Abstract The End-Triassic Extinction event (ETE) has been recognized in numerous sections worldwide and it is usually marked by three negative carbon isotope excursions (NCIEs), named “precursor” (P-NCIE), “initial” (I-NCIE) and “main” (M-NCIE) negative carbon isotope excursions. These three NCIEs are significant characteristics of this time interval, and they are likely related to the emplacement of the Central Atlantic Magmatic Province (CAMP) that is considered the main trigger of the ETE. Stable carbon isotope excursions, commonly related to biotic turnovers and extinctions, play an important role in stratigraphic correlations, particularly around the Triassic-Jurassic boundary (TJB). This time interval records the disappearance of conodonts, elements of a feeding apparatus belonging to marine organisms that populated the Paleozoic-early Mesozoic seas, and which became extinct across the TJB. So far, the interpretation of conodont extinction has remained ambiguous, as the timing of its last occurrence was debated which in turn hindered our understanding of the main cause(s) that could have led to their disappearance. Here we present and compare integrated data of nine TJB sections from different areas, Tethys and Panthalassa, and different depositional environments, i.e. shallow vs deep water or proximal vs distal shelf. Each of these sections record both the last occurrences of latest Triassic conodont taxa and pronounced changes in the carbon isotopic composition of organic matter across the TJB interval. Our analysis of chemo- and integrated biostratigraphic correlation suggests that the final extinction of the taxon Conodonta was asynchronous.

中文翻译：

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牙形石的异步消失：来自特提斯和潘塔拉萨三叠纪 - 侏罗纪边界部分的新限制

摘要 三叠纪末灭绝事件 (ETE) 已在世界范围内的许多部门中得到认可，通常以三个负碳同位素偏移 (NCIE) 为标志，命名为“前体”(P-NCIE)、“初始”(I-NCIE)和“主要”（M-NCIE）负碳同位素偏移。这三个 NCIE 是该时间段的显着特征，它们很可能与被认为是 ETE 主要触发因素的中大西洋岩浆区（CAMP）的就位有关。稳定的碳同位素漂移，通常与生物周转和灭绝有关，在地层相关性中起着重要作用，特别是在三叠纪-侏罗纪边界 (TJB) 附近。这个时间间隔记录了牙形石的消失，属于海洋生物的摄食装置的元素，这些生物居住在古生代-早中生代海域，并在 TJB 中灭绝。到目前为止，对牙形石灭绝的解释仍然模棱两可，因为对其最后一次发生的时间进行了辩论，这反过来又阻碍了我们对可能导致它们消失的主要原因的理解。在这里，我们展示并比较了来自不同区域、特提斯和泛塔拉萨以及不同沉积环境（即浅水与深水或近端与远端陆架）的九个 TJB 剖面的综合数据。这些部分中的每一个都记录了最近三叠纪牙形石类群的最后一次出现，以及整个 TJB 间隔有机质碳同位素组成的显着变化。