The Kellwasser event is one of Big Five mass extinctions of the Phanerozoic. It marks the boundary between the Frasnian and the Famennian, the two stages of the Upper Devonian. In order to discuss its effects on marine ostracod faunas, all well-dated occurrences from the literature have been gathered. We estimate that, at a global scale, the Kellwasser event has been responsible for the disappearance of 80% of ostracod species. However, the effect on ostracods was geographically heterogeneous, with values varying from 61% to 91%, probably related to local parameters. Our analyses show that this event mostly affected the ostracod diversity at low taxonomic levels (species and genera). Both nearshore and deep (Thuringian) benthic ostracods were affected. This event also influenced pelagic taxa, mostly represented by Entomozoidae, but they were still less affected than benthic ones at the global scale. Together with ostracods of the genus (Bairdiidae, Podocopida), Entomozoidae are among the most diversified taxa represented in event assemblages, suggesting that they were more tolerant to oxygen depletion as it was proposed, at least for , for the Permian-Triassic event. We show that the faunal recovery has mostly been characterized by diversification among cosmopolitan (particularly Bairdiidae and Bairdiocyprididae) and Thuringian taxa (particularly Bythocytheridae and, to a lesser extent Healdiidae, Tricorninidae and Rectonariidae). A global increase in endemism is observed through the Kellwasser event, likely related to the diversification of deep-water Thuringian taxa, leading to an increase in differences of taxonomic composition between the palaeoenvironmental settings. The widely reported sea-level fall at this time interval could also have participated in the increase in endemism by reducing the connexion between nearshore areas. This work is the first part of a two-part study focusing on the changes in ostracod community throughout the two Late Devonian biological crises (Kellwasser and Hangenberg events).

中文翻译：

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晚泥盆世灭绝事件中的海洋介形类动物群。第一部分：Kellwasser 事件


Kellwasser 事件是显生宙五次大灭绝之一。它标志着上泥盆统两个阶段——弗拉斯阶和法门阶之间的分界线。为了讨论其对海洋介形类动物群的影响，我们收集了文献中所有日期明确的事件。我们估计，在全球范围内，Kellwasser 事件导致了 80% 介形类物种的消失。然而，对介形类的影响在地理上是异质的，其值从 61% 到 91% 不等，可能与当地参数有关。我们的分析表明，这一事件主要影响低分类水平（种和属）的介形类多样性。近岸和深海（图林根）底栖介形类动物均受到影响。这一事件也影响了以昆虫纲为代表的中上层类群，但在全球范围内，它们受到的影响仍然小于底栖类群。与介形类（Bairdiidae、Podocopida）一样，昆虫科是事件组合中最多样化的类群之一，这表明它们对氧消耗的耐受性更强，至少在二叠纪-三叠纪事件中是这样。我们表明，动物区系恢复的主要特征是世界性分类群（特别是 Bairdiidae 和 Bairdiocyprididae）和图林根类群（特别是 Bythocytheridae，以及较小程度的 Healdiidae、Tricorninidae 和 Rectonariidae）之间的多样化。通过 Kellwasser 事件观察到全球特有现象的增加，可能与深水图林根类群的多样化有关，导致古环境背景之间的分类组成差异增加。 广泛报道的这一时间间隔的海平面下降也可能通过减少近岸地区之间的联系而参与了地方性的增加。这项工作是由两部分组成的研究的第一部分，重点关注两次晚泥盆世生物危机（Kellwasser 和 Hangenberg 事件）期间介形类群落的变化。