First-ever look at complete skeleton of Thylacoleo, Australia's extinct 'marsupial lion'. Thyalacoleo carnifex, the 'marsupial lion' of Pleistocene Australia, was an adept hunter that got around with the help of a strong tail, according to a new study. These insights come after newly discovered remains, including one nearly complete fossil specimen, allowed these researchers to reconstruct this animal's entire skeleton for the first time. Source 2v.