Acleistochelys, a new side-necked turtle (Pelomedusoides, Bothremydidae) from the Paleocene of Mali ; American Museum novitates, no. 3549

Abstract

The Paleocene Teberemt Formation south of the Adrar des Iforas Mountains, between Saguirilidad and In Fargas, Mali, yielded a nearly complete skull of a new genus and species of side-necked turtle, Acleistochelys maliensis. Acleistochelys is a member of the family Bothremydidae Baur, 1891, because: (1) the fossa precolumellaris is absent, (2) the foramen stapedio-temporale faces anteriorly, (3) the eustachian tube is separated from the stapes by bone, and (4) an exoccipital-quadrate contact is present. Within the Bothremydidae, Acleistochelys belongs to the tribe Taphrosphyini because: (1) the maxilla-quadratojugal contact is absent, (2) the palate is dorsally arched, (3) there is only a small contribution of the palatine to the triturating surfaces, and (4) the septum orbitotemporale is at least partially open. Acleistochelys is most closely related to Azabbaremys because both share a narrow vomer lacking a posterior attachment to the palatines. The specimen was found in a marine limestone associated with crocodiles, echinoids, and mollusks.