The thylacoleonids are specialized members of the diprotodont marsupials. Like them, their lower incisors have reduced to two. But the dentition of these marsupials is unique. The upper incisors reduced to two as well, giving them a bucktoothed appearance. The back teeth form a blade-like formation. It has been suggested that they were fruit-eaters, but evidence largely points them towards a carnivorous habit. Evidence for this includes an enlarged thumb claw, possibly for gripping its victim or slashing. Fossils of thylacoleonids last from the Miocene to the Pleistocene.