6.7.23

La cintura pélvica de la tortuga Algorachelus peregrina en el XX Annual Meeting de la EAVP


El esqueleto apendicular de las tortugas pleurodiras apenas ha sido estudiado, en parte debido a su relativa escasez en el registro fósil. En el caso de la tortuga cenomaniense Algorachelus peregrina (Pleurodira, Bothremydidae) encontramos en su localidad tipo (Algora, Guadalajara) una gran abundancia de estos restos. Entre ellos se han podido encontrar elementos pélvicos desarticulados y también articulados en los caparazones completos. Esta abundancia nos ha permitido realizar una descripción exhaustiva de la cintura pélvica de Algorachelus y una comparación de esta con la cintura pélvica de Chupacabrachelys complexus, que hasta ahora es la única tortuga botremídida en tener una descripción en profundidad de algunos de sus elementos apendiculares. Ambas cinturas pélvicas son muy similares pero existen diferencias entre ambas especies. El resumen es el siguiente:

The Cenomanian (earliest Late Cretaceous) Algorachelus peregrina is not only the oldest bothremydid turtle (Pleurodira, Podocnemidoidea) known for the European record, but it also corresponds to that represented by the largest number of specimens in the continent. Most of them come from its type locality: the uppermost middle to lowermost upper Cenomanian fossil site of Algora (Castilian Branch of the Iberian Ranges, Guadalajara Province, Castilla-La Mancha, central Spain). Partial and complete pelvic girdles of several dozen specimens have been found there, thanks to excavation campaigns carried out in recent years. In addition to isolated disarticulated or partially articulated elements of this anatomical region, numerous well-preserved pelvic bones have been found in its original position in complete and relatively complete shells. This is favoured by the firm suture of the pelvic girdle of pleurodires with both the carapace and the plastron. The abundance of carapace and plastral remains, corresponding to the sutured areas with the pelvis, allows studying the scar of the ilium in the visceral view of the dorsal shell and the scars of the ischium and pubis in the visceral view of the ventral shell. Considering this relatively extensive source of information, the detailed description of the pelvic girdle of A. peregrina is provided here. This will provide new data on the knowledge of the paleobiology of this animal, currently under study.

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