Hippodraco

Norman, David B., 2015, On the history, osteology, and systematic position of the Wealden (Hastings group) dinosaur Hypselospinus fittoni (Iguanodontia: Styracosterna), Zoological Journal of the Linnean Society 173 (1), pp. 92-189 : 149

HIPPODRACO SCUTODENS MCDONALD, KIRKLAND, DEBLIEUX, MADSEN, CAVIN, MILNER & PANZARIN, 2010 B

This taxon is based upon a nearly complete skull and fragmentary skeleton of a single individual collected from a different locality and stratigraphical horizon to Iguanacolossus in Grand County, Utah, USA ( McDonald et al., 2010b: 14). The material was recovered from the upper Yellow Cat Member of the Cedar Mountain Formation and is regarded as Barremian in age ( Hunt et al., 2011).

Teeth and jaws

The dentary teeth are described as being too badly damaged or matrix-obscured for adequate description; they are evidently shield-shaped and bear a distally offset primary ridge, but no further details are available ( McDonald et al., 2010b). The lower jaw appears to have a straight (not arched) dentary and a short diastema. The form of the coronoid process cannot be described because of overlying bones.

Axial skeleton

The dorsal vertebrae have comparatively short, ‘planklike’ neural spines ( McDonald et al., 2010b: fig. 27), quite distinct from the form of those seen in equivalent vertebrae of Hy. fittoni .

Appendicular skeleton

The scapula of H. scutodens ( McDonald et al., 2010b: fig. 30C, D) is typically ornithopod, and very similar in shape to that seen in Hy. fittoni . The sternal bone ( McDonald et al., 2010b: fig. 30A, B) is similar in morphology to that of Hy. fittoni with a broad, flattened ‘handle’ and a well-developed ‘blade’; however, there is no evidence of medial fusion into a conjoined sternal plate as seen in one specimen of Hy. fittoni . The remainder of the skeleton is poorly preserved and comparisons between these two taxa are uninformative.