Acheulean technological behaviour in the Middle Pleistocene landscape of Mieso (East-Central Ethiopia).

The Mieso valley is a new paleoanthropological sequence located in East-Central Ethiopia. It contains Middle and Upper Pleistocene deposits with fossil and lithic assemblages in stratified deposits. This paper introduces the Middle Pleistocene archaeological sequence, attributed to the late Acheulean. Low density clusters of artefacts suggest short-term use of the landscape by Acheulean hominins. In Mieso 31, one of the excavated assemblages, refit sets indicate fragmentation of the reduction sequences and enable study of the initial stages of biface manufacture. Mieso 7, also a stratified site, is primarily characterized by a small concentration of standardized cleavers, and portrays another dimension of Acheulean technology, that related to final stages of use and discard of large cutting tools. Available radiometric dates place the Mieso Acheulean around 212 ka (thousands of years) ago, which would make this sequence among the latest evidence of the Acheulean in East Africa, in a time span when the Middle Stone Age is already documented in the region.