The driving force behind tool-stone selection in the African Middle Stone Age.

In the Stone Age, the collection of specific rocks was the first step in tool making. Very little is known about the choices made during tool-stone acquisition. Were choices governed by the knowledge of, and need for, specific properties of stones? Or were the collected raw materials a mere by-product of the way people moved through the landscape? We investigate these questions in the Middle Stone Age (MSA) of southern Africa, analyzing the mechanical properties of tool-stones used at the site Diepkloof Rock Shelter. To understand knapping quality, we measure flaking predictability and introduce a physical model that allows calculating the relative force necessary to produce flakes from different rocks. To evaluate their quality as finished tools, we investigate their resistance during repeated use activities (scraping or cutting) and their strength during projectile impacts. Our findings explain tool-stone selection in two emblematic periods of the MSA, the Still Bay and Howiesons Poort, as being the result of a deep understanding of these mechanical properties. In both cases, people chose those rocks, among many others, that allowed the most advantageous trade-off between anticipated properties of finished tools and the ease of acquiring rocks and producing tools. The implications are an understanding of African MSA toolmakers as engineers who carefully weighed their choices taking into account workability and the quality of the tools they made.

Late Acheulean occupations at Montagu Cave and the pattern of Middle Pleistocene behavioral change in Western Cape, southern Africa.

Patterns of so-called modern human behavior are increasingly well documented in an abundance of Middle Stone Age archaeological sites across southern Africa. Contextualized archives directly preceding the southern African Middle Stone Age, however, remain scarce. Current understanding of the terminal Acheulean in southern Africa derives from a small number of localities that are predominantly in the central and northern interior. Many of these localities are surface and deflated contexts, others were excavated prior to the availability of modern field documentation techniques, and yet other relevant assemblages contain low numbers of characteristic artifacts relative to volume of excavated deposit. The site of Montagu Cave, situated in the diverse ecosystem of the Cape Floral Region, South Africa, contains the rare combination of archaeologically rich, laminated and deeply stratified Acheulean layers followed by a younger Middle Stone Age occupation. Yet little is known about the site owing largely to a lack of contextual information associated with the early excavations. Here we present renewed excavation of Levels 21-22 at Montagu Cave, located in the basal Acheulean sequence, including new data on site formation and ecological context, geochronology, and technological variability. We document intensive occupation of the cave by Acheulean tool-producing hominins, likely at the onset of interglacial conditions in MIS 7. New excavations at Montagu Cave suggest that, while Middle Stone Age technologies were practiced by 300 ka in several other regions of Africa, the classic Acheulean persisted later in the Fynbos Biome of the southwestern Cape. We discuss the implications of this regionalized persistence for the biogeography of African later Middle Pleistocene hominin populations, for the ecological drivers of their technological systems, and for the pattern and pace of behavioral change just prior to the proliferation of the southern African later Middle Stone Age.

Hunter-gatherer mobility and embedded raw-material procurement strategies in the mediterranean upper paleolithic.

Since the early 1980s, the sourcing of lithic raw materials has become central to studies of the territorial range and mobility strategies of Pleistocene foraging societies. Results have been fruitful but somehow repetitive. We will discuss the embedded procurement strategy, which presumes that raw material acquisition was part of other subsistence activities rather than an autonomous technological task. We argue that this theoretical assumption, when taken as dogma, restricts the role of technology in human history and also underestimates the way some lithic resources may have affected the organization of past hunter-gatherers. We base our discussion on the Upper Paleolithic (UP) from the Liguro-Provençal arc, with examples from the Proto-Aurignacian and the Epigravettian. Our regional record shows that in this context the movement of rocks over distances greater than 100 km was the norm rather than the exception. We argue that these long-distance procurements mirror technical needs that were oriented toward the selection of high-quality flints. We support the hypothesis that indirect procurement was an important component of regional socio-economic networks.

A previously undescribed organic residue sheds light on heat treatment in the Middle Stone Age.

