porosus) is typically long and weighs around ), with many being much larger than that. The female is much smaller, with typical body lengths of . An saltwater crocodile was reportedly shot on the Norman River of Queensland in 1957; a cast was made of it and is on display as a popular tourist attraction. However, due to the lack of solid evidence (other than the plaster replica), and the length of time since the crocodile was caught, it is not considered "official". The freshwater crocodile (Crocodylus johnsoni) is a relatively small crocodilian. Males can grow to in length, while females reach a maximum length of . Males commonly weigh around , with large specimens up to or more, as against the average female weight of . In places such as Lake Argyle and Nitmiluk National Park (Katherine Gorge), there exist a handful of confirmed 4 m (13 ft) individuals. Extinct Australian megafauna The following is an incomplete list of extinct Australian megafauna (monotremes, marsupials, birds and reptiles) in the format: Latin name, (common name, period alive), and a brief description. Monotremes Monotremes are arranged by size with the largest at the top. Murrayglossus hacketti was a sheep-sized echidna uncovered in Mammoth Cave in Western Australia, and is the largest monotreme so far uncovered. Obdurodon dicksoni was a platypus up to in total length, fossils of which were found at Riversleigh. Megalibgwilia ramsayi was a large, long-beaked echidna with powerful forelimbs for digging. Marsupials Marsupials are arranged by size, with the largest at the top. Diprotodon optatum is not only the largest known species of diprotodontid, but also the largest known marsupial to ever exist. Approximately long and high at the shoulder and weighing up to , it resembled a giant wombat. It is the only marsupial known, living or extinct, to have conducted seasonal migrations. Palorchestes azael was a diprotodontoid similar in size to Zygomaturus. It had long claws to grasp branches with. It lived during the Pleistocene. Euowenia grata Euryzygoma dunense Zygomaturus trilobus was a smaller (bullock-sized, about long by high) diprotodontid that may have had a short trunk. It appears to have lived in wetlands, using two fork-like incisors to shovel up reeds and sedges for food. Macropus pearsoni and M. ferragus Mukupirna nambensis, in its own family Mukupirnidae within the Vombatiformes suborder of the large marsupial order Diprotodontia Nototherium was a diprotodontoid relative of the larger