Two new Later Stone Age sites from the Final Pleistocene in the Falémé Valley, eastern Senegal.

The understanding of cultural dynamics at work at the end of the Final Pleistocene in West Africa suffers from a significant lack of excavated and dated sites, particularly in the Sahelian and Sudanian ecozones. While the Later Stone Age shows varied behavioral developments in different parts of the continent, the chrono-cultural framework of this period remains largely unknown in West Africa. We report on archaeological, geomorphological, and chronological research on two Final Pleistocene Later Stone Age sites in the Falémé Valley, eastern Senegal. Optically stimulated luminescence ages place the site of Toumboura I-2017 between 17 ± 1 and 16 ± 1 ka and the Ravin de Sansandé site between 13 ± 1 ka and 12 ± 1.1 ka. The excavated lithics show typical Later Stone Age industries, characterized by chaînes opératoires of core reduction mainly producing flakes and bladelets as well as blades and laminar flakes. Segments dominate the toolkits but a few backed bladelets and end-scrapers on flake blanks were recognized. Local raw materials were used, with a preference for chert and quartz, as well as greywacke. These Later Stone Age lithic assemblages are the oldest known in Senegal so far and add to the small number of sites known in West Africa for this period, which are mainly located farther south, in sub-tropical ecozones. The Later Stone Age sites of the Falémé Valley are contemporaneous with typical Middle Stone Age technologies in Senegal dated to at least the Pleistocene/Holocene transition. Our results thus provide new archaeological evidence highlighting the complex cultural processes at work during the Final Pleistocene in West Africa.

New Insights on the Palaeo-archaeological Potential of the Niokolo-Koba National Park, Senegal.

The study of the Palaeolithic in Senegal has made considerable progress in the last decade and has provided a renewed vision of the behavioral evolution of prehistoric populations in West Africa. The cultural trajectories within the region seem to be highly variable and bear witness to strong behavioral dynamics, the mechanisms of which still need to be better understood. However, the number of reliable, dated, and stratified sites, as well as the palaeoenvironmental data providing a context for populations in their palaeolandscapes, is still scarce. In order to provide new and solid data, we conducted new archaeological survey in the Niokolo-Koba National Park in south-central Senegal, aiming at a preliminary identification of Pleistocene and early Holocene sedimentary deposits. Here, we report an overview of the newly discovered industries found in different contexts. Most of the 27 identified sites show surface and out-of-context assemblages, but other sites are stratified and have all the criteria to justify the development of a long-term archaeological, geochronological, geomorphological, and palaeobotanical project. The Niokolo-Koba National Park, through which the Gambia River flows, is characterized by an abundance of sources of knappable material and by well-preserved sedimentary sequences. Therefore, archaeological research in the Niokolo-Koba National Park has the potential to provide major milestones in our understanding of the evolutionary dynamics at work in West Africa during the early periods of occupation of the region.

L'étude du Paléolithique au Sénégal connait des avancées considérables depuis cette dernière décennie, et permet d'apporter une vision renouvelée de l'évolution comportementale des populations préhistoriques en Afrique de l'Ouest. Les trajectoires culturelles au sein de la région semblent pourtant très variables et témoignent de fortes dynamiques comportementales, dont il s'agit à présent de mieux comprendre les mécanismes. Cependant, le nombre de sites fiables, datés et stratifiés, ainsi que les données paléoenvironnementales permettant de contextualiser les populations dans les paléopaysages, sont encore extrêmement rares. Dans l'optique d'apporter des nouvelles données solides, nous avons mené une première mission de prospections archéologiques dans le Parc National du Niokolo-Koba, dans le centre-sud du Sénégal, visant une reconnaissance des dépôts sédimentaires du Pléistocène et de l'Holocène ancien. Nous rapportons ici un aperçu des industries découvertes dans différents types de contextes. La majeure partie des 27 sites découverts montrent des assemblages en surface et hors contexte, mais d'autres sites sont stratifiés et possédent tous les critères justifiant le développement d'un projet archéologique, géochronologique, géomorphologique et paléobotanique à long terme. Le Parc National du Niokolo-Koba, traversé par le fleuve Gambie, est caractérise par l'abondance des matériaux taillables ainsi que par la très bonne préservation des séquences sédimentaires. Les recherches archéologiques dans le Parc National du Niokolo-Koba ont donc le potentiel d'apporter des jalons majeurs à notre compréhension des dynamiques évolutives à l'œuvre en Afrique de l'Ouest pendant les périodes d'occupation anciennes de la région.

Middle Stone Age Bifacial Technology and Pressure Flaking at the MIS 3 Site of Toumboura III, Eastern Senegal.