South Africa has in recent years gained increasing importance for our understanding of the evolution of 'modern human behaviour' during the Middle Stone Age (MSA). A key element in the suite of behaviours linked with modern humans is heat treatment of materials such as ochre for ritual purposes and stone prior to tool production. Until now, there has been no direct archaeological evidence for the exact procedure used in the heat treatment of silcrete. Through the analysis of heat-treated artefacts from the Howiesons Poort of Diepkloof Rock Shelter, we identified a hitherto unknown type of organic residue - a tempering-residue - that sheds light on the processes used for heat treatment in the MSA. This black film on the silcrete surface is an organic tar that contains microscopic fragments of charcoal and formed as a residue during the direct contact of the artefacts with hot embers of green wood. Our results suggest that heat treatment of silcrete was conducted directly using an open fire, similar to those likely used for cooking. These findings add to the discussion about the complexity of MSA behaviour and appear to contradict previous studies that had suggested that heat treatment of silcrete was a complex (i.e., requiring a large number of steps for its realization) and resource-consuming procedure.

From the Cover: A Howiesons Poort tradition of engraving ostrich eggshell containers dated to 60,000 years ago at Diepkloof Rock Shelter, South Africa.

Ongoing debates about the emergence of modern human behavior, however defined, regularly incorporate observations from the later part of the southern African Middle Stone Age and emphasize the early appearance of artifacts thought to reflect symbolic practice. Here we report a large sample of 270 fragments of intentionally marked ostrich eggshell from the Howiesons Poort at Diepkloof Rock Shelter, Western Cape, South Africa. Dating from approximately 60,000 years ago, these pieces attest to an engraving tradition that is the earliest reliable evidence of what is a widespread modern practice. These abstract linear depictions were made on functional items (eggshell containers), which were curated and involved in daily hunter-gatherer life. The standardized production of repetitive patterns, including a hatched band motif, suggests a system of symbolic representation in which collective identities and individual expressions are clearly communicated, suggesting social, cultural, and cognitive underpinnings that overlap with those of modern people.

Human exploitation of nocturnal felines at Diepkloof Rock Shelter provides further evidence for symbolic behaviours during the Middle Stone Age.

Within the animal kingdom, carnivores occupied a unique place in prehistoric societies. At times predators or competitors for resources and shelters, anthropogenic traces of their exploitation, often for non-nutritional purposes, permeate the archaeological record. Scarce but spectacular depictions in Palaeolithic art confirm peoples' fascination with carnivores. In contrast with the European record, research on hominin/carnivore interactions in Africa has primarily revolved around the hunting or scavenging debate amongst early hominins. As such, the available information on the role of carnivores in Anatomically Modern Humans' economic and cultural systems is limited. Here, we illustrate a particular relationship between humans and carnivores during the MIS5-4 Still Bay and Howiesons Poort techno-complexes at Diepkloof Rock Shelter, South Africa. The recovery of numerous felid remains, including cut-marked phalanges, tarsals and metapodials, constitutes direct evidence for carnivore skinning and, presumably, pelt use in the southern African Middle Stone Age. Carnivore exploitation at the site seems to have focused specifically on nocturnal, solitary and dangerous felines. The lines of evidence presented here suggest the capture and fur use of those felines in the context of highly codified and symbolically loaded cultural traditions.

Multi-proxy analyses of a mid-15th century Middle Iron Age Bantu-speaker palaeo-faecal specimen elucidates the configuration of the 'ancestral' sub-Saharan African intestinal microbiome.

