加拿大自然博物馆基金RS09;现代古生物学和地层学国家重点实验室中国科学院南京地质古生物研究所基金编号:153105资助。This work was supported by the grants from Canadian Museum of NatureRS09 for Wu Xiao-Chun;from State Key Laboratory of Palaeobiology and StratigraphyNanjing Institute of Geology and Palaeontology, CAS: 153105 for Li Chun