Over the past decade, the increasing wealth of new archaeological data on the Middle Stone Age (MSA) in Senegal and Mali has broadened our understanding of West Africa's contributions to cultural developments. Within the West African sequence, the phase of Marine Isotope Stage 3 (MIS 3, ca. 59-24 ka) yielded so far the best known and extensive archaeological information. The site of Toumboura III encompasses an occupation dated by optically stimulated luminescence (OSL) to between 40 ± 3 ka and 30 ± 3 ka. It provides the largest, well-dated, and stratified lithic assemblage in West Africa for the MSA and sheds light on an unprecedented cultural expression for this period, adding to the notable diversity of the late MSA in this region. We conducted a technological analysis of the lithic components following the chaîne opératoire approach. The lithic assemblage features a prevalence of bifacial technology and the exploitation of flakes as blanks for tool production. The craftspeople manufactured distinct types of bifacial tools, including small bifacial points shaped by pressure technique. The new data from Toumboura III demonstrate behavioral patterns that are entirely new in the region. By revealing behavioral innovations and technological particularities, these results on the techno-cultural dynamics during the MIS 3 phase of the MSA enhance our understanding of the complex Pleistocene population history in this part of Africa. Supplementary Information: The online version contains supplementary material available at 10.1007/s10437-021-09463-5.

Au cours de la dernière décennie, la multiplication des nouvelles données archéologiques sur le Middle Stone Age (MSA) au Sénégal et au Mali a mené à une meilleure introduction de l'Afrique de l'Ouest dans la discussion sur les développements culturels. Dans la séquence ouest-africaine, la phase relative au stade isotopique marin 3 (MIS 3, ~ 59 - 24 ka) est à ce jour la mieux documentée du point de vue archéologique. Le site de Toumboura III représente une occupation humaine datée entre 40 ± 3 ka et 30 ± 3 ka par luminescence stimulée optiquement (OSL). Il a fourni l'assemblage lithique stratifié MSA le plus abondant d'Afrique de l'Ouest et met en lumière une expression culturelle inédite pour cette période, ajoutant ainsi une industrie unique à la diversité considérable déjà reconnue pour le MSA tardif de cette région. Nous avons mené une analyse technologique des artefacts lithiques selon une approche des chaînes opératoires. L'assemblage lithique est caractérisé par une prévalence du façonnage bifacial et par l'exploitation d'éclats de façonnage comme supports d'outils. Les artisans ont confectionné différents types d'outils bifaciaux, dont des petites pointes bifaciales montrant la mise en oeuvre de la technique de façonnage par pression. Les nouvelles données obtenues à Toumboura III montrent des comportements jusque-là inconnus dans la région. Par la mise en évidence d'innovations comportementales et de particularités technologiques, ces résultats sur les dynamiques techno-culturelles au MSA au cours du MIS 3 contribuent à mieux comprendre l'histoire complexe du peuplement dans cette région.

A West African Middle Stone Age site dated to the beginning of MIS 5: Archaeology, chronology, and paleoenvironment of the Ravin Blanc I (eastern Senegal).

The Ravin Blanc I archaeological occurrence, dated to MIS 5, provides unprecedented data on the Middle Stone Age (MSA) of West Africa since well-contextualized archaeological sites pre-dating MIS 4/3 are extremely rare for this region. The combined approach on geomorphology, phytolith analysis, and OSL date estimations offers a solid framework for the MSA industry comprised in the Ravin Blanc I sedimentary sequence. The paleoenvironmental reconstruction further emphasizes on the local effects of the global increase in moisture characterizing the beginning of the Upper Pleistocene as well as the later shift to more arid conditions. The lithic industry, comprised in the lower part of the sequence and dated to MIS 5e, shows core reduction sequences among which Levallois methods are minor, as well as an original tool-kit composition, among which pieces with single wide abrupt notches, side-scrapers made by inverse retouch, and a few large crudely shaped bifacial tools. The Ravin Blanc I assemblage has neither a chronologically equivalent site to serve comparisons nor a clear techno-typological correspondent in West Africa. However, the industry represents an early MSA technology that could either retain influences from the southern West African 'Sangoan' or show reminiscences of the preceding local Acheulean. A larger-scale assessment of behavioral dynamics at work at the transition period between the Middle to Upper Pleistocene is discussed in view of integrating this new site to the global perception of this important period in the MSA evolutionary trajectories.

The Howiesons Poort lithic sequence of Klipdrift Shelter, southern Cape, South Africa.

