A review of Ichthyosauria from Portugal

Abstract

The ichthyosaur fossil record of Portugal is composed of specimens from the localities of S. Pedro de Moel, Alhadas, Cadima, Murtede, Casal do Combo, Condeixa, Alvaiázere and Tomar, within the confines of the Lusitanian Basin, ranging in age from the Sinemurian to the Aalenian. Historical classifications by Zbyszewski, Moitinho de Almeida and Veiga Ferreira have identified the specimens as belonging to the genera Ichthyosaurus and Stenopterygius, and in the cases a species could be determined, I. intermedius and S. uniter. However, over half a century has passed since these specimens have first been document, and new developments in Ichthyosaur phylogeny and taxonomy have rendered these classifications invalid. In this study, we’ve reviewed the specimens and attempted to perform a more detailed description, after which a phylogenetic analysis was performed in order to identify the specimens, but the fragmented, incomplete, and in some cases poorly preserved stat of these has resulted in a largely inconclusive analysis, with only one specimen, 85, being unambiguously assigned to the recently described species I. larkini. Further studies and new developments in ichthyosaur research are required for a more accurate classification of the Portuguese specimens.