Human history never ceases to amaze us! Recent research published in the international journal of trace fossils, Ichnos, has revealed that the world's oldest known human footprint has been identified in South Africa. This footprint dates back a whopping 153,000 years and has been attributed to our very own Homo sapiens.
It's incredible to think that just over two decades ago, only four sites had been reported in all of Africa that dated back more than 50,000 years. Today, the African tally for dated hominin ichnosites is 14 and includes seven newly discovered sites on South Africa's Cape south coast. These sites now form part of a "South African cluster" of nine sites and range in age from 71,000 to 153,000 years. These footprints are a valuable complement to the limited skeletal hominin remains found on the Cape coast, providing insight into the landscapes and movements of early anatomically modern humans in Africa.
The differences between the East African and South African tracksite clusters are significant. The East African sites are much older and consisted mostly of tracks made by earlier species such as australopithecines, Homo heidelbergensis and Homo erectus. In contrast, the South African sites are substantially younger and have all been attributed to Homo sapiens. The Cape south coast aeolianites are particularly fascinating as they are fully exposed when discovered. These rocks are cemented versions of ancient dunes and offer a unique opportunity to study early human footprints. However, they are vulnerable to erosion and require speedy analysis before the ocean and wind destroy them.
A key challenge when studying ancient sediment is determining its age. The optically stimulated luminescence dating method has been used to determine the age of the Cape south coast aeolianites. This method shows how long ago a grain of sand was exposed to sunlight and buried, allowing researchers to determine the age of the sediment. The work of the research team is far from over. They believe that further hominin ichnosites are waiting to be discovered on the Cape south coast and elsewhere, which will extend our understanding of early humans in Africa. It's incredible to think that just a decade from now, the list of ancient hominin ichnosites will be much longer, and scientists will be able to learn even more about our ancient ancestors and the landscapes they occupied.