:38Z
2019-08-06T23:13:38Z
Meet the ‘Hercules parrot’ from prehistoric New Zealand – the biggest ever discovered
<figure><img src="https://images.theconversation.com/files/286877/original/file-20190805-36377-18qqp9z.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">_Heracles inexpectatus_ on the forest floor, with three small wrens foraging at its feet.</span> <span class="attribution"><span class="source">Brian Choo</span>, <span class="license">Author provided</span></span></figcaption></figure><p>Say hello to <em>Heracles inexpectatus</em>, a parrot the size of a human child. But don’t worry, you won’t meet one face to face. Our new discovery, published today, lived around 20 million years ago in what is now New Zealand – adding to the islands’ rich and storied collection of remarkable bird species.</p>
<p><em>Heracles</em> was truly a giant among birds. It was about 1m long, stood 80-90cm tall, and weighed about 7kg. That makes it about the same size as a dodo, and far bigger than its modern-day cousin, the kākāpō. Unsurprisingly, given its heft, it was likely also flightless.</p>
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Read more:
<a href="https://theconversation.com/tall-turkeys-and-nuggety-chickens-large-megapode-birds-once-lived-across-australia-79111">Tall turkeys and nuggety chickens: large 'megapode' birds once lived across Australia</a>
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<p>Islands are renowned for huge birds, perhaps none more so than New Zealand. Its fame in this regard began in 1839, when the English scientist Richard Owen first revealed the giant moa to the scientific world. In the next few years, many species of moa were named; now there are <a href="https://teara.govt.nz/en/moa/page-1">nine species in six genera</a>, making them the world’s largest grouping of flightless birds.</p>
<p>Another famous island giant was the dodo of Mauritius. The dodo, now extinct, was a <a href="https://www.theatlantic.com/science/archive/2016/06/the-dodos-redemption/486086/">giant pigeon</a>, rivalled in size only by <em>Natunaornis altirostris</em> from Fiji. </p>
<p>Other now-extinct giant island birds represented outsized versions of various familiar bird types. There were giant flightless ducks (<em>Moa nalos</em>) in Hawaii, a giant flightless swan on Malta, and two prehistoric giant geese from New Zealand. Giant predatory hawks and owls roved about the Caribbean islands, preying on the giant rodents that also lived there.</p>
<p>Although islands, with their isolation and lack of interbreeding, are perfect breeding grounds for outsized creatures, there is no pattern to predict which bird family might spawn a giant on any particular island. </p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/286902/original/file-20190805-36358-beg42u.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/286902/original/file-20190805-36358-beg42u.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/286902/original/file-20190805-36358-beg42u.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=637&fit=crop&dpr=1 600w, https://images.theconversation.com/files/286902/original/file-20190805-36358-beg42u.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=637&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/286902/original/file-20190805-36358-beg42u.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=637&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/286902/original/file-20190805-36358-beg42u.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=801&fit=crop&dpr=1 754w, https://images.theconversation.com/files/286902/original/file-20190805-36358-beg42u.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=801&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/286902/original/file-20190805-36358-beg42u.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=801&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">Heracles shown in silhouette with woman and magpie for scale.</span>
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<p>New Zealand’s birds have long been considered unique in that it was they, rather than mammals, who dominated the land. They included an unusually high number of flightless species, often very large, and most found nowhere else besides New Zealand. </p>
<p>This is epitomised by the kākāpō. It is the heaviest living parrot, potentially weighing more than 3.5kg, and the only flightless one. It is nocturnal, and now <a href="https://www.iucnredlist.org/species/22685245/129751169">critically endangered</a>, the last surviving member of its family, Strigopidae. </p>
<p>Kākāpō, as well as the cheeky <a href="https://www.iucnredlist.org/species/22684831/119243358">alpine kea</a> and <a href="https://www.iucnredlist.org/species/22684840/93049267">kākā</a> represent a group that separated from all other parrots relatively early during their evolution. Cockatoos were the next to branch off. These facts suggest that parrots evolved in the region that is now Australia and New Zealand. But their exact evolutionary history remains elusive.</p>
