Mammalia Linnaeus, 1758 - mammals
   Cetartiodactyla Montgelard, Catzeflis & Douzery 1997 see Order Cetartiodactyla Montgelard, Catzeflis & Douzery, 1997
     Cetancodonta Arnason, Gullberg, Gretarsdottir, Ursing & Janke 2000
       Hippopotamoidea Gentry & Hooker 1988 [Boisserie 2007]
         Family Hippopotamidae Gray, 1821 - hippopotamuses
           Subfamily Hippopotaminae Gray, 1821
             Genus †Hexaprotodon Falconer & Cautley, 1836
               †Hexaprotodon? imaguncula (Hopwood, 1926)