Texas Find Suggests Earlier Settlers In N. America
(With additional reporting from Illinois Public Radio)
Archaeologists have hard evidence that humans lived in North America much earlier than previously thought, and an Illinois researcher played a key role in nailing down the dates.
The earliest North Americans were long thought to be the Clovis people. Now archaeologists have dug up stone tools and debris from underneath a Clovis site in central Texas. The findings were discovered by researchers led by Michael R. Waters of Texas A&M University.
It was "like finding the Holy Grail," Waters said in a telephone interview. To find what appears to be a large open-air campsite "is really gratifying. Lucky and gratifying."
The trove of 15,528 artifacts included chipping debris from working stones and 56 tools such as blades, scrapers and choppers. The archaeologists sent samples to Steven Forman's lab at the University of Illinois at Chicago, where he determined when the sediment around the objects was last exposed to sunlight.
The artifacts turn out to be about 15,000 years old - from millennia before the Clovis people. It's not the first evidence of cultures older than Clovis, but Forman says it may be the strongest.
"It appears to be that this might be kind of watershed piece of science in which people say, yes, there is really compelling evidence for pre-Clovis occupation in North America," Forman said. "It's no longer a red herring."
The small tools were "a mobile tool kit," Waters said, and of the type that could have led to the later development of the fluted points that trademark Clovis technology.
While there are other pre-Clovis sites across the country, Waters said the new find included significantly more artifacts than the others.
Anthropologist Tom D. Dillehay of Vanderbilt University, who was not part of the research team, said he is concerned that the separation of layers at the site "appears not to be as clear as the authors would have us believe."
University of Oregon archaeologist Dennis L. Jenkins said he was also initially skeptical of the find, commenting "it would have been a hard sell" from many other researchers.
Jenkins, who three years ago reported discovery of 14,000-year-old evidence of human DNA in a cave in Oregon, said he was concerned that settling or rodents had mixed up the specimens in Texas.
But, he said, Waters' team had done "incredible, meticulous scientific work." "I believe he's made the case," he said.
Jenkins said he would have preferred carbon-dating of the specimens, but that couldn't be done because there was no organic material to be tested in the newly found layer.
Steven L. Forman, of the University of Illinois, Chicago, a co-author of the paper, said the team used luminescence dating which can determine when the material was last exposed to light. They took samples by hammering black, sealed copper pipe into the layers. In a separate paper in the journal, researchers report evidence of early humans in south India more than a million years ago.
Researchers discovered more than 3,500 quartzite tools of the distinct Acheulian design used by the earliest humans in Africa starting more than 1.5 million years ago. They dated the tools to at least 1.07 million years old and some possibly 1.51 million years old.
The discovery at a site called Attirampakkam in the Kortallayar river basin helps anthropologists understand the spread of ancient people from Africa into Asia. Leading the research team was Shanti Pappu of the Sharma Centre for Heritage Education in Tamil Nadu, India.
The find is unprecedented for archaeological studies in India, said archaeologist Michael Petraglia of the University of Oxford, England, who was not part of the research team.
He said it could mean that early humans migrated out of Africa earlier than the oft-cited 1.4 million years ago, carrying the tools to southern Asia.
"The suggestion that this occurred at around 1.5 million years ago is simply staggering," he said.
The new find will likely overturn the history of ancient humans in North America. The results are out in the journal Science.
(Photo courtesy of Michael R. Waters/The Associated Press)