Roadoceras (Permian Ammonoidea) from the Qubuerga Formation in the Mt. Everest Area in Southern Tibet

The Quberga Formation of the Selong Group in the Mt. Everest area in southern Tibet was previously assigned to Artinskian or Kungurian in age mainly based on an occurrence of an ammonoid species Uraloceras xizangense. However, a restudy on the previously and subsequently collected specimens of Uraloceras xizangense suggests that this species is re-assignable to Roadoceras xizangense, and therefore probably indicates an age between late Capitanian and early Wuchiapingian for the lower part of the Qubuerga Formation. Temporally, Roadoceras ranges from late Wordian to Wuchiapingian and was palaeobiogeographically distributed in the Palaeoequatorial and bi-temperate regions.