Wallaby format dinosaur discovered in Australia (Crikey!)

A small agile dinosaur with powerful hind legs crisscrossed the ancient Rift Valley between Australia and Antarctica during the Cretaceous.

Archaeologists have recently discovered fossils belonging to this wallaby-sized species during the excavation of 125 million-year-old rocks in Victoria, Australia. They found five fossilized upper jaws that resembled the inverted hulls of ships called galleons.

Scientists have named the species Galleonosaurus dorisae, after the galleon and paleontologist Doris Seegets-Villiers, who earned her PhD while working in the area. The bone analysis showed that the new dinosaur was an ornithopod, a group of herbivorous dinosaurs that had bird-like feet and walked on their hind legs. [Images: These Downy Dinosaurs Sported Feathers]

"These little dinosaurs would have been agile runners on their powerful hind legs," said Matthew Herne, senior author of the study, a postdoctoral fellow at the University of New England.

The bones were buried in volcanic sediments probably driven by rivers from an active eastern volcanic chain during the Cretaceous period. "River-driven sediments in the Rift Valley have created a forested flood plain on which dinosaurs such as Galleonosaurus and many other types of dinosaurs and other animals have flourished, "Herne told Live Science.

Last year, the same team identified another small species of ornithopods from these volcanic sediments: Diluvicursor Pickeringi. Their analysis suggests that G. Dorisae is a close relative of D. pickeringi but 12 million years older.

They also found that this new species was more closely related to Patagonian ornithopods than those in North America and China, said Herne. "We regularly build an image of the terrestrial exchange of dinosaurs between the evolving Gondwanan continents of Australia, South America and the Antarctic during the Cretaceous period" said Herne. At the time, the supercontinent Gondwana was moving and Australia and Antarctica were separating (forming an ancient rift valley that eventually filled with water to form the ocean Southern).

The new discovery suggests that "terrestrial links (land bridges) between Australia and South America, via Antarctica, had to be sometimes accessible to dinosaur groups during the Cretaceous, which has resulted in closer genetic links between the dinosaurs of these continents than between these dinosaurs and those in other places, "he wrote in an email to Live Science.

the G. dorisae Fossils were discovered about ten years ago by volunteers of the Dinosaur Dreaming project, led by paleontologists from Victoria and Monash University museums, who were excavating near the towns of Inverloch and Wonthaggi, according to the press release. But it is only recently that scientists have studied and described the species.

Galleonosaurus is the fifth genus of ornithopods (the classification just above species) identified since Victoria, which "confirms" that these small-body dinosaurs were very diverse and thrived in the Rift Valley that covered the area. Australia and Antarctica, said Herne.

Researchers reported on their findings today (March 11) in the Journal of Paleontology.

Originally published on Science live.