BACKGROUND: The archaeological incidence of ancient human faecal material provides a rare opportunity to explore the taxonomic composition and metabolic capacity of the ancestral human intestinal microbiome (IM). Here, we report the results of the shotgun metagenomic analyses of an ancient South African palaeo-faecal specimen. METHODS: Following the recovery of a single desiccated palaeo-faecal specimen from Bushman Rock Shelter in Limpopo Province, South Africa, we applied a multi-proxy analytical protocol to the sample. The extraction of ancient DNA from the specimen and its subsequent shotgun metagenomic sequencing facilitated the taxonomic and metabolic characterisation of this ancient human IM. RESULTS: Our results indicate that the distal IM of the Neolithic 'Middle Iron Age' (c. AD 1460) Bantu-speaking individual exhibits features indicative of a largely mixed forager-agro-pastoralist diet. Subsequent comparison with the IMs of the Tyrolean Iceman (Ötzi) and contemporary Hadza hunter-gatherers, Malawian agro-pastoralists and Italians reveals that this IM precedes recent adaptation to 'Western' diets, including the consumption of coffee, tea, chocolate, citrus and soy, and the use of antibiotics, analgesics and also exposure to various toxic environmental pollutants. CONCLUSIONS: Our analyses reveal some of the causes and means by which current human IMs are likely to have responded to recent dietary changes, prescription medications and environmental pollutants, providing rare insight into human IM evolution following the advent of the Neolithic c. 12,000 years ago. Video Abtract.

The MIS5 Pietersburg at '28' Bushman Rock Shelter, Limpopo Province, South Africa.

In the past few decades, a diverse array of research has emphasized the precocity of technically advanced and symbolic practices occurring during the southern African Middle Stone Age. However, uncertainties regarding the regional chrono-cultural framework constrain models and identification of the cultural and ecological mechanisms triggering the development of such early innovative behaviours. Here, we present new results and a refined chronology for the Pietersburg, a techno-complex initially defined in the late 1920's, which has disappeared from the literature since the 1980's. We base our revision of this techno-complex on ongoing excavations at Bushman Rock Shelter (BRS) in Limpopo Province, South Africa, where two Pietersburg phases (an upper phase called '21' and a lower phase called '28') are recognized. Our analysis focuses on the '28' phase, characterized by a knapping strategy based on Levallois and semi-prismatic laminar reduction systems and typified by the presence of end-scrapers. Luminescence chronology provides two sets of ages for the upper and lower Pietersburg of BRS, dated respectively to 73±6ka and 75±6ka on quartz and to 91±10ka and 97±10ka on feldspar, firmly positioning this industry within MIS5. Comparisons with other published lithic assemblages show technological differences between the Pietersburg from BRS and other southern African MIS5 traditions, especially those from the Western and Eastern Cape. We argue that, at least for part of MIS5, human populations in South Africa were regionally differentiated, a process that most likely impacted the way groups were territorially and socially organized. Nonetheless, comparisons between MIS5 assemblages also indicate some typological similarities, suggesting some degree of connection between human groups, which shared similar innovations but manipulated them in different ways. We pay particular attention to the end-scrapers from BRS, which represent thus far the earliest documented wide adoption of such tool-type and provide further evidence for the innovative processes characterizing southern Africa from the MIS5 onwards.

Pressure flaking to serrate bifacial points for the hunt during the MIS5 at Sibudu Cave (South Africa).

Projectile technology is considered to appear early in the southern African Middle Stone Age (MSA) and the rich and high resolution MSA sequence of Sibudu Cave in KwaZulu-Natal has provided many new insights about the use and hafting of various projectile forms. We present the results of a functional and technological analysis on a series of unpublished serrated bifacial points recently recovered from the basal deposits of Sibudu Cave. These serrated tools, which only find equivalents in the neighbouring site of Umhlatuzana, precede the Still Bay techno-complex and are older than 77 ka BP. Independent residue and use-wear analyses were performed in a phased procedure involving two separate analysts, which allowed the engagement between two separate lines of functional evidence. Thanks to the excellent preservation at Sibudu Cave, a wide range of animal, plant and mineral residues were observed in direct relation with diagnostic wear patterns. The combination of technological, wear and residue evidence allowed us to confirm that the serration was manufactured with bone compressors and that the serrated points were mounted with a composite adhesive as the tips of projectiles used in hunting activities. The suite of technological and functional data pushes back the evidence for the use of pressure flaking during the MSA and highlights the diversity of the technical innovations adopted by southern African MSA populations. We suggest the serrated points from the stratigraphic units Adam to Darya of Sibudu illustrate one important technological adaptation of the southern African MSA and provide another example of the variability of MSA bifacial technologies.