Diversity of large ornithopod dinosaurs in the upper Hauterivian-lower Barremian (Lower Cretaceous) of Teruel (Spain): a morphometric approach

Abstract

We report some large ornithopod vertebrae from two upper Hauterivian-lower Barremian (Lower Cretaceous) localities in El Castellar (Maestrazgo Basin, Teruel, Spain). These fossils have been studied systematically as well as morphometrically using a multivariate analysis in order to analyse the diversity of the sample. In fact, principal component analysis has been demonstrated as an useful tool for establishing affinities in isolated iguanodontian vertebrae, at least when size eff ect is not removed from the analysed dataset. As result of this study, two large indeterminate styracosternans are distinguished in the sample: a large one with platycoelus anterior caudal vertebrae related to the genera Magnamanus and Iguanodon, and a middle-sized one with longer-than-high dorsal vertebrae and amphicoelus anterior caudal vertebrae related to Morelladon. Such diversity of large ornithopods observed in the upper Hauterivian-lower Barremian of the Maestrazgo Basin is similar to that previously observed in western Cameros Basin and it demonstrates the presence of at least two diff erent forms of styracosternan in this stratigraphic range of the Iberian Peninsula.

A highly pneumatic middle Cretaceous theropod from the British Lower Greensand

“…Furthermore, while synapomorphic ornithopodan characters are typically restricted to cranial and appendicular elements, the caudal vertebra retains its transverse processes and lacks the hexagonal or octagonal cross‐section present in iguanodontians (Norman 2004; Verdú et al . 2019), further supporting the element's theropodan affinities.…”