1. Biodiversity Institute, University of Kansas, Lawrence, KS 66045, USA
2. Department of Ecology and Evolutionary Biology, University of Kansas, Lawrence, KS 66045, USA
3. Key Laboratory of Vertebrate Evolution and Human Origins, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing 100044, People's Republic of China
4. CAS Center for Excellence in Life and Paleoenvironment, Beijing 100101, People's Republic of China
5. University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China