Hippopotamidae Gray 1821
Hippopotamidae Gray 1821, London Med. Repos., 15: 306.
Synonyms: Choeropsinae Gill 1872 .
Genera: 2 genera with 2 species:
Genus Hexaprotodon Falconer and Cautley 1836 (1 species with 2 subspecies)
Genus Hippopotamus Linnaeus 1758 (1 species with 3 subspecies)
Discussion: Hexaprotodon † madagascariensis (Guldberg, 1883), Hippopotamus † lemerlei Grandidier, 1868, and H. † laloumena Faure and Guerin, 1990 were present in the Holocene on Madagascar (Stuenes, 1989), but have not been shown to have survived into the last 500 years.