Ornithopod dinosaurs from the Late Jurassic of Portugal

Ornithopods are the most successful group of herbivorous dinosaurs, ranging from the Middle Jurassic to the Cretaceous, becoming extinct at the Cretaceous Paleogene boundary. However, most of the attention has been given to derived forms (Hadrosaurids). Herein, ornithopod material coming from Upper Jurassic of Lourinhã Fm. and housed at Museu da Lourinhã (ML) is described and discussed. Specimens studied include cranial and dental material, including cranial remains of a dryosaurid, axial skeleton elements, pectoral girdle elements and limb bones. Comparison with reference literature and phylogenetic analyses has allowed the attribution of the material either to Dryosauridae or and to Ankylopollexia. Since the lack of autapomorphic characters, it was not possible to assign the material to the two valid ornithopod Portuguese taxa, Draconyx loureiroi and Eousdryosaurus nanohallucis, although phylogenetic analyses hint a close relationship between the Lourinha dryosaurid material and E. nanohallucis. Principal Component Analysis (PCA) plotting limb bones proportions indicates a not fully mature ontogenetic stage for the Portuguese specimens. Comparing the Portuguese ornithopod fauna with the one in Morrison Formation and Kimmeridge Clay Formation, it is remarked the key-role of Portugal to understand biogeographic patterns in the distribution of iguanodontians