A team of Australian scientists discovered a new species of marsupial lion that became extinct at least 19 million years ago. The findings, published in Journal of Systematic Palaeontology are based on fossilized remains of the skull, teeth and humerus of the animal (upper arm bone) found by scientists at the University of New South Wales (UNSW) in Riversleigh World Heritage Area of remote northwest Queensland.
Named after paleo artist Peter Schouten, Wakaleo schouteni was a predator that lurked in the abundant tropical forests of Australia about 18 to 26 million years ago in the late Oligocene to Early Miocene era. It is estimated that this carnivorous marsupial was about the size of a dog and weighed about 23 kilograms.
The new species is approximately one fifth of the weight of the largest and last surviving marsupial lion, Thylacoleo carnifex which weighed about 130 kilograms and which has been extinct for 30,000 years. The members of this family, the Thylacoleonidae, had large, knife-shaped premolars, very different in shape, that they used to tear prey.
The discovery occurs just one year after the fossilized remains of a marsupial lion the size of a kitten found on the same famous fossil site in Queensland. Scientists at UNSW named that miniature predator Microleo attenboroughi after transmitting the legend Sir David Attenborough.
With this new finding, researchers believe that two different species of marsupial lions were present in the late Oligocene at least 25 million years ago. The other, originally called Priscileo pitikantensis but renamed Wakaleo pitikantensis was a bit smaller and was identified from bones and limb bones discovered near Pitikanta Lake in South Australia in 1961
The latest discovery reveals that the new species ( W. schouteni ) exhibits many cranial and dental characteristics of the genus Wakaleo, but also shares a series of similarities with P. pitikantensis – particularly the presence of three upper premolars and four molars, previously the diagnostic feature of Priscileo . Other similarities of the teeth and the humerus that are shared with W. schouteni indicate that P. pitikantensis is a species of Wakaleo .
According to the authors, these dental similarities distinguish W. schouteni and W. pitikantensis from later species of this genus, all of which show premolar and molar reduction, and suggest that they are the most primitive members of the genre.
Lead author Dr. Anna Gillespie, a paleontologist at the University of the New South Wales (UNSW) in Sydney, Australia, says that the latest finding raises new questions about the evolutionary relationships of the marsupial lions: "The identification of these new species has brought to light a level of diversity of marsupial lions that was quite unexpected and suggests even deeper sources for the family. "
New small species of extinct Australian marsupial lion that bears the name of Sir David Attenborough
Journal of Systematic Palaeontology 2017: www.tandfonline.com/doi/full/1 … 4772019.2017.1391885