Newly found Aussie dinosaur confirms diversity in ancient rift valley
The space between Australia and Antarctica was once rich with herbivorous life. Andrew Masterson reports.
The discovery of a previously unknown species of small herbivorous dinosaur in the south-eastern corner of Australia confirms that life thrived in a vast rift valley that once existed between the continent and Antarctica, palaeontologists say.
The dinosaur, identified from five fossilised jaw bones, would have been about the size of a wallaby, or a Labrador. The bones were unearthed from a site in the Gippsland region of the state of Victoria, and date from the Cretaceous period, which began about 145 million years ago.
The new dino has been formally named Galleonosaurus dorisae, and is described in a paper published in the Journal of Paleontology, by researchers led by Matthew Herne of Australia’s University of New England.
The animal, the researchers say, belonged to large family called ornithopods. It represents the fifth genus of small ornithopods found in Victoria, which at the time would have been at the northern edge of the valley created by the gradual separation of Australia and the Antarctic.
The finding, says Herne, “confirms that on a global scale, the diversity of these small-bodied dinosaurs had been unusually high in the ancient rift valley”.
The researchers established that G. dorisae was a close relation of another ornithopod found in the west of Victoria – by the same team – in 2018, called Diluvicursor pickeringi. However, the new find dates from about 12 million years later, indicating that the family was well and truly established in the valley for a very long period of time.
The jaw bones, which include a juvenile version, were not found where the dinosaurs died. Rather, the scientists say, they were part of a large collection of detritus washed along by erupting volcanoes and large rivers.
The research also revealed that the Victorian ornithopods were closely related to other species found in Patagonia in Argentina.
“We are steadily building a picture of terrestrial dinosaur interchange between the shifting Gondwanan continents of Australia, South America and Antarctica during the Cretaceous period,” says Herne.