Un peuplement antérieur à 20 000 ans en Amérique ? Le caractère anthropique des sites de Pedra Furada (Brésil) en question
Authors: Gómez coutouly Yan axel 
Published: June 2024

The first colonization of the Americas has always been a hotly debated issue. One of the current discussions is the presence of assemblages (and thus human occupation) in the Americas dating from or before the Late Glacial Maximum (LGM), i. e. before ca. 20.000 years ago. Many archaeologists are skeptical about the presence of humans in the Americas before the LGM, considering that the claim is not yet sustained by hard evidence. Indeed, there are relevant concerns about the published pre-LGM assemblages. The Boqueirão da Pedra Furada rock-shelter (Brazil) is one of the most famous and published pre-LGM sites from the Americas. However, the site has so far been considered very ambiguous because all alleged artifacts are simple cobble tools made on the same raw material cobbles as those naturally falling from the cliff’s wall hanging above the site. Nonetheless, for É. Boëda and co-workers, who have been working at various sites of the region for the last decade, researchers that are still skeptical about the anthropic origin of the assemblages have a psychological barrier and no scientific arguments. Were all skeptics completely blinded by their preconceptions that they could not see the obvious and unambiguous evidence coming out of these South American LGM/ pre-LGM sites ? In order to find out, I dove into the publications of the Piauí sites. Why the Piauí sites ? Because for the last 40 years there has been extensive research and publications on Boqueirão da Pedra Furada and related sites, thus offering the possibility of a detailed analysis. According to É. Boëda, most critics never took the time to go back to the published data. So to take up the challenge and refine my own judgment, I launched a large-scale comparative analysis of the published data on the Piauí site (close to 60 publications, including peer-reviewed articles, book chapters, unpublished master and PhD theses) concerning the Piauí sites, from the first article announcing the discovery of Boqueirão da Pedra Furada published in Nature in 1986 to the most recent research articles of the É. Boëda team in 2021. These publications include original research from the N. Guidon and F. Parenti excavations, from É. Boëda’s excavations, original work by other researchers, original ethological studies on tool-use by capuchin monkeys, as well as points of view from outside archaeologists arguing either for or against the anthropic nature of these sites.
In the following sections, I will present some of the main concerns archaeologists have with Boqueirão da Pedra Furada and other related sites (Vale da Pedra Furada, Sítio do Meio, Toca da Pena, Toca da Janela da Barra do Antonião, Toca da Tira Peia, etc). Indeed, the problems do not only lie in the geological context of the sites, but also with the raw materials, the selection protocol of artifacts (i. e., how archaeologists determine alleged artifacts within the large quantity of natural cobbles in the sediment), the taphonomical analyses of natural cobbles, the use-wear analysis and the anthropic nature of the structures and hearths. In the introduction of their very first article, É. Boëda and his colleagues state that “ this very passionate debate is actually little suited for scientific argument” and “ it would thus be futile to present arguments” and that we simply have “ to trust” in their capabilities. But the fact is that there are many questions about Pedra Furada and the Piauí sites that have yet to be addressed.
The outcome of my analysis is straightforward : the anthropic nature of the LGM/ pre-LGM levels of Pedra Furada and the other Piauí sites has not been demonstrated based on the data presently available in the scientific literature. Throughout this article, my goal is to show that far from skepticism based on ideological grounds with no scientific basis, many and major scientific issues remain with the Piauí sites. The present article focuses on deconstructing the methodological caveats concerning the alleged pre-LGM artifacts and structures/ hearths from Boqueirão da Pedra Furada and other related sites from the Piauí region. The final outcome of this analysis, based on the analysis of the numerous published data, is that it is difficult to support a human presence in this region during or before the Last Glacial Maximum. However, the published data seem to convincingly establish a human presence at these sites starting with the Serra Talhada phases (Pleistocene/ Holocene transition). Is it because the chronology is then acceptable and fits our colonization model ? No, the reason lies in the available and published archaeological data : (1) to date, no taphonomical study has been published to exclude the presence of geofacts in the assemblages from the older Pedra Furada phases ; (2) ethological data show how Capuchin monkeys have been using and making simple stone tools for at least a few millennia ; (3) during the Serra Talhada phases (Pleistocene/ Holocene transition), we see the appearance of unambiguous tools, exogenous raw materials, pit hearths, rock art, human remains and human coprolites ; (4) current paleogenetic data show a peopling of the Americas (excluding Beringia) starting around 20,000 years ago.