Footprints in the ash, 40,000 in the new world

Humans may have been walking around what is now central Mexico 40,000 years ago

Footprints left in volcanic ash that fell in central Mexico’s Valsequillo Basin about 40,000 years ago are evidence that humans have inhabited the Americas far longer than previously confirmed, a new study suggests.

Nevertheless, says Gonzalez, recent excavations at a site in Baja California have unearthed a rock shelter containing heaps of shells that have been carbon-dated as 44,000 years old, a finding that bolsters the notion that people lived throughout the region about 40 millennia ago.