摘要
黔北桐梓红花园剖面是华南扬子台地经典的奥陶系剖面之一,其中的湄潭组下部泥页岩段产出大量的腕足类化石。在前人研究的基础上,形态分析显示:红花园剖面湄潭组下部的腕足类化石共有27属,其中以正形贝类Sinorthis的丰度最高,为湄潭组下段腕足动物中的优势类型。此外,Paralenorthis,Desmorthis,Xinanorthis等也比较常见,同为早奥陶世扬子台地近岸浅水环境下Sinorthis动物群的共生腕足分子。通过与黔中乌当地区湄潭组下段的腕足动物组合进行多样性比较,结果显示:桐梓红花园剖面的腕足动物,无论是化石丰度还是形态分异度,都明显高于贵阳乌当地区。两地之间湄潭组沉积环境的差异和研究程度的不同可能是腕足动物化石面貌不一样的主要原因。红花园剖面湄潭组下部腕足动物的多样性迅速增加,为研究华南早奥陶世腕足动物演化史上首次辐射事件提供了新的证据,也为探讨该地质时期黔中古陆南、北缘近岸环境下腕足动物的地理区系划分提供了重要信息。
The Honghuayuan section in Tongzi area,northern Guizhou Province is one of the typical Ordovician sections in the Yangtze Platform of South China.There is a large number of brachiopoda in the lower shale section of Meitan.On the basis of previous studies and our new collection,a total of 27 genera of lower brachiopoda were found in the Meitan formation of the Honghuayuan section,among which the Sinorthis was the most abundant and dominant genus,and there were other several common genera like Paralenorthis,Desmorthis,and Xinanorthis.They are the same brachiopoda evolved from early Ordovician Sinorthis in near-shore environment of the Yangtze Platform.The result of a comparison with the brachiopoda from the lower Meitan formation in Wudang area(central Guizhou),showed that brachiopoda in Wudang area was relatively lower in diversity and disparity.The differences of sedimentary environment and collection level might contribute to this distinction.The rapidly increased diversity of brachiopoda of the lower Meitan formation at the Honghuayuan section,provided latest evidence for studying the first radiation event in early Ordovician brachiopoda’s evolution in South China,as well as for the geographical division of near-shore brachiopoda both in the southern and northern margins of the ancient Qianzhong land.
作者
王冬梅
杨宇宁
黎斌
钱庆环
WANG Dongmei;YANG Yuning;LI Bin;QIAN Qinghuan(College of Resources and Environmental Engineering, Guizhou University, Guiyang 550025, China;State Key Laboratory of Modern Paleontology and Stratigraphy, Nanjing 210008, China)
出处
《贵州大学学报（自然科学版）》
2020年第3期15-21,共7页
Journal of Guizhou University:Natural Sciences
基金
国家自然科学基金项目资助(41702022)
现代古生物学和地层学国家重点实验室开放课题项目资助(173130)
贵州省科技计划项目资助(2018-1053)
贵州大学引进人才科研项目资助(2016-83)。
关键词
腕足动物
组合特征
湄潭组
早奥陶世
红花园剖面
brachiopoda
assemblage features
Meitan formation
early Ordovician
Honghuayuan section
