Search

This study focuses on the previously marginally known Middle Pleistocene culture in the surroundings of Makuyuni village, located east of Lake Manyara (northern Tanzania) in the East African Rift System (EARS). Recent surveys resulted in the discovery of 56 new sites. Besides the discovery of Middle Stone Age (MSA)/Later Stone Age (LSA) artifacts and exclusive fossil sites, 45 sites yielded varying amounts of Acheulean artifacts that were recorded and collected during the survey. The majority were surface finds, with additional artifacts retrieved from test excavations. Based on technological and chronological classification, the vast majority of the assemblage was attributed to the Middle Acheulean, with a few artifacts dated to early Late Acheulean. Chronometric dating places the Makuyuni finds to between 630,000 and 270,000 years BP, with the majority of artifacts belonging to an earlier period between 630,000 and 400,000 years BP. A key result is the discovery of artifacts at the contact zone between the lacustrine (lower) and the terrestrial (upper) member of the Manyara Beds, which allows a stratigraphic attribution of the artifacts for the first time. It suggests that hominins exploited the landscape along the shoreline of the paleolake Manyara during the early Middle Pleistocene. [ABSTRACT FROM AUTHOR]

The Middle Awash region of Ethiopia contains a rich record of Acheulean occupation spanning from Early Pleistocene times through much of the Middle Pleistocene. Here we will present an overview of some of the major reported features of the Acheulean archaeological record of the Middle Awash (Clark et al., 1994; de Heinzelin et al., 2000) and compare and contrast earlier and later biface technological patterns in this important study area. As an overall pattern, later Acheulean bifaces, here tend to differ from earlier ones in the following characteristics: later biface forms tend to be smaller, more ovate, wider relative to length, thinner (both relative to length and width and in absolute terms), more symmetrical, more heavily flaked, show greater use of soft hammer flaking and Kombewa technique, be straighter-edged or less sinuous, and often exhibit a remarkably high degree of standardization at a given site. These technological changes over perhaps half a million years (between approximately 1.0 and 0.5 million years ago) accompany the transition from Homo erectus to Homo heidelbergensis in this region. The later technological patterns thus correlate with the emergence of larger-brained, more intelligent hominids that exhibit greater technological finesse and also appear to develop and maintain stronger rules and traditions pertaining to their technological behaviors. It is likely that, relative to earlier hominids, these later hominid forms (which would evolve into early anatomically modern humans or Homo sapiens ) had richer communicative abilities and cultural complexity, which we believe to be manifested in the technological finesse and standardization of their material culture. [ABSTRACT FROM AUTHOR]

The emergence of the Acheulean from the earlier Oldowan constitutes a major transition in human evolution, the theme of this special issue. This paper discusses the evidence for the origins of the Acheulean, a cornerstone in the history of human technology, from two perspectives; firstly, a review of the history of investigations on Acheulean research is presented. This approach introduces the evolution of theories throughout the development of the discipline, and reviews the way in which cumulative knowledge led to the prevalent explanatory framework for the emergence of the Acheulean. The second part presents the current state of the art in Acheulean origins research, and reviews the hard evidence for the appearance of this technology in Africa around 1.7 Ma, and its significance for the evolutionary history of Homo erectus. This article is part of the themed issue 'Major transitions in human evolution'. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Identifying when hominins first produced Lomekwian, Oldowan, and Acheulean technologies is vital to multiple avenues of human origins research. Yet, like most archaeological endeavors, our understanding is currently only as accurate as the artifacts recovered and the sites identified. Here we use optimal linear estimation (OLE) modelling to identify the portion of the archaeological record not yet discovered, and statistically infer the date of origin of the earliest flaked stone technologies. These models provide the most accurate framework yet for understanding when hominins first produced these tool types. Our results estimate the Oldowan to have originated 2.617 to 2.644 Ma, 36,000 to 63,000 years earlier than current evidence. The Acheulean's origin is pushed back further through OLE, by at least 55,000 years to 1.815 to 1.823 Ma. We were unable to infer the Lomekwian's date of origin using OLE, but an upper bound of 5.1 million years can be inferred using alternative nonparametric techniques. These dates provide a new chronological foundation from which to understand the emergence of the first flaked stone technologies, alongside their behavioral and evolutionary implications. Moreover, they suggest there to be substantial portions of the artifact record yet to be discovered. [ABSTRACT FROM AUTHOR]

Over the last thirty years, investigations in the Nachukui Formation (West Turkana, Kenya) have revealed the importance of the region for human evolution studies within an archaeological sequence spanning the period 3.3 million years (Ma) to 0.7 Ma. Despite the numerous sites discovered, little is known about pounding activities during this time period in the region. In this paper, we present an analysis of percussive tools from three West Turkana archaeological sites: Lokalalei 2C, Kokiselei 1 and Kokiselei 4, dated between 2.3 Ma and 1.76 Ma. Their chronological range allows us to conduct a diachronic comparison of the percussive activities during a time span with two hominin genera (Australopithecus boisei, early Homo and Homo erectus). The three assemblages are compared with others from the Early Stone Age and with experimental percussive tools. Despite the stable predominance of hammerstones associated with stone knapping activities over time in the Nachukui Formation, our macro- and microscopic analyses reveal an inter-site variability in the type and re-use of percussive tools for specific heavy-duty pounding activities. When compared with other Early Stone Age sites, Lokalalei 2C, Kokiselei 1 and Kokiselei 4 similarly present a low frequency of pounding tools but a high number of blanks used for both flaking and pounding activities, suggesting that the reutilization of the tools and the change in their functionality was common in the ESA lithic record. • We analyse synchronic and diachronic variability of pounding tools from West Turkana sites dated to 2.3–1.76 Ma. • Oldowan (Localalei 2C, Kokiselei 1) and Acheulean (Kokiselei 4) percussive tools are compared. • Hammerstones used for flaking dominate in the studied assemblages. • Cores re-utilized as hammerstones make up a significant component of the pounding tools identified. [ABSTRACT FROM AUTHOR]

The archaeological sequence of Olduvai Gorge Beds III and IV is essential for the study of the evolution of the African Acheulean between ∼1.3 Ma and 0.6 Ma. However, no further reexaminations of the lithic assemblages have been published after Mary Leakey's original work. In this article, we present an analysis of a part of these collections, with an emphasis on the microscopic and spatial analysis of percussive marks in the so-called pitted stones. To investigate the function of pitted stones and understand the formation process of depressions on lava cobbles, archaeological pitted stones were compared with experimental tools used in bipolar knapping, nut-cracking, and flake-splitting activities. Our results demonstrate that features of pitted stones remained homogeneous across Beds III and IV assemblages, with depressions preferentially located on the central areas of the tools and similar use-wear traces inside such depressions. Comparisons with the experimental collection demonstrate that these depressions are rapidly formed when splitting flakes, resulting in elongated morphologies similar to those documented in the archaeological tools. Our results are discussed within the context of other archaeological and nonhuman primate assemblages to further explore the function of pounding activities in which pitted stones could have potentially been involved. • We present the first microscopic analysis of pitted stones from the Acheulean Beds III and IV at the Olduvai Gorge. • The microscopic and geographic information system results show a consistency on their function through the stratigraphic sequence. • The results are compared with other experimental and archaeological assemblages. • Bipolar knapping and flake splitting are the most likely activities involved in their use. [ABSTRACT FROM AUTHOR]