Fossils of new species of giant kangaroos have been discovered in Australia and New Guinea
Paleontologists at Flinders University have described three new and unusual species of fossil kangaroos from Australia and New Guinea, finding that they are more diverse in shape, distribution and jumping method than previously thought.
The three new species belong to the extinct genus Protemnodon, which lived between 5 million and 40,000 years ago, and one of them is twice the size of the largest red kangaroo alive today.
The research follows the discovery of several complete fossil kangaroo skeletons from Lake Callabonna in arid South Australia in 2013, 2018 and 2019. These extraordinary fossils enabled lead researcher Dr. Isaac Kerr, then a graduate student, to decipher a nearly 150-year-old mystery surrounding the identity of species Protemnodon.
The new study from Flinders University looked at all types ProtemnodonThey discovered that they were very different. The species adapted to different environments and even jumped in different ways.
The Protemnodon They resembled gray kangaroos, but were generally stockier and more muscular. Some species weighed around 50kg, others were much larger than any living kangaroo.
However, one of the new species named in the latest study is Protemnodon viator, was much larger and weighed up to 170 kg. That’s about twice as much as the largest male red kangaroos.
Protemnodon viator was well adapted to its arid habitat in central Australia and lived in areas similar to those of red kangaroos living today. It was a long-limbed kangaroo that could jump quite quickly and efficiently. His name, Viator, means “traveller” in Latin.
The Australian researchers discovered two more new species – Protemnodon mamkurra and Protemnodon dawsonae – and reviewed the work of previous researchers, such as British naturalist Sir Richard Owen, who coined the term “dinosaur” in Victorian England.
He Protemnodon viatorwas much larger and weighed up to 170 kg
The first species of Protemnodon were described in 1874 by the British paleontologist Owen, who followed the usual approach of the time and focused mainly on fossil teeth. He noted slight differences between the teeth of his specimens and described six species of Protemnodon.
Successive studies have reduced some of these initial descriptions, but the new study from Flinders University coincides with one of its species, Protemnodon anak. This first-described specimen, called a holotype, is still kept in the Natural History Museum in London.
Dr. Kerr says it was previously suspected that some or all of these Protemnodon They were four-legged friends. “However, our study suggests that this is only true for three or four species Protemnodonwhich could have moved similarly to a quokka or a potoroo, sometimes jumping on four legs, sometimes on two.
“The thing just described Protemnodon mamkurra is probably one of them. It is a large kangaroo but with thick and sturdy bones. “It’s possible he jumped on rare occasions, perhaps only when he was startled.”
Dr. Kerr says the best fossils of this species come from Green Waterhole Cave in southeast South Australia, on the land of the Boandik people. The name of the species, Mamkurra, was chosen by Boandik elders and language experts from the Burrandies Corporation. It means “big kangaroo”.
They could have moved by jumping, sometimes on four legs and sometimes on two.
It’s unusual for a single kangaroo genus to live in such different environments, he says. “For example, it is now known that the different types of Protemnodon “They inhabited a wide range of habitats, from arid central Australia to the forested mountains of Tasmania and New Guinea, with high rainfall.”
The third of the new species, Protemnodon dawsonae, is known from fewer fossils than the other two and is more of a mystery. Most likely it was a medium-fast manakin, something like a swamp wallaby.
Its name comes from the research of Australian paleontologist Lyndall Dawson, who studied the systematics of the kangaroo and the fossil material from “Big Sink”, the part of the Wellington Caves in New South Wales from which it is primarily known. the species.
To collect data for the study, Dr. Kerr examined the collections of 14 museums in four countries and examined “almost every piece of it.” Protemnodon that exist”.
“We photographed and 3D scanned, measured, compared and described more than 800 specimens collected in Australia and New Guinea. It was quite an undertaking. After five years of research, 261 pages and over 100,000 words, I feel great to finally have it published. I hope it helps to conduct further studies on this Protemnodon and we can learn more about what these kangaroos did. “Living kangaroos are already extraordinary animals, so it’s amazing to imagine what these peculiar kangaroos might have been up to.”
About 40,000 years ago, all of them Protemnodon was extinct on mainland Australia
Although the fossils of Protemnodon They are quite common in Australia, in the past they have been found “isolated”, that is, as individual bones without the rest of the animal. This has made it difficult for paleontologists to study Protemnodon in the past, as it is difficult to know how many species there were, how to tell them apart, and how they differed in size, geographic distribution, movements, and adaptations to their natural environment differentiated.
By about 40,000 years ago, all protemnodons were extinct on mainland Australia, although they may have survived slightly longer in New Guinea and Tasmania. This extinction occurred despite their differences in size, adaptation, habitat, and geographic distribution.
For reasons that remain unclear, this was not the case for many similar and closely related animals such as the wallaroo and the gray kangaroo. This study could help answer this question soon.
“It’s great to have clarity about the species identity of Protemnodon,” says Gavin Prideaux, Flinders Professor and co-author of the important paper published in Megataxa.
“Fossils from this genus are widespread and are found regularly, but most of the time there is no way to know for sure which species they are.” “This study could help researchers feel more confident when working with Protemnodon.”
REFERENCE
Systematics and paleobiology of kangaroos of the late Cenozoic genus Protemnodon (Marsupialia, Macropodidae)
Images: FLINDERS UNIVERSITY