A 15,600-year-old footprint fossil found in southern Chile is believed to be the evidence of the oldest human presence in the Americas, according to a recent study.
"Little by little in South America we're starting to find sites with evidence of human presence, but this is the oldest in the Americas," Karen Moreno, lead author of the study, was quoted by Reuters as saying.
The 26 cm-long, bean-shaped footprint was first uncovered by the end of 2010 at the Pilauco archaeological site in the Chilean city of Osorno. It took years for researchers at the Austral University of Chile to figure out its formation and age.
The researchers radiocarbon dated organic plant materials found in the fossil to estimate its age and produced a series of X-ray images to analyze the footprint in detail. They also recreated the ancient scene by rehydrating soil samples obtained from Pilauco with different amounts of water and asked three people to walk across the muddy mixture.
"The results demonstrate that a human agent could easily generate a footprint morphology equivalent to the sedimentary structure when walking on a saturated substrate," they wrote in the study published on April 24 in the journal PLOS One.
"Based on the evidence, we conclude that the trackmaker might well have been a bare-footed adult human," they added.
Last year, 29 prehistoric human footprints that date back 13,000 years were found at a dig site on Calvert Island off the southwest shoreline of Canada. By then, those footprints were confirmed as the earliest known of their kind in North America, the Canadian Broadcasting Corporation said in an earlier report.
