Regnosaurus northamptoni, a stegosaurian dinosaur from the Lower Cretaceous of southern England

Abstract

AbstractThe type specimen ofRegnosaurus northamptoniMantell, a partial right mandible, is redescribed and compared with a wide variety of dinosaurian taxa. We suggest thatRegnosaurusis not an ankylosaur or a sauropod as previously thought, but represents the fragmentary remains of a ‘primitive’ stegosaur.RegnosaurusandHuayangosaurusshare two derived characters, suggesting that these two genera should be provisionally regarded as sister taxa. The implications of these findings for stegosaur evolution and biogeography are discussed briefly.