New record of a sauropod in the Jurassic–Cretaceous transition of the Iberian Peninsular (Spain): palaeobiogeographical implications

Abstract

In recent decades a unique association of basal neosauropod and turiasaur sauropods has been described from the Jurassic–Cretaceous transition of Spain. In this context, a sauropod femur from the Tithonian–Berriasian is studied for the first time. The femur in question is an isolated specimen, recovered from the Tera Group in Tera (Soria). It displays a unique mosaic of derived characters as yet undescribed in femora of the Upper Jurassic and Lower Cretaceous of Spain. A prominent lateral bulge, high eccentricity, and a lateromedially flattened proximal end link the femur from Tera with Titanosauriformes. Moreover, it presents a significant distal projection of the tibial condyle, a character observed in Asiatic Titanosauriformes of the Lower Cretaceous. The femur from Tera adds a fifth sauropod taxon to the Tithonian–Berriasian of Spain, and, for the first time, a representative of Titanosauriformes.