Footprints left behind in layers of clay and silt at New Mexico’s White Sands National Park may be between 23,000 and 21,000 years old. That’s based on radiocarbon dating of the remains of grass seeds buried in the layers of
Footprints left behind in layers of clay and silt at New Mexico’s White Sands National Park may be between 23,000 and 21,000 years old. That’s based on radiocarbon dating of the remains of grass seeds buried in the layers of