When a cave and Gippsland local, Joshua Van Dyk, stumbled upon the fossilized remains of a kangaroo species that had been extinct for about 46,000 years, the macropod seemed to make eye contact with him.
“It fell behind some rocks … and was looking straight at me,” Joshua recalled of the 2011 discovery he made in a cave near Buchan in east Gippsland.
“I knew it was something significant … especially since I could see a lot more of the body behind the skull.”
A decade later scientists at Museums Victoria recovered the remaining skeleton of what they now know was a cub Simosthenurus occidentalis, also known as the short-faced kangaroo.
They suspect the animal died after falling into a hidden cave entrance several thousand years before the species became extinct.
The fossil is one of the most intact skeletons of an extinct animal found in Australia, and the most complete skeleton found in a Victorian cave. It retained 71% of the animal’s bones, with only small parts of the legs missing.
Tim Ziegler, a paleontologist from the Museums Victoria Research Institute who led the dig, says fossils of “this quality and completeness are extremely rare in Australia”.
The discovery helps unlock the secret lifestyle of this long-extinct animal.
“We can now learn what they were able to do,” Ziegler says.
There is only one short-faced kangaroo fossil as complete as the Buchan fossil, which was found in South Australia about 50 years ago.
Ziegler says the expedition was one of the most physically challenging he has ever undertaken and involved working in extremely confined underground spaces.
Because of the narrowness of the cave, members of the excavation team sometimes had to verbally guide another person’s hands. Ziegler recalls that he also removed overlying sediment before getting each bone—there were 150—by touch.
“The incredible improbability of having it preserved for so long created a real sense of responsibility in bringing it to the surface.”
It is believed that the short-faced kangaroo, which lived alongside modern-day kangaroos, looked more like other animals.
to newsletter promotion
The kangaroo had a square head and a robust lower jaw, like koalas and pandas, which allowed it to digest matter such as leaves and branches. The youth’s skull was the same size as an adult human.
Its shoulders had a great deal of flexibility, similar to humans and chimpanzees, Ziegler says. It is also believed that they walked rather than hopped.
“The short-faced kangaroos illustrate a very different way of life among Australian marsupials that is different today.”
Short-faced kangaroos were about the same height as modern kangaroos, but they were much heavier. Scientists estimated that the weight of the young kangaroo is more than 80 kg – the weight of a full-grown male red kangaroo. They believe adult short-faced kangaroos weighed up to 120 kg.
Gavin Prideaux, the director of palaeontology at Flinders University, says the discovery highlights that “people who explore caves and new passages can sometimes make really amazing discoveries”.
“This is a very, very, good find … it gives us more information [the extinct animals’] anatomy, biology, what ecological role they played and how they moved.”
The short-faced kangaroo was affected by a major extinction event that wiped out 85% of large mammals, reptiles and birds.
Ziegler says constant cooling and drying of the environment, habitat loss, disease and human practices such as increased fires may have been factors that drove them to extinction.
He notes that powerful, short-faced kangaroos were once one of the continent’s most widespread and successful marsupials.
“Their sudden extinction along with almost all of Australia’s megafauna is a profound reminder to defend our modern environments from loss.”
