ttributing “Gomphotherium shensiense” to Platybelodon tongxinensis, and a new species of Platybelodon from the latest Middle Miocene

Platybelodon is the predominant proboscidean of northern China’s Middle Miocene.However, the cranial and cheek tooth morphologies are not clearly diagnosed. In particular, thedifferential diagnoses between Platybelodon and Gomphotherium have not been comprehensivelyexamined. Here we restudied the cranium previously identified as Gomphotherium shensiense.The upper tusks lack an enamel band, the rostrum is long and narrow, the facial part is rostrallypositioned, and a large “prenasal slope” is present. These characters are distinct from those ofany species of Gomphotherium, but fit well with some primitive species of Platybelodon, i.e.,P. tongxinensis and P. danovi. The molars are also close to the type specimen of P. tongxinensisin the tetralophodont M3 with mesiodistally wide interlophs, curved outline, and a tendency ofcementodonty. In this article, we synonymized Gomphotherium shensiense with P. tongxinensis.Moreover, we recognized a new species, Platybelodon tetralophus, from the P. grangeri materialcollected by the AMHN expedition in Tunggur region. Platybelodon tetralophus differs from P.grangeri and the other species in the tetralophodont M2 and m2, representing the most derivedspecies within Platybelodon. It has only occurred in the uppermost horizon of the TunggurFormation, i.e., the Tamuqin Fauna (Platybelodon Quarry and Wolf Camp Quarry of AMHN).This work is a comprehensive amending of the genus Platybelodon.