THE DISCOVERY OF A SINGULAR FAUNA: THE SAUROPODS FROM THE LATE JURASSIC AND EARLIEST CRETACEOUS OF SPAIN

CANUDO, J. Ignacio, BARCO, J. Luis, University of Zaragoza, Spain; GARCÍA- RAMOS, José C., PIÑUELA, Laura, RUIZ-OMEÑACA, J. Ignacio. MUJA, Asturias, Spain

In Spain there is a good record of Kimmeridgian to Berriasian continental and coastal facies. It is common to find fragmentary remains of dinosaurs, many of them linked to transition environments. Particularly interesting are the remains of sauropods, usually included in Diplodocidae and Camarasauridae, families typical of the end of Jurassic in North America (Morrison Fm). The description of more complete specimens and new studies of fragmentary material has made possible to interpret a new scenario. The phylogenetic proposals represented by postcranial remains (Galvesaurus, Losillasaurus), locate them outside Neosauropoda or as polytomies with other basal Neosauropoda. This part of the cladogram is poorly resolved, but according to our data it is the position occupied by some of the Iberian sauropods. In addition, the sauropod teeth from the Late Jurassic and earliest Cretaceous are included in two groups, one of them, the non-neosauropod eusauropods, with markedly spatulate teeth. The second has pencil like teeth (diplodocimorphs) from the Kimmeridgian of Asturias and the Berriasian of Galve (Teruel). This second group have slightly spatulate apex distinguishing them from the Diplodocidae, may be located as more primitive Diplodocimorpha. Noteworthy is the absence of Titanosauriformes such as Brachiosauridae, and even other macronarians such as Camarasauridae. This association implies that part of the Iberian Peninsula maintained more primitive sauropods than those present in adjacent areas of Gondwana and Laurasia, in spite of being situated in an intermediate paleogeographical position between these two great continental masses. This would suggest the isolation (endemism?) of the north-east of the Iberian Peninsula, at least its sauropods, during Late Jurassic and earliest Cretaceous.

Canudo J. I., Barco, J. L., García-Ramos, J. C., Piñuela, L. & Ruiz-Omeñaca, J. I. 2006. The discovery fauna: the sauropods from the Late Jurassic and earliest Cretaceous of Spain. Journal of Vertebrate Paleontology, 26, 3, 47A.