North American Archaeology: 40Kya footprints discovered in Mexico

It has nothing to do with Taiwan, but pre-Columbian history of North America is a fascination of mine. A major find was announced today, which, if it holds up, is going to revolutionize archaeology of North America. The Guardian reports that human footprints have been found in volcanic ash deposits dated to 40,000 years ago, in Mexico.

Mexico offers up ancient footprints

A group of British scientists claimed yesterday to have identified human footprints in central Mexico that are 40,000 years old, almost three times older than the most generally accepted evidence for human settlement in the Americas.

The team from universities in Liverpool, Bournemouth, and Oxford are convinced that the footprints are human and represent several adults and children who walked in freshly fallen volcanic ash in the Valsequillo Basin, about 80 miles south-east of Mexico City.

Working with international colleagues, they have applied dating techniques on the sediment itself and on finds including a land snail, a water snail and a mammoth tooth, all of which came back with an age of around 40,000 years.

The footprints had to be disentangled from animal tracks, more than 250 marks in all. Casts, which Matthew Bennett of Bournemouth University described as "unmistakably human" were produced from laser modelling at the site, employing a technique used to make industrial prototypes.

The prevailing view, which has been struggling against recent finds, is that humans peopled the americas after the end of the last glacial period some 12,000 years before present. If this holds up, many other controversial sites, such as Pedro Furada, and perhaps even the Calico Site in California, are going to get a major boost.

UPDATE: Nature Weighs in with Negative Perspective

Debate continues about what the marks really represent. "I've seen them up close and personal, and I don't think they are footprints," says Paul Renne, a geochronologist at the University of California, Berkeley. Renne is keen for the team to find further evidence of human occupation that might shore up its claim.

Bruce Latimer, a human anatomist at the Cleveland Museum of Natural History in Ohio who helped identify some 3.5-million-year-old Laetoli footprints in Tanzania, agrees that caution is necessary. He says that human prints are usually so distinctive they are hard to miss. "I have not seen them. But if you have to equivocate, it is probably not human."

*Sigh*