Abstract

Plenty of goniopholidid species from the Mesozoic have been found in the Iberian Peninsula. A previous goniopholidid taxon, Goniopholis baryglyphaeus Schwarz, 2002, from the Late Jurassic of the Guimarota coal mine (Leiria, central Portugal) was described. This taxon corresponds to a partial skull and some postcranial material, and it marked the oldest and first ever record of goniopholidid and Goniopholis species described for the Iberian Peninsula. Here we present a well-preserved, almost complete, skull of a new species, Ophiussasuchus paimogonectes gen. et sp. nov. from Upper Jurassic deposits of Praia de Paimogo (near Lourinhã, central west Portugal). The specimen corresponds to a mesorostrine, platyrostral skull of a medium-sized goniopholidid coming from the upper Kimmeridgian within the Lourinhã Formation. Phylogenetically, the new species is recovered as the sister taxon of the Early Cretaceous European clade made by Hulkepholis and Anteophthalmosuchus. Although its position is well-resolved, this new taxon displays intermediate morphological traits, sharing characteristics with Jurassic Asian and American basal goniopholidids (e.g., presence but lesser development of the secondary choana with the nasopharyngeal duct partially open), as well as more derived characters shared with Cretaceous European taxa such as Hulkepholis (e.g., the shape of the supratemporal fenestra and the palatines). As a result, Ophiussasuchus paimogonectes gen. et sp. nov. exhibits characteristics suggesting a reversion to primitive goniopholidid conditions or intermediate states between the goniopholidid taxa of North America and Europe. These findings support the shared Late Jurassic fauna between the Morrison and Lourinhã Formations, while also having high endemism of taxa.