There are only two prints - one left and one right - but an ancient hunter-gatherer's path through mineral-rich sediment in the Chihuahuan Desert of northeastern Mexico has been dated to around 10,500 BP.
     A team led by Doctor Nicholas Felstead, a geo-archaeologist at Durham University, was able to date the tracks because they were preserved in travertine, a sedimentary rock that contains minute traces of uranium from the waters in which it formed.
     The tracks were first discovered during highway construction in 1961. They were excavated and taken to Saltillo's Museo del Desierto, for study, but their precise location was lost to history.
     A search for the site in 2006 came up empty, but it did turn up an additional 11 tracks in a Cuatro Ciénegas quarry - in the general area where the original prints were believed to have been found - and dated back about 7,250 years,
     Although rare, fossil human footprints have been found elsewhere in North America, from Nicaragua to California. The oldest known human print in the Western Hemisphere is the tiny track of a child's foot in Chile dated to 13,000 years ago - adding to the debate about when humans first migrated to the New World.

Edited from Western Digs (9 December 2013)