The remains of a previously unknown juvenile carnivorous marsupial have been found at the Riversleigh World Heritage Fossil Site in northwestern Queensland, Australia. The researchers, led by the University of New South Wales, name this Malleodectes mirabilis, an escargot-eating mammal that lived 15 million years ago.

The findings published in the journal Scientific Reports state that the Malleodectes mirabilis had an extremely powerful hammer-like premolar which was used to crush hard snail shells. It was related to dasyures, group of carnivorous marsupials that includes the Tasmanian Devils and the extinct Tasmanian Tigers.

The team believes that the juvenile Malleodectes mirabilis could have fallen into the rocks in the cave where its mother was hunting for snails. Unfortunately, UNSW’s Suzanne Hand says that the young marsupial was not able to climb back out and remained trapped until it died.


This is a reconstruction of the 15 million-year-old Malleodectes from Riversleigh chomping down on snails. Illustration by Peter Schouten

The remains of the malleodectids, including teeth, have been unearthed before at Riversleigh, However, researchers only realized that these animals were a unique group of marsupials after analyzing the juvenile animal’s well-preserved skull portion using micro-computed tomography.

Moreover, malleodectids disappeared years before humans arrived in Australia. The species could have gone extinct due to the climate change that altered the continent’s terrain starting 15 million years ago.

The Riversleigh World Heritage fossil deposits have also revealed other previously unknown animals, including the Thingodonta, a marsupial that resembled a woodpecker, Drop crocs, leopard-like crocodiles, and Fangaroo, a kangaroo that sported tusks. Additionally, archaeologists also unearthed Nimbadon, an extinct ram-sized marsupial as well as the Dromornis, also known as the Demon Duck of Doom, which was among the largest birds on the planet.

The researchers say that the climate change affected animal life, transforming Australia’s land from rainforests teeming with animals into open forests and grasslands that we know of today. They aim to discover more strange animals waiting to be found.