Howiesons Poort (HP) sites, over the past decades, have provided exceptional access to anthropogenic remains that are enhancing our understanding of early modern human behaviour during the Middle Stone Age in southern Africa. Here, we analyse the technological and typological trends in the lithic record that form part of these behaviours, based on the HP sequence recently excavated at Klipdrift Shelter, located on the southern Cape coast of South Africa. This study contributes to enhance knowledge on the mechanisms of changes that occurred during the transition to the post-HP. Despite patterns of continuity observed, notably for core reduction methods, the seven successive lithic assemblages show significant changes in the typological characteristics and raw material selection but also in the relative importance of blade production over time. However, these changes are not necessarily synchronic and occur either as gradual processes or as abrupt technological shifts. Consequently, we cross-examine the association between the lithic phasing and other anthropogenic remains within the HP sequence at Klipdrift Shelter. We explore the implications of these patterns of changes in terms of cultural behaviours and population dynamics during the HP and we highlight the relationship between the different phases of the HP sequence at Klipdrift Shelter and those from other South African HP sites.

A reply to Sahle and Braun's reply to 'The pattern of emergence of a Middle Stone Age tradition at Gademotta and Kulkuletti (Ethiopia) through convergent tool and point technologies' [J. Hum. Evol. 91 (2016) 93-121].

Sahle and Braun's (in press) recent comments on our identification (Douze and Delagnes, 2016) of diachronic trends in Middle Stone Age point traditions in several lithic assemblages from the sites of Gademotta and Kulkuletti (Ethiopia) focuses on pointed tool function rather than the gradual technological shifts we observed between sites. Here we address several of what we consider to be inaccuracies and misinterpretations concerning our work with the Gademotta and Kulkuletti lithic assemblages (Douze, 2012, 2014), more specifically, Sahle and Braun's (in press) interpretation of the tranchet blow technique. This discussion is inseparable from a critical review of the evidence advanced by Sahle and Braun to support projectile technology being present in the Gademotta Formation as early as >279 ka.

Early Evidence for the Extensive Heat Treatment of Silcrete in the Howiesons Poort at Klipdrift Shelter (Layer PBD, 65 ka), South Africa.

Heating stone to enhance its flaking qualities is among the multiple innovative adaptations introduced by early modern human groups in southern Africa, in particular during the Middle Stone Age Still Bay and Howiesons Poort traditions. Comparatively little is known about the role and impact of this technology on early modern human behaviors and cultural expressions, due, in part, to the lack of comprehensive studies of archaeological assemblages documenting the heat treatment of stone. We address this issue through an analysis of the procedure used for heating and a technological analysis of a lithic assemblage recovered from one Howiesons Poort assemblage at Klipdrift Shelter (southern Cape, South Africa). The resulting data show extensive silcrete heat treatment, which adds a new dimension to our understanding of fire-related behaviors during the Howiesons Poort, highlighting the important role played by a heat treatment stage in the production of silcrete blades. These results are made possible by our new analytical procedure that relies on the analysis of all silcrete artifacts. It provides direct evidence of a controlled use of fire which took place during an early stage of core exploitation, thereby impacting on all subsequent stages of the lithic chaîne opératoire, which, to date, has no known equivalent in the Middle Stone Age or Middle Paleolithic record outside of southern Africa.

The pattern of emergence of a Middle Stone Age tradition at Gademotta and Kulkuletti (Ethiopia) through convergent tool and point technologies.

The Gademotta and Kulkuletti site complex, located in the central part of the Main Ethiopian Rift, is known to be one of the richest early Middle Stone Age (MSA) sequences in East Africa. The technological assessment of three main sites provides evidence of major changes in the production of convergent tools over a period from before 280 ka (thousands of years ago) to ca. 100 ka. Important diachronic changes are identified in the manufacturing process of convergent tools, by shaping or retouching of predetermined points, and in the core reduction process that produced the corresponding blanks. These are: 1) the development of specific Levallois methods for the production of points (classical Levallois point production and Nubian type 1 core reduction); and 2) the shift from uni-bifacial invasive shaping of convergent tools to localized slight retouch of predetermined points. These technological changes in convergent tool production reveal the gradual emergence of a new set of technological behaviors that can be considered specific to the MSA. While the eastern African MSA is often considered as stable over time with minimal innovation, our results provide an insight into local behavioral mechanisms that have given rise to changes in technological systems during the early MSA.

Techno-Cultural Characterization of the MIS 5 (c. 105 - 90 Ka) Lithic Industries at Blombos Cave, Southern Cape, South Africa.

Blombos Cave is well known as an important site for understanding the evolution of symbolically mediated behaviours among Homo sapiens during the Middle Stone Age, and during the Still Bay in particular. The lower part of the archaeological sequence (M3 phase) contains 12 layers dating to MIS 5 with ages ranging from 105 to 90 ka ago (MIS 5c to 5b) that provide new perspectives on the technological behaviour of these early humans. The new data obtained from our extensive technological analysis of the lithic material enriches our currently limited knowledge of this time period in the Cape region. By comparing our results with previously described lithic assemblages from sites south of the Orange River, we draw new insights on the extent of the techno-cultural ties between these sites and the M3 phase at Blombos Cave and highlight the importance of this phase within the Middle Stone Age cultural stratigraphy.