Raw material selectivity in Late Pliocene Oldowan sites in the Makaamitalu Basin, Hadar, Ethiopia

We report the results of an analysis of raw material selection patterns in the assemblages from two Late Pliocene in situ archaeological localities in the Makaamitalu Basin (Hadar, Ethiopia). While the same local conglomerate was used as a raw material source for both archaeological occurrences, different selection criteria are identified. At A.L. 894, selection for quality is subtle and the clearest selection is against non-homogeneous raw materials. In the A.L. 666 assemblage, higher-quality raw materials were selected and some rare raw materials reached the locality from unknown sources. A comparison between the Makaamitalu and other Oldowan assemblages reveals an overall shift toward higher complexity of both selectivity and transport behaviors from ca. 2.0 Ma onward, contrasting a typo-technological conservatism that pertains until ∼1.6 Ma. It is hypothesized that an increase in complexity of behaviors related to raw material selection and acquisition involved changes in the intensity and fidelity of technological knowledge transmission.     

Technological variation in the earliest Oldowan from Gona,Afar, Ethiopia

Inter-site technological variation in the archaeological record is one of the richest potential sources of information about Plio-Pleistocene hominid behavior and evolution. However, appropriate methods for describing and comparing Oldowan assemblages have yet to be agreed upon, and interpretation of the early record remains highly controversial. Particularly salient is disagreement over whether the Oldowan is a single technological phenomenon or is more accurately divided into multiple regional and/or chronological traditions, perhaps including a less developed Pre-Oldowan phase in the late Pliocene. Some of this disagreement reflects theoretical and methodological differences between research traditions and some is more directly evidential. Here we present a framework for describing and interpreting Oldowan variation and apply it to three Pliocene assemblages (EG-10, EG-12, and OGS-7) from Gona, all dated to c. 2.6 million years (Ma). Results indicate proficient knapping and a full range of Oldowan reduction strategies in these earliest known occurrences, consistent with the idea of an Oldowan “technological stasis” from 2.6–1.6 Ma. Patterns of variation in raw material selection and predominant reduction strategy at each site clearly indicate the importance of cultural transmission in the Oldowan, but confounding ecological and economic variation continue to render interpretation in terms of multiple tool making traditions or species inappropriate. We propose that cultural transmission and ecological adaptation should be recognized as complementary, rather than mutually exclusive, mechanisms in future attempts to explain Oldowan technological variation.     

Research on late Pliocene Oldowan sites at Kanjera South, Kenya

The late Pliocene is notable for the appearance of two new hominid genera as well as the first archaeological sites, generally attributed to the Oldowan Industrial Complex. However, the behavioral ecology of Oldowan hominids has been little explored, particularly at sites older than 2.0 Ma. Moreover, debates on Oldowan hominid foraging ecology and behavior have centered on data from only two regions, and often from single site levels. Here we describe the preliminary results of our investigation of Oldowan occurrences at Kanjera South. These occurrences preserve the oldest known traces of hominid activity in southwestern Kenya, and unlike most of the Oldowan sites in the 2.0-2.5 Ma time interval, artefacts are found in spatial association with a well-preserved fauna. In 1996 and 1997, this project initiated the first excavation program for Kanjera South. Magneto- and biostratigraphy indicate that deposition began approximately 2.2 Ma, substantially earlier than previously thought. At Excavation 1, artefacts were found in spatial association with a taxonomically diverse faunal assemblage in Beds KS-1 and KS-2. Excavation 2 yielded a partial hippopotamus axial skeleton with artefacts in KS-3. Cores from both sites were incidentally flaked and represent a Mode I lithic technology indistinguishable from the Oldowan. Approximately 15% of the artefacts were manufactured from non-local raw materials, indicating a flow of resources into the area. Stable isotopic analysis of KS-1 and KS-2 pedogenic carbonates suggests that the Excavation 1 assemblages formed in a relatively open (>75% C4 grass) habitat. The Excavation 1 and 2 faunas contain a high proportion of equids relative to Oldowan accumulations from Bed I Olduvai Gorge, Tanzania. Beds KS-1 and KS-2 thus preserve traces of Oldowan hominid activities in a more open setting than has been previously documented.     

