Hippopotamus Hippopotamus The common hippopotamus ("Hippopotamus amphibius"), or hippo, is a large, mostly herbivorous, semiaquatic mammal native to sub-Saharan Africa, and one of only two extant species in the family Hippopotamidae, the other being the pygmy hippopotamus ("Choeropsis liberiensis" or "Hexaprotodon liberiensis"). The name comes from the ancient Greek for "river horse" (). After the elephant and rhinoceros, the common hippopotamus is the third-largest type of land mammal and the heaviest extant artiodactyl. Despite their physical resemblance to pigs and other terrestrial even-toed ungulates, the closest living relatives of the Hippopotamidae are cetaceans (whales, dolphins, porpoises, etc.) from which they diverged
Mountain pygmy possum is hairless. On the underside of the female's body is a pouch containing four teats. This possum is the only extant species in the genus "Burramys". It is also the only Australian mammal restricted to alpine habitat. The mountain pygmy possum was first discovered in the fossil record in 1895 when a portion of the jaw and skull bones were found in the Wombeyan Caves in central New South Wales. At the time, the species was believed to be extinct. It was not until 1966 that a living individual was found at a ski resort at Mount Hotham in Victoria.