The ‘Semi-Sterile Mousterian’ of Riparo Bombrini: evidence of a late-lasting Neanderthal refugium in Liguria

Constrained by the Maritime Alps and a steep coastal shelf, Liguria served as a biogeographic corridor linking mainland Western Europe to peninsular Italy throughout the Late Pleistocene. It may also have served as a biogeographic refugium for Neanderthals, since sites in the region have yielded some of the latest Mousterian dates in Western Europe and, paradoxically, some of the earliest dates for Protoaurignacian occupations. This paper presents an overview of the Neanderthal presence in Liguria between Marine Isotope Stage (MIS) 5 and MIS 3, with a particular focus on the record from the Balzi Rossi site complex. This permits a critical evaluation of diachronic shifts in the Neanderthal occupation of Liguria. This is followed by an analysis of new data from ‘semi-sterile Mousterian’ Level MS at Riparo Bombrini that show it was occupied very ephemerally by the end of the Mousterian, highlighting major late Neanderthal behavioral shifts. We conclude by proposing that this behavioral pattern is best explained by the last Neanderthals of the Balzi Rossi having occupied the region as an ecologically stable, taxon-specific in situ micro-refugium. This has implications for our understanding of Paleolithic refugia more broadly and of the social and ecological conditions in place during the terminal Mousterian period in western Liguria.