abstract:The marsupial lion (Thylacoleo carnifex, the "murderous (or 'meat-cutting') marsupial lion" from thylakos – pouch, leo – lion, carnifex – murderer, tormentor, 'butcher') is an extinct species of carnivorous marsupial mammal that lived in Australia from the early to the late Pleistocene (1,600,000–46,000 years ago).Thylacoleo (panel 1) at Western Australian Museum Despite its name it is not closely related to the lion, but is a member of the order Diprotodontia.