One of the 146,000-year-old stone cores used to make butcher's tools, found in Lingjing, China. Credit: Yuchao Zhao Archaeologists working at an ancient site in central China have uncovered evidence that early humans may have become more inventive while living through a brutal ice age. The discovery comes from the Lingjing archaeological site, where researchers have spent more than 10 years excavating animal bones and sophisticated stone tools linked to an extinct human relative called Homo