An update of the spinosaurid fossil record from the Lower Cretaceous of the Iberian Peninsula: distribution, diversity, and evolutionary history

The fossil record of spinosaurid theropods from the Lower Cretaceous of the Iberian Peninsula is relatively abundant, but not very informative. This record, as generally occurs in other geographic areas, is mainly represented by isolated teeth, probably due to the distinctive features of the dentition of these theropods. However, cranial and postcranial elements attributed to spinosaurids have been described and reported from different Iberian fossil sites. The currently known record of these theropods spans from the upper Hauterivian to the lower Aptian of the Cameros and Maestrazgo basins in Eastern Spain whereas it is early Barremian in age in the Lusitanian Basin of Western Portugal. Spinosaurid remains from the Iberian fossil record were traditionally attributed to Baryonyx, firstly described in the upper Barremian-lower Aptian of United Kingdom. However, the recent description of a specimen collected in the locality of Santa Águeda (Vallibona, Castellón), from sediments of the Morella Formation, implies the presence of a new taxon with a combination of derived features more closely related with some Gondwanan spinosaurines than with Baryonyx. Therefore, the currently known Iberian spinosaurid record would be made up of at least three taxa: Baryonyx (or a closely related baryonychine), the spinosaurine Vallibonavenatrix cani, and possibly Camarillasaurus cirugedae, which was recently re-interpreted as belonging to a megalosauroid tentatively related with spinosaurids. This faunal diversity is also compatible with the assortment of spinosaurid tooth morphotypes (distinguished mostly by the presence or absence of serrated mesial carina) that has been described in the Lower Cretaceous of the Iberian Peninsula. Keywords Spinosauridae * Lower Cretaceous * Lusitanian Basin * Cameros Basin * Maestrazgo Basin * Palaeobiogeography El registro fósil de terópodos espinosáuridos del Cretácico Inferior de la península ibérica es relativamente abundante pero habitualmente poco informativo. En general, este registro está representado por dientes aislados, que debido a sus características particulares se distinguen con cierta facilidad de la dentición del resto de los terópodos. Aunque son menos abundantes, también se han atribuido a espinosáuridos otros elementos craneales y postcraneales en diferentes yacimientos ibéricos. Temporalmente, el registro de estos terópodos conocido actualmente se extiende desde el Hauteriviense superior hasta el Aptiense inferior en las