Nesting at extreme polar latitudes by non-avian dinosaurs
Nesting at extreme polar latitudes by non-avian dinosaurs
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DOI：
10.1016/j.cub.2021.05.041
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发表时间：
2021-08-23
期刊：
影响因子：
9.2
通讯作者：
Eberle，Jaelyn J.
中科院分区：
文献类型：
--
作者：
Druckenmiller，Patrick S.;Erickson，Gregory M.;Eberle，Jaelyn J.
在北极和南极地区意外发现的非鸟类恐龙引起了相当大的争论，关于它们是否有能力在高纬度地区繁殖，尤其是体型较大的，假设是迁徙的分类群。恐龙极地繁殖的证据仍然非常罕见，特别是那些生活在古纬度最高的物种（零下75度）。在这里，我们报告了在阿拉斯加北部白垩纪王子溪组（PCF）已知的最高古纬度发现的围产儿和非常年轻的恐龙。这些数据表明，在北极繁殖的大型和小型鸟臀目和兽脚亚目物种的多样性组合。就整体多样性而言，PCF中70%的已知恐龙科以及鸟类（鸟类）都是围产期个体，这是北美白垩纪地层中最高的比例。这些发现，再加上较长的潜伏期、较小的新生儿体型和较短的繁殖窗口，表明大多数（如果不是全部的话）PCF恐龙是全年不迁徙的北极居民。值得注意的是，我们利用精细的古环境/植物物候数据和对恐龙孵化期的新见解，重建了鸟臀目恐龙繁殖事件的年表。由于长时间的冬季黑暗和低温造成的季节性资源限制严重限制了恐龙的繁殖、发育和维持，这表明这些分类群表现出极地特有的生活史策略，包括恒温动物。
The unexpected discovery of non-avian dinosaurs from Arctic and Antarctic settings has generated considerable debate about whether they had the capacity to reproduce at high latitudes—especially the larger-bodied, hypothetically migratory taxa. Evidence for dinosaurian polar reproduction remains very rare, particularly for species that lived at the highest paleolatitudes (>75°). Here we report the discovery of perinatal and very young dinosaurs from the highest known paleolatitude for the clade—the Cretaceous Prince Creek Formation (PCF) of northern Alaska. These data demonstrate Arctic reproduction in a diverse assemblage of large- and small-bodied ornithischian and theropod species. In terms of overall diversity, 70% of the known dinosaurian families, as well as avialans (birds), in the PCF are represented by perinatal individuals, the highest percentage for any North American Cretaceous formation. These findings, coupled with prolonged incubation periods, small neonate sizes, and short reproductive windows suggest most, if not all, PCF dinosaurs were nonmigratory year-round Arctic residents. Notably, we reconstruct an annual chronology of reproductive events for the ornithischian dinosaurs using refined paleoenvironmental/plant phenology data and new insights into dinosaur incubation periods. Seasonal resource limitations due to extended periods of winter darkness and freezing temperatures placed severe constraints on dinosaurian reproduction, development, and maintenance, suggesting these taxa showed polar-specific life history strategies, including endothermy.