On Mongolian ornithopods (Dinosauria: Ornithischia). 1. Iguanodon orientalis Rozhdestvensky 1952

Abstract

The type material of the Cretaceous ornithopod Iguanodon orientalis Rozhdestvensky, 1952 is redescribed. The characters which were originally used to establish a new species are shown to be either incorrect or indistinguishable from Iguanodon bernissartensis Boulenger, 1881. Additional material, previously unrecognized, further confirms the similarity of I. orientalis to I. bernissartensis. It is proposed that I. orientalis should be relegated in synonymy as a junior subjective synonym of I. bernissartensis Boulenger, 1881. The identification of the Barremian species I. bernissartensis in Asia indicates an unusually wide geographic spread for this species, and provides a potential biostratigraphic indicator for beds in Mongolia which had been previously dated variously between the Cenomanian and Maastrichtian stages.