Tasmanian tiger Australia
Whollydooleya tomnpatrichorum was similar in size to the Tasmanian Tiger (pictured)Hulton Archive/Getty Images

Australian scientists have found the fossil of a carnivorous marsupial which would have been the largest on the continent before dying out some five million years ago. Whollydooleya tomnpatrichorum weighed around 25 kg, three times more than the current largest Australian carnivore of its type, the Tasmanian devil, and was almost as large as the Tasmanian tiger, which died out in 1936.

Whollydooleya had huge teeth capable of ripping apart larger animals and would have been a fearsome hunter. It was one of a group of megafauna which were active in the continent during the Late Miocene (16 million to 11 million BC). The fossil was found at a site called New Riversleigh in Queensland, a four hour drive from Mount Isa. New Riversleigh had been identified by satellite as being potentially a rich source for new discoveries and a team from University of New South Wales (UNSW) began exploring in 2013.

"New Riversleigh is producing the remains of a bevy of strange new small to medium-sized creatures,"UNSW professor and lead author Mike Archer told Sky News. "These new discoveries are starting to fill in a large hole in our understanding about how Australia's land animals transformed from being small denizens of its ancient wet forests to huge survivors on the second most arid continent on Earth."

Professor Archer told ABC the discovery of Whollydooleya may be just the start. "It turns out this area which we're calling New Riversleigh is bigger than the world heritage area, and yet it's not within the world heritage area," he said. "We're just beginning to understand there's a massive deposit of fossils out there which we had no idea about."

Australia was home to a wide variety of large creatures, including the wombat-like Diprotodon, which wasthe size of a hippopotamus and depicted in paintings by Aborigines. There were also carnivorous goanna lizards up to seven metres (23 feet) long, six-metre snakes and carnivorous kangaroos. Few were as fearsome as another predatory reptile which emerged four million years ago and still terrorises parts of the continent: the saltwater crocodile.