The middle Eocene Washakie Formation of Wyoming, USA, provides a rare window, within a single depositional basin, into the faunal transition that followed the early Eocene warming events. Based on extensive examination, we report a minimum of 27 species of carnivorous mammals from this formation, more than doubling the previous taxic count. Included in this revised list are a new species of carnivoraform, Neovulpavus mccarrolli n. sp., and up to ten other possibly new taxa. Our cladistic analysis of early Carnivoraformes incorporating new data clarified the array of middle Eocene taxa that are closely related to crown-group Carnivora. These anatomically relatively derived carnivoraforms collectively had an intercontinental distribution in North America and east Asia, exhibiting notable variations in body size and dental adaptation. This time period also saw parallel trends of increase in body size and dental sectoriality in distantly related lineages of carnivores spanning a wide range of body sizes. A new, model-based Bayesian analysis of diversity dynamics accounting for imperfect detection revealed a high probability of substantial loss of carnivore species between the late Bridgerian and early Uintan North American Land Mammal ‘Ages’, coinciding with the disappearance of formerly common mammals such as hyopsodontids and adapiform primates. Concomitant with this decline in carnivore diversity, the Washakie vertebrate fauna underwent significant disintegration, as measured by patterns of coordinated detection of taxa at the locality level. These observations are consistent with a major biomic transition in the region in response to climatically induced opening-up of forested habitats.UUID: http://zoobank.org/9162f1a6-a12c-4d55-ba1d-dc66e8cda261

中文翻译：

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美国怀俄明州中始新世Washakie组的食肉哺乳动物及其在变暖后世界中的多样性轨迹

美国怀俄明州中始新世 Wasakie 组在一个单一的沉积盆地内提供了一个难得的窗口，可以进入早期始新世变暖事件之后的动物群过渡。根据广泛的检查，我们报告了该地层中至少有 27 种食肉哺乳动物，是之前计入数量的两倍多。这份修订后的清单中包括一种新的食肉动物，新乌龟n. sp.，以及多达十个其他可能的新分类群。我们结合新数据对早期食肉形目的分支分析阐明了与冠群食肉目密切相关的始新世中期分类群。这些解剖学上相对衍生的食肉目在北美和东亚共同分布于洲际，在体型和牙齿适应方面表现出显着差异。在这段时间里，在跨越各种体型的远缘食肉动物谱系中，体型和牙齿部门性也出现了平行增加的趋势。一项新的、基于模型的对多样性动力学的贝叶斯分析解释了不完善的检测，揭示了在布里奇利亚晚期和早期 Uintan 北美陆地哺乳动物“时代”之间食肉动物物种大量丧失的可能性很高，恰逢以前常见的哺乳动物如弓齿象和适应灵长类动物的消失。伴随着食肉动物多样性的下降，Washakie 脊椎动物群经历了显着的解体，这是通过在地方一级对分类群进行协调检测的模式来衡量的。这些观察结果与该地区响应气候引起的森林栖息地开放而发生的重大生物组学转变是一致的。UUID：http://zoobank.org/9162f1a6-a12c-4d55-ba1d-dc66e8cda261