Iberian plesiosaurs: a juvenile specimen from the Lower Jurassic of Asturias, Northern Spain

BARDET, N.; FERNÁNDEZ, M. ; GARCIA RAMOS, JC, PIÑUELA, L., VINCENT, P. & PEREDA SUBERBIOLA, X.

Paris, Francia

Simposio; 54th Annual Symposium of Vertebrate Palaeontology and Comparative Anatomy; 2006

Mesozoic marine reptiles, especially Plesiosauria, are poorly known in the Iberian Peninsula except Triassic sauropterygians. From Spain, the only plesiosaur fossil record includes a 19th century specimen (now lost) from the Lower Jurassic of Asturias (Schulz, 1858) - one of the earliest plesiosaur discoveries, elasmosaurid and pliosaurid isolated teeth and vertebrae from the Lower Cretaceous of Castellón (Yagüe et al., 2003), and an isolated elasmosaurid tooth from the Late Cretaceous of the Basque Country (Bardet et al., 1999). From Portugal, only an incomplete plesiosaurid skull has been described from the Lower Jurassic (Sauvage, 1897-1898). The new discovery of a partial skeleton from the Pliensbachian of Asturias improves our knowledge of plesiosaurs in Spain. The specimen includes vertebrae, ribs, limb and girdle elements. The incomplete and immature nature of the specimen precludes a precise systematical attribution. It is referred to as Plesiosauroidea indet. on the basis of centra roughly as long as wide and bicephalous cervical ribs. It represents one of the very few juvenile plesiosaur records worldwide and contributes to fill the Pliensbachian marine reptile fossil gap.