A revision and a redescription of the external and internal morphology of the carapace, ontogeny and sexual dimorphism of Sergipella transatlantica Krömmelbein, 1967, from the uppermost Aptian and lower Albian of Brazil and West Africa is presented. Two new species are described: S. grosdidieri nov. sp. and S. viviersae nov. sp. The three species of Sergipella are restricted to areas of the South Atlantic during the late Aptian-early Cenomanian. The present data provide detailed taxonomic criteria for the identification of the type-species of Sergipella and its closely related species. A detailed analysis of the internal and external characteristics of the valves shows that the genus Sergipella that belongs to the Family Trachyleberididae, although it possesses some characteristics close to those of Protocytheridae. This study is based on samples from Riachuelo Formation, lower Albian, Sergipe/Alagoas basin, Sergipe State, NE-Brazil and from wells in West Africa, Madiéla Formation, lower Albian, Gabon basin, east of Libreville, Gabon.