The Tasmanian tiger had the fierce name, but new research suggests a distant cousin was a more ferocious killer.
An examination of the skull of the ancient Nimbacinus dicksoni has revealed its powerful bite could kill prey bigger than its small, foxed-sized body.
"It was a pretty tough little bugger," said University of New England palaeontologist Steve Wroe, who supervised the research.
Nimbacinus lived between 25 million and 15 million years ago and was a member of the thylacinid family – a group of about 10 carnivorous marsupials.
It feasted on a range of prey including other marsupials, birds, lizards and snakes. By comparison, the larger Tasmanian tiger or thylacine, the last of the family declared extinct in 1936, mostly hunted prey much smaller than itself.
As part of her PhD research, Marie Attard, now at the University of New England, built a 3D model of Nimbacinus' skull based on the only fossil specimen of the creature, which lived about 15 million years ago and was uncovered in the Riversleigh World Heritage site in north-west Queensland.
The 3D models, which use the same digital technology used to crash-test cars and planes, simulate different animal behaviours, such as bite force or the stress on an animal's skull when it captured and shook its prey.
"The idea [of the model] is that you can get an idea of how something is going to work without having to build it and smash it up – that's especially handy for things like fossils which are difficult to replace," said Dr Wroe, whose findings are published in the journal PLoS One.
The group compared the bite force and mechanics of Nimbacinus to that of its closest living relatives including the spotted-tailed quoll and the Tasmanian devil as well as its extinct cousin, the thylacine.
"To our surprise the Nimbacinus performed much more like a living quoll than a Tasmanian tiger despite being more closely related to the tiger," Dr Wroe said.
University of NSW palaeontologist Mike Archer, who helped discover the only complete skull in 1993, said the animal had most likely died after falling into a cave.
"We found, from the posture of the skeleton, it had folded its arms, and put its head down for a quiet little 15 million-year-long nap. Hence, we nick-named it the 'Philosophical Thylacine'," he said.
Apart from thylacine fossils, the Nimbacinus specimen was the only other extinct thylacinid skeleton known and provided many insights into the evolutionary origins and behaviours of Australia's carnivorous marsupials, Professor Archer said.
