Wei Wang, Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, Nanjing, China, Chengguo Guan, State Key Laboratory of Paleobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology and Center for Excellence in Life and Palaeoenvironment, Chinese Academy of Sciences, Nanjing, China, Yongliang Hu, Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences,, Nanjing, China and Chuanming Zhou, Nanjing Institute of Geology and Paleontology, Chinese Academy of Sciences, Key Laboratory of Economic Stratigraphy and Palaeogeography, Nanjing, China