Four localities of Early Miocene age in the Northern Sperrgebiet, Namibia (Elisabethfeld, Grillental, Langental and Fiskus) combined, have yielded 53 species of mammals. The autecological and synecological studies of this association shows that it corresponds to a countryside that was clearly more forested and more humid than that represented at the basal Middle Miocene site at Arrisdrift, Namibia.