New hadrosauriform cranial remains from the Arcillas de Morella Formation (lower Aptian) of Morella, Spain

This article describes isolated skull bones of at least three ornithopod dinosaurs from the lower Aptian “Arcillas de Morella” Formation at Morella (Castellón, Spain). These bones correspond to two right maxillae and a partial left quadrate. Analysis of the two maxillae belonging to the large-sized European ornithopod Iguanodon bernissartensis provided new information about this taxon. Hence, for the first time in Iguanodon, a rostrodorsal process and a straight shape, both in the maxilla and in the tooth row, are described when viewed dorsally and occlusally, respectively. Regarding the left quadrate, in the lateral and medial views, the presence of a bowed quadrate shaft related the left quadrate to the monospecific genus of large-sized ornithopod from the European Early Cretaceous Mantellisaurus. Given the scarce information about the left quadrate, we tentatively refer this bone to cf. Mantellisaurus atherfieldensis. Furthermore, new evidence of these Hadrosauriformes in the Iberian Peninsula corroborates the great similarity between the Barremian–early Aptian dinosaur faunas in British, Belgium and Iberian records.