Dinosaur discovery a world first- and it hails from Australia

The world has a new dinosaur: a barrel-bellied giant herbivore that stood as tall as a giraffe and grazed the grasslands of what is now central-west Queensland.

While its height of up to six metres places it alongside the dainty giraffe, that's where the similarities end.

This newly discovered cretaceous creature named Savannasaurus elliottorum had stumpy legs, which it needed to support its solid frame and wide girth. Its hips alone were 1.5 metres wide.

"You could almost look at it as a long-legged, long-necked and long-tailed hippopotamus with a much smaller head," said paleontologist Stephen Poropat.

An artist's impression of the new dinosaur, Savannasaurus elliottorum.Credit: Travis Tischler

The first dinosaur bone was found by chance in March 2005 by grazier David Elliott while mustering sheep on his outback Queensland property near Winton, 177 kilometres north-west of Longreach.

It took two digs and years of painstaking work to release the bones from the clay-rich soil. A front end loader was used to scrape off the topsoil before paleontologists attempted to remove the earth surrounding the fossils. The traditional tools of choice were defeated and instead, pneumatic tools with special tips had to be called upon to remove rock from bone.

"That's why, even though this dinosaur was discovered in 2005, it hasn't been announced until now," said Dr Poropat, a research associate at the Australian Age of Dinosaurs Museum in Winton.

But unearthing the 95-million-year-old dinosaur remains was worth the wait. The find represents not only a new species of dinosaur but a new genus.

Stephen Poropat with the fossilised remains of Savannasaurus elliottorum - found in Queensland. Credit: David Elliott, Australian Age of Dinosaurs Museum

"It represents a new end point on the sauropod family tree," Dr Poropat said.

Almost a quarter of the skeleton has been retrieved - making this the third-most complete Australian dinosaur skeleton.

The central-western Queensland site in 2005, when the fossils were found.Credit: David and Judy Elliott, Australian Age of Dinosaurs Museum

The largest individual fossil collected was the dinosaur's humerus, or upper arm bone, which weighs about 100 kilograms.

The bones collected include vertebrae, pelvis, shoulder and limb bones. However there are just a few neck and tail bones, leaving researchers to guess the length these body parts might have been.

A skeletal reconstruction of the new dinosaur, based on the fossils found. Credit: Travis Tischler

Having gathered almost a quarter of the skeleton, paleontologists were able to build up a picture of what the dinosaur, which belongs to the titanosaurus group, might have looked like.

Its barrel of a belly would have housed a huge gut, where the nutrients from the vegetation it snipped off plants with its front teeth were slowly extracted. It didn't have back teeth, so was unable to chew.

Dr Stephen Poropat with five back vertebrae from Savannasarus elliottorum.Credit: Judy Elliott

"These dinosaurs may well have been like walking, fermenting vats," Dr Poropat said. "They could have retained food in their system for up to two weeks in order to extract sufficient nutritional value from their food."

Its ancestors probably came from South America - meaning the Australian dinosaur could provide an explanation as to how and when dinosaurs dispersed across the globe.

"It's a really exciting find as it sheds light on exactly how animals moved across the continents and through time," Dr Poropat said.

"And another thing the fossil record can help us answer is when the Australian fauna started to show such a unique character. It's quite possible that that process started long before Australia finally detached from Antarctica."

The discovery, as well as the identification of the first fossilsed dinosaur head bones ever found in Australia, has been outlined in the journal Scientific Reports.