Does the evidence at Arroyo del Vizcaíno (Uruguay) support the claim of human occupation 30,000 years ago?

Abstract

Researchers at Arroyo del Vizcaíno (AdV), Uruguay, have argued that human occupation dates prior to the Last Glacial Maximum (33,000–31,000 cal BP) based on the presence of purported stone tools and cutmarks on bones. We provide a summary of their research and critically evaluate these claims. We conclude that the claims of a pre-LGM occupation at AdV are unsupported due to: (1) equivocal evidence that the purported stone tools are culturally modified; (2) insufficiently documented spatial and contextual information; (3) inadequate geological research leading to an unconvincing site formation model; and (4) inadequate testing of alternative hypotheses for bones with surface modifications. We conclude that the site is best interpreted as a natural time-transgressive accumulation of mammal bones and other organic and inorganic materials within a fluvial setting spanning four millennia, and that bone surface modifications are the product of natural site formation processes rather than human agency.