Largest Australian carnivorous dinosaur found in Queensland

Scientists have unearthed the remains of the largest carnivorous dinosaur ever discovered in Australia.

The bones were found in 2017 in the area around Winton in western Queensland, which has become world-renowned for its high number of fossilised remains.

The animal was part of the group of dinosaurs known as theropods, which includes Tyrannosaurus rex, and appears to be similar to the previously discovered Australian carnivore Australovenator wintonensis.

An artist's impression of the carnivores attacking a larger plant-eating dinosaur in the ancient outback.Credit: Travis Tischler

Dr Matt White, lead researcher from the University of New England, said the dinosaur was likely another specimen of A. wintonensis or very closely related to it.

"I would suspect it’s another Australovenator skeleton, but one slightly larger [than previously discovered]," Dr White said.

"These remains were quite partial, when we had a look they were a slightly different size and shape, but that could be because this animal was slightly older or that there was a male-female [size] difference."

In total, the dig team discovered more than 200 bone fragments, some of them quite small, and eventually managed to identify two partial vertebrae and three bones from the hands and feet.

Dr Matt White has led a dig team which has uncovered the bones of the largest carnivorous dinosaur yet discovered in Australia

Because of the relatively low number of bones they can’t confirm one way or another whether this was another A. wintonensis, but it was definitely within the theropod sub-group megaraptoridae, which were much larger than the velociraptors popularised in Jurassic Park.

This dinosaur would have been about two metres tall and between five to seven metres long, with foot-long claws on its powerful forearms that were likely used to grab and slash prey.

It would have likely hunted the numerous long-necked, herbivorous sauropod dinosaurs that would have roamed the area approximately 95 million years at the start of the Cretaceous period, when that part of Australia was the swampy shore of a great inland sea.

Numerous fossils of those sauropods have been found around Winton, however.

Dr White said because of the ratio of large prey animals to smaller predators, discovering these theropod fossils was extremely rare.

"With regard to skeletons, this is only the second one we’ve found [at Winton] in 20-odd years, so that’s quite exciting in itself," he said.

"It’s only the third theropod specimen discovered in Australia that consists of more than one bone."

The first Australovenator wintonensis fossil was discovered in the Winton area in 2006, confirming that the large predators did exist in ancient Australia.

Dr White is one of dozens of scientists and volunteers who go to Winton every year to participate in fossil digs, and said he would love to get his hands on more theropod remains.

"We’re due to uncover a more complete one but it hasn’t turned up yet. Maybe in the coming years it’ll show up," he said.