吉林南部义和盆地早侏罗世几种苏铁类化石及其古气候意义

EARLY JURASSIC FOSSIL CYCADS FROM YIHE BASIN IN SOUTHERN JILIN PROVINCE: Paleoclimatic significance

摘要: 报道了吉林南部早侏罗世义和植物群中的苏铁类化石3属7种，即Pterophyllum baotoum Zhang，Pterophyllum exhibens Li，Pterophyllum cf. tietzei Schenk，Pterophyllum sp.，Nilssonia inouyei Yokyama，Nilssonia orientalis Heer，Cycadolepis corrugata Zeiller.同时，讨论了苏铁类化石的古气候意义，认为吉林南部早侏罗世时期位于濒古太平洋带，气候温暖潮湿，有利于苏铁类繁茂生长.

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.