Galleonosaurus dorisae: New Species of Plant-Eating Dinosaur Discovered in Australia

Tuesday, March 12, 2019

Galleonosaurus dorisae. Image credit: James Kuether.

Paleontologists in Australia have found fossil fragments from a new genus and species of ornithopod dinosaur that walked the Earth during the Early Cretaceous Period.

The new dinosaur belongs to Ornithopoda (ornithopods), a major group of herbivorous bird-hipped dinosaurs.

Dubbed Galleonosaurus dorisae, it inhabited the rift between Australia and Antarctica approximately 125 million years ago (Cretaceous Period).

Five fossilized upper jaws of the ancient beast were found at the Flat Rocks locality of the Wonthaggi Formation in a region of Gippsland, Victoria, Australia.

Galleonosaurus is the fifth small ornithopod genus named from Victoria,” said Dr. Matthew Herne, a postdoctoral researcher at the University of New England.

“The discovery confirms that on a global scale, the diversity of these small-bodied dinosaurs had been unusually high in the ancient rift valley that once extended between the spreading continents of Australia and Antarctica.”

“Small ornithopods appear to have thrived on the vast forested floodplain within the ancient rift valley.”

Specimens of Galleonosaurus dorisae from the Flat Rocks Sandstone in the upper Barremian, Wonthaggi Formation, Gippsland Basin, southeastern Australia. Scale bars – 10 mm (1-6); 1 mm (7). Image credit: Herne et al, doi: 10.1017/jpa.2018.95.

Galleonosaurus dorisae is a close relative of Diluvicursor pickeringi, another small ornithopod named by Dr. Herne and co-authors in 2018, from excavations along the Otway coast to the west of the Gippsland region.

“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.

“However, Galleonosaurus dorisae is about 12 million years older than Diluvicursor pickeringi, showing that the evolutionary history of dinosaurs in the Australian-Antarctic rift had been lengthy.”

Prior to discovery of Galleonosaurus dorisae, the only other ornithopod known from the Gippsland region was Qantassaurus intrepidus, named in 1999.

“However, Qantassaurus intrepidus had a shorter more robust snout than that of Galleonosaurus dorisae,” Dr. Herne said.

“We consider that these two, similarly-sized dinosaurs fed on different plant types, which would have allowed them to coexist.”

The researchers also found that the ornithopods from Victoria are closely related to those from 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,” Dr. Herne noted.

The study was published in the Journal of Paleontology.

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Matthew C. Herne et al. New small-bodied ornithopods (Dinosauria, Neornithischia) from the Early Cretaceous Wonthaggi Formation (Strzelecki Group) of the Australian-Antarctic rift system, with revision of Qantassaurus intrepidus Rich and Vickers-Rich, 1999. Journal of Paleontology, published online March 11, 2019; doi: 10.1017/jpa.2018.95

Source: www.sci-news.com