Footprints in the ash By Sid PerkinsMay 29th, 2008Humans may have been walking around what is now central Mexico 40,000 years ago HUMAN PRINTSFootprints (one left) left in volcanic ash that fell in central Mexico’s Valsequillo Basin about 40,000 years could be evidence that humans have inhabited the Americas far longer than previously confirmed. Laser scans of the prints (right) confirm their human origins, the researchers report today at the American Geophysical Union meeting. 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...