Late pliocene hominid occupation in Central Africa: the setting, context, and character of the Senga 5A site, Zaire

Senga 5A is a late Pliocene archaeological occurrence discovered in 1985 on the eastern bank of the Semliki River in the Western Rift Valley of eastern Zaire. Excavations in 1985 and 1986 yielded stone artifacts of an Oldowan character, fossil mammal, reptile, fish, and mollusc remains, as well as coprolites and fossil wood. The site is situated in low-energy lacustrine deposits indicative of a shallow, littoral or paludal setting. Paleoenvironmental reconstruction indicates that a savanna mosaic existed in the Upper Semliki in the late Pliocene. Dating estimates based on faunal correlation indicate an age of about 2·0–2·3 million years B.P. making it the earliest archaeological site of its size and state of preservation currently known in Africa. As the westernmost Oldowan site known in Africa, Senga 5A significantly expands our knowledge of the geographic range of early tool using hominids.     

The Middle Stone Age of the northern Kenyan Rift: age and context of new archaeological sites from the Kapedo Tuffs

Rift Valley sites in southern Ethiopia and northern Kenya preserve the oldest fossil remains attributed to Homo sapiens and the earliest archaeological sites attributed to the Middle Stone Age (MSA). New localities from the Kapedo Tuffs augment the sparse sample of MSA sites from the northern Kenya Rift. Tephrostratigraphic correlation with dated pyroclastic deposits from the adjacent volcano Silali suggests an age range of 135-123 ka for archaeological sites of the Kapedo Tuffs. Comparisons of the Kapedo Tuffs archaeological assemblages with those from the adjacent Turkana and Baringo basins show broad lithic technological similarity but reveal that stone raw material availability is a key factor in explaining typologically defined archaeological variability within this region. Spatially and temporally resolved comparisons such as this provide the best means to link the biological and behavioral variation manifest in the record of early Homo sapiens.     

Adaptive Flexibility of Oldowan Hominins: Secondary Use of Flakes at Bizat Ruhama,Israel

The lithic assemblage of the Early Pleistocene site of Bizat Ruhama, Israel demonstrates the earliest evidence for systematic secondary knapping of flakes. The site, dated to the Matuyama chron, is one of the earliest primary context Oldowan occurrences in Eurasia. According to the experimental replication of the stone-tool production sequence, the secondary knapping of flakes was a part of a multi-stage operational sequence targeted at the production of small (<2 cm) flakes. This sequence included four stages: acquisition of chert pebbles, production of flakes, deliberate selection of flakes of specific morphologies, and their secondary knapping by free-hand or bipolar methods. The results suggest that flakes with retouch-like scars that were produced during this sequence and which commonly are interpreted as shaped tools are unintentional waste products of the small flake production. The intentional manufacture of very small flakes at Bizat Ruhama was probably an economic response to the raw material constrains. Systematic secondary knapping of flakes has not yet been reported from other Early Pleistocene sites. Systematic secondary knapping for small flake production became increasingly important only in the lithic industries of the second half of the Middle Pleistocene, almost a million years later. The results from Bizat Ruhama indicate that Oldowan stone-tool production sequence was conceptually more complex than previously suggested and offer a new perspective on the capabilities for invention and the adaptive flexibility of the Oldowan hominins.     

Quantifying Oldowan Stone Tool Production at Olduvai Gorge,Tanzania

Recent research suggests that variation exists among and between Oldowan stone tool assemblages. Oldowan variation might represent differential constraints on raw materials used to produce these stone implements. Alternatively, variation among Oldowan assemblages could represent different methods that Oldowan producing hominins utilized to produce these lithic implements. Identifying differential patterns of stone tool production within the Oldowan has implications for assessing how stone tool technology evolved, how traditions of lithic production might have been culturally transmitted, and for defining the timing and scope of these evolutionary events. At present there is no null model to predict what morphological variation in the Oldowan should look like. Without such a model, quantifying whether Oldowan assemblages vary due to raw material constraints or whether they vary due to differences in production technique is not possible. This research establishes a null model for Oldowan lithic artifact morphological variation. To establish these expectations this research 1) models the expected range of variation through large scale reduction experiments, 2) develops an algorithm to categorize archaeological flakes based on how they are produced, and 3) statistically assesses the methods of production behavior used by Oldowan producing hominins at the site of DK from Olduvai Gorge, Tanzania via the experimental model. Results indicate that a subset of quartzite flakes deviate from the null expectations in a manner that demonstrates efficiency in flake manufacture, while some basalt flakes deviate from null expectations in a manner that demonstrates inefficiency in flake manufacture. The simultaneous presence of efficiency in stone tool production for one raw material (quartzite) and inefficiency in stone tool production for another raw material (basalt) suggests that Oldowan producing hominins at DK were able to mediate the economic costs associated with stone tool procurement by utilizing high-cost materials more efficiently than is expected and low-cost materials in an inefficient manner.     

