EARLY JURASSIC FOSSIL CYCADS FROM YIHE BASIN IN SOUTHERN JILIN PROVINCE: Paleoclimatic significance
SUN Chun-lin, LI Tao, SUN Yue-wu, CHEN Yue-jun, LI Chun-tian, ZHAO Guo-wei
Key-Lab for Evolution of Past Life and Environment in Northeast Asia, Ministry of Education, Changchun 130026, China;Research Center of Paleontology and Stratigraphy, Jilin University, Changchun 130026, China
Abstract:Abundant fossil cycad leaves preserved as impression are collected from the Early Jurassic Yihe Formation in Southern Jilin Province, China. In this paper, three genera belonging to seven species are recognized based upon leaf morphology, i. e. Pterophyllum baotoum Zhang, Pterophyllum exhibens Li, Pterophyllum cf. tietzei Schenk, Pterophyllum sp., Nilssonia inouyei Yokoyama, Nilssonia orientalis Heer and Cycadolepis corrugata Zeiller. The occurrence of these species in the Early Jurassic of Southern Jilin significantly infers that they grew in an area with a warm and humid climate in the warm temperate zone close to Paleopacific Ocean.