Known as "Clovis First," the predominant hypothesis among archaeologists in the latter half of the 20th century had been that the people associated with the Clovis culture were the first inhabitants of the Americas.
According to researchers Michael Waters and Thomas Stafford of Texas A&M University, new radiocarbon dates place Clovis remains from the continental United States in a shorter time window beginning 450 years later than the previously accepted threshold (13,200 to 12,900 BP) [REF].