Scientists have for the first time pieced together the full skeleton of Thylacoleo carnifex, that existed on the continent until about 40,000 years ago.

It weighed around 100kgs but was a skilled tree climber thanks to a heavy muscular tail.

"It had this really interesting combination of features," professor Rod Wells, lead author of the Flinders University study published this week in scientific journal PLOS ONE, said.

"It had a cat-like head but instead of having big canine teeth it's got stabbing incisor teeth that come together like a chisel at the front - a pretty ferocious looking animal."

Researchers analysed complete skeletons of the animal found in 2007 at caves in Naracoorte, South Australia, and on the Nullarbor Plain.

Prof Wells said the marsupial lion was not related to the Tasmanian devil but they shared a similar stiff awkward walking style.

"To find skeletons with everything in the right position is pretty damn rare," Prof Wells said.

"We concluded that the marsupial lion was a stealth or ambush predator of larger prey, a niche not dissimilar to that of the Tasmanian devil, which feeds on smaller prey in comparison."

In an Aussie-fauna mish-mash, it also had powerful hindquarters with feet like an overgrown brush-tail possum, and would have climbed a bit like a koala, researchers say.

It is hoped further finds of tracks and other bones will shed light on the animal's social behaviour and diet.

Thylacoleo carnifex was Australia's largest mammalian predator until the megafauna died out around 40,000 years ago.

Australian Associated Press