Thylacoleo carnifex was one of the most efficient predators in Australian prehistory. Despite its name, "marsupial lion," it was not a feline, but rather a carnivorous marsupial, related to modern wombats.

It lived during the Pleistocene. At about 1.5 meters long and weighing up to 160 kg, Thylacoleo possessed a bite as powerful as that of an adult lion, capable of breaking bones and tearing flesh like a hot knife through butter.