Around 10,500 years ago, a hunter-gatherer walked through the mineral-rich sediment of the Chihuahuan Desert. The resulting footprints, locked in stone for millennia, have now been confirmed as the oldest human prints ever found in North America — shattering the previous record by 5,000 years.
The footprints, one left and one right, were discovered many years ago at a construction site in northeastern Mexico, about 186 miles south of Texas.
They were found at a quarry called Cuatro Ciénegas, also known as the the Cuatrociénegas Basin, which was once a marshy, spring-fed desert oasis.
A team of archaeologists led by Nicholas Felstead recently decided to date the prints after realizing they were preserved in travertine, a sedimentary rock containing traces of uranium. Analysis of the uranium decay indicated that the prints formed about 10,550 years ago. Other prints found in the same region date back some 7,250 years ago.
While these holocene-aged prints are now considered the oldest found in North America, they're still not as old as the tiny track of a child's foot found in Chile — a print that has been dated at 13,000 years old.
So who left these prints? Blake de Pastino from Western Digs explains:
The region where the tracks were found is known to have been home to a somewhat amorphous culture known as the Coahuiltecans, a diverse group of nomadic hunter-gatherers that ranged from central Mexico to the Texas plains.
While many of these bands are known to have frequented Cuatro Ciénegas over thousands of years, the Coahuiltecans left precious little evidence that could be fixed to specific dates.
The oldest previously reported human fossil evidence in the area were coprolites — fossil feces — found in a rockshelter dated to about 9,000 years ago, Felstead said.
"So our reported footprint date is not only the oldest human fossil evidence, but also the oldest archaeological evidence, reported from the Cuatro Ciénegas Basin," he noted.
Interestingly, the analysis also showed that the region was cooler and wetter than it is today. The area has since become far more arid and far more challenging for human habitation.
Read the entire study at Journal of Archaeological Science: "Holocene-aged human footprints from the Cuatrociénegas Basin, NE Mexico".
Images: Silvia Gonzalez.