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.