Les Tortues Du Pliocène d'Ahl al Oughlam (Casablanca, Maroc) et De Localités Mio-Pliocènes Avoisinantes

Abstract

Turtles from the Pliocene of Ahl al Oughlam (Casablanca, Morocco) and nearby Mio-Pliocene localities.The Late Pliocene locality Ahl al Oughlam (Casablanca, Morocco) yielded a fauna of cryptodiran testudinoid turtles, all of them related to extant African forms. Two terrestrial and one freshwater species are recognized. First, a new small species of the palaearctic genus Testudo Linnaeus, 1758, T. oughlamensis n. sp., is abundantly represented and is closely related to T. kenitrensis Gmira, 1993, from the Middle Pleistocene of Kenitra, Morocco. It is compared to other new remains of Testudo from nearby localities of similar age, including Dehar Mouak and Ar Rehamna. Together with T. kenitrensis, it constitutes a new clade within Testudo, providing a minimum age for the divergence between this clade and T. graeca Linnaeus, 1758 from Morocco. Secondly, the giant ?Centrochelys marocana n. sp., is probably related to the extant C. sulcata (Miller, 1779). Its description gives the opportunity to examine the earliest member of this genus in Morocco, from the nearby Late Miocene/Early Pliocene locality of Lissasfa. Comparisons with Miocene to extant genera of large size from Europe and northern Africa are made. The freshwater species from Ahl al Oughlam is close to the extant species Mauremys leprosa (Schweigger, 1812). It is the earliest record in Morocco of this second palaearctic genus. Thus, the fossil turtle fauna of Casablanca demonstrates the antiquity in Morocco of the three extant genera. Their geographical origin is considered.