21.7.14

Tortugas pleurodiras de Mali en la 15 edición del congreso Gondwana


Entre los días 14 y 18 de Julio, Madrid ha sido la sede del congreso internacional Gondwana 15. Aunque la paleontología, y más concretamente la de vertebrados, ha estado escasamente representada, un grupo de reptiles supone la excepción: las tortugas. Varios trabajos sobre quelonios africanos, o sobre linajes, de origen gondwánico, que alcanzaron Europa en distintos momentos de la historia geológica, han sido defendidos.

El primero de ellos, cuyo título es “New data on Taphrosphyini (Pleurodira, Bothremydidae) from the Paleogene of Mali: the study of the shells”, tiene por resumen lo siguiente:

One of the most diverse groups of Pleurodira is the extinct clade Bothremydidae (Pelomedusoides). It was composed of forms inhabiting both freshwater and littoral environments (Lapparent de Broin and Werner, 1998). The northern half of Africa has been identified as an area of bothremydid diversification in the Late Cretaceous and Paleogene, with many taxa recorded in near-shore marine deposits (Lapparent de Broin, 2000; Gaffney et al., 2007). The Paleogene record of this group from Mali is very relevant. In fact, two new representatives, Azabbaremys moragjonesi and Acleistochelys maliensis, both corresponding to new genera and species, have recently been described there (see Gaffney et al. 2001, 2007). Furthermore, the presence of Nigeremys gigantea, or a possible closely-related form, has been notified (Gaffney et al., 2006), and Taphrosphys sp. has been recognized there (Lapparent de Broin and Werner, 1998; Lapparent de Broin, 2000). All these taxa of side-necked turtles correspond to large coastal bothremidids, belonging to Taphrosphyini (sensu Gaffney et al., 2006).

Azabbaremys is only known by its holotype, a complete skull lacking lower jaws. Acleistochelys is also exclusively known by its holotype, which gives good cranial information but few and uninformative associated shell fragments. The material assigned by Gaffney et al. (2006) to Nigeneremys corresponds to a single specimen, consisting of the articulated right and left premaxillae and maxillae, and a partial quadrate. The material attributable to Taphrosphys sp. has not been described, but it includes isolated plates. Thus currently available information on the shells of Bothremydidae from the Paleogene record of Mali is extremely limited.

Abundant and well-preserved shell material of Bothremydidae from the Paleogene of Mali is presented here. These hitherto unpublished specimens were found in expeditions in the early 1980s, and deposited in the Natural History Museum (London). The holotype of Azabbaremys was also found as a result of these surveys. The specimens analyzed here not only correspond to isolated plates and articulated fragments of shells, but also to nearly complete plastra and shells. This study sheds new light on the anatomy of the members of Taphrosphyini that lived during the Paleogene in Africa.

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Más información:
  • Referencia: Pérez-García, A. 2014. New data on Taphrosphyini (Pleurodira, Bothremydidae) from the Paleogene of Mali: the study of the shells. In: Pankhurst, R.J., Castiñeiras, P., Sánchez Martínez, S. (Eds.). Abstract Book of Gondwana 15, North meets South: 135
  • Imagen: Parte del espaldar de uno de los caparazones analizados.