Provenience,age and associations of archaic Homo sapiens crania from Lake Eyasi,Tanzania

Fifty years ago, an ethnographic expedition found primitive human fossils at Lake Eyasi, Tanzania. Subsequent emphasis has centered almost exclusively on cranial morphology, neglecting the discovery site and associated finds. Fauna has been deemed “essentially modern” and racemization dates suggest a late Pleistocene age for the hominid remains; these assessments have been advanced as consistent with a “terminal Middle Stone Age” antiquity. Based on recent observations at the site and new sediment analyses, a provisional sequence is now proposed: an earlier formation, the Eyasi Beds, is distinguished from later Pleistocene deposits, the Mumba Beds, the latter being partially calibrated by uranium series and radiocarbon dates. This evidence indicates that the Eyasi Beds, the probable source of the human fossils, are older than 130,000 years, and the fauna may include seven extinct large mammal species. Documented Eyasi Beds artifacts are mostly unspecialized Middle Stone Age types; no typological or technical features suggest later MSA specializations or innovations foreshadowing Later Stone Age industries. A series of core tools from the lakeshore suggests an industry of Sangoan aspect. All lines of evidence from the locality contradict the young amino acid racemization dates; artifacts and fauna, including archaic Homo sapiens remains, are of probable Middle Pleistocene age.