The Xiahe mandible was originally found in 1980 in Baishiya Karst Cave. Researchers say the bone is 160,000 years old and came from a Denisovan. In by May 1, 2019 The Xiahe mandible was originally found in 1980 in Baishiya Karst Cave. Researchers say the bone is 160,000 years old and came from a Denisovan