For a long time, common knowledge about human migration held that people who crossed over the Beringian land bridge stayed in the far north until around 13,000 years ago, when they began to populate North America, moving gradually into South America. But subsequent discoveries keep pushing this timeline back further. Now a cave in Mexico has evidence that humans lived there least 26,500 years ago.
Chiquihuite cave is perched high in the Astillero Mountains, 9000 feet above sea level and 3,280 feet higher than the valley below. Excavations there were launched when a 2012 test pit unearthed a few stone artifacts that suggested a human presence dating back to the Last Glacial Maximum between 18,000 and 26,000 years ago. More extensive excavations detailed in the new study were carried out in 2016 and 2017, unearthing some 1,900 stone points or possible tools used for cutting, chopping, scraping, or as weapons.
The artifacts were dated by 46 different radiocarbon samples of adjacent animal bones, charcoal, and sediment samples. To the team, they represent a previously unknown technological tradition of advanced flaking skills. More than 90 percent of the artifacts were of greenish or blackish stone, though those colors are less common locally, suggesting to the authors that they were singled out as desirable. The bulk of the material is from deposits dating to between 13,000 and 16,600 years ago, leading the scientists to hypothesize that the humans may have used the cave for more than 10,000 years.
Evidence from this cave and other sites indicate that people traveled from Asia to the Americas either much earlier than previously thought, or else they traveled across glaciers. Read about the implications of these finds at Smithsonian.
(Image credit: Mads Thomsen)