powerful hindlimbs and a relatively short tail. Skeleton In 1995, Sampson only described the skull, not the postcrania, the parts behind the skull. This was motivated by the fact that in centrosaurines the postcranial skeleton is "conservative", i.e. differs only slightly among species. Sampson could not find traits in which Einiosaurus differed from a generalised centrosaurine. The holotype skull is the largest known and has a total length of . The snout is relatively narrow and pointed. The top of the snout is formed by the paired nasal bones. Their top surfaces together bear the core of the nasal horn. In 1995, apart from the skulls eight nasal horns from both bonebeds were referred to Einiosaurus. Two of these were from subadults. These show how the horn developed during the growth of the animal. The initially separated core halves fused from the tip downwards and joined into a single structure on the midline. In the subadult stage, the core still showed a suture, however. The subadult cores were transversely flattened and relatively small, not higher than . Six cores were of adults. They showed two distinctive types. Two cores were small and erect, i.e. vertically directed. The four others were large and procurved, strongly curving to the front. The adult horns resembled the subadult ones in being transversely compressed and having a long base from front to rear. To behind they nearly reached the frontal bones. Sampson compared the nasal horn of Einiosaurus with the horns of two related species, Centrosaurus and Styracosaurus. From large bonebeds, numerous nasal horns of Centrosaurus are known, presenting a considerable range of morphologies. Despite all this variation, Einiosaurus horns can be clearly distinguished from them. They are more laterally compressed, unlike the more oval cross-section of Centrosaurus horns. The adult horns are also much more procurved than any nasal horn found in Centrosaurus beds. Styracosaurus horncores are much longer than those of Einiosaurus, up to half a metre in length, and erect or slightly recurved to the rear. Apart from a horn on the snout, centrosaurines also had horns above the eye sockets, supraorbital horncores. These cores were formed by a fusion of the postorbital bone with the much smaller palpebral bone in front of it. Nine subadult or adult "brow horns" were found. They all shared the same build in being low, long and rounded. This differs from the usual pointed horns with