One of the longest standing debates in modern archaeology deals with the mystery of human arrival in the Americas. Such mysterious human migrations were once thought to have conclusively rested on the premise that early human hunter gatherers crossed the Bering Land Bridge en route from Siberia, entering the North American continent and dispersing outward from there. However, the possibility that multiple entry points might have occurred, via ancient seafarers who sailed all along the Western coastlines, cannot be ruled out. The same must be said of those more controversial theories involving ancient sailors from Europe—possibly members of the Solutrean culture—making their way across the Atlantic and entering from the northeast.
In likelihood, there were many cultures and people who entered North America in the ancient past, arriving from a much wider variety of locations than once thought. What brought them to the Americas may remain somewhat mysterious, although it seems evident that the ancient quest for sustenance pushed them onward, and the discovery of lands rich with vegetation and, of course, megafauna kept them there. However, one of the greatest and most perplexing questions about their arrival that remains has to do with who the first arrivals were, and more specifically, when did they arrive?
The presence of archaeological sites associated with the Clovis culture, as well as a growing number of sites that present evidence of even earlier habitation, have continued to push back the timeline on early human arrival in the Americas. Among the best evidence for such discoveries have been bifacial stone tools (that is, projectile points or stone knives worked on both faces of the blade) discovered throughout North and South America, often found alongside or in situ with extinct animal remains; the earliest, and still among the most famous of these had been discoveries of megafaunal butchering sites at Folsom, New Mexico, and later discoveries at nearby Clovis, which established the thusly-named Folsom and Clovis cultures in the early part of the last century.
However, evidence of earlier lithic types also turn up in the mix from time to time. In 1967, a most unusual artifact turned up at a Mexican archaeological site at Tlapacoya, just south of Mexico City. The stone blade, made of obsidian, was radiocarbon dated to around 21,000 BCE, and helped establish the existence of a Mesoamerican pre-bifacial-point horizon in the region, further suggesting much earlier occupations in the region than once thought.
Tlapacoya was not the only location in the region that presented unusual ancient discoveries. Near Puebla, in what is called the Valsequillo region of Mexio, excavations similarly turned up unifacially worked stone tools that dated back to at least 21,800 years BCE.
The Valsequillo region, despite its confirmed antiquity, has remained somewhat controversial in archaeological circles. 21,800 years BCE is not an inconceivable time period for early human habitation, nor is it by any means the earliest suggested time of human settlement in the Americas. Recent controversial discoveries at the Cerutti Mastodon Site in Southern California were the latest to argue a much earlier human presence in North America, going as far back as 130,000 years. Understandably, most in the archaeological community simply cannot accept this, and the veracity of the alleged evidence of human butchering found at the site remains in dispute.
However, decades before the recent discoveries in California, a more obscure Mexican site at Valsequillo managed to arouse similar controversy for boasting an even greater potential antiquity for humans in the region… perhaps going back more than 100,000 years earlier than that which has been claimed for the Cerutti site.