Mary Leakey Research Articles

Taphonomic and technological analyses of Lower Palaeolithic bone tools from Clacton-on-Sea, UK

The exceptional survival of Middle Pleistocene wooden spears at Schöningen (Germany) and Clacton-on-Sea (UK) provides tantalizing evidence for the widespread use of organic raw materials by early humans. At Clacton, less well-known organic artefacts include modified bones that were identified by the Abbé Henri Breuil in the 1920s. Some of these pieces were described and figured by Hazzledine Warren in his classic 1951 paper on the flint industry from the Clacton Channel, but they have been either overlooked in subsequent studies or dismissed as the product of natural damage. We provide the first detailed analysis of two Clactonian bone tools found by Warren and a previously unrecognized example recovered in 1934 during excavations directed by Mary Leakey. Microscopic examination of percussion damage suggests the bones were used as knapping hammers to shape or resharpen flake tools. Early Palaeolithic bone tools are exceedingly rare, and the Clacton examples are the earliest known organic knapping hammers associated with a core-and-flake (Mode 1) lithic technology. The use of soft hammers for knapping challenges the consensus that Clactonian flintknapping was undertaken solely with hard hammerstones, thus removing a major technological and behavioural difference used to distinguish the Clactonian from late Acheulean handaxe (Mode 2) industries.

Bone tools from Beds II–IV, Olduvai Gorge, Tanzania, and implications for the origins and evolution of bone technology

The advent of bone technology in Africa is often associated with behavioral modernity that began sometime in the Middle Stone Age. Yet, small numbers of bone tools are known from Early Pleistocene sites in East and South Africa, complicating our understanding of the evolutionary significance of osseous technologies. These early bone tools vary geographically, with those in South Africa indicating use in foraging activities such as termite extraction and those in East Africa intentionally shaped in a manner similar to lithic tool manufacture, leading some to infer multiple hominin species were responsible for bone technology in these regions, with Paranthropus robustus assumed to be the maker of South African bone tools and Homo erectus responsible for those in East Africa. Here, we present on an assemblage of 52 supposed bone tools primarily from Beds III and IV, Olduvai Gorge, Tanzania, that was excavated by Mary Leakey in the late 1960s and early 1970s, but was only partially published and was never studied in detail from a taphonomic perspective. The majority of the sites from which the tools were recovered were deposited when only H. erectus is known to have existed in the region, potentially allowing a direct link between this fossil hominin and bone technology. Our analysis confirms at least six bone tools in the assemblage, the majority of which are intentionally flaked large mammal bones. However, one of the tools is a preform of the oldest barbed bone point known to exist anywhere in the world and pushes back the initial appearance of this technology by 700 kyr.

Pitted stones in the Acheulean from Olduvai Gorge Beds III and IV (Tanzania): A use-wear and 3D approach

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.

The paleoecology of Pleistocene birds from Middle Bed II, at Olduvai Gorge, Tanzania, and the environmental context of the Oldowan-Acheulean transition

Fossil bird data (community composition and taphonomic profiles) are used here to infer the environmental context of the Oldowan-Acheulean transitional period at Olduvai Gorge, Tanzania. This is the first comprehensive report on the Middle Bed II avifauna and includes fossils excavated by the Olduvai Geochronology and Archaeology Project (OGAP) and recently rediscovered fossils collected by Mary Leakey. Crane, ibis, darter, owl, raptor, crow, and vulture are reported from Bed II for the first time. The presence of these taxa, absent earlier in this Bed, point to a general opening and drying of the landscape with grassland and open woodland expansion. Taxa associated with dense, emergent wetland vegetation, such as dabbling ducks and rails, are uncommon and less diverse than earlier in Bed II. This suggests more mature wetlands with clearer waters. Cormorants continue to be common, but are less diverse. Cormorants and other roosting taxa provide evidence of trees in the area. Compared to lowermost Bed II, the Middle to Upper Bed II landscape is interpreted here as more open and drier (but not necessarily more arid), with matured wetlands, scattered trees, and a greater expansion of grasslands.

