Blasisaurus canudoigen. et sp. nov., a new lambeosaurine dinosaur (Hadrosauridae) from the Latest Cretaceous of Arén (Huesca, Spain)

Abstract

Blasisaurus canudoi gen. et sp. nov. is described on the basis of disarticulated skull and lower jaw remains found in the Blasi 1 locality of Arén (Huesca, south-central Pyrenees of Spain), located in the upper part of the Arén Formation, late Maastrichtian in age. This new lambeosaurine hadrosaurid is characterized by a jugal combining a hook-like dorsal edge of the posterior process and a narrow, D-shaped infratemporal fenestra. Blasisaurus differs from Arenysaurus from the Blasi 3 site of Arén mainly by the absence of secondary ridges in the dentary teeth, and from Koutalisaurus (probably a junior synonym of Pararhabdodon ) from the Isona region of Lleida by the anteriormost portion of the dentary that is modestly deflected ventrally. A phylogenetic analysis places Blasisaurus as closely related to Arenysaurus in a clade of basal lambeosaurines more derived than Tsintaosaurus and Jaxartosaurus ; this clade forms part of a polytomy with Amurosaurus and with more derived lambeosaurines. Palaeobiogeographically, the presence of Blasisaurus and other hadrosaurids in the Maastrichtian European archipelago suggests one or, more probably, a series of dispersal events from Asia across intermittent land bridges during the second half of the Late Cretaceous.