Another Mousterian Debate? Bordian facies, chaîne opératoire technocomplexes, and patterns of lithic variability in the western European Middle and Upper Pleistocene

The classic Mousterian Debate of the 1970s has recently been revived, as researchers propose cultural, functional, and chronological interpretations for the Mousterian "technocomplexes". These interpretations, however, are likely to lead to the same impasse that was previously reached forty years ago. The root cause of the problem is analyzing assemblages according to taxonomic units, whether they are Bordian facies or chaîne opératoire technocomplexes, which conflate as well as mask multiple sources of variability. In this paper, we use a database of well-excavated, well-dated sites from the Middle and Upper Pleistocene in western Europe to track changes in key lithic variables through time. We show that the chronological patterning of typological and technological facies yields little information useful for elucidating the causes of Mousterian variability. When individual lithic variables from within assemblages are plotted through time, however, new patterns of variability emerge. Our results show that bifaces are not characteristic only of the "Acheulean" and the "Mousterian of Acheulean Tradition." They occur continuously and in low frequencies across the European landscape from MIS 14 onwards. Second, we reveal chronological patterning in Levallois technology, which reaches a height of popularity between MIS 6-4. In the future, more progress in understanding technological behavior during the Paleolithic will be made if we compare the properties of the lithics themselves across assemblages, rather than comparing assemblage types.