Pedra Furada sites

Pedra Furada ("drilled rock") is an important collection of over 800 archaeological sites and rock paintings in Brazil which suggest a human presence prior to the arrival of Clovis people in North America. A Brazilian and French team excavating a site located in the Southeastern portion of the state of Piaui in what is now the Serra da Capivara National Park discovered the site in 1973. The discovery was reported by the Brazilian archaeologist Niède Guidon, who published her findings in 1986.^[1]

Excavations

Pedra Furada includes a collection of rock shelters used for thousands of years by human populations. The first excavations yielded artifacts with Carbon-14 dates of 48,000 to 32,000 years BP. Repeated analysis has confirmed this dating, carrying the range of dates up to 60,000 BP.^[2] Archaeological levels that are well excavated yield dates between 32,160 ± 1,000 years BP and 17,000 ± 400 BP. The collection of stone age artifacts includes darts and atlatls but no arrows or bows.

Guidon has established 15 distinct levels, classified in three cultural phases, called Pedra Furada, that includes the oldest remains, Serra Talhada, from 12,000 to 7,000 BP, with tools like knives, scrapers, flakes used "as is" or with some retouch and lithic cores, all made of quartz or quartzite. Finally there is Agreste late phase. The site also has hundreds of rock paintings dated from 5,000 to 11,000 years ago.^[3]

Significance

The discoveries are the subject of debate as they apparently contradict the "Clovis first" view for humans in the Americas, or short chronology theory with the first movement beyond Alaska into the New World occurring no earlier than 15,000 – 17,000 years ago, followed by successive waves of immigrants.^[4][5] Pedra Furada provides arguments for the proponents of the long chronology theory, which states that the first group of people entered the hemisphere at a much earlier date, possibly 21,000–40,000 years ago,^[6][7] with a much later mass secondary wave of immigrants.^[8][9]

Additional discoveries at Monte Verde, Chile, dated to 14,800 years BP, were initially contested in the very same way and with similar arguments,^[10] as well as other anthropological discoveries in Piedra Museo in the Argentinian province of Santa Cruz, dated 11,000 years BP,^[11] in Topper in the state of South Carolina, U.S.A. dated 50,000 years BP,^[12][13] and the Meadowcroft Rockshelter located near Avella in Washington County in southwestern Pennsylvania, United States, dated to 16,000 years BP, have raised doubts about the "Clovis First" theory, and have led to alternative proposals for the routes of colonization and the diffusion of culture through the continent, in a heated dispute that has not been solved.

Indigenous Amerindian genetic studies have concluded that the "colonizing founders" of the Americas emerged from a single-source ancestral population that evolved in isolation, likely in Beringia.^[14][15] The isolation in Beringia might have lasted 10,000–20,000 years.^[16][17] Age estimates based on Y-chromosome micro-satellite place diversity of the American Haplogroup Q1a3a (Y-DNA) at around 10,000 to 15,000 years ago.^[18][19] However, mtDNA data suggests a primary wave of migration coming to the americas from 35 to 25 kyA.^[20]The Y-chromosome evidence does not address if there were any previous failed colonization attempts by other genetic groups, that could be represented by those settling the Piedra Furada site, as genetic testing can only address current population ancestral heritage.^[18]

Controversy

Debate continues as to whether or not the artifacts and hearths are instead geofacts that were made naturally. This seems to be a dividing line on the debate between archaeologists disputing Guidon's theory that the site's artifacts prove pre-Clovis human settlement in the Americas. The controversy has been characterized by Alex Bello, at The Guardian, as "U.S." archaeologists believing that the items are geofacts created naturally, "because the North Americans cannot believe that they do not have the oldest site", while David Meltzer, of the Southern Methodist University in Dallas asks "...if we have (pre-Clovis) humans in South America, then by golly, why don't we have them in North America too?". Guidon has answered critics of her theory, saying that "The carbon is not from a natural fire. It is only found inside the sites. You don't get natural fires inside the shelters" and adding that "The problem is that the Americans criticize without knowing. The problem is not mine. The problem is theirs. Americans should excavate more and write less".^[21] French palaeolithic archaeologist Jacques Pelegrin, believes there is a possibility for natural processes creating flaked stones that could mimic the Pedra Furada specimens because of their simplicity, but he finds this very unlikely in this case because of continuous human presence in the site.^[22]

See also

• Buttermilk Creek Complex – Salado, Texas

References