Melbourne, Dec 7 (PTI) Australian scientists have discovered a new species of marsupial lion which has been extinct for at least 19 million years.
The findings are based on fossilised remains of the animal's skull, teeth, and humerus (upper arm bone) found by University of New South Wales (UNSW) scientists in the Riversleigh World Heritage Area of remote north-western Queensland.
The species named Wakaleo schouteni was a predator that stalked Australia's abundant rainforests some 18 to 26 million years ago in the late Oligocene to early Miocene era.
The meat-eating marsupial is estimated to have been about the size of a dog and weighed around 23 kilogrammes, the researchers said.
The new species is about a fifth of the weight of the largest and last surviving marsupial lion, Thylacoleo carnifex, that weighed in at around 130 kilogrammes and which has been extinct for 30,000 years, they said.
Members of this family, the Thylacoleonidae, had highly distinct large, blade-like, flesh-cutting premolars that they used to tear up prey.
The discovery, published in the Journal of Systematic Palaeontology, comes just a year after the fossilised remains of a kitten-sized marsupial lion were found in the same famous fossil site in Queensland.
With this new find, the researchers believe that two different species of marsupial lion were present in the late Oligocene at least 25 million years ago.
The other, originally named Priscileo pitikantensis, but renamed Wakaleo pitikantensis, was slightly smaller and was identified from teeth and limb bones discovered near Lake Pitikanta in South Australia in 1961.
The latest discovery reveals that the new species (W schouteni) exhibits many skull and dental features of the genus Wakaleo.
However, it also shared a number of similarities with P pitikantensis - particularly the presence of three upper premolars and four molars, previously the diagnostic feature of Priscileo.
The latest finding raises new questions about the evolutionary relationships of marsupial lions, said Anna Gillespie, a palaeontologist from UNSW.
"The identification of these new species have brought to light a level of marsupial lion diversity that was quite unexpected and suggest even deeper origins for the family," said Gillespie. PTI SAR SAR .
This is unedited, unformatted feed from the Press Trust of India wire.