Paleontologists at the University of New South Wales in Australia say they have identified a tiny new species of marsupial lion that lived around 18 million years ago.

The extinct, squirrel-size animal weighed about 1.3 pounds, very likely lived in trees and had teeth that suggest it was capable of ripping apart other small creatures with its molars.

The researchers named it Microleo attenboroughi in honor of Sir David Attenborough, the famed British naturalist who has hosted numerous documentaries on wildlife.

As the researchers write in their study, published in the online journal Palaeontologia Electronica, the etymology of the name is:

"From micro meaning small (Greek) and leo meaning lion (Latin). The species name honors Sir David Attenborough for his dedication and enthusiasm in promoting the natural history of the world and the palaeontological treasures of the Riversleigh World Heritage Area in particular."

M. attenboroughi is the ninth, and smallest, marsupial lion species paleontologists have identified from fossils recovered at the Riversleigh World Heritage fossil site in Queensland, Australia. The first such species, Thylacoleo carnifex, which was identified in 1858 and more fully described in 1999, was much larger than the newly identified "micro lion." T. carnifex was about 5 feet long, 2 feet tall, and had the impressive ability to rip through prey with its jaws.

On its website, the Australian Museum describes T. carnifex's bite as "the most powerful bite of any mammalian predator, living or extinct" and says "it could have taken prey much larger than itself."

The other species range in size from that of a leopard down to the size of a dog. Over time, Australian marsupial lions grew in size, from the Miocene period, when the newly discovered lion species lived, up to the Pleistocene period, when T. carnifex hunted. At any given point over about 5 million years, no more than two species of Australian marsupial lion existed at the same time.

Marsupial lions are not the ancestors of modern lions living in parts of Africa, though they are related to modern marsupials such as koalas. The term "lion" refers instead to the status of the ancient hunters as dangerous carnivores, much like the current status of big cats.

M. attenboroughi is not alone in its honorific name among the prehistoric marsupial lions of Australia.

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