Guang-Hui Xu1, Li-Jun Zhao2. 1. Key Laboratory of Vertebrate Evolution and Human Origins of Chinese Academy of Sciences, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing 100044, People's Republic of China xuguanghui@ivpp.ac.cn. 2. Zhejiang Museum of Natural History, Hangzhou, Zhejiang 310014, People's Republic of China.