Paleoecology of the Serengeti during the Oldowan-Acheulean transition at Olduvai Gorge, Tanzania: The mammal and fish evidence

Eight years of excavation work by the Olduvai Geochronology and Archaeology Project (OGAP) has produced a rich vertebrate fauna from several sites within Bed II, Olduvai Gorge, Tanzania. Study of these as well as recently re-organized collections from Mary Leakey's 1972 HWK EE excavations here provides a synthetic view of the faunal community of Olduvai during Middle Bed II at ∼1.7–1.4 Ma, an interval that captures the local transition from Oldowan to Acheulean technology. We expand the faunal list for this interval, name a new bovid species, clarify the evolution of several mammalian lineages, and record new local first and last appearances. Compositions of the fish and large mammal assemblages support previous indications for the dominance of open and seasonal grassland habitats at the margins of an alkaline lake. Fish diversity is low and dominated by cichlids, which indicates strongly saline conditions. The taphonomy of the fish assemblages supports reconstructions of fluctuating lake levels with mass die-offs in evaporating pools. The mammals are dominated by grazing bovids and equids. Habitats remained consistently dry and open throughout the entire Bed II sequence, with no major turnover or paleoecological changes taking place. Rather, wooded and wet habitats had already given way to drier and more open habitats by the top of Bed I, at 1.85–1.80 Ma. This ecological change is close to the age of the Oldowan-Acheulean transition in Kenya and Ethiopia, but precedes the local transition in Middle Bed II.The Middle Bed II large mammal community is much richer in species and includes a much larger number of large-bodied species (>300 kg) than the modern Serengeti. This reflects the severity of Pleistocene extinctions on African large mammals, with the loss of large species fitting a pattern typical of defaunation or ‘downsizing’ by human disturbance. However, trophic network (food web) analyses show that the Middle Bed II community was robust, and comparisons with the Serengeti community indicate that the fundamental structure of food webs remained intact despite Pleistocene extinctions. The presence of a generalized meat-eating hominin in the Middle Bed II community would have increased competition among carnivores and vulnerability among herbivores, but the high generality and interconnectedness of the Middle Bed II food web suggests this community was buffered against extinctions caused by trophic interactions.

A hidden treasure of the Lower Pleistocene at Olduvai Gorge, Tanzania: The Leakey HWK EE assemblage

HWK EE is a little-known archaeological site from the top of Lower Bed II and the basal part of Middle Bed II, Olduvai Gorge, Tanzania. The site was originally excavated in the early 1970s by Mary Leakey, but the excavations and resulting lithic and fossil assemblages were never described. Here we report for the first time on the lithic and fossil assemblages that were recovered by Mary Leakey from the site. The lithic assemblage is one of the largest of any Oldowan site and is characterized by a core-and-flake technology with simple flaking techniques and minimal reduction of cores. Retouched flake frequencies and battered tools are higher than those reported for Olduvai Bed I and Lower Bed II assemblages, but flaking schemes are poorly organized. The fossil assemblage is well-preserved, taxonomically-rich, but dominated by bovids, and includes abundant feeding traces of both hominins and carnivores. Hominins are inferred to have broken the majority of limb bones at the site for access to marrow, while both carnivores and hominins likely had access to at least some flesh. HWK EE may represent one of the last Homo habilis sites at Olduvai Gorge, and is important to understanding the behavioral and cultural mechanisms that led to the emergence of the Acheulean and Homo erectus in the region.

The impact of hydraulic processes in Olduvai Beds I and II, Tanzania, through a particle dimension analysis of stone tool assemblages

AbstractThe effect of post‐depositional processes on the formation of Plio‐Pleistocene sites at Olduvai Gorge is the subject of considerable debate, due mainly to its implications for the behavioral interpretation of the Beds I and II assemblages. In light of this debate, here we contribute to the discussion that investigates the role of water flow in site formation at Olduvai. This is achieved by assessing the artifact size and shape ranges of lithic assemblages excavated by Mary Leakey from both Oldowan (FLK North Levels 3 and 1, FLK Zinj, FLK North Levels 6‐1, Sandy Conglomerate andDeinotherium, HWKE Level 1) and early Acheulean (TK Lower and Upper Floor) sites. We apply grain size and shape statistical techniques to these stone tool assemblages in order to classify sites according to patterns in artifact dimensions. These patterns are then compared to those produced during experimental flaking, thus providing a referential framework against which the archaeological assemblages can be interpreted. Artifact size distribution results show pronounced differences between the archaeological and experimental assemblages. Most of the archaeological assemblages are characterized by a bimodal size trend that is opposed to the dominantly unimodal distribution seen in the flaking experiments. The few archaeological assemblages where the distribution is predominantly unimodal (TF Lower Floor, TK Upper Floor and FLK Zinj) also show a significant underrepresentation of smaller artifacts, when compared to the experimental distributions. Overall, the comparison of archaeological materials with experimental results enables a more accurate assessment of the impact of natural processes over the Bed I and II assemblages, and further, it helps to refine our understanding of taphonomic and behavioral contexts for the Oldowan and early Acheulean sites at Olduvai Gorge.

