These amazing 107-million-year-old pterosaur bones are the oldest ever found in Australia

New research on older bones from Australia’s Early Cretaceous period, about 107 million years ago, has shed light on pterosaur fossils.

The bones were discovered at a fossil site in Victoria in the late 1980s. Dinosaur CoveA few hours drive west of Melbourne.

Our paper describing the bones Published today in Historical Biology.

The oldest pterosaur bones we have

Dinosaur Cove fossils are geologically oldest pterosaur remains. Lower Cretaceous of Australia.

These bones belong to two separate individuals because of the difference in relative size between the two.

One specimen is a partial sacrum (the fused vertebrae from between the pelvic bones), relatively rare in the pterosaur fossil record. Another is a relatively small fourth metacarpal (part of a wing toe) – the first evidence of a young pterosaur found in Australia.

Although we cannot pinpoint which species of the pterosaur these bones came from, the partial sacrum belonged to an individual with a wingspan of over two meters. In contrast, young pterosaurs had wingspans of over a meter.

Including wingspan estimates of Australian pterosaurs Ferrodraco lendoniAn adult from the Upper Cretaceous of Queensland compared with newly described Victorian pterosaurs from the Lower Cretaceous.
Presented by the author

In the Early Cretaceous, approximately 110-107 million years ago, Victoria was virtually unrecognized. Bass Strait is a narrow valley encroached by fast-flowing rivers. Cones and ginkgos grew here instead of eucalypts and grasses, and dinosaurs ruled.

On the ground, the dominant herbivores were small-bodied, beaked ornithopods, always alert rapacious megaraptoran theropods.

For more than 30 years, it has become clear to scientists that flying reptiles known as pterosaurs soared in the Victorian Cretaceous skies above the heads of dinosaurs. However, until recently, they remained a mystery.

READ  Physicists demonstrate how sound can travel through a vacuum

Dinosaur temple treasure

Large-scale excavations at Dinosaur Cove Started in 1984, more than 40 years ago, a group of volunteers called Dinosaur Dream Fossil sites have been excavated at several sites scattered across the coast of Victoria.

Tom Rich And Pat Vickers-RichThe co-authors of our newly published paper led excavations that yielded not only newly described pterosaurs but countless other discoveries.

Two paleontologists holding pterosaur bones
Co-authors Pat Vickers-Rich and Tom Rich held the pterosaur specimens we described.
Presented by Tim Ziegler, Editor

Work at this rich fossil site has yielded thousands of dinosaur bones and other fossils. These include fossil fish (bony fish and lungfish), skeletal remains of ornithopods, megaraptoran theropods, aquatic plesiosaurs, and prehistoric mammals. was also Australia’s only elaphrosaurine theropod: A lightly built dinosaur with a small head, long neck, relatively short forelimbs, long hind legs, and a long tail.

But rare vertebrate fossils from Dinosaur Cove include fossils of pterosaurs.



Read more: Meet the diverse group of plant-eating dinosaurs that roamed Victoria 110 million years ago


Australia’s Pterosaur Record

Most of Australia’s pterosaur fossils have been found in central-west Queensland. In fact, First pterosaurs reported from the continent Isolated remains from the Eromanga Basin described in 1980.

Since then, more pterosaur material has come to light, with four Australian pterosaur species currently recognized: Maidunga Camera, Ausydrago molnari, Ferrodraco lendoni And Tabungaka said.

Irondrake It is the most complete Australian pterosaur to date, and is referred to An adult individual with a wingspan of approximately four metersWe named a new breed in 2019.



Read more: 4m flying reptile found in Queensland is our best pterosaur fossil


Other pterosaur fossils from Australia include isolated remains from the Cretaceous of Western Australia. opalised pterosaur teeth From the middle of the Lightning Ridge in New South Wales.

Three pterosaur wing bones
Three pterosaur wing bones from three individuals. Left: A right metacarpal from the Toolbuck Formation at Slashers Creek Station, east of Paulea, Queensland. Middle: Left metacarpal Ferrodraco lendoni From the Winton Formation discovered northeast of Winton, Queensland. Right: A left metacarpal from a juvenile pterosaur from Dinosaur Cove, Victoria.
Presented by the author

We don’t know which species the Victorian pterosaurs belonged to. However, a relatively small fourth metacarpal – a bone from the wing – is the first clear evidence of a young pterosaur from Australia.

Pterosaurs at high latitudes

Age of Reptiles – A few pterosaur remains have been reported from fossil sites at high latitudes during the Mesozoic Era.

All of Antarctica was at high latitudes. Three pterosaur fossils have been produced. One of these awaits formal description, and the other was recovered from the charred remains of the National Museum of Brazil.

There are only reports of high-latitude pterosaurs in the Northern Hemisphere Isolated footprints.

During the Cretaceous period, Australia was further south than it is today. In fact, Victoria was within the Arctic Circle during most of the Cretaceous. South-eastern Australia did not freeze at this time, but continued darkness for weeks or months during the winter. Despite these Extreme polar conditionsFound a way to survive and thrive.

This prompts some questions: Were pterosaurs permanent residents of southeastern Australia? Or did they migrate south in the summer and go north in the winter?

From an early age, pterosaurs were capable of flight, their bones are already capable of withstanding the stresses of both launch and flight. However, subtle variations in the shape of the bones indicate that chicks differ from their adult counterparts in terms of speed and maneuverability.

Until pterosaur eggs or embryonic individuals are found in locations at higher latitudes at the time, it cannot be confirmed whether pterosaurs were year-round residents or migrants.

Although pterosaurs are rare in the fossil record, it’s only a matter of time before we find more complete pterosaur material from Dinosaur Cove and other Cretaceous sites in coastal Victoria. Then, we can finally discover the identity of these ancient, enigmatic winged reptiles.

Dodaj komentarz

Twój adres e-mail nie zostanie opublikowany. Wymagane pola są oznaczone *