Per an article in today’s New York Times, this may have been australopithecine art, depicting a face. (The pebble seems to have been transported to the site where it was found, and the holes gouged into it deliberately.)

And this may have been (technically and conceptually more advanced) Neanderthal art, also depicting a face.

OK, I realize that we don’t know for sure that this is a correct interpretation in either case. But interesting to contemplate.