The end-Permian mass extinction (EPME) profoundly shaped shallow marine ecosystems. Although much has been learned about this event based on the body-fossil record, the global infaunal response to the EPME, as represented by ichnofossils, is much less understood. Here we analyze secular changes in ichnodiversity and ichnodisparity from the late Permian to the Middle Triassic based on a global trace-fossil data set. Results show that, in contrast to the body-fossil record, late Permian global ichnodiversity and ichnodisparity maintained their level until the Griesbachian, followed by a sharp loss in the Dienerian. Notably, the Griesbachian shows an unusual dominance of shallower tiers. The discrepancy between the body- and trace-fossil record is interpreted to be the result of the resurgence of widespread microbial matgrounds in the Griesbachian that aided the preservation of surface, semi-infaunal, and shallow-tier ichnofossils. Our study shows that the EPME strongly affected the sediment mixed layer, allowing the preservation of shallower tier trace fossils. The disappearance of the mixed layer in the earliest Triassic may have enhanced pyrite burial in sediments and inhibited its further re-oxidation, therefore impacting sea water sulfate concentrations.

中文翻译：

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二叠纪末大灭绝期间的不良反应

二叠纪末期生物大灭绝（EPME）深刻地塑造了浅海生态系统。尽管根据人体化石记录已经学到了很多有关该事件的信息，但对于鱼类化石所代表的全球对EPME的不良反应却知之甚少。在这里，我们根据全球痕迹化石数据集分析了二叠纪晚期到中三叠纪的鱼类多样性和鱼类差异的长期变化。结果表明，与人体化石记录相反，二叠纪晚期的全球鱼类多样性和鱼类物种差异一直保持到Griesbachian之前的水平，随后在Dienerian中急剧下降。值得注意的是，格里斯巴赫式方法在浅层显示出不同寻常的优势。人体化石和痕迹化石记录之间的差异被认为是由于格里斯巴赫河中广泛的微生物基层复活的结果，这些微生物基层帮助了表层，半无动物和浅层鱼类化石的保存。我们的研究表明，EPME强烈影响沉积物混合层，从而保留了较浅的层层化石。最早的三叠纪混合层的消失可能增加了沉积物中黄铁矿的埋藏并抑制了其进一步的再氧化，因此影响了海水中硫酸盐的浓度。