La primera tortuga mesozoica española en las XXXIX Jornadas de la SEP

De los trabajos presentados en las XXXIX Jornadas de la Sociedad Española de Paleontología, uno de ellos trataba sobre tortugas primitivas. En concreto, se analizaba un representante de un linaje con distribución tanto europea como norteamericana: Helochelydridae. Es a este grupo de quelonios al que pertenece la primera tortuga mesozoica definida en el registro español. Se trata de la problemática ‘Trachyaspis turbulensis’, del final del Cretácico Inferior (Albiense) de Teruel. La validez de esta forma es revisada en esta presentación, gracias al hallazgo de nuevo material que podría pertenecer al mismo taxón. El resumen de este trabajo, con el título “Re-evaluating the validity of the first Mesozoic turtle species described in Spain thanks to the discovery of new fossils from the Albian of Teruel”, es el siguiente:

As with other reptile lineages, the description of the first Mesozoic turtle taxon erected from Spanish material occurred much later than those based on fossils identified in any other Western European country. Thus, the French paleontologist Frédéric-Marie Bergounioux, the highest European authority at that time in the study of fossil turtles, described, in the 1950s, the Spanish species ‘Trachyaspis turbulensis’. This taxon was based on a fossil found in the lower Albian levels of La Pintada Quarry, in the municipality of Gargallo (Andorra-Sierra de Arcos Region, Teruel Province, Northeastern Spain). The holotype and only known specimen of this taxon was identified by Bergounioux as corresponding to the medial region of a shell, putatively preserving elements of both the carapace and the plastron. The author inadvertently used a previously occupied genus of a turtle that, unlike this one, corresponded to a marine form. Furthermore, given the limited anatomical information of systematic value provided by that specimen, ‘Trachyaspis turbulensis’ is currently considered as a nomen dubium. The specimen is now recognized as attributable to the lineage of basal terrestrial turtles Helochelydridae. Our detailed first-hand study of this fossil allows its reinterpretation as belonging to a different shell region. The keys to evaluate the potential validity of the species, or to justify its synonymy with any previously described European form, come from recent finds also in the lower Escucha Formation and in the Andorra-Sierra de Arcos Region. However, they come from the Santa María Quarry, in Ariño, and not from Gargallo. In addition to the recently described Aragochersis lignitesta, a second helochelydrid is identified in Ariño. It is compatible with the holotype of ‘Trachyaspis turbulensis’. It is represented by numerous specimens, a selection of them having been made for this study. Thus, a relatively complete postcranial skeleton, as well as several isolated plates that allow intraspecific variability to be recognized, are analyzed.

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Más información:

• Referencia: Pérez-García, A., Espílez, E., Mampel, L., Cobos, A. Re-evaluating the validity of the first Mesozoic turtle species described in Spain thanks to the discovery of new fossils from the Albian of Teruel. In Moncunill-Solé, B., Blanco, A., Grandal d’Anglade, A., González Fortes, G., Santos Fidalgo, L., Bao, R. (Eds.), Libro de Resúmenes de las XXXIX Jornadas SEP. Palaeontological Publications 5, 206.