An artist’s impression of Mukupirna nambensis living in central Australia that was much greener 25 million years ago. Credit: Peter Schouten / UNSW
A giant marsupial that roamed prehistoric Australia 25 million years ago is so different from its wombat cousins that scientists have had to create a new family to accommodate it.
The unique remains of a giant wombat-shaped prehistoric marsupial: Mukupirna nambensis – which was unearthed in central Australia is so different from all other previously known extinct animals that it has been placed in an entirely new family of marsupials.
Mukupirna – which means “big bones” in the Aboriginal languages Dieri and Malyangapa – is described in an article published on June 25, 2020 in Scientific reports by an international team of paleontologists including researchers from UNSW Sydney, the University of Salford in the United Kingdom, Griffith University in Brisbane, the Museum of Natural History in London and the American Museum of Natural History in New York. The researchers reveal that the partial skull and most of the skeleton originally discovered in 1973 belonged to an animal more than four times the size of any living uterus today and may have weighed around 150 kg.
An analysis of MukupirnaEvolutionary relationships reveal that although it was more closely related to wombats, it is as different from all known wombats as it is from other marsupials, so it had to locate itself in its own unique family, Mukupirnidae.
Stroke of luck
UNSW Science Professor Mike Archer, co-author of the article, was part of the original international team of paleontologists along with Professor Dick Tedford, another co-author, who found the skeleton in 1973 on the clay soil of Lake Pinpa, a remote, salty lake Dry east of the Flinders mountain range in South Australia. He says his discovery of Mukupirna This was due in part to good luck after an unusual change in local conditions exposed the 25 million-year-old fossil deposit in the soil of the dry salt lake.
The original expedition to Lake Pinpa in 1973 discovered a treasure trove of unusual prehistoric animals, including Mukupirna. Credit: Mike Archer / UNSW
“It was an extremely fortuitous discovery because in most years the surface of this dry lake is covered by sand washed away or washed away by the surrounding hills,” he says.
“But due to the rare environmental conditions before our arrival that year, the fossil-rich clay deposits were left fully exposed to view. And this unexpected sight was impressive.
“On the surface, and just below, we find skulls, teeth, bones and, in some cases, articulated skeletons of many types of new and exotic mammals. In addition, there were extinct lungfish teeth, skeletons of bony fish, and bones of many types of waterfowl, including flamingos and ducks.
“These animals ranged from tiny mouse-sized carnivorous marsupials to Mukupirna it was similar in size to a live black bear. It was an incredibly rich fossil deposit full of extinct animals that we had never seen before. “
Mukupirna’s skull. Although it is very fragmented, it retains the teeth and the basic characteristics of the head. The muzzle is on the right, while the rounded occipital condyle at the back of the skull, which articulates with the spine, is visible on the left. Credit: Julien Louys / UNSW
large gentleman
Professor Archer says when MukupirnaThe skeleton was first discovered just below the surface, no one had any idea what kind of animal it was because it was solidly enclosed in clay.
“We found him probing the flat, dry surface of the lake with a thin metal pole, like acupuncturing the skin of Mother Earth. We only dug down into the clay if the post made contact with something hard below the surface, and in this case it turned out to be the articulated skeleton of a more mysterious new creature. “
The researchers’ recent study of the skull and partial skeleton reveals that despite its bear size, Mukupirna It was probably a gentle giant. His teeth indicate that he subsisted only on plants, while his powerful limbs suggest that he was probably a strong digger. However, a detailed examination of its characteristics revealed that the creature was best suited to dig from scratch, and it is unlikely that it was a true excavator like modern wombats, the authors say.
The lead author of the article, Dr. Robin Beck of the University of Salford, says: Mukupirna It is one of the best preserved marsupials to have emerged from the late Oligocene in Australia (about 25 million years ago).
“Mukupirna It was clearly an impressive and powerful beast, at least three times larger than modern wombats, “he says.” It probably lived in an open forest environment with no grass, and developed teeth that would have allowed it to feed on sedges, roots, and tubers that could having excavated with their powerful front legs. “
Central Australia was green 25 million years ago with vast freshwater lakes surrounded by forests, but without grasslands. An archaic and omnivorous kangaroo, contemporary of Mukupirna nambensis, gobbles up a gecko in the foreground. Credit: Rod Scott / UNSW
Seriously strange
Griffith University associate professor Julien Louys, co-author of the study, said, “The description of this new family adds a huge new piece to the puzzle about the diversity of ancient and often very strange ancient marsupials that preceded those who rule the continent today. ” “
Scientists examined how body size has evolved in vombatiform marsupials, the taxonomic group that includes Mukupirna, wombats, koalas and their fossil relatives, and showed that body weights of 100 kg or more evolved at least six times in the past 25 million years. The largest known vombatiform marsupial was the relatively recent Diprotodon, which weighed over 2 tons and survived to at least 50,000 years ago.
“Koalas and wombats are amazing animals,” says Dr. Beck, “but animals like it. Mukupirna they show that their extinct relatives were even more extraordinary, and many of them were giants. “
Reference: “A New Family of Diprotodontian Marsupials from the Late Oligocene of Australia and the Evolution of Wombats, Koalas, and Their Relatives (Vombatiforms)” by Robin MD Beck, Julien Louys, Philippa Brewer, Michael Archer, Karen H. Black, and Richard H. Tedford, June 25, 2020, Scientific reports.
DOI: 10.1038 / s41598-020-66425-8
The original party that Mukupirna discovered in 1973 was an international exploration team led by Professor Dick Tedford of the American Museum of Natural History along with paleontologists from the Museum of South Australia (Neville Pledge), the Museum of Queensland (where Professor Archer was Curator of Fossils and Modern Mammals at the moment), Flinders University (Professor Rod Wells) and the Australian Organization for Geological Studies (Mike Plane and Richard Brown).
