More than two decades ago, when the new millennium began, the traces left by our ancient human ancestors, who were more than 50,000 years old, seemed extremely rare. At that time, only four sites were registered in all of Africa. Two were from East Africa: Laetoli from Tanzania and Koobi Fora from Kenya; two were from South Africa (Nahoon and Langeban). In fact, the Nahun site reported in 1966 was the first identified hominin footprint site.

In 2023, the situation is completely different. It seems that people are not looking carefully enough or are looking in the wrong places. Today, the number of hominid ichnosites (a term that includes both traces and other traces) in Africa dating back more than 50,000 years is 14. These are aptly divided into an East African cluster (five regions) and a southern African cluster from Cape Coast. There are ten other sites in other countries of the world, including the United Kingdom and the Arabian Peninsula.

Given that relatively few hominid skeletal remains are found on Cape Coast, the footprints left by our human ancestors as they moved across ancient landscapes are a useful way to add to and enhance our understanding of ancient hominids in Africa.

In a recently published article ichnosThe International Journal of Trace Fossils have provided the ages of seven newly dated hominid ichnosites we have identified over the past five years off the southern Cape coast of South Africa. These sites are now part of a “South African cluster” of nine sites.

We’ve seen sites vary by age; the second is about 71,000 years old. The oldest, dating back 153,000 years, is one of the most remarkable finds recorded in this study: it is the oldest print ever attributed to our species, Homo sapiens.

The new dates are confirmed by archaeological data. Along with other evidence from the region and period, including sophisticated stone tools, art, jewellery, and shellfish production, this confirms that the southern Cape coast was a region where early anatomically modern humans survived, thrived, and thrived before they spread. From Africa to other continents.

There are significant differences between the East African and Southern African track sets. The East African sites are much older, with the oldest being Laetoli at 3.66 million years old and the youngest at 0.7 million years old. The tracks were not left by Homo sapiens, but by earlier species such as Australopithecus, Homo heidelbergensis, and Homo erectus. Surfaces with mostly East African traces had to be excavated and uncovered with great care and attention.

On the contrary, the South African attractions in Cape Coast are much younger. All attributed to Homo sapiens. And traces tend to be fully exposed when found in rocks known as eolianites, which are cemented versions of ancient dunes.

Excavations are therefore often overlooked, and due to exposure to the elements and relatively coarse sand in the dunes, they are often not as well preserved as East African sites. They are also susceptible to erosion, so we often need to work quickly to record and analyze them before they are destroyed by the ocean and wind. We can date the deposits, although this limits the possibility of detailed interpretation. This is where optically stimulated luminescence comes into play.

lighting method

A major problem when studying paleochrochronies (traces, fossils, or any other type of ancient sediment) is determining the age of the materials.

Without it, it is difficult to appreciate the wider significance of the find or interpret the climate changes that make up the geological record. In the case of Cape South Coast eolianites, optically induced luminescence is generally the preferred dating method.

This method of dating shows how long a grain of sand was exposed to sunlight; in other words, how long that part of the sediment was buried. Given how the tracks in this study were formed – tracks made in wet sand and then burial with new sand – this is a good method because we can be sure that the dating “time” began approximately when there was a trail. created.

The Cape’s south coast is the perfect place for the application of optically stimulated luminescence. First, the deposits are rich in quartz grains that produce a lot of luminescence. Second, ample sunlight, expansive beaches, and wind-blown sand to form coastal dunes means that all pre-existing luminescence signals are completely eliminated prior to the respective burial event and reliable age estimates are made. This method supported much of the dating of previous finds in the area.

The overall date range of our findings of hominin ichnosites, of about 153,000 to 71,000 years, is consistent with the ages in previous surveys of similar geological deposits in the area. The 153,000-year-old footprint was found in Garden Route National Park, west of the coastal town of Knysna on the Cape’s south coast. Two previously dated South African settlements, Nahun and Langeban, gave ages of about 124,000 and 117,000 years, respectively.

increased understanding

The work of our research team, based at the Center for African Coastal Paleontology at Nelson Mandela University in South Africa, has not been completed. We suspect that there are other hominid ichnosites waiting to be discovered on the southern coast of the Cape and elsewhere along the coast. The research also needs to be extended to older deposits in the region, whose ages range from 400,000 to 2 million years.

We hope that decades from now, the list of ancient hominid ichnosites will be much longer than now, and that scientists will be able to learn much more about our ancient ancestors and where they lived. Source