Cell wall ultrastructures of the Proterozoic acritarch Leiosphaeridia asperata and their implications for biological affinity  

作　　者：GONG Miao ZHOU ChuanMing YIN LeiMing YUAN XunLai WANG ChunZhao 

机构地区：[1]State Key Laboratory of Palaeobiology and Stratigraphy,Nanjing Institute of Geology and Palaeontology,Chinese Academy of Sciences,Nanjing 210008,China [2]Hunan Geological Museum,Changsha 410007,China

出　　处：《Science China Earth Sciences》2010年第12期1750-1755,共6页中国科学（地球科学英文版）

基　　金：supported financially by Chinese Academy of Sciences (Grant No. KZCX2-YW-153);National Basic Research Program of China (Grant No. 2006CB806400;National Natural Science Foundation of China (Grant Nos. 40772021,40625006)

摘　　要：Abundant sphaeroidal acritarch Leiosphaeridia asperata,with vesicle size ranging from 13 to 360 μm,occurred in the Proterozoic Liulaobei Formation shales in Huainan,Anhui Province.TEM/SEM studies of these sphaeroidal acritarchs have revealed complex ultrastructures,including ridges,bands,and possible trilaminar structures(TLS).Ridges,spaced ~1 μm apart,are distributed regularly on the vesicle internal surface of one specimen.Some specimens have alternating electron-dense and electron-tenuous bands that are perpendicular to vesicle walls.Some specimens have trilaminar structures(TLS),while a few others have both bands and TLS.These wall ultrastructures provide evidence that the Liulaobei leiosphaerids are of green microalgae.The variation in wall ultrastructures may represent various stages in a life cycle or developmental phases in the cyst formation analogous to some modern chlorophyceaen microalgae.Abundant sphaeroidal acritarch Leiosphaeridia asperata,with vesicle size ranging from 13 to 360 μm,occurred in the Proterozoic Liulaobei Formation shales in Huainan,Anhui Province.TEM/SEM studies of these sphaeroidal acritarchs have revealed complex ultrastructures,including ridges,bands,and possible trilaminar structures(TLS).Ridges,spaced ~1 μm apart,are distributed regularly on the vesicle internal surface of one specimen.Some specimens have alternating electron-dense and electron-tenuous bands that are perpendicular to vesicle walls.Some specimens have trilaminar structures(TLS),while a few others have both bands and TLS.These wall ultrastructures provide evidence that the Liulaobei leiosphaerids are of green microalgae.The variation in wall ultrastructures may represent various stages in a life cycle or developmental phases in the cyst formation analogous to some modern chlorophyceaen microalgae.

关 键 词：ULTRASTRUCTURE AFFINITY Leiosphaeridia asperata PROTEROZOIC Liulaobei Formation 

分 类 号：N[自然科学总论]