Prospects and pitfalls of an intrusive model for the Chatelperronian stone tool industry during the Middle to Upper Palaeolithic transition in France and northern Spain

The Middle to Upper Palaeolithic transition in France and northern Spain reflects the transition from Neandertals to Homo sapiens and the emergence of novel cultural entities and standardised laminar technologies between ~50 and 40 thousand years ago. The Chatelperronian stone tool industry sits at the centre of this period, and is commonly considered as representing a geographically isolated archaeological entity produced by late Neandertals. However, debate as to the makers and origin of this industry has long persisted. Fuel has recently been thrown onto this discussion through the formulation of a hypothesis in which the Chatelperronian directly originates from the Northern Early Ahmarian industry of the Levant. This model proposes that the Chatelperronian is in fact indicative of a direct migration of a population of Homo sapiens from the Levant to France around 44-40 thousand years ago - potentially via the crossing (or series of crossings) of the Mediterranean Sea. Such a scenario would have significant implications for how we interpret this key portion of recent human evolutionary history. In this paper, we highlight some of the prospects and pitfalls of an intrusive origin model for the emergence of the Chatelperronian industry in western Europe - taking into account technological, chronological, geographic, and stratigraphic perspectives. To frame this discussion, we review the state of understanding on the Chatelperronian and provide a detailed, synthetic review of Chatelperronian lithic technology. Our review reinforces the distinctive and fully Upper Palaeolithic character of this industry, and we subsequently suggest a few avenues of research which, in our opinion, may help shed progressively clearer light on the demographic and cultural processes operating during the Middle to Upper Palaeolithic transition in western Europe.