Las tortugas primitivas de Algora (Guadalajara) en las VIII Jornadas de Salas de los Infantes

Otro de los trabajos sobre tortugas mesozoicas europeas presentados en las recientemente celebradas VIII Jornadas Internacionales sobre Paleontología de Dinosaurios y su Entorno (Salas de los Infantes, Burgos) analizó el hasta ahora mal conocido registro de tortugas primitivas del yacimiento del Cenomaniense de Algora (Guadalajara). Los fósiles de tortugas acuáticas son muy numerosos en ese yacimiento, disponiéndose actualmente de abundante información sobre la forma allí representada, que fue atribuida a un nuevo taxón, Algorachelus peregrina, correspondiendo al más antiguo linaje de Pleurodira que alcanzó Laurasia desde Gondwana. Sin embargo, la información sobre las tortugas terrestres de Algora era, hasta ahora, extremadamente limitada. El estudio de nuevo material, hasta ahora inédito, permite ampliar el conocimiento sobre estas formas.

El resumen de este trabajo es el siguiente:

Thanks to the recent findings made during the last decade, the Spanish paleontological area of Algora (Guadalajara Province, Castilla-La Mancha) has provided the largest collection of Cenomanian vertebrate macroremains currently known in south-western Europe. However, the available faunistic list of the site has not yet been updated, being mainly based on the analysis of scarce and partial remains collected in geological surveys carried out more than thirty years ago. Two excavation campaigns have been recently performed. As a result, numerous vertebrate remains were found, and a new project is currently in process, allowing a much greater potential knowledge about several of the clades represented there. However, most of these remains have not been, so far, published. They are currently under study.

Turtles are the most abundant group of vertebrates in Algora. A new pleurodiran turtle, corresponding to the oldest bothremydid in Europe, was defined there: Algorachelus peregrina. In addition to this very abundant littoral turtle, a much scarcer taxon, corresponding to a terrestrial form, was recognized. It is attributable to a basal form (Stem Testudines), corresponding to the clade Helochelydridae. Only a partial plate of uncertain anatomical position, recognized as belonging to an indeterminate helochelydrid, was analyzed so far. However, the new findings have allowed recognizing numerous plates and other bones corresponding to this clade. The anatomical study of these remains is presented here, so that the precise systematic attribution of the form represented in Algora is discussed, taking into account the European record of Helochelydridae.

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Más información:

• Referencia: Pérez-García, A. 2019. New information on the anatomy and systematics of the basal turtles (Helochelydridae) from the Spanish Cenomanian site of Algora. Póster. Libro de resúmenes del VIII Jornadas Internacionales sobre Paleontología de Dinosaurios y su Entorno: 103.
• Imagen: Detalle de un fragmento de placa de la tortuga primitiva de Algora, en la que su singular patrón ornamental puede ser claramente apreciado.