Si ayer hablábamos de la descripción de una nueva tortuga en Algora (Algorachelus peregrinus), hoy lo hacemos sobre las novedades en el estudio de la paleodiversidad registrada en este singular yacimiento del Cenomaniense de Guadalajara (España). Los nuevos datos sobre los taxones allí registrados acaban de ser defendidos en la reunión anual organizada por la Society of Vertebrate Paleontology, cuya sede ha sido en Salt Lake City (Utah, EEUU). El resumen publicado es el siguiente:
The European faunas of reptiles from both the Early Cretaceous as the lattermost Cretaceous are well-represented. However, little information about the taxa living between both periods is available. Scarce and fragmentary remains of turtles, crocodiles and theropod dinosaurs were found in the Spanish site of Algora in the 1980s, as result of geological surveys. Algora is located in the Guadalajara Province (Castilla-La Mancha), in the Castilian Branch of the Iberian Ranges. Its fossiliferous levels correspond to the upper part of the Arenas de Utrillas Fm., deposited in the transit between the middle and the upper Cenomanian. They represent sandy coastal deposits, with subtidal and intertidal events. Considering the potential systematic and paleobiogeographic implications, a first excavation in Algora was recently performed. This yielded numerous remains of reptiles, the turtles being the most abundant.
New and relevant data on the clades previously identified were obtained. In addition of scarce remains of the Laurasian terrestrial turtles Solemydidae, abundant fossils of a second taxon are identified. Thus, a skull, complete and partial shells, abundant plates, and appendicular elements correspond to a new bothremydid. It is the oldest member of the crown Pleurodira in Europe, showing the first evidence of dispersion of the group from Gondwana to Laurasia. The previously discovered crocodyliform remains lack diagnostic features for an accurate attribution. The new findings allow recognizing the presence of at least a eusuchian, not attributed to any described taxon. New teeth of theropods allow confirming the presence of carcharodontosaurids, and improving the understanding of their positional variation.
Several groups hitherto not identified in this site were found. The partial pelvis and a caudal vertebra of an individual of Plesiosauria are recognized. Some characters allow to refer it to Plesiosauroidea and, most probably, to Elasmosauridae. Pterosaur postcranial elements corresponding to a big taxon, tentatively referred to Ornithocheiroidea, were found. Pterosaurs are rare in the Iberian Cretaceous and only a few teeth were so far known in the early Late Cretaceous. Sauropods are identified by axial and appendicular elements that probably correspond to a derived titanosaur within Lithostrotia.
The reptile fauna from Algora is composed by terrestrial, freshwater, and coastal forms, but also of taxa from open marine environments. Both Laurasian lineages as others originated in Gondwana are recognized.
- Imágenes (de arriba abajo): Póster correspondiente al trabajo presentado. / Imagen de grupo realizada durante la campaña de campo en Algora en 2013.
- Referencia: Pérez-García, A., Bardet, N., Barroso-Barcenilla, F., Cambra-Moo, O., Mocho, P., Narváez, I., Ortega, F., Segura, M., Rotices, A., 2016. The fauna of reptiles from the Cenomanian of Algora (Guadalajara, Spain): Systematic and paleobiogeographic implications. 76th Annual Meeting of SVP. Abstract book. 204-205.