Hippopotamidae is a family from the Artiodactyla order.Hippopotamuses are stout, naked-skinned, and amphibious artiodactyl members of the family Hippopotamidae possessing three-chambered stomachs and walking on four toes on each foot. While they resemble pigs physiologically, their closest living relatives are actually the whales.There are two living species of hippopotamus among two genera; the pygmy hippo, Choeropsis liberiensis of the forests of west Africa, and the common Hippo, Hippopotamus amphibius, which kills more humans yearly than any other mammal.
Hippopotamids are large mammals, with short, stumpy legs, and barrel-shaped bodies. They have large heads, with broad mouths, and nostrils placed at the top of the snout. Like pigs, they have four toes, but unlike pigs, all of the toes are used in walking. Hippopotamids are unguligrade, although, unlike most other such animals, they have no hooves, instead using a pad of tough connective tissue. Their stomach has three chambers, but they are not true ruminants.
Genus Hippopotamus Hippopotamus amphibius - Hippopotamus †Hippopotamus antiquus †Hippopotamus creutzburgi - Cretan Dwarf Hippopotamus †Hippopotamus minor †Hippopotamus melitensis †Hippopotamus pentlandi †Hippopotamus lemerlei †Hippopotamus laloumena †Hippopotamus gorgops †Hippopotamus aethiopicus †Hippopotamus afarensis †Hippopotamus behemoth †Hippopotamus kaisensis †Hippopotamus sirensis Genus Hexaprotodon †Hexaprotodon bruneti †Hexaprotodon coryndoni †Hexaprotodon crusafonti †Hexaprotodon hipponensis †Hexaprotodon imagunculus †Hexaprotodon iravaticus †Hexaprotodon karumensis †Hexaprotodon madagascariensis †Hexaprotodon namadicus †Hexaprotodon palaeindicus †Hexaprotodon pantanellii †Hexaprotodon protamphibius †Hexaprotodon siculus †Hexaprotodon sivalensis Genus Archaeopotamus †Archaeopotamus harvardi †Archaeopotamus lothagamensis Genus Choeropsis Choeropsis liberiensis - Pygmy Hippopotamus Genus Saotherium Saotherium mingoz