Article: The skull of Fabrosaurus australis, a Triassic ornithischian dinosaur
Richard A. Thulborn
The skull of Fabrosaurus australis is described in detail. This study is based upon previously undescribed specimens from the late Triassic Red Beds of Lesotho.The presence of a predentary bone at the mandibular symphysis substantiates Ginsburg's concept (1964) of Fabrosaurus as a member of the order Ornithischia—though there is no evidence for any close relationship between Fabrosaurus and the Liassic Scelidosaurus. Certain cranial features (the toothed premaxilla, the inter-parietal suture) indicate that Fabrosaurus should be referred to the family Hypsilophodontidae of the suborder Ornithopoda. Ornithischian origins and ornithopod phylogeny are re-examined in the light of new evidence from Fabrosaurus. Fabrosaurus seems to be a fairly direct antecedent of Hypsilophodon and appears to fulfil many of the requirements of a genuine 'archetypal' Ornithischian.