Geographic dynamics of some major graptolite taxa of the Diplograptina during the Late Ordovician mass extinction in South China
Geographic dynamics of some major graptolite taxa of the Diplograptina during the Late Ordovician mass extinction in South China
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DOI：
10.1080/11035897.2014.880511
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发表时间：
2014-01
期刊：
影响因子：
1
通讯作者：
Linna Zhang;Junxuan Fan;Qing Chen;M. Melchin
中科院分区：
文献类型：
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作者：
Linna Zhang;Junxuan Fan;Qing Chen;M. Melchin
笔石古生物地理的研究对于理解地理与笔石演化动力学之间的关系具有重要意义。然而，在晚奥陶世的笔石古生物地理学，或地理在赫南阶大灭绝（HME）中所扮演的角色的详细研究很少。本文利用GBDB在线数据库，对华南地区卡田晚期-赫南田61个地点的笔石产状进行了数据整理，以探讨HME期间主要笔石类群的地理动态。应用最小多边形法重建了双笔石亚门5个主要类群的14种分布图。大多数diplographtine类群的地理动态显示，其地理范围从Dicellograptus complexus带到Paraorthograptus pacificus带，可能是因为在同时代的海洋沉积物的分布区的收缩。从P. pacificus带到Metabolograptus extraordinarius带，大多数双笔石类的分布大幅减少，主要代表了大灭绝事件的影响。我们的研究还表明，在HME期间，每个分类群的地理范围缩小到长江陆表海的中心。地理范围的变化反映在研究期间物种一级总多样性的类似减少。
The study of graptolite paleobiogeography is important for understanding the relationship between geography and evolutionary dynamics in graptolites. However, there have been few detailed studies of graptolite paleobiogeography during the Late Ordovician, or the role that geography played in the Hirnantian Mass Extinction (HME). In this study, in order to investigate the geographic dynamics of major graptolite taxa during the HME, a data-set of graptolite occurrences in the late Katian–Hirnantian from 61 localities in South China was compiled using the GBDB online database. The minimum polygon method was used to reconstruct 14 distribution maps of 5 major taxa belonging to the Diplograptina. The geographic dynamics of most diplograptine taxa show a small reduction in their geographic ranges from the Dicellograptus complexus Zone to the Paraorthograptus pacificus Zone, probably because of the contractions in the distribution areas of the coeval marine sediments. A substantial reduction in the distributions of most diplograptine taxa from the P. pacificus Zone to the Metabolograptus extraordinarius Zone mainly represents the effect of the major extinction event. Our study also demonstrates a reduction in the geographic ranges of each taxon to the center of the Yangtze epicontinental sea during the HME. The changes in geographic ranges are mirrored by a similar reduction in species-level total diversity during the study interval.