Delapparentia, Ruiz-Omenaca, 2011

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 : 148

DELAPPARENTIA TUROLENSIS RUIZ- OMENACA, 2011

This taxon is based upon a partial associated skeleton collected at Galve in the Province of Teruel in the Autonomous region of Aragon (Camarillas Formation: lower Barremian ) .

Axial and appendicular skeletons

The skeletal elements include an articulated series of anterior caudal vertebrae, a variety of cervical and dorsal rib fragments, and portions of all three pelvic bones. Suggested autapomorphies of this taxon include the ‘stepped’ form of the capitulum and tuberculum in posterior dorsal ribs, ossified sternal ribs, pneumatic foramina in dorsal ribs, a transversely expanded preacetabular process of the ilium, and a very large ischium. The posterior rib-head characters cannot be used to distinguish this taxon from Hy. fittoni , which has similarly ‘stepped’ posterior dorsal ribs (this is a feature common to all ornithopod dinosaurs); the presence of ossified sternal ribs and pneumatic dorsal ribs are unique and unexpected in ornithischian dinosaurs. The preacetabular process of the ilium differs significantly in shape from that seen in Hy. fittoni and, although the structure of the proximal end of the ischium is similar to that seen in ornithopods generally, its large size relative to the ilium is highly unusual.

Taxonomic note

The stepped rib-head character is not a valid autapomorphy because it is widely seen in tetrapod vertebrates. The reported presence of ossified sternal ribs and pneumatic openings in some dorsal ribs would be unique. However, there is a pressing need to exclude the likelihood that these fragmentary elements belong to the large theropod whose remains were collected at the same locality ( Ruiz-Omenaca, 2011: 85). The preacetabular process of the ilium closely resembles that described in I. bernissartensis ( Norman, 1980) and the ischium (and pubis), judged by their comparative size, cannot belong to the same individual as the ilium; this suggests that there has been some mixing of skeletal elements from different individuals. Subject to further study this taxon is considered provisionally to be a nomen dubium.

IGUANACOLOSSUS FORTIS MCDONALD,