Some 73,000 years ago, a prehistoric Picasso crayoned a red hashtag design on a palm-size flake of rock in a South African cave. The artwork isn’t much to look at by modern standards, but it’s the world’s earliest known example of drawing on a surface, a new study concludes.
Researchers excavated the jagged flake in 2011 inside the oceanfront Blombos Cave. Once they had rinsed it off, they noticed nine faint red lines crisscrossing one of its surfaces. A chemical analysis revealed the lines were made of ochre, a reddish brown clay powder that can be molded into chunks.