A new rhinocerotoids (Mammalia, Perissodactyla) from the Late Oligocene of Linxia Basin, China

The Jiaozigou Formation, the lowest fossiliferous stratum in the Linxia Basin, produces the most abundant mammalian fossils in East Asia. Although the Jiaozigou Fauna is renowned for the 'giant rhino' (Paraceratheriidae), evidence of relatively small rhinocerotoids is scant, consisting only of fragments. The newly identified species, Megacanodon dongxiangense gen. et sp. nov. is characterised by its small-sized body, the presence of a large canine, nearly completely molarised upper premolars, retracted nasal notch, and not-elevated occipital part. It remains unclear whether the new genus is phylogenetically close to Hyracodontidae, Eggysodontidae, or Rhinocerotidae. We tentatively designate it as a basal genus within Rhinocerotoidea, with the uncertain family affiliation.