1. Department of Anatomical Sciences, Stony Brook University, Stony Brook, NY 11794-8081
2. Fossil Reptiles, Amphibians and Birds Section, Natural History Museum, London SW7 5BD, UK
3. Department of Earth Sciences, University College London, London WC1E 6BS, UK
4. Key Laboratory of Vertebrate Evolution and Human Origins of the Chinese Academy of Sciences, Institute of Vertebrate Paleontology and Paleoanthropology, Beijing 100044, PR China
5. Research Center of Jurassic Stratigraphy and Paleontology, Zigong Dinosaur Museum, Zigong, Sichuan 643013, PR China
6. Centre for Vertebrate Evolutionary Biology, Yunnan University, Kunming, 650091, PR China