NINGXIA, CHINA—During a new examination of stone tools uncovered in northwest China in 1980, archaeologists found an engraved artifact  and examined its incisions with a digital microscope. Each line was made without repeated cutting, and so may have been used for counting or recording. “The blade technology was probably introduced from the Altai region of Russian Siberia, and the flake technology is typical of the Late Paleolithic in north China. So, who created the incisions, the migrants from the west or the aborigines in north China? At this time, we cannot provide a clear scenario,” said Gao Xing of the Chinese Academy of Sciences.