Australian researchers have announced the discovery of an extinct species of marsupial lion, which they say adds a new level of diversity to their understanding of the prehistoric mammal’s evolution.

The new discovery, dubbed Wakaleo schouteni, was a meat-eating animal that weighed approximately 23 kilograms (50 pounds), and hunted in the Australian rainforests 18-26 million years ago. The creature was not a real lion, despite its name.

The mammal is just one-fifth the size of the largest marsupial lion known to science, the Thylacoleo carnifex, which died out 30,000 years ago. The Thylacoleo carnifex boasted massive front teeth that it used to snare its prey.

The Wakaleo schouteni didn’t have nearly the same toothy “smile,” based on fossilized remains of its skull, teeth and an upper arm bone.

Nevertheless, paleontologists say the discovery of Wakaleo schouteni may have a profound impact on their understanding of the marsupial lion evolutionary tree.

“The identification of this species has brought to light a level of marsupial diversity that was quite unexpected, and suggest even deeper origins for the family,” lead study author Anna Gillespie said in a statement.

Gillespie and researchers from the University of New South Wales found the lion in the Riversleigh world heritage area of remote northwestern Queensland. Their findings are published in the Journal of Systematic Palaeontology.

A smaller marsupial lion was found at the same site in Queensland last year. That one was dubbed Microleo attenboroughi, in honour of Sir David Attenborough, noted broadcaster and frequent narrator for nature documentaries.

The newly-discovered Wakaleo schouteni was named for paleontologist Peter Schouten.