Examining time trends in the Oldowan technology at Beds I and II,Olduvai Gorge

The lithic analysis of the Bed I and II assemblages from Olduvai Gorge reveals both static and dynamic time trends in early hominids' technology from 1.8 to 1.2 m.y.a. The Bed I Oldowan (1.87-1.75 m.y.a.) is characterized by the least effort strategy in terms of raw material exploitation and tool production. The inclusion of new raw material, chert, for toolmaking in the following Developed Oldowan A (DOA, 1.65-1.53 m.y.a.) facilitated more distinctive and variable flaking strategies depending on the kind of raw materials. The unique characters of DOA are explainable by this raw material factor, rather than technological development of hominids. The disappearance of chert in the subsequent Developed Oldowan B and Acheulian (1.53-1.2 m.y.a.) necessitated a shift in tool production strategy more similar to that of Bed I Oldowan than DOA. However, the evidence suggests that Bed II hominids might have been more skillful toolmakers, intensive tool-users, and engaged in more active transport of stone tools than the Bed I predecessors. Koobi Fora hominids maintained a more static tool-using behavior than their Olduvai counterparts due mainly to a stable supply of raw materials. They differed from Olduvai hominids in terms of less battering of cores, consistent transport behavior, and few productions of side-struck flakes, indicating a regional variation of toolmaking and using practice. However, they shared with Olduvai hominids a temporal trend toward the production of larger flakes from larger cores after 1.6 m.y.a. Increased intake of animal resources and the expansion of ranging area of Homo ergaster would have led to the development of technological organization. Technological changes in the Oldowan industry are attested at Olduvai Gorge, Koobi Fora, and Sterkfontein, suggesting that it was a pan-African synchronous phenomenon, beginning at 1.5 m.y.a.     

Chaînes opératoires and resource-exploitation strategies in chimpanzee (Pan troglodytes) nut cracking

We apply archaeological methods to extend our knowledge of chimpanzee material culture. The cha?ne opératoire conceptual framework, as introduced by ethnography, established technology as a phased process. Prehistoric archaeology adopted this concept to elucidate technological variability in tool-making procedures, based on knowledge of tool functions or subsistence patterns. We focused on the detection of operational sequences by wild chimpanzees (Pan troglodytes verus) when nut cracking with lithic implements at the sites of Bossou and Diecké, Guinea, West Africa. Thus, while it has recently been claimed that chimpanzees leave behind recognizable assemblages of stone hammers that can be morphologically distinguished from Oldowan hammers, this is the first study to focus specifically on the existence of operational sequences during the utilization of stone tools by wild chimpanzees. By combining primatological and archaeological methods and examining ecological areas inhabited by different chimpanzee groups, we sought technological variability and identified variables influencing regional diversity in tool typology and technology. We compared three case studies: (1) Bossou-direct recording of experimental nut-cracking sessions; (2) Bossou- direct and indirect monitoring of nut-cracking sites in the wild; (3) Diecké-indirect monitoring of nut-cracking sites in the wild. Results suggest that chimpanzees perform sequences of repeated tool transport and nut cracking. Data show discrimination of tool functions based on tool features. We identified the most technologically complex tool for nut cracking, which was composed of four stones. We found regional diversity in chimpanzee stone assemblages. Raw-material type and tool mobility constrain technological development in human and nonhuman primates. Spatial analysis of tool distribution indicates a pattern of resource-exploitation strategy, revealing affinities with Oldowan.     

Landscape-scale variation in hominin tool use: Evidence from the Developed Oldowan

The relationship between artifact manufacture, use, and discard in the Developed Oldowan is complex. Here we use digital-image-analysis techniques to investigate the intensity of reduction in single-platform cores of the Developed Oldowan of the Okote Member, Koobi Fora Formation. Data suggest that this method provides a more accurate measure of reduction intensity than previous applications of a unifacial-scraper model. Assemblages of single-platform cores excavated from extensive lateral exposures of the Okote Member provide insights into the relationship between raw-material availability and discard patterns. Variation in reduction intensity suggests that tools are not always discarded in patterns that would be predicted by the availability of raw material. Further, it appears that hominin transport decisions involved an assessment of the potential use-life of certain forms. Many aspects of Developed Oldowan technology conform to previously developed models of curated technologies.     

