Stone tools and human DNA from ancient caves in Oregon offer new evidence of how the first Americans spread through the continent: quite apart from the better-known Clovis culture, a separate group that may have occupied the West.
Archaeologists reported Thursday they have dated broken spear points from the caves to about 13,200 years ago, as old as much different stone tools found elsewhere from the Clovis culture.
University of Oregon archaeologist Dennis Jenkins says that indicates the Clovis style of chipping stone tools was not the mother of Stone Age technology. He says the two styles were developed independently by different groups that may have taken separate routes through the continent after crossing the Ice Age land bridge from Asia.
The findings appeared Thursday in the online edition of the journal Science.