Humans arrived in North America more than 30,000 years ago, a study shows. Archaeologists have obtained radiocarbon dates for the bones of the creatures excavated in the Coxcatlán Cave, a dry rock refuge located in the southern part of the Tehuacán Valley in southern Puebla, Mexico.
Bone samples from the cave’s early deposition date ranged from 33,448 to 28,279 years. The Coxcatlán Cave is a rock refuge located in the southern part of the Tehuacán Valley in Mexico. Image credit: Andrew Somerville.
Cueva Coxcatlán, a rock refuge located in the southern part of the Tehuacán Valley in Mexico. Image credit: Andrew Somerville. Coxcatlán Cave is a north-facing dry rock refuge in the southern part of the Tehuacán Valley along the alluvial slopes of the Sierra Madre Oriental.
The cave is located on a cliff several meters above the valley floor. Its length is about 30 meters and its width is 8 meters. Inside the cave, archaeologists previously excavated to a maximum depth of 4 meters, documenting 28 horizontal stratigraphic levels, or habitat zones, and 42 separate occupational episodes.
The areas occupied by people who did not make or use ceramics, called preceramic zones, are the first levels of rock shelters. These regions are divided into four cultural phases, the Agueredo, El Rigo, Coxcatlán and Abajas phases, based on the technology of stone tools, basketry and woven mats, and changes in settlement patterns.
The earliest evidence of human occupation in the Tehuacán Valley occurred during the Ajuredo phase. Andrew Somerville, a researcher in the Department of World Languages and Culture at Iowa State University, said: “Although the elements of the bottom of Coxcatalan Cave in previous studies were not dated, we did not expect such an advanced age.”
“The findings add to the debate over a long-standing theory that the first humans crossed the Bering Land Bridge into the Americas 13,000 years ago.” “We weren’t trying to weigh in on this debate or even find really old specimens. We were trying to organize our agricultural studies on a solid timeline,” they said.
“We were surprised to find really old dates on the cave floor, and that means we have to take a closer look at the artifacts recovered from those levels.”
Dr. Somerville and his colleagues selected 17 bone samples, eight lagomorphs (rabbits and hares), and nine deer specimens, from the Coxcatlán Cave Ajedrez strata for radiocarbon dating.
The findings give researchers a better understanding of the region’s chronology. However, questions remain. More importantly, is there any human connection to the lower layer of the cave where the bones were found?
“If a closer examination of the bones provides evidence of a human link, what we know about the time and how the first people arrived in the Americas will change,” said Dr. Somerville.
“Rolling back the arrival of humans in North America to 30,000 years ago would mean that humans were already in North America before the Last Glacial Maximum period, when the Ice Age was at its worst.”
“Much of North America would have been inaccessible to human populations. The glaciers would have completely blocked any passage over land from Alaska and Canada, meaning that people probably traveled up the Pacific coast to the United States in boats. “. You have to come.
The results appear in the magazine Latin American Antiquities.