Australia's 'marsupial lion' was a meat-ripping, tree-climbing terror

The most detailed reconstruction yet of Australia’s extinct “marsupial lion” shows it was unlike any animal living today, shredding its prey like a Tasmanian devil, biting like a lion, and climbing like a koala.

The first partial remains of the fearsome predator – which went extinct about 45,000 years ago – were discovered in Victoria in the 1850s. British naturalist Richard Owen named it Thylacoleo carnifex – meaning “meat-cutting marsupial lion” – based on its large blade-like teeth and cat-like skull.

Other remains of T. carnifex were found in the 1960s and 70s, but it was only in 2002 that the first complete skeleton was discovered in a cave beneath the Nullarbor Plain in Western Australia. In 2005, another two mostly complete skeletons were found in a cave in Naracoorte, South Australia.

Since then, Rod Wells at Flinders University and his colleagues have carefully studied the skeletons to better understand the mysterious creature.

Their reconstruction shows that T. carnifex would have measured over a metre long and over half a metre tall while standing on all four feet, with a weight of about 100 kilograms. “It was probably the size of a big pig,” says Wells. Like other marsupials, it carried its young in a pouch.

Comparisons with living Australian marsupials suggest that T. carnifex was most similar in appearance to the Tasmanian devil, but would have been about 10 times bigger. It had the same stiff back and strong, rigid tail that Tasmanian devils use for balance while tearing apart prey with their paws and teeth, says Wells.

The wear patterns on its blade-like teeth suggest it was a carnivore that cut and swallowed prey without chewing, with a similar bite force to that of an African lion, says Wells. “It had a large area for muscle attachment at the back of its head so it could resist the twists and turns and flailing of a live animal,” he says.

Kangaroos and wombat remains have been found with bite marks matching the shape of T. carnifex teeth, suggesting they may have been the animal’s preferred prey, says Wells.

The predator’s stiff back hints that it wasn’t geared for chasing prey, meaning it probably procured its dinners by ambush hunting or scavenging, says Wells.

Adept climber

The structure of the marsupial lion’s forearms, along with its strong collarbones and large thumb claw, suggest that it climbed like a koala, says Wells. “We think it could reach around a tree the way a koala does, dig that claw in and push up with its hindlegs in a kind of hopping motion,” he says.

This climbing ability would also have come in handy for getting in and out of caves. Scratch marks on the walls of caves where the animal’s remains have been found appear to match their hand dimensions. “It may have dragged its prey down into its cave dens or up trees to keep it away from other scavenger predators,” says Wells.

No one knows why the animal went extinct, but it was probably wiped out at the same time as the rest of Australia’s giant animals – known as megafauna, says Wells. This occurred after humans first occupied the continent, but we still don’t know if their demise was due to hunting or climate shifts, he says.