Hipposaurus ('horse lizard') is an extinct genus of basal therapsids known from the Tapinocephalus Assemblage Zone of the Main Karoo Basin, South Africa. Chronologically this is within the Capitanian stage of the Guadalupian Series (Middle Permian). The genus was first described by S.H. Haughton as H. boonstrai on the basis of a skull and associated skeletonHaughton, S.H. (1929). On some new therapsid genera. Annals of the South African Museum, 28, 55-78. and was later considered a gorgonopsian in the family 'Ictidorhinidae' by Robert Broom.Broom, R. 1932. The mammal-like reptiles of South Africa and the origin of mammals. Witherby, London, 376 pp. It is now considered a basal biarmosuchian,Sigogneau-Russell, D. 1989. Theriodontia I. Pp. 1-127. In Wellnhofer, P. (ed.). Encyclopedia of paleoherpetology, Part 17B. Gustav Fischer, Stuttgart. but its affinities remain uncertain. Some authors note the similarity of its braincase with that of Herpetoskylax. H. boonstrai is currently known from only two specimens in the Iziko South African Museum, Cape Town.
"H. brinki" is based on a single skull that was described by D. Sigogneau in 1970;Sigogneau, D. 1970. Révision systématique des gorgonopsiens Sud Arficains. Cahiers de Paléontologie, Paris. [In French] however, the poor condition of the holotype means most considerations of biarmosuchians ignore it.
See also
List of therapsids
References
General The main groups of non-mammalian synapsids at Mikko's Phylogeny Archive