The BBC has a good article on Neanderthal art. "Naughts and crosses" is British for "tic-tac-toe." I think the Neanderthals were merely marking the cave or creating a map of some kind. Calling a little grid-like symbol art may be a stretch.
Incidentally, the BBC really has good articles from time to time. Too many American newspaper and TV web sites are just an intellectual wasteland with only the bare minimum in detail, readable in two minutes or less. For really good reporting, I turn to government-operated media, such as PBS and the BBC. Capitalism doesn't work where journalism is concerned. Sooner or later an editor takes charge with the bright idea to promote sex & crime & celebrity gossip rather than do any real journalism. Sales go up, costs go down. That's where capitalism takes journalism.