Thylacoleonids (meaning "pouched lions") were prehistoric Australia's apex predators. Thylacoleonids are not actually lions, but are instead a line of predatory marsupials that superficially resemble big cats. They would start out small in the Oligocene epoch (approximately 24 million years ago) in the form of the opossum-sized Priscileo, with the dog-sized Wakaleo to follow in the Miocene epoch (approximately 10-16 million years ago). The Thylacoleonids would eventually produce the genus that gives this family its name, Thylacoleo; prehistoric Australia's equivalent to the African lion. Thylacoleo had a bite force that was greater than most carnivorous mammals, which was achieved by use of massive jaw muscles, along with enormous shearing cheek teeth. Thylacoleo is also noted for its muscular forelimbs, as well as retractable claws and semi-opposable thumbs. Petroglyphs discovered in 2008 in a region in Western Australia known as the Kimberley portrays a striped animal that could indeed be that of a Thylacoleo.
Click on the images below to see the incredible fossils we offer in our Thylacoleonid selection: