A hefty bone-crunching extinct relative to the Tassie devil discovered

By Natsumi Penberthy 26 July 2016
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Scientists have found the tooth of a carnivorous Aussie marsupial that weighed as much as a 10-year-old and hails from the same family as the Tassie devil.

PALEONTOLOGISTS HAVE FOUND evidence of a new bone-crunching, flesh-eating Aussie marsupial from the same family as the Tassie devil at a significant new fossil site in north-western Queensland.

Whollydooleya tomnpatrichorum is currently known only from a single tooth. It’s thought to have weighed about 20 to 25kg – about the same as an average 10-year-old person – and have been capable of taking down and chewing up large prey.

“Its teeth were very wide at their base, which suggests a powerful biting capacity,” said lead author Professor Mike Archer from the University of NSW. Mike added that he thinks this was an animal that was crunching whole animals, possibly bone and all.

Bone-crunching marsupial a clue to how Aussie animals developed  

He adds that W. tomnpatrichorum is showing excited Australian paleontologists a whole new world. The World Heritage-listed Riversleigh fossil site nearby where they found the new marsupial has given them clues to the last 24 million years of history, says Mike. But, he says, there’s been a hole of knowledge in the Miocene 12 to 5 million years ago that a site called New Riversleigh is starting to fill.

The missing bit covered the transitional period between a heavily forested and rainforested country to more arid cover as the world was drying out. It transformed Australia from forested to the driest climate on earth, so what happened is important to how we understand how animals developed, he says.

Fossils of land animals from this time are rare however, because of the changes to the environment. “One of the weird things about the older mammal fossils from Riversleigh is their teeth look like they’ve just come out of a factory,” says Mike. Not so at the new site, New Riversleigh, where W. tomnpatrichorum was found, he says. A number of fossils have emerged here and all dental evidence have been quite worn. There are a number of reasons this could be says Mike – the arid conditions may have been making food more abrasive or the animals in the Miocene were living for longer.

When animals became bigger and began to live longer 

It’s not uncommon for animals to live longer in stressful environments Mike says. Animals don’t know if their offspring will have a good chance of surviving so they live for longer. There are also fewer species and they get bigger, as animals have to be more generalist eaters to survive on fewer resources which they had to compete for.  

“While it was at least distantly related to living and recently living carnivorous marsupials such as devils, thylacines and quolls, it appears to have represented a distinctive subgroup of hypercarnivores that did not survive into the modern world,” adds Mike. He says that while they’re picturing the animal as simialr to a devil, it’ll likely turn out to be quite different. 

A description of the new marsupial, based on its fossil molar tooth, is published in the Memoirs of Museum Victoria.