The dawn of the Middle Paleolithic in Atapuerca: the lithic assemblage of TD10.1 from Gran Dolina

The Western European Acheulean: Reading variability at a regional scale

In the context of the Western European Acheulean Project, this study aims to characterize Acheulean technology in Western Europe through the analysis of handaxes and cleavers from 10 key sites (Britain 4, France 4, and Spain 2) to acquire a regional view of the occupation. The historically different systems used to categorize and analyze the data have made it difficult to compare results. Here we apply a unified and simple method (Western European Acheulean Project) that combines the traditional technological and metrical analysis of assemblages containing handaxes and cleavers with an in-depth geometric morphometric approach using three-dimensional models. This approach allows us to achieve a regional interpretation that identifies innovations through time and shaping strategies across the area. Our findings indicate the existence of two main technological groups in the sampled record: 1) northwestern and central France and Britain, from MIS 17/16 to MIS 11, and 2) Atlantic edge (Atapuerca in Spain and Menez-Dregan in France), from MIS 12/11 to MIS 8. Based on our technological analysis, the shaping of handaxes and cleavers was developed through time as a continuum of accumulative actions, with longer and more complex shaping strategies over time. Shaping technology shows traditions of manufacture over both time and geographical areas, which suggest cultural diffusion. Our geometric morphometric analysis further helped to identify not only general trends but also local adaptations in handaxe forms. Based on our findings, there were no apparent sudden innovations, but rather the application and development of specific techniques to refine size and shape.

Variations by degrees: Western European paleoenvironmental fluctuations across MIS 13-11

Marine Isotope Stages (MIS) 13-11 saw a major transformation in the hominin occupation of Europe, with an expansion in the scale and geographical distribution of sites and artifact assemblages. That expansion is explored here in the context of paleoenvironmental variability, focusing on geographical and chronological trends in climatic and habitat conditions at and between key Lower Paleolithic sites in Western Europe. Climatic conditions at British sites are compared across MIS 13-11, and used to test predicted values from the Oscillayers data set. Conditions at hominin and nonhominin sites are compared to explore possible limitations in hominin tolerances during MIS 13-11. Trends in conditions are explored with reference to long-term global patterns, short-term substage events, and seasonal variations. The apparent increase in the scale of hominin activity in north-western Europe during MIS 13 is surprising in light of the relatively harsh conditions of late MIS 13, and is likely to reflect significant physiological and/or behavioral adaptations, a mild south-north temperature gradient in western Europe during MIS 13, and the relatively mild, sustained conditions spanning MIS 15-13. The expanded occupation of north-western Europe during MIS 11 probably reflects the extended mild conditions of MIS 11c, since marked seasonal temperature differences and substantial behavioral changes between hominin sites in MIS 13 and 11 are not clearly evident. Site-specific conditions in south-western Europe during MIS 11 suggest milder winters, warmer summers, and reduced seasonal variability compared to north-western Europe. Some or all of these conditions may have supported larger, core populations, as may the relatively mild conditions associated with south-western European sites during MIS 12. Finally, comparisons between north-western and north-central European sites indicate relatively small differences in seasonal temperatures, suggesting that climate may only be a partial factor behind the smaller-scale occupations of north-central Europe during MIS 13-11.

Flake tools in the European Lower Paleolithic: A case study from MIS 9 Britain

Studies of flake tools in the British Lower Paleolithic are rare owing to lower quantities of flake tools than handaxes and the perception that flake tool technology became more important in the succeeding Middle Paleolithic. In Britain, and Europe more broadly, MIS 9 (328-301 ka) has been characterized as a period of technological transition owing to the presence of early prepared core technology and the status of the period as the final interglacial prior to the onset of the Middle Paleolithic. It has been argued that the period demonstrates an increase in both the numbers and importance of flake tools, possibly showing emerging Middle Paleolithic behaviors. This study presents the results of a technological examination of flake tools in Britain during MIS 9, focusing on 25 sites, including 15 assemblages previously recorded as having higher quantities of flake tools. We use these assemblages to assess whether the flake tools of MIS 9 represent a transition toward the technology of the Middle Paleolithic. We consider factors including collection history, site formation, function, reduction, and cultural groups. We argue that in Britain the archaeological record of MIS 9 does not show an increase in the use of flake tools and demonstrates more continuity than change in relation to earlier periods of the Lower Paleolithic. There is a technological background of ad hoc retouch of simple flake tools with occasional evidence of more invasively retouched scrapers. Furthermore, aside from the introduction of Levallois technology, flake tools change little in the Early Middle Paleolithic. These results are contextualized within the broader evidence from Europe and comparisons to the longer sequences at key sites. We conclude that the major changes in technology began between MIS 13 and MIS 11 and these merely became cemented during MIS 9 and the following Middle Paleolithic.