Assessing the function of pounding tools in the Early Stone Age: A microscopic approach to the analysis of percussive artefacts from Beds I and II, Olduvai Gorge (Tanzania)

This study explores the function of quartzite pounding tools from Olduvai Gorge (Tanzania) using microscopic and use wear spatial distribution analysis. A selection of pounding tools from several Bed I and II assemblages excavated by Mary Leakey (1971) were studied under low magnification (<100×), and the microscopic traces developed on their surfaces are described. Experimental data and results obtained from analysis of the archaeological material are compared in order to assess activities in which pounding tools could have been involved. Results show that experimental anvils used for meat processing, nut cracking and/or bone breaking have similar wear patterns as those observed on archaeological percussive artefacts. This is the first time that a microscopic analysis is applied to Early Stone Age pounding artefacts from Olduvai Beds I and II, and this paper highlights the importance that percussive activities played during the Early Pleistocene, suggesting a wider range of activities in addition to knapping and butchering.

Louis Leakey and Mary Leakey

Louis and Mary Leakey are two famous palaeoanthropologists and archaeologists of the twentieth century whose discoveries have had a major influence on our understanding of human evolution. These discoveries were spectacular and brought popular attention to the field of palaeoanthropology, though at times they also courted controversies. Though, debate on the proper interpretation of many of the fossil hominid finds made by them continues even today, no one questions their tremendous contribution to our knowledge about evolution of humankind. This article is focussed on their life and works.

The larger mammal palimpsest from TK (Thiongo Korongo), Bed II, Olduvai Gorge, Tanzania

Ever since Mary Leakey's initial excavations in the 1960s, TK (Thiongo Korongo) has been recognized as one of Olduvai Gorge's most important Acheulean sites. The significant concentrations of lithics and fauna reported by Mary Leakey have been augmented in recent years by Santonja et al., who argue that human activities appear to be largely related to the manufacture of lithic implements. In contrast, the faunal remains have been interpreted to be of uncertain origin, and their anthropogenic nature remains in question. This paper presents new data on the formation of the TK bone accumulation. Our results reveal a diverse list of taxa, many of which reflect open habitats. Only limited evidence of anthropogenic activity is documented.

Palaeoart at Two Million Years Ago? A Review of the Evidence

Current archaeological evidence supports the claim that symbolic behavior, including palaeoart, first emerged in human evolution around 1 million years ago. The purpose of this article is to review archaeological studies that might support the hypothesis that the earliest palaeoart actually is evident around 2 million years ago. This review identifies nine Oldowan artifacts that have been proposed as possible non-utilitarian and possibly symbolic behavior. Among seven stone tools, the three strongest candidates are the Olduvai Gorge, the FLK North grooved and pecked cobble, ~1.80 million years ago, and MNK Main subspheroid with hexagon shape framing an apparent natural dot-and-undulating-line motif, ~1.5–1.6 million years ago, both initially reported and described by Mary Leakey; and the curated Koobi Fora FxJj1 “broken core” with inner rhomboid shape, ~1.87 million years ago. All six stone tools from Olduvai Gorge need scientific re-examination to determine their chaîne opératoire and assess non-utilitarian features. If even one of the Olduvai Gorge artifacts were validated as symbolic behavior this would indicate the emergence of palaeoart one million years earlier than current proposals. It would also suggest that Homo habilis/rudolfensis or a very early Homo erectus had substantially more advanced cognitive, design and symbolic competencies than inferred in current theories. It would constitute a challenge to develop more advanced cognitive semiotic and art-theoretic analytical tools for illuminating the role of such palaeoart in hominin cultural evolution.

