"They seemed to know that seal bone is really rich in oil and fat, which is a critical component in making a paint-like substance," Henshilwood said.
"They also knew to add charcoal to the mixture to bind and stabilize it, and a little bit of fluid, which could have been water or seawater or urine."
While relatively few ingredients were used in the ancient paint, each item had to be individually prepared before everything could be combined inside the shells. For example, the ochre pieces had to be crushed and ground into a powder, the bones had to be heated to release their oils and then crushed, and wood had to be burned to create charcoal.
"The mixture was very gently stirred, and you can see the traces of the stirring [done by fingers] on the bottom surface of the abalone shell," Henshilwood said.
It's not clear what the ochre paint was later used for, but Henshilwood said it's easy to imagine early humans using the substance to decorate their bodies or cave walls.
The article was published in Science magazine. Excerpt from National Geographic News
Photo from Science / AAAS