Scientists have identified the oldest known Homo sapiens footprints in South Africa. The newly discovered tracks have been dated to over 150,000 years ago.
A wealth of fossil evidence suggests that Homo sapiens first diverged from earlier species about 300,000 years ago. The international team of scientists has identified the oldest known set of fossil footprints from a member of our species. The team calculated the dates of seven “ichnosites” (locations containing ancient human traces) along South Africa’s Cape south coast. It was found that they ranged between 71,000 and 153,000 years old.
The researchers have dated the South African footprints using optically stimulated luminescence. In this method, scientists take grains of quartz and other minerals from a sample, and expose them to ionising radiation. The way the grains fluoresce after this exposure can reveal how long it has been since they last saw sunlight. The tracks on the Cape south coast are particularly well-suited to being dated through this method, as they were made in wet sand dunes that are rich in quartz grains and then quickly covered, by new sand blowing over them.
The team said more ichnosites are likely to be discovered in the area, and could provide more information in understanding human history.