辽宁西部早三叠世苏铁植物一新属——Mediocycas gen.nov.及其演化意义  

A NEW GENUS OF CYCADALEAN PLANTS FROM THE EARLY TRIASSIC OF WESTERN LIAONING, CHINA—— MEDIOCYCAS GEN. NOV. AND ITS EVOLUTIONARY SIGNIFICANCE

作　　者：李楠[1] 傅晓平[1] 张武[2] 郑少林[2] 曹雨[1] 

机构地区：[1]深圳仙湖植物园 [2]国土资源部沈阳地质矿产研究所,沈阳110032

出　　处：《古生物学报》2005年第3期423-434,共12页Acta Palaeontologica Sinica

基　　金：深圳市科技局和深圳城市管理科学研究所资助课题。

摘　　要：报道苏铁植物大孢子叶化石一新属———中间苏铁属(Mediocycasgen.nov.)。标本采集于辽宁省西部,喀左县杨树沟煤矿后山的早三叠世红砬组。这些标本以前曾被处理为疑问化石(Problematicum)。因当时资料不足,所以没有确定属种名称。但鉴于这些化石在苏铁类早期起源与演化研究中具有重要意义,故对它们作了重新研究。文中除了以喀左中间苏铁(Mediocycaskazuoensisgen.etsp.nov.)为典型种进行描述以外,还对新属、种在苏铁类起源与演化方面的意义作了较为详细的讨论。A new genus--Mediocycas gen. nov. of fossil cycad megasporophylls is proposed based on the specimens collected from Yangshugou village, Kazuo county, western Liaoning Province, China. The stratum of plant-bearing bed belongs to the Lower Triassic Hongla Formation. The specimens were previously considered as a problematical fossil due to the lack of material. These fossils, however, are of vital importance in understanding the early evolution of cycads, and therefore worthy of reinvestigation. In the present paper, description of the typical species Mediocycas kazuoensis gen. et sp. nov. was made, and its important significance in the origin and early evolution of the megasporophyll of cycads was discussed.

关 键 词：苏铁植物 早三叠世 新属 辽宁西部 演化 标本采集 苏铁类 苏铁属 叶化石 大孢子 辽宁省 喀左县 中间 起源 属种 

分 类 号：Q914[天文地球—古生物学与地层学]