作者单位:肖良(长安大学,西安,710054;现代古生物学和地层学国家重点实验室(中科院南京地质古生物研究所),南京,210008)李相传,郭俊锋,蔡玥(长安大学,西安,710054)杨洪(Laboratory of Terrestrial Environments, Department of Science and Technology, College of Arts and Sciences, Bryant University, Smithfield, Rhode Island 02917, U.S.A.)