Wilma den Hartigh
Archaeological excavations have delivered yet another significant find – this time at a rock shelter near Durban in KwaZulu-Natal province. The fossil discovery, made by a team of researchers, reveals fascinating insights into the development of behavioural practices of early modern humans in Southern Africa.
Archaeologists have been excavating the middle Stone Age site at the Sibudu cave, a sandstone cliff in northern KwaZulu-Natal about 40km north of Durban, since 1998.
In the latest discovery new evidence of well preserved and fossilised plant bedding, dating back 77 000 years, has been found.
The fossilised leaves and other artefacts discovered at Sibudu, such as the oldest bone and arrow, the oldest needle, and fossilised grass stems and leaves, are now on show in a new fossil display at Maropeng at the Cradle of Humankind in Gauteng.
Evidence of modern human behaviour
The discovery is an important addition to South Africa's existing archaeological collection.
What makes the plant bedding discovery so significant is that it reveals new information about the evolution of modern human behaviour, and shows how early Homo sapiens lived.
Lindsay Marshall, curator at Maropeng, says that similar evidence has been discovered elsewhere in the world, but these discoveries date back to a more recent period than that of the Sibudu caves.
The newest discovery is 50 000 years older than earlier reports of preserved bedding.
The fossilised leaves reveal that early humans were using plants with insect repellent properties and placing them on the ground to sleep on – and possibly to live and work on too.
This discovery could also be the earliest evidence of modern floor coverings, such as the carpets that we have in our homes today.
According to the research team, led by Wits University archaeologist Prof Lyn Wadley, the findings suggest that during the Middle Stone Age, 77 000 years ago, our human ancestors had the cognitive ability to choose plants that contained insect repellent to sleep on.
The fossilised grass stems and leaves were most likely sourced from the uThongathi River near Sibudu. Wits botanist Marion Bamford identified the leaves as belonging to Cryptocarya woodii, also known as the Cape laurel or river wild quince.
The leaves of this tree contain chemicals that are insecticidal, and would be suitable for repelling mosquitoes.
Wadley says that the selection of these leaves for the construction of bedding suggests that early inhabitants of Sibudu had an intimate knowledge of the plants surrounding the shelter, and were aware of their medicinal uses.
Microscopic analysis of the bedding, conducted by Christopher Miller, a junior professor in geoarchaeology at the University of Tübingen in Germany, suggests that the inhabitants repeatedly refurbished the bedding during the course of occupation.
In what could be an early form of house cleaning, the microscopic analysis found that the inhabitants of Sibudu regularly burned the bedding after use, possibly as a way to remove pests.
According to Miller, this would have prepared the site for future occupation and indicates a novel use of fire for the maintenance of an occupation site.
A rare fossil display
Marshall says that this discovery is one of a long list of important finds at Sibudu over the past decade. Over the years, this rock shelter has become a highly valuable site for archeological research.
Other items discovered during the excavations include perforated seashells, believed to have been used as beads.
"It is interesting to wonder what the beads were used for," she says. "They were probably used either as gifts or for exchanges with other communities. Either way they had value," she says.
Wadley considers the discovery of the fossil plants and the perforated shells as major career highlights.
"Sibudu is only the second site in South Africa where these shells have been found," she says. "The other is Blombos Cave in the Western Cape."
Sharpened bone points which could have been used for hunting were also found at Sibudu, and indicate some of the earliest examples of modern human technology.
The exhibition consists of lots of smaller items such as pieces of stone tools, tiny shells and fossilised leaves that can be viewed with magnifying glasses placed in each display cabinet.
At a glance it might seem like a random collection of bits and pieces of stone, but what you are actually looking at are rare finds that are usually not displayed in exhibitions open to the public.
"In the exhibition you look at small things, but their historical significance is huge," says Marshall. "These discoveries are usually reserved for laboratories and journals."
• The exhibition, What makes us human: The significance of the Sibudu cave shelter, runs until the end of May at the Maropeng.