The early Acheulean of Eastern Africa: lithic technologies and Hominin evolution

Abstract : The Acheulean techno-complex is considered as one of the longest-lasting prehistoric cultures which exist in the archaeological record, covering more than a million and a half years [4]. The earliest evidence is recorded in eastern Africa at -1.75 Ma at Kokiselei 4, in the Nachukui Formation, West Turkana-Kenya [5] and at KGA6 in the Konso Formation, Ethiopia [1]. This techno-complex is divided into three phases: Early Acheulean (1.75-1 Ma), Middle  Acheulean  (-1.0-0.6Ma)  and  Late  Acheulean (-0.6-0.3 Ma) [7]. The beginning of the Acheulean culture is marked by the emergence of complex behavioral and technological traits [1, 5, 6, 7]. ln the Early Acheulean of eastern Africa, these innovative behaviors are demonstrated by clear organization, careful planning, predetermination of the tool form and complex  reduction  sequences  as well as developed  raw material  selection and procurement strategies [6, 7, 8]. Previously, there was a trend ta categorize the Acheulean sites based on only handaxes' proportions [3]. However, the Early Acheulean of Eastern Africa is a technologically and typologically variable techno-complex which also includes small débitage [3, 4] and sometimes sequentially shaped spheroid and sub-spheroid tools [2]. lt is also considered as a major transition in human evolution. The hominin fossil record indicates the contemporaneous emergence of Homo ergaster/Homo erectus, a species which had increased cranial capacity, in eastern Africa together with the early Acheulean techno-complex. Based on these evidence,  the most plausible scenario is that H.ergaster/H.erectus was the hominin responsible for the invention of the Acheulean [1, 5, 6, 7].