1. a Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences , Beijing , 100044 , People's Republic of China E-mail:
2. c Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences , Beijing , 100044 , People's Republic of China
3. b Department of Geology and Mineralogy , Graduate School of Science, Kyoto University , Kyoto , 606-8502 , Japan