Hipposaurus boonstrai (Haughton 1929, skull length 21cm, length 1.2m) Capitanian, Mddle Permian ~260 mya is the most primitive kynodont. Derived from a sister to Cutleria, Hipposaurus phylogenetically preceded Biarmosuchus, the Burnetiadae and the rest of the Therapsida, including mammals and man, sans Anomodontia.
Much larger than its ancestors, Hipposaurus kept the small round skull but had longer, more slender limbs capable of a more erect pose and probably a faster gait. The long fang and gracile indicate it retained predatory habits.
(SAM 8950) is a complete skeleton.
SAM 9081 distorted skull and postcranial elements, type of H. major