For the first time, scientists have precisely dated prehistoric paintings inside Font-de-Gaume, a decorated cave in Dordogne, southwestern France. Accurately determining the age of the paintings, however, has historically proved difficult. This is because researchers had long assumed that the black pigments used by the paintings’ makers were purely mineral, making radiocarbon dating—a method that measures the amount of carbon-14 in organic materials—impossible. Yet scientists had never confirmed that the pigments contained no carbon at all. The results showed that the bison was painted about 13,000 years ago, while different sections of the mask were created during different periods, some separated by thousands of years.