A new species of "marsupial lion" extinct in Australia for 19 million years has been discovered at one of the most significant fossil deposits in the world, researchers said Thursday.
The predator, with blade-like, flesh-cutting premolars used to tear up prey, stalked the country's rainforests during the late Oligocene to early Miocene era.
"This meat-eating marsupial is estimated to have been about the size of a dog and weighed around 23 kilograms," said Anna Gillespie, lead author of a study on the find in the Journal of Systematic Palaeontology.
It was found at the internationally-renowned Riversleigh World Heritage Area in remote north-western Queensland state, where the remains of a bevy of strange new small to medium-sized creatures have been discovered.
Last year, a tiny "kitten-sized" marsupial lion was found at the site and named after veteran British naturalist David Attenborough.
The latest find includes the fossilised remains of the animal's skull, teeth, and humerus, or upper arm bone.
Gillespie said it was about a fifth of the weight of the largest and last surviving marsupial lion, Thylacoleo carnifex, which weighed in at around 130 kilograms and has been extinct for 30,000 years.
It likely pursued its food -- small vertebrates like lizards, frogs, birds and mammals -- through the tree-tops.
The marsupials were given the name lion due to their secateur-like teeth by 19th century palaeontologist Sir Richard Owen. There are now nine known species, which increased in size over millions of years.