Abstract Conodonts, one of the longest-lived early groups of vertebrates, have a very complete fossil record ranging from the late Cambrian to the end of the Triassic and persisted through many global climatic and biotic events. In this paper, we analyse a large dataset harvested from the Paleobiology Database to compute global diversity curves at the generic level and explore patterns of conodont paleogeographic distribution. Our results partly confirm the most prominent findings of earlier studies including the occurrence of an Ordovician acme, a Permian nadir and a short-lived Triassic recovery. Major peaks of origination were found in the Early Ordovician and Early Triassic, while major extinctions occurred in the Upper Ordovician and Pennsylvanian. Paleogeographical extent of conodonts was impacted by i) the position of paleo-continents (notably impacting the latitudinal gradient of diversity), ii) the available continental shelf area and iii) ice sheets expansion. Diversity trends were mostly impacted by transitions between hothouse and icehouse ages, with major glaciations and associated marine regressions co-occurring with major extinctions. The influence of global sea level was less marked than that of temperature. However, the final demise of conodonts at the end of the Triassic did not coincide with either a major glaciation or marine regression. This supports the view that extinction of the group was mostly due to biotic factors such as competition with ‘Mesozoic’ taxa.

中文翻译：

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全球气候变化是牙形石多样性的主要趋势，但不是它们最终消亡的原因

摘要 牙形石是寿命最长的早期脊椎动物群之一，具有从晚寒武纪到三叠纪末期的非常完整的化石记录，并在许多全球气候和生物事件中持续存在。在本文中，我们分析了从古生物学数据库中收集的大型数据集，以计算通用级别的全球多样性曲线，并探索牙形石古地理分布的模式。我们的结果部分证实了早期研究中最突出的发现，包括奥陶纪顶点、二叠纪最低点和短暂的三叠纪恢复的发生。主要的起源峰出现在早奥陶世和早三叠世，而主要的灭绝发生在上奥陶世和宾夕法尼亚纪。牙形石的古地理范围受 i) 古大陆的位置 (特别是影响多样性的纬度梯度)、ii) 可用的大陆架面积和 iii) 冰盖扩张的影响。多样性趋势主要受温室和冰库时代之间过渡的影响，主要的冰川作用和相关的海洋退化与大灭绝同时发生。全球海平面的影响不如温度显着。然而，三叠纪末牙形石的最终消亡与大冰川作用或海洋退化并不同时发生。这支持了该群体的灭绝主要是由于与“中生代”类群竞争等生物因素的观点。ii) 可用的大陆架面积和 iii) 冰盖扩张。多样性趋势主要受温室和冰库时代之间过渡的影响，主要的冰川作用和相关的海洋退化与大灭绝同时发生。全球海平面的影响不如温度显着。然而，三叠纪末牙形石的最终消亡与大冰川作用或海洋退化并不同时发生。这支持了该群体的灭绝主要是由于与“中生代”类群竞争等生物因素的观点。ii) 可用的大陆架面积和 iii) 冰盖扩张。多样性趋势主要受温室和冰库时代之间过渡的影响，主要的冰川作用和相关的海洋退化与大灭绝同时发生。全球海平面的影响不如温度显着。然而，三叠纪末牙形石的最终消亡与大冰川作用或海洋退化并不同时发生。这支持了该群体的灭绝主要是由于与“中生代”类群竞争等生物因素的观点。然而，三叠纪末牙形石的最终消亡与大冰川作用或海洋退化并不同时发生。这支持了该群体的灭绝主要是由于与“中生代”类群竞争等生物因素的观点。然而，三叠纪末牙形石的最终消亡与大冰川作用或海洋退化并不同时发生。这支持了该群体的灭绝主要是由于与“中生代”类群竞争等生物因素的观点。