Wendiceratops

Wendiceratops weighed about one ton and had a length of about 6 metres (20 ft).[2]

The describing authors indicated two unique traits, or autapomorphies: On the rear rim of the neck frill, the second and third epiparietals, which are skin ossifications attached to the rim, have a wide base, are vertically thick and curve obliquely upwards to the front, overhanging the rear and outer side branches of the parietal bone. The ischium has an expanded rectangular lower end.[1]

Wendiceratops is further distinguished by the presence of an erect nose horn, and the lack of a vertical spike on the rear frill. The Chinese Sinoceratops has similar epiparietals, but in addition a central midline epiparietal and bumps below the epiparietals, which are lacking in Wendiceratops.[1]

Rostral and nasal bones

The maxilla, the upper jaw bone, of Wendiceratops had at least twenty-six tooth positions, in each of which several teeth were stacked to form a tooth battery. No orbital horns have been found. The nasal bone bore a vertical nasal horn. The exact size and profile of this horn are unknown but one broken specimen has a height of 11.5 centimetres (4.5 in) and a base length of 9 centimetres (3.5 in). Contact facets with the prefrontal bone suggest that the horn was located just in front of the eye sockets.[1]

Parietal bone

The skull frill of Wendiceratops was broad. The front side of the frill was formed by the squamosal bone which had a rectangular shape. To its edge four skin ossifications or osteoderms were attached, the episquamosals. They had an asymmetrical triangular shape. Uniquely, they curled upwards. From the position of the fourth, frontmost, episquamosal a relatively high ridge was running to the inside, adorned with three substantial bumps. In cross-section, this ridge gave the squamosal the typical "stepped" centrosaurine profile. The rear of the frill consisted of the rounded parietal bones. They too had osteoderms attached to their edges, in this case called epiparietals. Each parietal had five of them, conventionally numbered "p1" to "p5". The fifth and fourth epiparietals, the ones in front, resembled the episquamosals. However, more to the back the epiparietals became increasingly wider, longer and thicker, curving upwards and to the front. This resulted in the first epipariatal becoming tongue-shaped and overhanging a large part of the frill, slightly pointing outwards. In this area the frill edge continued the curvature of these osteoderms, concavely curling upwards. Close to the edge two paired large openings were present, the parietal fenestrae. As no complete frill has been found, their exact form is uncertain but they probably were shaped like transversely oriented ovals. These openings were separated by a broad bone bar which featured a midline ridge that was rather smooth, not adorned by bumps. The bar ended at a gentle embayment of the frill rear edge. This lacked a central epiparietal or "p0".[1]

Whereas centrosaurine species each possessed a unique pattern of frill ornamentation, their postcranial skeleton, the parts of the body behind the skull, was very conservative, i.e. it showed little variation. Accordingly, the describers could find little of distinction among the Wendiceratops postcranial bones. An exception was the ischium. In other centrosaurines this pelvic bone had, in side view, the widest point of its shaft at midlength. The ischium of Wendiceratops however, grew wider towards its lower end, resulting in a generally rectangular shape.[1]

Though most specimens were robust, apparently of adult individuals, some bones were of juveniles. Two shinbones were found with a length of just twenty centimetres.[1]