People concocted a colorful pigment of their imagination around 100,000 years ago. In a cave hugging what’s now South Africa’s coast, Stone Age humans stirred up a recipe for a red-hued paint that they stored in abalone shells and possibly used to decorate themselves or their belongings.
In a technological advance impressive for its time, these hardy foragers worked out a system for collecting components of a pigmented compound, producing the substance and storing it.
“Recovery of these tool kits shows that Homo sapiens at Blombos Cave 100,000 years ago had an elementary knowledge of chemistry and an ability to make long-term plans,” says archaeologist Christopher Henshilwood of the University of Bergen in Norway. Abalone-shell paint holders found at the site represent the oldest known containers, he adds.
Excavations in Blombos by Henshilwood and his colleagues have yielded a pair of ancient tool kits. Pieces of soft rock containing iron oxides, known as ochre, were rubbed on stone slabs to produce a red powder that was mixed in a pre-designated order with ochre chips, heated and crushed animal bone that acted as a binder, charcoal fragments, quartz grains and an unknown liquid, the team reports in the Oct. 14 Science.
Each tool kit consisted of several stone tools, some stained with red ochre, lying above and below an abalone shell partly coated with a red mixture. A 6-centimeter-long animal bone with a red-tinged, spatula-shaped end found next to one shell probably served as a paint stirrer and utensil for dabbing paint on people or objects.
It’s possible that this ancient substance was a glue used to attach wooden handles to stone tools, but the researchers found no signs of any sticky, gumlike substance in the mixture’s remnants.
“It’s tough to tell what they did with the stuff,” says anthropologist Sally McBrearty of the University of Connecticut in Storrs. “I would call it paint.” Whatever the Blombos tool kits were used to make, she says, they imply that people of that time carefully planned out how to gather various ingredients that were mixed in a specific sequence to produce a compound.
Soil layers containing the tool kits included only a few additional stone implements and little food waste, indicating that paint making occurred over perhaps a couple of days before the cave was abandoned.
Previous Blombos discoveries of ochre chunks engraved with geometric designs denoted symbolic thinking among southern Africans by 100,000 years ago (SN Online: 6/12/09). A nearby cave has yielded even older evidence of shellfish collecting at low tides, an activity that required knowledge of the moon’s phases (SN: 8/13/11, p. 22).
Though researchers need to test the effectiveness of the ancient Blombos recipe as a paint, adhesive or possibly some other product, says archaeologist Lyn Wadley of the University of the Witwatersrand in Johannesburg, “making compounds of any kind implies complex cognition.”
Comparably sophisticated thinking characterized European Neandertals, who heated birch bark at high temperatures to make an adhesive for tool handles more than 100,000 years ago, holds Stanford University anthropologist Richard Klein.