Manual 3D analysis database.

During the transition from the Pleistocene to the Holocene and in the early Holocene period, hunter-gatherer communities across tropical South America deployed a range of technological strategies to adapt to diverse environmental conditions. This period witnessed a rich tapestry of technological practices, from enduring, widely disseminated tools to local and sporadically utilized technologies, shaping a multifaceted landscape of technological traditions. Lithic technology during this period was mainly marked by localized sourcing of raw materials, the use of multifunctional tools, a variety of projectile point designs, and the frequently utilization of unifacial shaping technology. In tropical Central Brazil, the Itaparica technocomplex, with unique unifacial lithic tools like limaces, is a pivotal innovation from the Late Pleistocene through the Holocene. However, the factors influencing their morphological and structural variability remain largely unexplored, obscuring our understanding of their ergonomics and their role as mediators between humans and tropical environments. This study hypothesizes that the variability observed within and among unifacial tools from the GO-Ni sites in Central Brazil is a result of a combination of factors, including raw material availability and functional and ergonomic requirements. To test this hypothesis, a study of 67 unifacial tools from this region was conducted, employing techno-structural analysis and 3D geometric morphometrics. This approach was designed to precisely quantify tool geometry and uncover their functional potentials. The analysis revealed significant variability within the techno-structural groups, often intersecting with typological classifications. These results indicate that despite their production attributes, unifacially shaped artifacts demonstrate considerable morpho-structural diversity. The study delineated nine distinct techno-structural groups, each suggesting potentially different functional organizations and deviating from conventional typologies. These results indicate that unifacially shaped artifacts, while embodying a novel technological paradigm of production, exhibit a broader spectrum of variation mainly due to different tool functions. The combined approach adopted in this research highlights on the cultural significance of unifacial tools within Paleoamerican technological systems. It suggests probable unique tool concepts specific to the study area, challenges existing classifications, and enriches our comprehension of early lithic technology in South America.在更新世（Pleistocene）至全新世（Holocene）的过渡时期以及全新世早期，热带南美洲各地的狩猎采集社群采用了一系列技术策略以适应多样的环境条件。这一时期孕育了丰富多元的技术实践体系，从持久流传、广泛传播的工具到地方性且偶发性使用的技术，共同塑造了多元的技术传统格局。此时期的石器技术（Lithic technology）主要特征为：原材料的本地化获取、多功能工具的使用、多样的投射器尖设计，以及单面修整技术（unifacial shaping technology）的频繁应用。在巴西中部热带区域，伊塔帕里卡技术复合体（Itaparica technocomplex）以蛞蝓状石器（limaces）这类独特的单面石器为代表，是晚更新世至全新世时期的关键性技术革新。然而，影响这类工具形态与结构变异的因素在很大程度上仍未得到系统探究，这阻碍了我们对其人类工效学（ergonomics）适配性以及其作为人类与热带环境之间媒介的作用的认知。本研究提出假说：巴西中部GO-Ni遗址出土的单面工具内部及不同工具间的形态与结构变异，是原材料可得性、功能需求与人类工效学要求等多种因素共同作用的结果。为验证该假说，本研究针对该区域出土的67件单面工具展开研究，采用技术-结构分析（techno-structural analysis）与三维几何形态测量学（3D geometric morphometrics）方法。该方法旨在精准量化工具的几何形态特征，揭示其功能潜力。分析结果显示，技术-结构群组内部存在显著变异，且常与传统类型学分类存在交叉重叠。上述结果表明，尽管具备统一的生产特征，单面修整制品仍展现出可观的形态-结构多样性。本研究界定出9个独立的技术-结构群组，每个群组均对应潜在的不同功能组织模式，且与传统类型学划分存在差异。上述结果还表明，单面修整制品尽管代表了一种全新的生产技术范式，但其变异范围更广，这主要源于不同的工具功能需求。本研究采用的整合分析方法凸显了单面工具在古美洲（Paleoamerican）技术体系中的文化意义。研究结果暗示该研究区域存在独特的工具制作理念，对现有分类体系提出了挑战，并深化了我们对南美洲早期石器技术的认知。