New dating for White Sands footprints confirms controversial theory

The 2009 discovery of footprints (human and animal) left behind in layers of clay and silt at New Mexico’s White Sands National Park sparked a contentious debate about when, exactly, human cultures first developed in North America. Until about a decade ago, it seemed as if the first Americans arrived near the end of the last Ice Age and were part of the Clovis culture, named for the distinctive projectile points they left behind near what’s now Clovis, New Mexico. But various dating methods indicated...