The description of original material of anthracothere and proboscidean in the new locality of Bir el Ater 3 from East Algeria, and a thorough review of early Libycosaurus remains of Bir el Ater 2 allows us validating L. algeriensis as the smallest and earliest species of Libycosaurus and probably the earliest migrant of the genus from Asia. The presence of a Tetralophodon in the Neogene Nementcha formation might represent the earliest occurrence of the genus in Africa. These original fossil remains allow us to discuss the age of the Neogene part of the Nementcha formation close to the Serravalian/Tortonian boundary. 

The earliest cetaceans are found in the early Eocene of Indo-Pakistan. By the late middle to late Eocene, the group colonized most oceans of the planet. This late Eocene worldwide distribution clearly indicates that their dispersal took place during the middle Eocene (Lutetian). We report here the first discovery of a protocetid fossil from middle Eocene deposits of Senegal (West Africa). The Lutetian cetacean specimen from Senegal is a partial left innominate. Its overall form and proportions, particularly the well-formed lunate surface with a deep and narrow acetabular notch, and the complete absence of pachyostosis and osteosclerosis, mark it as a probable middle Eocene protocetid cetacean. Its size corresponds to the newly described Togocetus traversei from the Lutetian deposits of Togo. However, no innominate is known for the Togolese protocetid, which precludes any direct comparison between the two West African sites. The Senegalese innominate documents a new early occurrence of this marine group in West Africa and supports an early dispersal of these aquatic mammals by the middle Eocene.