<h2>Branching out</h2>
<p>Now our research team at Flinders University, the University of New South Wales and <a href="https://www.canterburymuseum.com/">Canterbury Museum</a> has shed some light on these issues. Our new research, <a href="https://doi.org/10.1098/rsbl.2019.0467">published in the journal Biology Letters</a>, reveals a newly discovered prehistoric giant from New Zealand - the first known giant parrot. </p>
<p>We discovered <em>Heracles</em> in the <a href="https://www.nzgeo.com/stories/deep-secrets/">St Bathans Fauna</a>, a collection of 20 million-year-old fossils from Central Otago. </p>
<p>Over the past 20 years, our research has discovered around 40 species from the St Bathans Fauna, including a wealth of fascinating prehistoric bird remains. These include eggshell and fragments of moa ancestors, a <a href="http://www.sci-news.com/paleontology/science-proapteryx-micromeros-kiwis-australia-01645.html">tiny kiwi</a>, many ducks, a couple of pigeons, <a href="https://news.flinders.edu.au/blog/2018/03/01/going-cheep-tiny-birds-follow-dodo/">flightless rails</a>, hawks and eagles, shorebirds, songbirds, and several small parrot species. Crocodilians, turtles, bats and even rare land mammals complete this eclectic group. </p>
<p><em>Heracles</em> now reveals that another avian giant existed in this fauna. For the first and only time since, a giant parrot occupied the herbivore/omnivore niche on a forest floor.</p>
<h2>Delayed discovery</h2>
<p>Remarkably, the fragments of bone that allowed us to discover this giant parrot had sat on a shelf since 2008, patiently waiting for their turn to be described. We had known that St Bathans also contains eagle fossils of similar size, so the <em>Heracles</em> fossils were put on the eagle pile while we waited to find some more fossils that might tell us more. </p>
<p>But upon pulling them out and looking more closely, it was immediately clear that these were not eagle bones, so we started trying to work out what they were. Parrots were not on our radar at first, purely because these bones were far larger than those of any known parrot. But after a while the bones told their story – they were of a parrot, and nothing else was remotely similar. Moreover, they were in some ways fairly similar to the kākāpō. </p>
<p>And so <em>Heracles inexpectatus</em> was born, the name derived from Greek mythology. The large New Zealand parrots, kea and kākā, are in the genus <em>Nestor</em>. The mythical ancient Greek hero Heracles, in Latin known as Hercules, killed Neleus and his sons, except for Nestor. So it is only fitting that this giant parrot, an ancient predecessor of <em>Nestor</em>, be bestowed the name <em>Heracles</em>. Neleus, Nestor’s father, we had already used for the genus of small parrots <em>Nelepsittacus</em> that lived with <em>Heracles</em>. The species name <em>inexpectatus</em> relates to the wholly unexpected nature of discovering a giant parrot.</p>
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Read more:
<a href="https://theconversation.com/a-case-of-mistaken-identity-for-australias-extinct-big-bird-52856">A case of mistaken identity for Australia's extinct big bird</a>
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<p>So what was a giant parrot doing in ancient New Zealand? What did it eat? Could it have had a taste for meat, as the kea still does? These mountain parrots <a href="https://teara.govt.nz/en/video/14010/kea-digging-out-a-shearwater-chick">prey on the chicks of burrowing petrels</a> and are notorious for <a href="https://www.nzgeo.com/stories/kea-the-feisty-parrot/">attacking sheep</a>. </p>
<p>But in New Zealand 20 million years ago there were no sheep, and in fact no large mammals at all. Probably, like most parrots, <em>Heracles</em> ate plants. Its size meant no fruit was too big, no nut too tough to crack. And the botanical evidence shows that it lived in a rich and diverse subtropical forest, where cycads, palms, casuarinas and up to 60 species of laurels thrived. </p>
<p>All these plants would have provided a rich bounty for this large parrot. But we warrant that it likely still snacked on moa occasionally, as kea still did more recently, when they got mired in swamps.</p>
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<p><em>This article was coauthored by <a href="https://www.canterburymuseum.com/about-us/management-team/paul-scofield-phd-mschons-bsc/">Professor Paul Scofield</a>, Senior Curator of Natural History, Canterbury Museum.</em></p><img src="https://counter.theconversation.com/content/121437/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Trevor H. Worthy receives funding from Australian Research Council. </span></em></p>
The newly discovered Heracles inexpectatus stood nearly a metre tall. And its fossil bones sat undiscovered on a museum shelf for more than a decade before its hefty status was finally appreciated.
Trevor H. Worthy, Associate professor, Flinders University
Licensed as Creative Commons – attribution, no derivatives.