Ancient marsupials discovered in Australia regularly ate snails as part of their regular diet, researchers discovered. The 15-million-year old fossils represent animals, which once roamed the Land Down Under, but are now extinct.

Malleodectes mirabilis artifacts were unearthed at the Riversleigh World Heritage Fossil Site, located in Queensland. Not much of this cave is left, apart from a limestone floor and the bones and fossilized remains of thousands of animals who perished in the cavern. The walls and ceiling of the cave eroded over time, leaving behind just the floor of the structure and a plethora of ancient animal remains.

"Two of the world's most important fossil sites, Riversleigh and Naracoorte, located in the north and south of Australia respectively, provide a superb fossil record of the evolution of this exceptional mammal fauna. This serial property provides outstanding, and in many cases unique, examples of mammal assemblages during the last 30 million years," said the Unesco official report.

The animals were found to be related to Tasmanian devils, as well as the extinct species, the Tasmanian tiger. These animals can only be found in Australia and New Guinea.

"Uniquely among mammals, it appears to have had an insatiable appetite for escargot — snails in the whole shell. Its most striking feature was a huge, extremely powerful, hammer-like premolar that would have been able to crack and then crush the strongest snail shells in the forest," Mike Archer of the University of New South Wales said.

Teeth and a few other remains of the animals have been found at the site over the last few decades. However, the unique nature of this marsupial was not known until examination of the skull of a juvenile animal was carried out, revealing secrets of the long-extinct creatures.

Investigation revealed the youngster still possessed many of its baby teeth, while adult sets were due to erupt within the creature's mouth.

Other bizarre creatures discovered at the Riversleigh site include drop crocs, an animal with features of both leopards and crocodiles, the tusked kangaroo known as a fangaroo and one of the largest birds in the world, the Demon Duck of Doom.

These creatures likely went extinct when the climate of the continent changed, replacing rainforests with temperate woodlands and grassy fields.

Analysis of the fossils was detailed in the journal Scientific Reports.

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