A Wallaby the Size of a Dinosaur Found in the Antarctic Rift Valley

Artist's impression of a Galleonosaurus dorisae herd on a riverbank in the Australian-Antarctic rift valley during the Early Cretaceous, 125 million years ago. The newly-named, wallaby-sized herbivorous dinosaur was identified from five fossilized upper jaws in 125-million-year-old rocks from the Cretaceous period of Victoria, southeastern Australia. (Image: copyright James Kuether)

A new wallaby-sized herbivorous dinosaur has been identified from five fossilized upper jaws in 125 million-year-old rocks from the Cretaceous period of Victoria, southeastern Australia. Reported in the Journal of Paleontology, the new dinosaur is named Galleonosaurus dorisae, and is the first dinosaur named from the Gippsland region of Australia in 16 years.

According to Dr. Matthew Herne, a Postdoctoral Fellow at the University of New England, NSW, and lead author of the new study:

Galleonosaurus was a small-bodied herbivorous dinosaur within the large family called ornithopods. Dr. Herne explained:

The name Galleonosaurus dorisae refers to the shape of the upper jaw, resembling the upturned hull of a sailing ship called a galleon, and also honors the work of Dr. Doris Seegets-Villiers, who produced her Ph.D. thesis on the paleontology of the locality where the fossils were discovered.

Galleonosaurus is the fifth small ornithopod genus named from Victoria, which according to Dr. Herne:

Small ornithopods appear to have thrived on the vast forested floodplain within the ancient rift valley. At the time of Galleonosaurus, sediments were shed from a 4,000-km-long massif of large, actively erupting volcanoes that once existed along the eastern margin of the Australian continent.

Fossils and 3D CT model of the newly named dinosaur, Galleonosaurus dorisae. The wallaby-sized herbivorous dinosaur has been identified from five fossilized upper jaws in 125-million-year-old rocks from the Cretaceous period of Victoria, southeastern Australia. (Credit: Matthew Herne)
Fossils and 3D CT model of the newly named dinosaur Galleonosaurus dorisae. The wallaby-sized herbivorous dinosaur has been identified from five fossilized upper jaws in 125-million-year-old rocks from the Cretaceous period of Victoria, southeastern Australia. (Image: Matthew Herne)

Some of these sediments were carried westward by large rivers into the Australian-Antarctic rift valley where they formed deep sedimentary basins. However, as these sediments washed down the rivers of the rift valley, the bones of dinosaurs, such as Galleonosaurus and other vertebrates, along with the logs of fallen trees, became mixed in. According to Dr. Herne:

The new article shows that Galleonosaurus dorisae is a close relative of Diluvicursor pickeringi, another small ornithopod named by Dr. Herne and his team in 2018 from excavations along the Otway coast to the west of the Gippsland region. Dr. Herne explained:

The jaws of Galleonosaurus were discovered by volunteers of the Dinosaur Dreaming project during excavations near the town of Inverloch. The most complete jaw and the key specimen carrying the name Galleonosaurus dorisae was discovered in 2008 by the seasoned fossil hunter Gerrit (Gerry) Kool, from the nearby town of Wonthaggi.

Gerry and his wife Lesley have been instrumental in organizing the Dinosaur Dreaming excavations along the Victorian coast for 25 years. Prior to the discovery of Galleonosaurus dorisae, the only other ornithopod known from the Gippsland region was Qantassaurus intrepidus, named in 1999. However, Qantassaurus had a shorter more robust snout than that of Galleonosaurus, explained Dr. Herne, adding:

The new study reveals that the ornithopods from Victoria are closely related to those from Patagonia in Argentina. Dr Herne said:

These are exciting times for dinosaur research, explained Dr. Herne:

Provided by: Cambridge University Press [Note: Materials may be edited for content and length.]

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