New Mexico footprints are oldest sign of humans in Americas, research shows

Fossil footprints date back to between 21,000 and 23,000 years ago, upending previous theory that humans reached continent later

New research confirms that fossil human footprints in New Mexico are probably the oldest direct evidence of human presence in the Americas, a finding that upends what many archaeologists thought they knew.

The footprints were discovered at the edge of an ancient lakebed in White Sands national park and date back to between 21,000 and 23,000 years ago, according to research published on Thursday in the journal Science.