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 continued development of the newborn while latched to the nipples on the mother’s lower belly.
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 engaged in “scratch-digging” but was unlikely to have burrowed.
“It is surprisingly large, particularity for that time period,” lead author Robin Beck, from 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 — the group that includes Mukupirna, wombats, koalas and their fossil relatives — and found that body weights of 220 pounds or more 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 aren’t 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 possibly may have driven it extinct,” he suggested.
“Mukupirna reveals a fascinating mix of characteristics and provides evidence of a close link between wombats and an extinct group of marsupials called wynyardiids,” report 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 very earliest members of the wombat family and likely led to their eventual survival to the present day. Although suggested previously, it had not been possible to test this, as the oldest fossil wombats discovered are only known from teeth and a few skull fragments,” Brewer said.