Fossil of unusual toothless dinosaur discovered in Australia

By Australian Geographic 18 May 2020
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Meet Eric the Elaphrosaur.

A STRANGE TOOTHLESS dinosaur once roamed Australia, according to new research on a Museums Victoria fossil specimen.

The fossil, described today in the journal Gondwana Research, belonged to a group of theropods known as elaphrosaurs.

“Elaphrosaurs were strange looking dinosaurs – they ran low to the ground on two legs, with a slender body, long neck, stubby arms, and a delicate toothless skull,” says Tim Zieglerthe, the collection manager of vertebrate palaeontology at Museums Victoria.

“They started life eating a wide range of foods, but shed their teeth as they aged. Elaphrosaurs are unusual among theropods because adults had a plant-based diet, rather than hunting prey.”

Elaphrosaur fossils from other continents suggest these dinosaurs lived during the Late Jurassic, however the Australian fossil dates to almost 40 million years later, from the Early Cretaceous period.

“Young elaphrosaurs might have hunted the tiny monotremes (ancestors to platypus and echidna) that lived in polar Victoria, along with snapping up insects and fruits,” Tim says.

The fossilised neck vertebra was first discovered by museum volunteer Jessica Parker at Eric the Red West, a fossil site near Cape Otway, Victoria.

The remains were originally mistaken for those of a flying pterosaur until palaeontologists Stephen Poropat and Adele Pentland from Swinburne University struggled to identify exactly which pterosaur it was.

“Pterosaur neck vertebrae are very distinctive,” Stephen says. “In all known pterosaurs, the body of the vertebra has a socket at the head end, and a ball or condyle at the body end. This vertebra had sockets at both ends, so it could not have been from a pterosaur.”

Extensive research and analysis eventually identified it as the first known fossil of an elaphrosaur ever found in Australia.

The dinosaur has been affectionately named ‘Eric the Elaphrosaur’, after the area it was discovered. 

“New discoveries like this elaphrosaur fossil overturn past ideas, and help to interpret discoveries yet to come,” says Tim. 

“The Museums Victoria collection plays an important role in presenting this new aspect of Victoria’s natural heritage and ensuring the public and scientists can learn more about Victoria’s fossil record for generations to come.”