A complex-toothed flying squirrel is seen at a deep sinkhole discovered in northwest China's Shaanxi Province. A cluster of giant karst sinkholes, also known as tiankengs, has been discovered in northwest China's Shaanxi Province, one of the largest tiankeng clusters in the world, geologists announced on November 24, 2016. In total, 49 tiankengs and over 50 funnels of between 50 to 100 meter in diameter were found in the over 200-km karst landform belt in Hanzhong City, said Liu Tongliang, head of the karst geology research institute under the Chinese Academy of Geological Sciences (CAGS). (Photo/Weibo account of CCTV)
