Tuesday, July 29, 2014

A Very Large Carcharodontosaur Found in Barremian Cretaceous Spain

A large-bodied theropod (Tetanurae: Carcharodontosauria) from the Mirambel Formation (Barremian) of Spain


Gasca et al


We describe an isolated distal femur of a large-sized theropod dinosaur from the Mirambel Formation, Teruel province, Spain. It comes from the Ladruñán-3 fossil locality, which represents a sandstone channel deposit that is early Barremian (Early Cretaceous) in age. This femur can be identified as belonging to an undetermined stem carcharodontosaurid allosauroid. The distal outline is similar to that of the basal carcharodontosaurid Acrocanthosaurus, which bears a ridge for the cruciate ligaments in the flexor groove and a deep but narrow extensor groove. This new carcharodontosaurid remnant extends the presence of this large-bodied theropod lineage in the Iberian Peninsula back to the early Barremian. The coexistence of carcharodontosaurids, ceratosaurians and spinosaurids in the Barremian of the Iberian Peninsula echoes the clade composition of large-bodied predator dinosaurs characteristic of other Early Cretaceous faunas in Gondwana. This suggests that Early Cretaceous Iberian ecosystems were as diverse as other Barremian European assemblages, with carcharodontosaurids being exclusive to Iberia.

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