A biface production older than 600 ka ago at Notarchirico (Southern Italy) contribution to understanding early Acheulean cognition and skills in Europe.

For the past decade, debates on the earliest evidence of bifacial shaping in Western Europe have focused on several key issues, such as its origin (i.e., local or introduced), or on what should define the Acheulean culture. Whatever hypotheses are proposed for its origin, the onset and technological strategies for making Large Cutting Tools (LCTs), including biface production, are key issues and are often associated with other behavioural changes, such as increased core technology complexity. Current archaeological patterns do not support the existence of transitional industries. Rather, the scant evidence suggests that biface production associated with the management of bifacial volume was widespread around 700 ka. Among the earliest sites, the site of Notarchirico in Southern Italy stands out as one of the most significant examples. 40Ar/39Ar ages and ESR dates recently provided a revised chronology for the whole sedimentary sequence and constrained the archaeological levels between ca. 610 and 670 ka. Five archaeosurfaces (A, A1, B, D and F) yielded LCTs, including bifaces, during Marcello Piperno's excavations from 1980 to 1995. In light of this new chronological framework, which is much shorter than previously thought, we propose in this contribution a revision of the bifaces by applying the "chaine opératoire" method for the first time (analysis of reduction processes). Our goals are to assess biface production in this early Western European locality and to characterize the strategies applied at the site throughout the sequence. A corpus of 32 tools was selected from the A-A1, B, D and F archaeosurfaces. The technological analysis shows that hominins had the capacity to manage bifacial volumes, when raw material quality was adequate. Clear differences do not emerge between the different levels in terms of shaping modes or final forms. However, we demonstrate that the oldest level (level F), with the richest corpus, lacks flint and displays a higher diversity of bifaces. This ability to manage bifacial and bilateral equilibrium, as well as the diversity of the morphological results, is observed in a few penecontemporaneous sites (700-600 ka), both in the north-western and southern parts of Western Europe. These patterns suggest that hominins mastered well-controlled and diversified biface production, combining intense shaping and minimal shaping, and shared a common technological background regardless of the geographical area, and applied this technology regardless of the available raw materials. The degree of skill complexity of hominins in Western Europe between 700 and 600 ka, the current lack of evidence suggesting "gradual industries" between core-and-flake series and Acheulean techno-complexes, raise numerous questions on the origin of new behaviours in Western Europe, their mode of diffusion, and their association with Homo heidelbergensis or other Middle Pleistocene populations.