With this discovery, there are now five small-sized ornithopods that have been named from the Australian-Antarctic rift valley, meaning the diversity of "turkey-sized up to about emu-sized" dinosaurs was unusually high here, Herne said. It's 125 million years old and once bopped about Victoria, southeastern Australia on its hind legs during the Cretaceous.
Researchers discovered five fossilized jaws from a previously unknown dinosaur in the state of Victoria that was about the size of a modern-day wallaby. It's the fifth small ornithopod genus named from Victoria in Australia.
"These small dinosaurs would have been agile runners on their powerful hind legs", said Matthew Herne, lead author of the study and a postdoctoral fellow at the University of New England in New South Wales, in a statement.
More than 10 years later, with the aid of rapidly advancing technologies like 3D micro-CT scanning and 3D printing, Herne's analysis is bringing new anatomical information to light.
The researchers believe this shows that dinosaurs were living and evolving in the rift valley for a long time. Millions of years ago, part of the rift was located within the Arctic Circle, but the climate was relatively warm, allowing plants and animals to thrive there. But traces of some of the species that once lived there have been preserved, thanks to miles of once-active volcanoes along the rift.
"Interestingly, the jaws of the new species and the partial skeleton of Diluvicursor pickeringi were similarly buried in volcanic sediments on the floor of deep powerful rivers", Dr. Herne said.
By looking at fossils from these basins, experts can also get a better sense of how prehistoric creatures were moving across the globe.
This marks "the first time an age range has been identified from the jaws of an Australian dinosaur", according to Herne.
The new finding suggests, "land connections (land bridges) between Australia and South America, via Antarctica, must have been available to dinosaur groups at times during the Cretaceous that resulted in closer genetic links between the dinosaurs on these continents than between these dinosaurs and those in other places", he wrote in an email to Live Science.