On the Taxonomic Affinity of Davletkulia gigantea Ivachnenko

The holotype (an isolated tooth) of the largest-known member of the family Bolosauridae, Davletkulia gigantea Ivachnenko, 1990, from the middle Permian Yaman-Yushatyr’ locality, Orenburg Region, Russia, is reassigned to the herbivorous dinocephalians of the superfamily Tapinocephaloidea. This attribution is supported by the shape of the tooth crown and patterns of wear and resorption, as well as by the absence of reparative (tertiary) dentine inside the pulp cavity at the late stage of tooth functioning. The morphology of the holotype reveals that D. gigantea is a valid species and the third representative of the group after Ulemosaurus svijagensis and U. gigas, to be described from Eastern Europe. Judging from the Ocher age of the type locality, D. gigantea is the oldest-known tapinocephaloid known from the tetrapod assemblages of the region.