Francesco d'Errico, an archaeologist from the University of Bordeaux, France, has found crafted lumps of pigment – essentially crayons – left behind by Neanderthals across Europe.

He says that Neanderthals, who most likely had pale skin, used these dark pigments to mark their own as well as animal skins. And, since body art is a form of communication, this implies that the Neanderthals could speak, d'Errico says.