Acheulean variability in Western Europe: The case of Menez-Dregan I (Plouhinec, Finistère, France)

The establishment of the Acheulean in Europe occurred after MIS 17, but it was after the harsh glaciation of MIS 12 and during the long interglacial of MIS 11 that human occupation of Western Europe became more sustained, with an increased number of sites. Menez-Dregan I (Brittany, France) is one of the key sites in Western Europe that dates from this threshold, with an alternating sequence of 16 occupation levels and four marine deposits, from MIS 12 to 8. The large lithic assemblages of more than 154,000 artifacts from knapping (cores, flakes) and shaping (macrotools and shaping flakes) show the varying use of raw materials and activities at the site through the sequence. This work focuses on the study of the handaxes and cleavers using technological and metrical methods with multivariate analysis, in combination with geometric morphometrics, and places these analyses within the context of other technological changes at the site. Collectively, results show the persistent use through the sequence of the same lithic raw materials and technologies, including fire use and the import of glossy sandstone from 20 km away, but with variation in activities at the site. These findings suggest that Menez-Dregan I shows the development of a specific material culture that reflects the local resources and environment. Results further indicate that the site shows the sustained hominin occupation of the area, despite varying climate and environment, with strong traditions of social learning that were maintained through flexibility of site use, deep understanding of the local territory, and the innovation of new technologies, such as the use of fire. Evidence from the site is placed within the wider context of Europe, and contrasted with areas to the north, such as Britain, where hominin occupation was more sporadic and driven by cyclical climate change.

Tracking behavioral persistence and innovations during the Middle Pleistocene in Western Europe. Shift in occupations between 700 and 450 ka at la Noira site (Centre, France)

Some areas in Western Europe indicate hiatuses in human occupations, which cannot be systematically attributed to taphonomic factors and poor site preservation. The site of la Noira in the center of France records two occupation phases with a significant time gap. The older one is dated to around 700 ka (stratum a) with an Acheulean assemblage, among the earliest in Western Europe, and the upper phase of the sequence (stratum c) is dated to ca. 450 ka. Humans left the area at around 670 ka, at the beginning of the marine isotope stage (MIS) 16 glacial stage, when cold conditions became too severe. No sites between 650 and 450 ka have yet been discovered in the center region despite systematic surveys over the past three decades. The archaeological evidence indicates that populations returned to the area, at the end of MIS 12 or the beginning of the long interglacial MIS 11. Here, we use technological behaviors common to the two levels of la Noira-strata a and c to evaluate their differences. Compared to other key European sequences, this site can be used to address the evolution of the behavioral strategies in Europe between MIS 17 and 11. We formulate two hypotheses concerning the human settlement of this area: (1) local behavioral evolution over time of populations occasionally occupying the region when the climate was favorable or (2) dispersal and arrival of new populations from other areas. The results focus on (1) changes in land-use patterns with the extension of the territory used by hominins in the upper level, (2) the introduction of new core technologies, including some evidence of early Levallois debitage, and (3) more intensive shaping of bifaces and bifacial tools. Results attest that the la Noira archaeological assemblages record similar regional behavioral evolution as observed at a larger scale in Europe.

Coping with arid environments: A critical threshold for human expansion in Europe at the Marine Isotope Stage 12/11 transition? The case of the Iberian Peninsula

Archaeological remains have highlighted the fact that the interglacial Marine Isotope Stage (MIS) 11 was a threshold from the perspective of hominin evolution in Europe. After the MIS 12 glaciation, considered one of the major climate-driven crises experienced by hominins, the archaeological records show an increasing number of occupations, evidence of new subsistence behaviors, and significant technical innovations. Here, we used statistical and geographic techniques to analyze the amphibian- and reptile-based paleoclimate and habitat reconstructions generated from a large data set of the Iberian Peninsula to (1) investigate if temperature, precipitation, and/or forest cover may have impacted the hominin occupation of the territory during the Early and Middle Pleistocene, (2) propose an 'Iberian' ecological model before and after the MIS 12/11 transition, and (3) evaluate, based on this model, the potential hominin occupation at a European scale. The results indicate the existence of climatic constraints on human settlement related to rainfall and environmental humidity. The Early Pleistocene and the first half of the Middle Pleistocene are dominated by the occupation of relatively humid wooded areas, whereas during the second part of the Middle Pleistocene, a broadening of the earlier ecological niche is clearly observed toward the occupation of more open arid areas. Based on the estimated occupational niche for hominins, a maximum potential distribution for early hominins is proposed in Europe before and after 426 ka. Results also indicate that parts of the Iberian Peninsula may not have been suitable for early hominin occupation. Our ecological model is consistent with the pattern of hominin occupation observed in northern and central Europe, where the earliest evidence reflects only pioneering populations merely extending their ranges in response to the expansion of their preferred habitats, as compared with a more sustained occupation by 400 ka.

Polish is quantitatively different on quartzite flakes used on different worked materials

Metrology has been successfully used in the last decade to quantify use-wear on stone tools. Such techniques have been mostly applied to fine-grained rocks (chert), while studies on coarse-grained raw materials have been relatively infrequent. In this study, confocal microscopy was employed to investigate polished surfaces on a coarse-grained lithology, quartzite. Wear originating from contact with five different worked materials were classified in a data-driven approach using machine learning. Two different classifiers, a decision tree and a support-vector machine, were used to assign the different textures to a worked material based on a selected number of parameters (Mean density of furrows, Mean depth of furrows, Core material volume-Vmc). The method proved successful, presenting high scores for bone and hide (100%). The obtained classification rates are satisfactory for the other worked materials, with the only exception of cane, which shows overlaps with other materials. Although the results presented here are preliminary, they can be used to develop future studies on quartzite including enlarged sample sizes.