A hundred thousand years ago, not long after Homo sapiens emerged as a species, a craftsman — or woman — sat in a cave overlooking the Indian Ocean, crushed a soft rusty red rock, mixed it inside a shell with charcoal and animal marrow, and dabbed it on something — maybe a face, maybe a wall.
Before the person left, he or she stacked the shell and grindstones in a neat pile, where they lay undisturbed for a hundred millennia.
Unearthed in 2008 and described Friday in the journal Science, these paint “tool kits,” researchers say, push deeper into human history the evidence for artistic impulses and complex, planned behavior. Previously, the oldest evidence of ochre paint was found at another site in South Africa dated to about 60,000 years ago.
“They probably understood basic chemistry,” said Christopher Henshilwood, the archaeologist who led the discovery team.
Traces of paint on the tools show that the cave-dwellers mixed ochre — red or yellow minerals that contain metal oxides — with bone marrow, charcoal, flecks of quartz, and a liquid, probably water. Paint experts at the Louvre in Paris performed the analysis.
With ground ochre as the base, the marrow and charcoal acted as binders. The quartz could have made the compound sticky, with water — in the right amount — providing the proper consistency.
This deliberate mixture “implies that people at the time had complex cognition,” said Lyn Wadley, an archaeologist at the University of Witwatersrand in Johannesburg. Wadley studies early ochre paint but was not involved in the research. “They could . . . multitask and think in abstract terms,” Wadley said.
The cave, called Blombos, sits in a cliff on the coast of South Africa about 180 miles east of Cape Town. It shows signs of human use starting 130,000 years ago. Protected from wind and rain and close to seafood, antelope and other game, the cave apparently made for an inviting stopover for wave after wave of nomadic hunter-gatherers.
Henshilwood, who splits his time between the University of Bergen in Norway and Witwatersrand, began excavating Blombos in 1992, digging through layers of animal bones, crustacean shells and other evidence of occupation during the Paleolithic, or Stone Age.
But the deepest layer, which the team reached in 2008, was different. Instead of scattered remains, two tidy “tool kits” emerged, covered by sand. Both included fist-size abalone shells and lay in neat piles.
In one kit, a round stone sat inside the shell. Six other grinding or pounding stones were arrayed around the shell and were probably used to smash the ochre. A small slab — a grinding stone — rested on top of the assemblage. A shoulder blade from a seal revealed evidence of heating and marrow extraction, and paint at the end of a thin forearm bone from a dog or a wolf showed that it was used to spread the paint, Henshilwood said.
Ochre comes in colors from mellow yellow to raging red. Whoever made the ancient paint selected only the brightest of reds.
“It could’ve been ornamental,” Henshilwood said. Even today, groups in southern Africa paint their faces and torsos with ochre to identify which group they belong to or whether they’re married. Ochre paint can also serve as a sunscreen and an insect repellant.
For whatever reasons the paint was made, early humans had a fondness for ochre. “Nearly all” South African sites from the Paleolithic show ochre, and it has been found at ancient sites in the Middle East and Europe, Henshilwood said. But all of those finds are tens of thousands of years younger than the Blombos paint kits.
The discovery adds to other early artistic treasures at Blombos, including 49 beads smeared with ochre and large pieces of ochre inscribed with cross-hatch patterns that date to 77,000 years ago — widely recognized as the oldest known art.
The cave walls show no paintings, but quickly accreting limestone would have obscured any obvious signs, Henshilwood said.
He plans to return with lights that can detect traces of ochre paint. If he finds any on the walls, it would push deeper into the past solid evidence of the human artistic impulse. The oldest known cave paintings, in France, are about 35,000 years old.