Prehistoric human artwork is simple but breathtaking, as anyone who has seen some up close or in movies such as Werner Herzog's 2011 documentary Cave of Forgotten Dreams can attest. But now archaeologists say that there is more to it than meets the eye: a group of rock carvings in the Italian Alps act as still frames that become animated as the Sun moves across the sky, according to archeologists at University of Cambridge in the UK. "Watching the sun arc and fall over one of these panels and seeing the individual figures leap out then disappear was revelatory," said Frederick Baker, a researcher at Cambridge's McDonald Institute for Archaeological Research, in a news release. "They form a landscape-based proto-cinema."

Baker and his colleagues at Cambridge made the discovery by using laser scanners to import 150,000-plus rock carvings in Italy's Valcamonica valley into computers. The carvings include animal figures, human characters, weapons and tools, and other geometric shapes, but researchers focused on ones that appeared to be expressing motion, showing thrusting spears or a bird flapping its wings. They then took the digitized images and reanimated them with software as if they were still frames in a movie, speeding up the natural motion caused by sunlight. “We animated an image of a bird,” Baker said in a statement, “and not only got it to fly in an absolutely naturalistic sense, but found that concentric arcs inside its body were not plumage but follow the graphic logic of a bird’s beating wings.”

The researchers also believe early humans played instruments to provide a type of soundtrack to accompany the rock carving animations. To recreate the experience, archaeologists made their own interactive film first shown in March at an exhibit at the University Museum of Archaeology and Anthropology in Cambridge. Now they plan to do follow-up studies of the valley carvings using micro drones and other portable scanning equipment, to try and link carvings to one another and distinct artists.