Diprotodon (Ancient Greek: “two protruding front teeth”) is an extinct genus of marsupial from the Pleistocene of Australia containing one species, D. optatum. The earliest finds date to 1.77 million to 780,000 years ago but most specimens are dated to after 110,000 years ago. Its remains were first unearthed in 1830 in Wellington Caves, New South Wales, and contemporaneous paleontologists guessed they belonged to rhinos, elephants, hippos or dugongs. Diprotodon was formally described by English naturalist Richard Owen in 1838, and was the first named Australian fossil mammal, and led Owen to become the foremost authority of his time on other marsupials and Australian megafauna, which were enigmatic to European science.
Diprotodon is the largest-known marsupial to have ever lived, it greatly exceeds the size of its closest living relatives wombats and koalas. It is a member of the extinct family Diprotodontidae, which includes other large quadrupedal herbivores. It grew as large as 1.8 m (5 ft 11 in) at the shoulders, over 4 m (13 ft) from head to tail, and possibly weighed almost 3,500 kg (7,700 lb). Females were much smaller than males. Diprotodon supported itself on elephant-like legs to travel long distances, and inhabited most of Australia. The digits were weak; most of the weight was probably borne on the wrists and ankles. The hindpaws angled inward at 130°. Its jaws may have produced a strong bite force of 2,300 newtons (520 pounds-force) at the long and ever-growing incisor teeth, and over 11,000 newtons (2,500 lbf) at the last molar. Such powerful jaws would have allowed it to eat vegetation in bulk, crunching and grinding plant materials such as twigs, buds and leaves of woody plants with its bilophodont teeth.