A new Isectolophid Tapiromorph (Perissodactyla, Mammalia) from the Early Eocene of Pakistan

A new genus and species of tapiromorph, Karagalax mamikhelensis, is described from the Eocene Mami Khel Formation of northwest Pakistan. The new species is known from adult and juvenile dentitions, juvenile skulls, and partial postcrania. It is the most primitive perissodactyl yet reported from Indo-Pakistan. The morphology of its lophodont molars indicates that Karagalax is a tapiromorph, and it is here included in the primitive family Isectolophidae. Karagalax is more derived (more lophodont) than North American isectolophids Systemodon and Cardiolophus or the Asian early Eocene Orientolophus and Homogalax wutuensis, and more primitive (less lophodont) than North American Homogalax and Isectolophus. It is distinct from the poorly known and enigmatic Indian isectolophid Sastrilophus. Karagalax lacks any derived features of the Deperetellidae, Helaletidae or Lophialetidae, including Kalakotia, a primitive lophialetid from the middle Eocene of northwest India. The partial postcrania of Karagalax, which include fragmentary humeri, femora, ulnae, tibiae and metapodials, show a combination of primitive and derived features and suggest that it was more cursorial than other basal tapiromorphs for which postcrania are known.A provisional analysis of the phylogenetic positions of Karagalax and Kalakotia supports the hypothesis that primitive perissodactyls dispersed to Indo-Pakistan, most probably by way of continental Asia. The evolutionary position of Karagalax is consistent with an early Eocene age for H-GSP Locality 300, as argued previously on the basis of other mammals.