Tool-using strategies by early hominids at bed II, Olduvai Gorge, Tanzania

This study examines the current prevailing model of Oldowan technology-the opportunistic, least-effort strategy of stone tool making and using by early hominids. The sample includes the MNK chert factory site and three contemporaneous assemblages from Olduvai Gorge, all dated between 1.65 and 1.53 m.y.a. The analysis suggests that early hominids at Olduvai may have been selective, applying distinctive strategies in making and using tools depending on the different types of raw materials available to them. The preponderance of lava cores and near absence of flakes associated with the cores suggest that lava cores at Olduvai did not provide a source of flakes. They were primarily heavy-duty core tools, despite the fact that the majority of Olduvai lava is of excellent quality for flaking. Contrary to this pattern, the abundance of chert flakes and the lack of large chert cores suggest that the production of flakes was the most important strategy applied to chert. Original forms and flaking mechanics of the raw materials may have been important factors in the simultaneous application of the different, complementary strategies. The Oldowan tool-using strategy was dynamic and flexible, in response to changes in raw material availability. The use of chert between 1.65 and 1.53 m.y.a. was apparently related to the drastic decrease in flake production in lava and quartz. Finally, lack of initial reduction episodes of lava material challenges the idea of the stone cache strategy at Olduvai between 1.65 to 1.53 m.y.a.     

史前人类对资源的认知和开发能力——石器原料研究的方法与意义

石器原料研究一直是史前考古学研究工作的一项重要内容。在探明石器原料质量和来源的基础上,将原料的选择和利用方式与石器技术、环境背景等相结合,可以进一步解读当时人类的认知和活动能力。本文立足于原料性质和原料来源两个方面,总结了现有的主要石制品原料研究方法及其应用情况。在此基础上,结合近年来我国泥河湾及东北地区相关研究案例,讨论石器原料研究及多学科研究方法对于解读史前人类资源认知和开发能力的重要作用。     

The Unknown Oldowan: ~1.7-Million-Year-Old Standardized Obsidian Small Tools from Garba IV,Melka Kunture,Ethiopia

The Oldowan Industrial Complex has long been thought to have been static, with limited internal variability, embracing techno-complexes essentially focused on small-to-medium flake production. The flakes were rarely modified by retouch to produce small tools, which do not show any standardized pattern. Usually, the manufacture of small standardized tools has been interpreted as a more complex behavior emerging with the Acheulean technology. Here we report on the ~1.7 Ma Oldowan assemblages from Garba IVE-F at Melka Kunture in the Ethiopian highland. This industry is structured by technical criteria shared by the other East African Oldowan assemblages. However, there is also evidence of a specific technical process never recorded before, i.e. the systematic production of standardized small pointed tools strictly linked to the obsidian exploitation. Standardization and raw material selection in the manufacture of small tools disappear at Melka Kunture during the Lower Pleistocene Acheulean. This proves that 1) the emergence of a certain degree of standardization in tool-kits does not reflect in itself a major step in cultural evolution; and that 2) the Oldowan knappers, when driven by functional needs and supported by a highly suitable raw material, were occasionally able to develop specific technical solutions. The small tool production at ~1.7 Ma, at a time when the Acheulean was already emerging elsewhere in East Africa, adds to the growing amount of evidence of Oldowan techno-economic variability and flexibility, further challenging the view that early stone knapping was static over hundreds of thousands of years.     

湖北郧县余嘴2号地点砍砸器的实验研究

2009年在湖北郧县余嘴2号旧石器地点的发掘过程中, 我们利用文化层中出土的砾石原料与从该地点附近地表采集的砾石原料进行复制与使用实验。各复制样本50件, 并根据原料类型、大小与刃角选取样本进行了使用实验, 最后与出土标本进行对比。实验结果表明, 燧石最适合用作砍砸器的原料, 砂岩最不适合; 遗址出土砍砸器原料却以相对丰富的角页岩、石英岩为主, 这表明古人选取原料的策略是以方便与适度为原则。实验还显示, 碰砧法制作砍砸器非常有效, 但是出土标本却表现为以锤击法为主, 导致这种差别的原因可能是古人的上肢有更强大的打击力和图方便的目的。另外,实验还表明, 砍砸器的使用有最佳的力轴与握姿以及最佳的边刃长度, 考古标本的观察也印证了这一点。在此基础上, 我们对砍砸器的性质、传统以及作为一种文化适应所代表的意义进行了探讨。     

Earliest Archaeological Evidence of Persistent Hominin Carnivory

The emergence of lithic technology by ∼2.6 million years ago (Ma) is often interpreted as a correlate of increasingly recurrent hominin acquisition and consumption of animal remains. Associated faunal evidence, however, is poorly preserved prior to ∼1.8 Ma, limiting our understanding of early archaeological (Oldowan) hominin carnivory. Here, we detail three large well-preserved zooarchaeological assemblages from Kanjera South, Kenya. The assemblages date to ∼2.0 Ma, pre-dating all previously published archaeofaunas of appreciable size. At Kanjera, there is clear evidence that Oldowan hominins acquired and processed numerous, relatively complete, small ungulate carcasses. Moreover, they had at least occasional access to the fleshed remains of larger, wildebeest-sized animals. The overall record of hominin activities is consistent through the stratified sequence – spanning hundreds to thousands of years – and provides the earliest archaeological evidence of sustained hominin involvement with fleshed animal remains (i.e., persistent carnivory), a foraging adaptation central to many models of hominin evolution.     

