Thursday, March 24, 2011

Clovis People Weren’t First in Americas, Texas Arrowheads Suggest

But in more recent years, archaeologists have found more and more traces of even earlier people with a less refined technology inhabiting North America and spreading as far south as Chile.

And now clinching evidence in the mystery of the early peopling of America — Clovis or pre-Clovis? — for nearly all scientists appears to have turned up at a creek valley in the hill country of what is today Central Texas, 40 miles northwest of Austin.

The new findings establish that the last major human migration, into the Americas, began earlier than once thought. And the discovery could change thinking about how people got here (by coastal migrations along shores and in boats) and how they adapted to the new environment in part by making improvements in toolmaking that led eventually to the technology associated with the Clovis culture.

Archaeologists and other scientists report in Friday’s issue of the journal Science that excavations show hunter-gatherers were living at the Buttermilk Creek site and making projectile points, blades, choppers and other tools from local chert for a long time, possibly as early as 15,500 years ago. More than 50 well-formed artifacts as well as hundreds of flakes and fragments of chipping debris were embedded in thick clay sediments immediately beneath typical Clovis material.

“This is the oldest credible archaeological site in North America,” Michael R. Waters, leader of the discovery team, said at a news teleconference.

Dr. Waters, director of the Center for the Study of the First Americans at Texas A&M University, and his colleagues concluded in the journal article that their research over the last six years “confirms the emerging view that people occupied the Americas before Clovis and provides a large artifact assemblage to explore Clovis origins.”

If the migrations began at earlier, pre-Clovis times, moreover, extensive glaciers probably closed off ice-free interior corridors for travel to the warmer south. Archaeologists said this lent credence to a fairly new idea in the speculative mix: perhaps the people came to the then really new New World by a coastal route, trooping along the shore and sometimes hugging land in small boats. This might account for the relatively swift movement of the migrants all the way to Peru and Chile.

The first of the distinctive Clovis projectile points represented advanced skills in stone technology. About a third of the way up from the base of the point, the artisans chipped out shallow grooves, called flutes, on both faces. The bifacial grooves probably permitted the points to be fastened to a wooden spear or dart.

Other archaeologists pointed out that the Buttermilk Creek dates, more than 2,000 years earlier than the Clovis chronology, are not significantly older than those for other sites challenging the Clovis-first hypothesis. In recent years, early human occupation sites have been examined coast to coast: from Oregon to Wisconsin to western Pennsylvania and from Maryland and Virginia down to South Carolina and Florida.

James M. Adovasio, an archaeologist who found what appears to be pre-Clovis material at the Pennsylvania site known as Meadowcroft Rockshelter, was not involved in the Buttermilk Creek excavations but has visited the site and inspected many of the artifacts. These pre-Clovis projectile points were also bifacial but not as large and well turned as the later technology. The most striking difference was the absence of the characteristic fluting.

Dr. Adovasio, a professor at Mercyhurst College in Erie, Pa., said some of the Buttermilk Creek material resembled tools at his site and others at Cactus Hill, Va., and Miles Point, Md.

“It would appear the assemblage of artifacts is enough different from typical Clovis to be a distinct technology,” Dr. Adovasio said in an interview. “But it is not as much different as not to be ancestral to Clovis material.”

That is another likely implication of the new findings, also noted by Dr. Waters and his team. It would appear that the Clovis technology was not an Asian import; it was invented here.

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