湖南张家界地区田坪剖面埃迪卡拉系陡山沱组疑源类的发现及其生物地层意义  

ACRITARCHS FROM THE EDIACARAN DOUSHANTUO FORMATION AT THE TIANPING SECTION IN ZHANGJIAJIE AREA OF HUNAN PROVINCE, SOUTH CHINA AND THEIR BIOSTRATIGRAPHIC SIGNIFICANCE

作　　者：尚晓冬[1] 刘鹏举[1] SHANG Xiao-dong;LIU Peng-ju(MNR Key Laboratory of Stratigraphy and Palaeontology,Institute of Geology,Chinese Academy of Geological Sciences,Beijing 100037)

机构地区：[1]中国地质科学院地质研究所,自然资源部地层与古生物重点实验室,北京100037

出　　处：《地层学杂志》2020年第2期150-162,共13页Journal of Stratigraphy

基　　金：国家自然科学基金(41872024、41902019);中国博士后科学基金(2019M660742);中国地质调查局项目(DD20190008);中国科学院战略性先导科技专项(B类)(XDB 26000000)共同资助。

摘　　要：本文首次报道并描述湖南张家界地区田坪剖面埃迪卡拉系陡山沱组下部燧石条带中发现的疑源类微体化石,经系统鉴定共5属6种和1个不定属种,包括Appendisphaera grandis,A.tenuis,Cavaspina acuminata,Megasphaera inornata,Mengeosphaera gracilis,Tanarium tuberosum,Acritarcha gen.et sp.indet.。新的化石材料扩大了华南埃迪卡拉纪早期微体生物群的分布范围,这些疑源类属种在分类学上同华南地区及全球其他埃迪卡拉纪微体化石组合相似,为生物地层学研究提供了更多的古生物数据。虽然所发现的化石属种数量较为有限,同其他地区的精确生物地层对比关系尚不能建立,但由于包含Tanarium tuberosum,故将当前的生物组合与Tanarium tuberosum-Schizofusa zangwenlongii组合带相对比。此外,在Tanarium tuberosum膜壳内发现许多大小一致的球状内含物,可能是其生殖阶段的子细胞,为研究埃迪卡拉纪具刺疑源类的生物亲缘关系提供了新的化石证据。The acritarch microfossils are recovered for the first time from the chert bands in the lower part of the Ediacaran Doushantuo Formation at the Tianping section in Zhangjiajie area of Hunan Province(South China).The new microfossils are represented taxonomically by 5 genera,6 species and one undetermined species,namely Appendisphaera grandis,A.tenuis,Cavaspina acuminata,Megasphaera inornata,Mengeosphaera gracilis,Tanarium tuberosum,Acritarcha gen.et sp.indet.,showing a taxonomic similarity to other Ediacaran acritarch assemblages in South China or in the globe.Due to the limited number of species,precise biostratigraphic correlation of the Tianping microfossil assemblage with that from other areas cannot be achieved.It could be tentatively assigned to the second assemblage biozone(Tanarium tuberosum-Schizofusa zangwenlongii Assemblage Zone)owing to the occurrence of Tanarium tuberosum in the new assemblage.Additionally,numerous spheroidal internal bodies of similar sizes preserved within the vesicle of Tanarium tuberosum are the possible daughter cells at the reproductive stage of the microorganism,providing new information for understanding the biological affinities of the Ediacaran acanthomorphic acritarchs.

关 键 词：陡山沱组 埃迪卡拉纪 疑源类 生物地层 田坪 湖南 

分 类 号：P534.31[天文地球—古生物学与地层学]