Spatial behaviours of Early Oldowan toolmakers in the Shungura Formation (Lower Omo Valley,Ethiopia): Proposal for an integrated approach

The spatial relationships of the Early Oldowan toolmakers with their environment have been so far addressed through raw material procurement analyses and the characterization of hominid habitat. This paper proposes to integrate these two approaches into a broader spatial analysis encompassing archaeological and environmental data (palaeontological, geological and isotopic data) from Member F and lower Member G of the Shungura Formation (Lower Omo Valley, Ethiopia). Heterogeneity in data resolution induces a multiscale approach with three levels of analysis. The level of occurrence complex allows focusing on the characterization of archaeological occurrences and on their environmental settings. The level of “study area” allows working on hominid habitats and on their raw material procurement behaviours. Finally, at the Shungura Formation scale, we can address temporal issues related to the evolution of spatial behaviours between Member F and the lower part of Member G, ca. 2.3 to 2 million years (Ma).     

Soanian lithic occurrences and raw material exploitation in the Siwalik Frontal Zone, northern India: a geoarchaeological perspective

In the Himalayan foothills of northern India, evidence of widespread hominin occupation since at least the late Middle Pleistocene has been known since the early 20th century and indicates varied patterns of land-use and intraregional mobility. This lithic evidence primarily belongs to the Soanian industry, representing some of the highest concentrations of Paleolithic assemblages in the Old World based exclusively on pebble and cobble clasts. This body of evidence also signifies interregional dispersal from peninsular India or northern Pakistan, leading to environmental preferences that spread quickly through hominin populations in the region within a relatively short timespan. While rich in its technological repertoire, the Soanian industry is poorly- understood regarding site selection and raw material exploitation over time. Recent efforts demonstrate that Soanian sites on Siwalik frontal slopes between two major rivers vary considerably in their artifact quantities regardless of abundant raw material sources found across the landscape. Most of the assemblages suggest raw material transport distances of three kilometers or less from the localized sources. Geoarchaeological investigations at the richest known Soanian site, Toka, reveal dynamic evidence of pre- and postdepositional site formation including the exploitation of quartzite pebbles and cobbles by Pleistocene hominins from terrace and streambed contexts within a 1 km2 radius. Some field observations also disprove claims made by previous workers, of artifacts eroding out of late Pliocene exposures of the Upper Siwalik Tatrot Formation around Toka.     

An Analysis of Waste Flakes from Sites in the Upper Knife-Heart Region,North Dakota

Abstract

An analysis of lithic debitage from seven archaeological sites was undertaken with the assumption that itcould provide insights into the technological and behavioral background of the craftsman. The analysis describes lithic debitage in terms of six categories. The sites are grouped into two phases: the Heart River phase (about A.D. 1675-1780) and the Knife River phase (about A.D. 1780-1845). The use of Chi-Square and Difference of Means statistics indicates that the present categorization of archaeological units (phases), based on ceramic analysis, is substantiated by an analysis of lithic debitage. Differences between the phases are related to the increasing loss of native material culture after White contact.     

The manipulative complexity of Lower Paleolithic stone toolmaking

Background

Early stone tools provide direct evidence of human cognitive and behavioral evolution that is otherwise unavailable. Proper interpretation of these data requires a robust interpretive framework linking archaeological evidence to specific behavioral and cognitive actions.

Methodology/Principal Findings

Here we employ a data glove to record manual joint angles in a modern experimental toolmaker (the 4^th author) replicating ancient tool forms in order to characterize and compare the manipulative complexity of two major Lower Paleolithic technologies (Oldowan and Acheulean). To this end we used a principled and general measure of behavioral complexity based on the statistics of joint movements.

Conclusions/Significance

This allowed us to confirm that previously observed differences in brain activation associated with Oldowan versus Acheulean technologies reflect higher-level behavior organization rather than lower-level differences in manipulative complexity. This conclusion is consistent with a scenario in which the earliest stages of human technological evolution depended on novel perceptual-motor capacities (such as the control of joint stiffness) whereas later developments increasingly relied on enhanced mechanisms for cognitive control. This further suggests possible links between toolmaking and language evolution.