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New methodological approaches focused on studying the reduction and use-life of stone tools have emerged in recent years, enabling researchers to move beyond strict technical and technological characterizations and explore specific aspects of occupation dynamics and economic management of resources. Previous studies have shown the importance of reduction distributions of individual measurements rather than averaged values. In this sense, survival analysis, and more specifically Weibull distributions, are one of the main inferential tools used in reduction studies. However, the resolution of Weibull distribution obtained from different methods has not been tested experimentally. In this paper, we present an evaluation of some of the main methods used in the study of core reduction intensity, such as the Volumetric Reconstruction Method, the Scar Density Index, and the non-cortical surface percentage. Our results show 1) strong and positive correlations between these approaches and actual reduction intensity, 2) similar Weibull distributions for non-cortical surface percentage, Volumetric Reconstruction Method, and logarithmic transformation of Scar Density Index. In addition, 3) the results from each method show a similar intra-assemblage variation, with a high percentage of agreement between them. As a result, all the evaluated proposals are useful and reliable methods for estimating the degree of reduction. Finally, a workflow is proposed for approaching reduction in archaeological assemblages by integrating different methods in the same study.

Understanding the temporal resolution of archaeological deposits is a critical issue for drawing behavioural inferences. In the case of TD10.2 (Gran Dolina, Sierra de Atapuerca), this factor becomes essential in defining the mass communal bison hunting level and the different butchering events that took place at the sub-unit, which is characterised as a kill-butchering site. Traditionally, the dissection of events within an assemblage is performed by visual archaeostratigraphic techniques. This method, however, can be challenging in high-density sites without marked sterile gaps between levels. In this study, we present a combination of archaeostratigraphic techniques, supervised machine learning, and lithic refits applied to TD10.2. This integration of techniques offers a more automated and time-efficient archaeostratigraphic analysis, supports a more quantitative strand of evidence, and enables final verification using refits, even though it still requires prior visual archaeostratigraphic processing to set up qualitative data. Results have allowed for the definition of three distinct levels within the sub-unit along the entire excavation surface, highlighting the potential of these methods. Moreover, this approach facilitates the accurate delineation of level boundaries in the bison bone bed level, assessing its high spatiotemporal resolution, and identifying a minimum of two seasonal communal hunting events. This result reinforces previous interpretations while also providing new insights into the subsistence and behavioural strategies of the hominins that occupied the cavity

The ability of early hominins to overcome the constraints imposed by the characteristics of raw materials used for stone tool production is a key topic on the discussion about the evolution of hominin cognitive capabilities and technical behaviours. Thus, technological variability has been the centrepiece on this debate. However, the variability of lithic assemblages cannot be correctly interpreted without understanding site occupational models and function and considering that individual tools represent specific discard moments in a continuous reduction process. In Europe, the earliest technological record is represented by the scarce and scattered Mode 1 technologies, often deriving from occasional occupations or restricted activity areas yielding unrepresentative assemblages. In this paper, we approach the technological behaviours exhibited by Lower Palaeolithic hominins from the subunit TD6.2 of the Gran Dolina site (Atapuerca, Burgos) by including the perspective of reduction intensity studies on the analysis of technological variability. Gran Dolina TD6.2 is a unique and extremely significant archaeological context, as it represents the oldest multi-layered unit of domestic hominin occupations in the Early Pleistocene of Europe. We use the Volumetric Reconstruction Method (VRM) to estimate the original volume of the blanks and quantify the reduction intensity of each core individually to characterise the reduction distribution patterns using Weibull probability distribution functions. Our results suggest differential raw material management in terms of reduction intensity, according to the characteristics of each lithology. This could reflect a solid understanding of raw material qualities and a certain degree of planning. Altogether, the continuity between knapping strategies through reduction denotes constant adaptation to raw material constraints as well as particular knapping conditions, rather than specific compartmentalised mental schemes. In conclusion

The TD6 unit of the Gran Dolina contains an assemblage of the Early Pleistocene, interpreted firstly as a home base. Morerecently has been proposed a transported origin of the remains according to the sedimentology. Following this model, the remainsshould be dragged or lagged in a predictable pattern related to their weight, density, shape, and size. Conversely, the debrisgenerated in an undisturbed residential camp should retain spatial relations of codependence caused by the depositional process,not related to inherent variables of materials. To check if the remains were recovered in their original depositional place(aggregated) or are the product of transportation (segregated or random spatial relation), we have evaluated different variables:the spatial arrangement between osteological and lithic tools; the integrity of the bones and their structural characters (shape andtissue composition); postdepositional modifications; and the specimen size distribution. The combined results indicate that thelayers that conform the TD6.2 subunit were undisturbed, while TD6.1 was affected by postdepositional processes, probablywater flows, resulting in a lagged assemblage. In conclusion, TD6.2 is best interpreted as a well-preserved home base and shouldplay a key role in studies of the behavior of the first European populations.

