Prepare to embark on a thrilling journey through time as we uncover the secrets of South Africa's ancient past! A Fossil Hunter's Paradise Unveiled: Uncovering 3-Million-Year-Old Tracks in South Africa's Hidden Depths.
South Africa, a land renowned for its fossil heritage, holds a treasure trove of stories from the distant past. Imagine a world frozen in time, where the traces of ancient life are imprinted on the very rocks beneath our feet. Our research team at the African Centre for Coastal Palaeoscience has been on an extraordinary quest, delving into the mysteries of the Pleistocene Epoch, a period spanning from 1.8 million to 11,700 years ago, often referred to as the Ice Ages.
Over the last 15 years, we've identified an impressive 350 vertebrate tracksites along the South African coast, each a snapshot of life from this ancient era. These tracks, imprinted on sandy surfaces that hardened into rock over millennia, offer a unique glimpse into the past. The oldest among them, approximately 400,000 years old, is a testament to the enduring nature of these ancient records.
But here's where it gets intriguing: our team suspected there was more to uncover, deeper within the heart of South Africa. We knew that, further inland, there existed cemented dunes, formed from wind-blown sand, dating back an estimated 3 million years. These dunes, now transformed into rock, are known as the Wankoe Formation.
However, finding these hidden treasures was no easy feat. The challenges were many: limited suitable rock outcrops, erosion, calcification, and the majority of the formation being on private property. But our determination paid off.
One of our team members, Given Banda, made a remarkable discovery near his home community - a potential trackway on an inland surface. This find sparked a series of events, leading us to the Grootbos Private Nature Reserve, where we stumbled upon more intriguing track-like features. A thorough exploration of the reserve revealed a treasure trove of tracks, including one that left no doubt - it was a trackway (see photo below).
Our findings, recently published, have revolutionized our understanding of the Wankoe Formation. For the first time, vertebrate tracks have been identified in this formation, revealing a rich fossil record and a common occurrence of vertebrate tracks. These discoveries are believed to be the first recorded Pliocene vertebrate tracks from southern Africa, dating back to an epoch that existed 5.3 million to 2.6 million years ago.
But why are these discoveries so significant? Here's where it gets even more exciting:
Unveiling the Secrets of Body Fossils: Just a stone's throw away lies a remarkable Pliocene body fossil site known as Langebaanweg or the West Coast Fossil Park. This site boasts an incredible array of extinct creatures. By combining the body fossil record with our trace fossil (ichnological) findings, we can unlock new insights and enrich our understanding of these ancient environments.
The Quest for Human Ancestor Species: Our work on the younger deposits along the coast has led to the discovery of over 20 hominin tracksites, forming the largest archive of its kind in the world, dating back over 40,000 years. Applying this knowledge to our Pliocene discoveries, we believe there's a real possibility of finding traces of our human ancestor species in the Wankoe Formation.
The Enigma of Raised Tracks: The tracks we've discovered are unique - they are "pedestalled", meaning they are raised above the surface, rather than forming hollows. This phenomenon can be replicated on modern dune surfaces with slightly moist (cohesive) sand and a strong wind. The same principle applies to snow, as you can observe in the photo below.
The potential for finding more of these globally rare, fossilized pedestalled tracks is truly captivating.
Our subsequent explorations have continued to bear fruit. We've realized that even weathered rocks can sometimes preserve tracks, often in profile. We've also discovered body fossils in the form of trees, roots, and bone material embedded in these layers of wind-blown, hardened sand, which require further study.
While it's not surprising that the Wankoe Formation dunes contained tracks, the real excitement lies in the fact that these tracks have withstood the test of time, despite calcification and weathering. We now know that with the right knowledge, there are countless suitable surfaces and exposures waiting to be explored.
And so, our research team embarks on a new quest - the search for the tracks of ancestral hominins from the Pliocene, a true "holy grail" in our field of study.
Charles Helm, Research Associate, African Centre for Coastal Palaeoscience, Nelson Mandela University
