Oldest human footprint in Americas may be this 15,600-year-old mark in Chile

The earliest human footprint discovered in the Americas was discovered much further south, in Chile, and dates back an astonishing 15,600 years, according to a new study.

Reconstruction by an artist of a hypothetical author of the footprint walking through what is now Pilauco 15,600 years ago. The footprint will be on display at the Parque Chucaya museum in Osorno beginning this Saturday. Alvarez, Mauricio
The discovery sheds light on when humans first arrived in the Americas, most likely by crossing the Bering Strait land bridge during the last ice age.

According to the researchers, this 10.2-inch-long (26-centimeter) print could even be evidence of pre-Clovis people in South America, the group that came before the Clovis, who are known for their distinctive spearheads.

At the time, Salvadores and her fellow students were investigating a well-known archaeological site known as Pilauco, which is about 500 miles (820 km) south of Santiago, Chile.

However, it took years for study lead researcher and paleontologist Karen Moreno and study lead investigator and geologist Mario Pino, both at the Austral University of Chile, to verify that the print was human, radiocarbon date it (they tested six different organic remnants found at that layer to be sure) and determine how it was made by a barefoot adult.

Part of these tests involved walking through similar sediment to see what kinds of tracks got left behind. These experiments revealed that the ancient human likely weighed about 155 lbs. (70 kilograms) and that the soil was quite wet and sticky when the print was made.

It appears that a clump of this sticky dirt clung to the person’s toes and then fell into the print when the foot was lifted, as the image below suggests.

This sequence shows how the footprint may have been made. K. Moreno et al., PLOS One, 2019.
According to the researchers, the footprint is classified as Hominipes modernus, a type of Homo sapiens footprint. (Trace fossils, such as footprints, are given scientific names, just like species.) Previous excavations at the site uncovered other late Pleistocene fossils, such as elephant relatives, llama relatives, and ancient horses, as well as rocks that humans could have used as tools, according to the researchers.

The study “adds to a growing body of fossil and archaeological evidence suggesting that humans dispersed throughout the Americas earlier than many people have previously thought,” said Kevin Hatala, an assistant professor of biology at Chatham University in Pittsburgh, Pennsylvania, who was not involved in the research.

This discovery comes just a year after the discovery of the oldest known human footprints in North America, which date back 13,000 years, according to Hatala.

More data from the Chile site would be useful — “more footprints, more artifacts, more skeletal material, and so on,” Hatala wrote in an email.

“However, the fossil and archaeological records are never as generous as we would like!” The authors extracted as much information as they could from a single human footprint. When combined with other data, this evidence makes a strong case for the antiquity of [human] presence in Patagonia.”

The footprint is now housed in a glass box at the newly established Pleistocene Museum in the Chilean city of Osorno.

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