By ALEX BELLOS
The Guardian
February 14, 2000
SAO RAIMUNDO NONATO, Brazil - In the most underdeveloped state of Brazil, Piaui, lies one of the richest prehistoric archaeological sites in the world. Pedra Furada is also one of the most controversial sites in the Americas -- splitting archaeologists into two emotionally charged camps and threatening to rewrite the history of the continent's colonization.
A thinly inhabited, semi-arid area of sandstone rock shelters, 500 miles west of the coastal city Recife, Pedra Furada contains more than 400 prehistoric sites, including 340 stone walls full of ancient paintings. Researchers are still finding new remains at the rate of 40 a year.
But it is not the vast number of archaeological discoveries that has the academic world excited. It is their age.
Brazilian excavators, led by Niede Guidon, claim to have proved the existence of the oldest Americans. Guidon claims that charcoal she says is the remnant of camp fires has been carbon dated to 50,000 years ago.
This makes it the most ancient site in the Americas by a long shot -- about 40,000 years _ and if true, poses fundamental questions about how humans arrived in South America well before it is believed they arrived in the North.
This year she went one step further. In January she said the results of carbon dating tests on three fossilized teeth and a part of a human skull she found in 1987 had put their age at 15,000 years.
This would make them the oldest human remains in the Americas.
The results are controversial because they smash the traditional view, established in the 1950s, that the earliest Americans were the "Clovis hunters" from New Mexico -- whose spear points have been dated at 12,000 years ago. The Clovis hunters are thought to have migrated across the Bering strait.
Guidon says: "I don't have any doubt that the oldest traces of humans yet discovered are here in Brazil. But there will be others found. These humans had to get here somehow.
"But I think it's wrong that everyone came running across Bering chasing mammoths _ that's infantile. I think they also came along the seas. I don't see why they couldn't have come across the Atlantic."
Guidon's research has divided the academic community into two sides -- roughly between U.S. archaeologists, who refuse to accept it, and the south Americans and Europeans, who do.
Stephen Shennan, professor of archaeology at University College London, says that there has been a degree of nationalism because the north Americans cannot believe that they do not have the oldest site.
"There is a feeling that it's a blow against U.S. imperialism. The evidence is open to different interpretations, so people tend to choose their favorite interpretation in terms of their biases. There is a certain tendency to cast aspersions on other people's excavation techniques.
"The whole thing is very fraught. People get very defensive and sensitive."
Guidon has not published as much as she, perhaps, could have. But some commentators have suggested that the skeptical attitude toward her is also partly because of her gender and nationality.
Pedra Furada ("perforated rock") was put on the map by Guidon, who in 1970 was the first person to make a proper excavation there. At 66, she still excavates indefatigably despite having two metal pins in her legs.
Because of the poor state of funding in Brazil, only five archaeologists work there and only two of the 420 sites are fully excavated.
The North Americans' doubts over Guidon's claims concern the charcoal remains and chipped pebbles that she believes are manmade. "We are concerned that the hearths are in fact hearths and not natural fires. Are the pebbles truly artifacts -- or has nature been mischievous?" asks David Meltzer, of the Southern Methodist University in Dallas.
"In the last 30 years there have been thousands of pretenders to the pre-Clovis crown. Each one dissolved under scrutiny. So we have got pretty skeptical," he said.
"But it is the case that if we have (pre-Clovis) humans in South America, then by golly, why don't we have them in North America too?"
Guidon gets fired up by North American criticism. "The carbon is not from a natural fire. It is only found inside the sites. You don't get natural fires inside the shelters.
"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."