Researchers named the animal “Mukupirna,” meaning “big bones” in Dieri and Malyangapa, the indigenous languages spoken in the region of South Australia where the fossil was first discovered.
In a paper published in Scientific Reports on Thursday, researchers confirmed that the mammal belonged to a new family of marsupials – mammals characterized by premature birth and the newborn’s continued development while latched to the nipples on the lower abdomen.
From studying the creature’s fossilized teeth, bones and cranium, experts concluded that the animal, which would have weighed up to 330 pounds, would have been involved in “scratch-digging” but was unlikely to have burrowed.
“It’s surprisingly large, in particular for that time period,” lead author Robin Beck, of the University of Salford, told CNN. “It was one of the largest animals in Australia at that time.”
Beck said that while the creatures most closely resemble wombats, they were about five times the size.
Scientists studied how body size has evolved in vombatiforms – a group that includes Mukupirna, wombats, koalas and their fossil relatives – and found that body weights of 220 pounds or more have evolved at least six times over the past 25 million years.
The largest known vombatifom, named “Diprotodon,” weighed more than 2 tonnes and survived until approximately 50,000 years ago.
Speaking about Mukupirna, Beck said: “This fossil didn’t have teeth that grew throughout its life, so it probably wasn’t feeding on grass,” adding that researchers were not certain when the animal became extinct.
“About 23 million years ago, the environment changed to become more like a rainforest in Australia, and so there were environmental changes that could have driven it extinct,” he suggested.
“Mukupirna reveals a fascinating mix of traits and provides evidence of a close link between wombats and an extinct group of marsupials called wynyardiids,” reports co-author Pip Brewer, of London’s Natural History Museum, added in a statement.
“It suggests that adaptations for digging for food may have existed in the earliest members of the wombat family and likely led to their survival event to the present day. Although previously suggested, it has not been possible to test this, as the oldest fossil. Discovered wombats are only known from the teeth and a few skull fragments, ”Brewer said.