Beside the Indian Ocean on South Africa’s Cape south coast, a rock surface holds traces of animals that once crossed it as sand. In 2016, researchers found twelve fossil tracks there that they identified as giraffe footprints. The site lies near Still Bay, well south of the reliable historical records reviewed in their study.
Charles Helm and colleagues described the discovery in a 2018 paper. Its significance comes from a simple property of a footprint: an animal had to put its foot there. The prints add a kind of evidence that a collection of bones, assembled elsewhere, might miss.
A visit recorded in sand
The rock is aeolianite: former wind-blown sand that has become cemented into stone. Before that transformation, a yielding surface could receive a hoofprint. Burial and preservation could then carry the impression into the geological record.
A fossil footprint is a trace of activity, rather than a surviving part of an animal’s body. That distinction changes the question it answers. A bone found in a cave may have been carried there by a predator or a person. A footprint preserved on its original surface records contact with that place.
Neither type of evidence offers an unbiased census. Bodies have to be preserved, transported or discovered; tracks have to be made in suitable ground and survive subsequent disturbance. Bringing the records together can reveal an animal that one archive alone fails to capture.
The Cape discovery is therefore about ancient occurrence. It does not, by itself, establish how long giraffes remained in the region or how extensive their population was.
Why identify the tracks as giraffe?
Size was one clue. The best-preserved adult print measured 20.5 centimetres long and 16.5 centimetres wide. Compared with the largest bovids, such as buffalo, giraffe tracks are notably long and relatively narrow. The researchers also examined the characteristic shape of the cleft between the two hoof impressions in the better-preserved prints.
Extinct alternatives required a different comparison. The researchers had no known sivathere trackways to consult. Instead, the robust limb anatomy of these heavy-built giraffe relatives led them to expect broader prints than those at Still Bay. They also considered giant hartebeest, but judged a print over 20 centimetres long unlikely by comparison with living relatives.
Those are anatomical inferences about extinct animals, not measurements of their footprints. Taken together with the observed shape and dimensions, they explain why the authors favored giraffe as the trackmaker. The reconstruction of Sivatherium’s body mass explores another question approached through the skeleton of an extinct giraffe relative.
Twelve prints cannot be counted as twelve animals
One walking giraffe can make many impressions. More than one animal can also cross the same patch, with later steps overlapping earlier ones. Counting prints therefore does not count individuals.
At Still Bay, the researchers could not confidently connect the impressions into separate trackways. They noted smaller prints of similar shape and raised the possibility of a family group, but the surface does not establish that social relationship. It also does not provide secure stride measurements from which to tell a detailed story about gait.
The preserved surface gives a glimpse of presence and movement. Assigning named roles—parent, calf, leader or follower—would require evidence beyond a difference in print size.
The age comes from the surrounding geology
The authors provisionally placed the deposits in Marine Isotope Stage 5e, within the Late Pleistocene. Their comparison used nearby deposits with reported ages of 126,000 ± 7,100 and 121,000 ± 6,500 years. Those are dates for the comparison deposits, not direct measurements of the giraffe prints.
Geological correlation connects separated exposures by their layers and position in a sequence. If that connection is sound, a dated deposit can help constrain an undated one. The uncertainty includes both the dating measurement and whether the layers have been matched correctly.
This is why “roughly 120,000 years old” needs the explanation beside it. The study offered a reasoned age assignment while calling for dating around the track-bearing horizon to place it more securely.
A coast whose wider landscape has disappeared
Today’s shoreline is only one position in a long history of changing sea level. During lower sea levels, more of the continental shelf lay above water, forming the Palaeo-Agulhas Plain. Helm and colleagues proposed that river valleys on that broader landscape could have supported suitable giraffe habitat.
The footprints do not preserve a map of that vegetation. Nor does the shelf’s exposure during glacial periods establish its exact configuration at the uncertain time of these tracks. Dating, landform reconstruction and ecological interpretation have to be connected carefully.
Giraffes depend on usable vegetation, as the habitat and range guide explains. Evidence that giraffes once occurred in a region is not enough to show that its present landscape can support them. The coastline, climate and resources can all change.
The discovery nevertheless expands the question beyond a modern map. An ancient giraffe range must be reconstructed against ancient land and habitat, including terrain now beneath the ocean.
Keeping a record as the surface wears away
The team recorded the site with photogrammetry, building a three-dimensional representation from photographs. Their paper also described erosion affecting the exposed surface.
A digital model preserves measurable shape at the time of recording. It cannot replace the rock for every future investigation, but it allows later researchers to examine details that weathering may remove. Here, preservation means retaining the evidence behind the identification, so that the interpretation can be checked even as the coast continues to change.
Sources
Charles Helm, Hayley Cawthra, Richard Cowling, Jan De Vynck, Curtis Marean, Richard McCrea and Renee Rust (2018). “Palaeoecology of giraffe tracks in Late Pleistocene aeolianites on the Cape south coast.” South African Journal of Science, 114(1/2), Article 2017-0266. DOI. Full paper.
