Refuting the technological cornerstone of the Ice-Age Atlantic crossing hypothesis

•Clovis and Solutrean stone biface-production techniques are asserted to be similar.•These similarities are used to support Solutrean–Clovis technological divergence.•The key shared element is the supposed intentional use of “controlled overshot flaking”.•Experimental and archaeological data suggest that overshot flakes are accidental.•Clovis and Solutrean stone-tool production illustrates technological convergence.

The “North Atlantic Ice-Edge Corridor” hypothesis proposes that sometime during the Last Glacial Maximum, roughly 26,500–19,000 years ago, human populations from southern France and the Iberian Peninsula made their way across the North Atlantic and colonized North America. A key element of that hypothesis is the apparent similarity between stone-tool-production techniques of Solutrean peoples of Western Europe and Clovis and purportedly pre-Clovis peoples of eastern North America, most especially the supposed intentional use of “controlled overshot flaking,” a technique for thinning a bifacial stone tool during manufacture. Overshot flakes, struck from prepared edges of the tool, travel across the face and remove part of the opposite margin. Experimental and archaeological data demonstrate, however, that the most parsimonious explanation for the production of overshot flakes is that they are accidental products created incidentally and inconsistently as knappers attempt to thin bifaces. Thus, instead of representing historical divergence, overshot flakes in Clovis and Solutrean assemblages mark convergence in the use of the same simple solution for thinning bifaces that produced analogous detritus.