Lothagam: A record of faunal change in the late Miocene of east Africa

Lothagam is a richly fossiliferous late Miocene site near the western shore of Lake Turkana, northern Kenya. This site has yielded a diverse fauna documenting a chronological interval poorly known from elsewhere in Africa. Lothagam was first collected by an American research group in the late 1960s and early 1970s. Field studies by the National Museums of Kenya between 1989-1993 have recovered many additional vertebrate fossils, including species previously unknown from Lothagam. This contribution presents a revised, formal stratigraphic framework, initial results of a vertebrate systematic revision, and new interpretations of the paleoenvironmental setting. Analysis of the sedimentary facies and their fossil content indicates the presence of a large, slow moving, well-oxygenated perennial river with abundant backswamps and ponds. Comparisons with faunas from earlier middle to late Miocene Kenyan localities suggest that a major environmental change occurred at the end of the Miocene.