“Kilroy was here,” 15,000 B.C.
Once upon a time, before the Sahara was a desert, people lived there and sometimes painted pictures on the rocks. Sometimes they just spread a hand on the rock and squirted paint around it: probably a kind of signature.
We are occasionally asked to believe that lizards did this, too.
https://leeduigon.com/2016/03/01/a-prehistoric-mystery/
I’ve had a lot of different kinds of lizards as pets, and not a single one of them ever displayed the slightest interest in painting anything.