Size variation of conodonts during the Smithian-Spathian (Early Triassic) global warming event
Size variation of conodonts during the Smithian-Spathian (Early Triassic) global warming event
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DOI：
10.1130/g34171.1
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发表时间：
2013-08-01
期刊：
影响因子：
5.8
通讯作者：
Wang, Lina
中科院分区：
文献类型：
--
作者：
Chen, Yanlong;Twitchett, Richard J.;Wang, Lina
二叠纪末大灭绝后，海洋生态系统的最终恢复花了数百万年，部分原因是恶劣的环境和早三叠世期间发生的三次进一步灭绝：格里斯巴赫晚期，史密斯-斯帕蒂安边界（SSB）附近和斯帕蒂安晚期。SSB危机与一段极端温暖的时期相吻合，但很少有人研究。南盘江盆地是我国二叠-三叠系研究的重点地区，该研究首次对南盘江盆地的SSB危机进行了地层和古生态分析。提供了一个全面的，高分辨率的地层框架，包括六个牙形石带。牙形刺是一种已经灭绝的海洋脊索动物，其进食器官由微小的“牙齿状”元件组成。它们是进化最快的化石群之一，对环境压力敏感，因此是测试对过去气候变化的生态反应的理想生物。对近缘属Neo-spathodus、Triassospathodus和Novispathodus的441个牙形石元素的详细粒度测量首次表明，该分支在SSB危机期间经历了暂时但显著的粒度减小，随后在早期Spathian期间粒度逐渐稳定地增大。牙形刺的尺寸缩小是由全球变暖引起的，进一步加强了化石记录中记录的形态和气候变化之间的联系。
Final recovery of marine ecosystems after the end-Permian mass extinction took several million years, partly due to inhospitable environments and three episodes of further extinction that occurred during the Early Triassic: in the late Griesbachian, near the Smithian-Spathian boundary (SSB), and in the late Spathian. The SSB crisis coincides with an episode of extreme warmth, but has been little studied. This study represents the first stratigraphic and paleoecological analysis of the SSB crisis in the Nanpanjiang Basin, south China, which is a key area for Permian-Triassic studies. A comprehensive, high-resolution stratigraphic framework comprising six conodont zones is provided. Conodonts are an extinct group of marine chordates with a feeding apparatus composed of microscopic "tooth-like" elements. They are one of the fastest-evolving fossil groups, sensitive to environment stress, and are thus an ideal organism to test ecological responses to past episodes of climatic change. Detailed size measurements of 441 conodont elements of the closely related genera Neo-spathodus, Triassospathodus, and Novispathodus show for the first time that this clade suffered a temporary, but signifi cant, size reduction during the SSB crisis, followed by gradual and steady size increase during the early Spathian. Size reduction of conodonts was caused by an episode of global warming, further strengthening the link between morphological and climatic changes recorded in the fossil record.