News in Science

Mammals' tusked ancestor roamed Australia

'Strange looking' beast Scientists say rare fossils found in Tasmania's south-east prove that an ancient species of prehistoric animal did exist throughout Australia.

The dicynodont was an early ancestor of modern-day mammals and lived about 250 million years ago.

Roughly the size of a cow, the plant-eating animal had two tusks and a horny beak.

Queensland Museum palaeontologist Dr Andrew Rozefelds says they lived on every continent, including Antarctica.

But until now, the only Australian specimen was found in Queensland almost 30 years ago.

He says it is surprising more remains have not been found, given the animal's size.

"There must be more material out there to be found," he says.

"Obviously we'd love to find more, because at the moment, [of] this entire group of animals called dicynodonts, there's only about four bones known from Australia.

"We've got better fossil records from Antarctica for these animals than we have for Australia."

He describes the dicynodont as a bizarre-looking creature.

"They're a strange-looking beast," he says.

"They had tusks at the front of their skull, which makes you think maybe they were a carnivore but in fact they were a plant eater.

"They had slightly splayed legs, so their posture was quite different to say some of the modern mammals you see and they're very, very distantly related to modern mammals."

Significant find

Bob and Penny Tyson discovered the bone fragments a few years ago when they were walking along the beach on the Tasman Peninsula.

Mr Tyson had gone for a walk along the rocky foreshore when he found some rare amphibian skulls.

He took a few photos of the fossils and then went back to the place where they were staying to get his wife.

She started looking closer to the waterline and found a fossilised tusk, right on the low tide mark, sitting in seaweed.

"It was sitting on top of the rock surface, so all the surrounding rock had been worn away," says Mrs Tyson.

"It was just sitting there waiting to be knocked off."

University of Tasmania sedimentologist Dr Stuart Ball, who dated the fossils, says the remains are from the early Triassic period.

They predate the dinosaurs by at least 30 million years.

He says it is likely floods washed the animals' remains into billabongs, which is why only fragments have turned up.

Rozefelds says the latest find proves that not only did dicynodonts exist in Australia, but they may have survived here longer than anywhere else in the world.

He says scientists from places like China have been contacting him about the Tasmanian find.

"We're looking at animals that survived the Permian Triassic extinction," he says.

"Now, most of the animal life on the planet was destroyed, it was exterminated. Yet these animals for some reason survived that extinction event and we don't know why."

The research team's findings have been published in the international Journal of Vertebrate Palaeontology.

The specimens are being stored at the Tasmanian Museum and Art Gallery but are not yet on display.