The Transition to the Acheulean in East Africa: an Assessment of Paradigms and Evidence from Olduvai Gorge (Tanzania)

The origin of the Acheulean constitutes a key aspect of current research in the archaeology of human evolution. Olduvai Gorge is one of the main sites in Africa in the study of the transition from the Oldowan to the Acheulean, due to both the uniqueness of its archaeological record, and the influence of early investigations at Olduvai on the development of Early Stone Age research. This paper reviews the impact of work at Olduvai in shaping a modern view of cultural evolution from the Oldowan to the Acheulean. It also evaluates the lithic assemblages excavated by Mary Leakey in Olduvai Middle and Upper Bed II, based on a first-hand review of the collections. We conclude that previous paradigms used to explain inter-assemblage variability are not superseded as much as generally assumed, and that a modern view of the origins of the Acheulean requires a reassessment of the cultural, biological, and paleoecological evidence at Olduvai and elsewhere in Africa.

Phillip Vallentine Tobias (1925–2012)

Phillip Vallentine Tobias (1925–2012)

Application of GIS methods to retrieve orientation patterns from imagery; a case study from Beds I and II, Olduvai Gorge (Tanzania)

The role of natural processes in the formation of the Bed I and II sites at Olduvai Gorge (Tanzania) remains the subject of much debate, five decades after their original excavation. Preferred orientation of items is indicative of water disturbance, but compass bearings were not available in Mary Leakey's (1971) study. Using GIS methods, we have vectorized maps from 1960s excavations at Olduvai, and applied a range of statistical techniques to calculate items strike. The GIS analysis suggests strongly preferred orientation patterns in Bed I, and more heterogeneous angular histograms in Bed II. Two complementary lines of evidence support these results. Firstly, modelling of potential mapping errors provides a large interval of confidence for preferred orientation patterns. Second, the GIS study was extended to photographs of the earlier excavations and to maps from recent fieldwork at Olduvai; both yielded patterned arrangement of lithics and bones, and are consistent with results based on the analysis of the 1960s maps, i.e. a large number of the Bed I and II assemblages are preferentially oriented. These results highlight the potential of GIS applications to the analysis of imagery in Stone Age studies, and bear important implications for the understanding of the role of natural agents in site formation processes at Olduvai.

Phillip Vallentine Tobias (1925–2012)

Phillip Vallentine Tobias (1925–2012)

Autochthony and orientation patterns in Olduvai Bed I: a re-examination of the status of post-depositional biasing of archaeological assemblages from FLK North (FLKN)

Recent excavations at FLK North (Olduvai Gorge, Tanzania) have produced new information on the orientation of archaeological materials at various levels of the site. This information includes the uniform distribution of material azimuths, which contrasts with previous inferences of highly patterned orientations of materials in the Bed I archaeological sites. Those previous inferences of patterned material orientations are based on Mary Leakey's 50-year-old drawings of artifact and fossil bone distribution, but are not verified by our precise measurements of archaeological objects made in situ. Nor do those previous results agree with the general lack of geological, geomorphological, and/or taphonomic data that would indicate significant post-depositional movement of archaeological materials in the sites. We argue here that Leakey's drawings are incomplete (only portions of each assemblage were drawn) and inaccurate in their representation of the original locations, shapes and orientations of most archaeological specimens. This argument is supported by several important mismatches in object representations between a photograph taken of a small portion of the FLK 22 Zinjanthropus site floor before the removal of the archaeological items, and the sketch of the same area drawn by Leakey. Thus, we conclude that primary orientation data of excavations (i.e., direct measurements taken from items) generated prior to object removal are the only valid indicators of the relative isotropy or anisotropy of these important paleoanthropological assemblages.

Analysis of orientation patterns in Olduvai Bed I assemblages using GIS techniques: Implications for site formation processes

Mary Leakey’s excavations at Olduvai Beds I and II provided an unparalleled wealth of data on the archaeology of the early Pleistocene. We have been able to obtain axial orientations of the Bed I bone and stone tools by applying GIS methods to the site plans contained in the Olduvai Volume 3 monograph ( Leakey, 1971). Our analysis indicates that the Bed I assemblages show preferred orientations, probably caused by natural agents such as water disturbance. These results, based on new GIS techniques applied to paleoanthropological studies, have important implications for the understanding of the formative agents of Olduvai sites and the behavioral meaning of the bone and lithic accumulations in Bed I.

