Early Evolution of Modern Birds Structured by Global Forest Collapse at the End-Cretaceous Mass Extinction
Early Evolution of Modern Birds Structured by Global Forest Collapse at the End-Cretaceous Mass Extinction
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DOI：
10.1016/j.cub.2018.04.062
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发表时间：
2018-06-04
期刊：
影响因子：
9.2
通讯作者：
Gauthier, Jacques A.
中科院分区：
文献类型：
--
作者：
Field, Daniel J.;Bercovici, Antoine;Gauthier, Jacques A.
化石记录和最近的分子生物学研究支持冠鸟（新鸟类）在白垩纪-古近纪（K-Pg）大灭绝后的异常早新生代辐射[1-3]。然而，关于冠鸟跨越K-Pg边界的最深谱系的生存机制仍然存在疑问，特别是因为这场全球性灾难甚至消除了新鸟类最接近的干群亲属[4]。在这里，祖先状态重建的新鸟氨酸生态揭示了一个强烈的偏见，主要表现为非乔木生活方式的K-Pg的类群，多个收敛过渡到主要是乔木生态后来在古新世和始新世。相比之下，生态形态学推断表明，反鸟雀（最多样化和分布最广泛的中生代鸟类）的生活方式主要是树栖生活方式[5-7]。全球古植物学和孢粉学数据表明，K-Pg希克苏鲁布的影响引发了广泛的森林破坏[8，9]。我们认为，由于K-Pg边界上的大量植物覆盖的暂时丧失而导致的生态过滤选择了任何致力于树栖生态的飞行恐龙（Avialae [10]），导致主要由全进化支古颚类，Galloanserae和陆地全进化支Neoaves组成的非树栖灭绝后新鸟类区系迅速多样化为今天熟悉的广泛的鸟类生态。这里提出的解释提供了一个统一的假设，为K-Pg-相关的大规模灭绝的树栖干鸟类，以及后K-Pg辐射的树栖冠鸟。它还提供了一个基线假设，以进一步完善等待发现更多的新鸟化石从最后的白垩纪和最早的古近纪。
The fossil record and recent molecular phylogenies support an extraordinary early-Cenozoic radiation of crown birds (Neornithes) after the Cretaceous-Paleogene (K-Pg) mass extinction [1-3]. However, questions remain regarding the mechanisms underlying the survival of the deepest lineages within crown birds across the K-Pg boundary, particularly since this global catastrophe eliminated even the closest stem-group relatives of Neornithes [4]. Here, ancestral state reconstructions of neornithine ecology reveal a strong bias toward taxa exhibiting predominantly non-arboreal lifestyles across the K-Pg, with multiple convergent transitions toward predominantly arboreal ecologies later in the Paleo-cene and Eocene. By contrast, ecomorphological inferences indicate predominantly arboreal lifestyles among enantiornithines, the most diverse and widespread Mesozoic avialans [5-7]. Global paleobotanical and palynological data show that the K-Pg Chicxulub impact triggered widespread destruction of forests [8, 9]. We suggest that ecological filtering due to the temporary loss of significant plant cover across the K-Pg boundary selected against any flying dinosaurs (Avialae [10]) committed to arboreal ecologies, resulting in a predominantly non-arboreal post-extinction neornithine avifauna composed of totalclade Palaeognathae, Galloanserae, and terrestrial total-clade Neoaves that rapidly diversified into the broad range of avian ecologies familiar today. The explanation proposed here provides a unifying hypothesis for the K-Pg-associated mass extinction of arboreal stem birds, as well as for the post-K-Pg radiation of arboreal crown birds. It also provides a baseline hypothesis to be further refined pending the discovery of additional neornithine fossils from the Latest Cretaceous and earliest Paleogene.