Researchers have long regarded remains of the prehistoric Clovis culture as the oldest solid evidence of people in the Americas. However, new radiocarbon dates for North American Clovis sites challenge that assumption.
Clovis culture lasted from 11,500 to 10,900 years ago, according to prior radiocarbon measures. That estimate should be revised to extend only from 11,050 to 10,800 years ago, contend Michael R. Waters of Texas A&M University in College Station and Thomas W. Stafford Jr. of Stafford Research Laboratories in Lafayette, Colo. Thus, Clovis people—who made distinctively shaped stone spear points—inhabited the New World consid