Was FLK North levels 1–2 a classic “living floor” of Oldowan hominins or a taphonomically complex palimpsest dominated by large carnivore feeding behavior?

From excavation at FLK North levels 1–2 in 1960–1962, Mary Leakey reported approximately 1200 Oldowan artifacts and 3300 large mammal fossils as a hominin “living floor”. Preliminary taphonomic analysis by Bunn seemed supportive, based on the presence of some cut-marked bones, the concentration of several dozen bovid individuals, and the relative abundance of limbs and mandibles over other axial elements. Recent taphonomic analysis of Leakey's entire fossil assemblage by Domínguez-Rodrigo and Barba, however, documents a minor hominin role at the site, contrasted to the dominant role of carnivores. Felids brought prey animals; hyenas scavenged from abandoned felid meals. At different times, hominins butchered several bovids and discarded artifacts at this dynamic location. Since 2006, renewed excavations at FLK North and other sites by the Olduvai Paleoanthropology and Paleoecology Project (TOPPP) have expanded artifact and fossil samples and implemented new analytical approaches to clarify taphonomic histories of the Olduvai paleolandscape. At FLK North, > 1000 new large mammal fossils from levels 1 to 2 show minimal butchery evidence amid abundant evidence of carnivore gnawing/fracture, rodent gnawing, and sediment abrasion. To help guide future excavation and analyses, we have developed several alternative working hypotheses of site formation.

Pliocene Animal Trackways at Laetoli: Research and Conservation Potential

Laetoli, a paleoanthropological site in Northern Tanzania, is perhaps best known for its famous fossil hominid footprints that were discovered by Mary Leakey and her co-workers in 1978. The site not only preserves the hominid footprints but also trackways, which provide a snapshot of Pliocene faunal communities from East Africa and their inferred environments. Unlike the hominid footprints at site G, which have received tremendous attention, the animal trackways, especially at Localities 7, 8 and 10 have been neglected and are fast disappearing. In this paper, we discuss animal tracks at a newly discovered exposure and provide preliminary data on the tracks at this exposure and other sites. We also discuss the importance of the animal trackways as ecological indicators, which we have investigated as part of ongoing research and conservation efforts initiated by the Tanzania Field School in Paleoanthropology and the Associated Colleges of the Midwest (ACM) Tanzania Semester Abroad programs.

Taphonomic perspectives on hominid site use and foraging strategies during Bed II times at Olduvai Gorge, Tanzania

The faunal assemblages excavated by Mary Leakey in Bed II of Olduvai Gorge, Tanzania, have, like the more well-known Bed I assemblages, traditionally been interpreted as the result of hominid butchering activities in the lake margin and riverine settings of the paleo-Olduvai Basin. A reexamination of all of Leakey's Bed I sites has shown that hominids played little or no role in the formation of all but one of those faunal assemblages, a finding that prompted the reanalysis of the Bed II sites presented here. We expand upon a previous taphonomic study that provided systematic data for HWK East Levels 1–2, MNK Main, and BK. In addition to these assemblages, we provide data on HWK East Levels 3–5, FC West, TK, and SHK. Our data contradict previous interpretations of MNK Main as a hominid accumulation but uphold the contention that BK represents a primarily hominid accumulation reflecting early access to carcasses. The small and poorly preserved assemblages from FC West and TK are difficult to link unambiguously to either hominids or carnivores. Site MNK Main and HWK East Levels 3–5 appear to be death arenas where carcasses accumulated via natural deaths and/or serial predation. Site SHK is severely biased by selective retention and therefore little can be said of its formational history. Nevertheless, no hominid modifications were documented in this assemblage. Comparisons with other Olduvai sites indicate a more conspicuous hyena taphonomic signal during Bed II times than Bed I times, which appears to mirror the changing configuration of the large carnivore guild. These findings also beg the question of what activities were being carried out by hominids with the stone tools discarded at these sites. Although it seems clear that hominids were utilizing stone tools to carry out subsistence activities unrelated to carcass butchery, more excavation and techniques such as phytolith analysis should be employed to explore alternative explanations.