The TD6 unit of the Gran Dolina contains an assemblage of the Early Pleistocene, interpreted firstly as a home base. More recently has been proposed a transported origin of the remains according to the sedimentology. Following this model, the remains should be dragged or lagged in a predictable pattern related to their weight, density, shape, and size. Conversely, the debris generated in an undisturbed residential camp should retain spatial relations of codependence caused by the depositional process, not related to inherent variables of materials. To check if the remains were recovered in their original depositional place (aggregated) or are the product of transportation (segregated or random spatial relation), we have evaluated different variables: the spatial arrangement between osteological and lithic tools; the integrity of the bones and their structural characters (shape and tissue composition); postdepositional modifications; and the specimen size distribution. The combined results indicate that the layers that conform the TD6.2 subunit were undisturbed, while TD6.1 was affected by postdepositional processes, probably water flows, resulting in a lagged assemblage. In conclusion, TD6.2 is best interpreted as a well-preserved home base and should play a key role in studies of the behavior of the first European populations.

As enquisas son un instrumento cun papel chave na nosa sociedade, pois constitúenunha base para a toma de decisións, tanto no ámbito privado coma no público. Para a súaelaboración será necesario en primeiro lugar a selección dunha mostra, tendo en conta que o tratamento de datos de toda a poboación non vai resultar posible por razóns financeiras e de tempo. Neste traballo profundizamos nun tipo concreto de mostraxe probabilística, coma é a mostraxe sistemática. Malia non ser o método máis axeitado para determinados casos, pretendemos examinarcales son os seus pros e contras, enfatizando os primeiros a través dunha aplicación empírica. Por outra banda, pertencendo ao ámbito estatístico, será necesariaa introdución dunha serie de fórmulas que nos van permitir calcular os estimadores do total, da media e da proporción, así coma da súa varianza. Deste xeito, o traballo permítenos obter unha análisedesta modalidade de mostraxe, tanto dende un punto de vista teórico coma práctico. Mais non se trata dunha visión estática, senón que podemos apreciar coma os investigadores están introducindo cambios constantemente, aparecendo así novos casos particulares da mostraxe sistemática,coma son a replicada ou a especial

The Atapuerca localities present evidence of a long series of hominin occupations from the Early Pleistocene onward and are a key site for understanding the continuity and discontinuity of Western European technological and settlement dynamics. The TD10 unit from Gran Dolina is located in the upper part of the sequence and divided into four lithostratigraphic subunits (TD10.4 to TD10.1, from bottom to top) dated between ca. 450 ka and ca. 250 ka (Marine Isotope Stage 11 to Marine Isotope Stage 8). The technological analysis of the lithic assemblages belonging to the TD10.1 sequence aims to determine the trends among its archeological levels and check its relation to late Middle Pleistocene technological evolution and site functionality. Archeostratigraphic studies have identified several occupation events within its approximately 1.5 m of thickness, whose artifact densities and occupational models differ. However, no remarkable technical differences have been observed among them. Lithic assemblages from those events show more evolved features than other Atapuerca Mode 2 assemblages. These changes are reflected in the selective raw material management strategies; more hierarchized and predetermined reduction methods; and the progressive decrease of large cutting tools in the lithic assemblages with respect to flake tools, the latter defined by a greater typological diversification. These technological changes did not lead to a clear break with respect to previous technological models and were accompanied by other sporadic but significant changes in subsistence and behavioral strategies (bone tools and retouchers; lithic recycling, and so on), which were consolidated during the Middle Paleolithic. Hence, the archeological record from the TD10.1 subunit of Gran Dolina reflects a local stratigraphic transition from Mode 2 to Mode 3 technocomplexes, paralleling that observed in other sites in southwestern Europe.

Knowing to what extent lithic cores have been reduced through knapping is an important step toward understanding the technological variability of lithic assemblages and disentangling the formation processes of archaeological sites. In addition, it is a good complement to more developed studies of reduction intensity in retouched tools and provides information on raw material management or site occupation dynamics. This paper presents a new methodology for estimating the intensity of reduction in cores and tools on cobbles, the Volumetric Reconstruction Method (VRM). It is based on a correction of the dimensions (length, width, and thickness) of each core from an assemblage. The median values of thickness and platform thickness of the assemblage's flakes are used as corrections for the cores' original dimensions, after its diacritic analysis. Then, based on these new dimensions, the volume or mass of the original blank are reconstructed using the ellipsoid volume formula. The accuracy of this method was experimentally tested, reproducing a variety of possible archaeological scenarios. The experimental results demonstrate a high inferential potential of the VRM, both in estimating the original volume or mass of the original blanks and in inferring the individual percentage of reduction for each core. The results of random resampling demonstrate the applicability of VRM to not size-biased archaeological contexts.