BIZKAIA, SPAIN—An ancient engraving may depict a hunter-gatherer campsite, according to Marcos García-Diez of the University of the Basque Country, and Manuel Vaquero of the Catalan Institute of Human Paleoecology and Social Evolution (IPHES), who published their study in PLOS ONE. The image, carved onto a schist slab some 13,800 years ago, has seven semicircular motifs decorated with internal lines and arranged in two rows. Microscopic and comparative analysis of the motifs suggests that they had been engraved with a similar technique and instrument in a short amount of time. The researchers think the motifs represent huts. Vaquero explained in a press release that this “Paleolithic engraving from northeastern Spain brings us the first representation of a human social group.” To read about an engraving on a cave wall by Neanderthals, go to "Symbolic Neanderthals."