Abstract：
Angiosperms, a trigger for the Cretaceous Terrestrial Revolution (KTR), underwent a rapid expansion and occupied all the environments during the Mid-Upper Cretaceous. Yet, Cretaceous biogeographic patterns and processes underlying the distribution of angiosperm diversity in the Northern Hemisphere are still poorly known. Here, we elucidated the biogeographic diversification of the angiosperm family Papaveraceae, an ancient Northern Hemisphere clade characterized by poor dispersal ability and high level of regional endemism. Based on both plastome and multi-locus datasets, we reconstructed a robust time-calibrated phylogeny that includes all currently recognized 45 genera of this family. Within the time-calibrated phylogenetic framework, we conducted 72 biogeographic analyses by testing the sensitivity of uncertainties of area delimitation, maxarea constraints, and the parameters of the model, i.e., j (describing jump-dispersal events) and w (modifying dispersal multiplier matrices), to ancestral range estimations. We also inferred ancestral habitat and ecological niches. Phylogenetic analyses strongly support Papaveraceae as monophyletic. Pteridophylloideae is strongly supported as sister to Hypecoideae-Fumarioideae. Our results indicate that the j parameter and number of predefined areas strongly affect ancestral range estimates, generating questionable ancestral ranges, whereas maxarea constraint and w parameter have no effect and improve model fit. After accounting for these uncertainties, our results indicate that Papaveraceae differentiated in Asian wet forests during the Lower Cretaceous and subsequently occupied the Asian and western North American arid and open areas. Three dispersals from Asia to western North America via the Bering land bridge occurred in the Mid-Upper Cretaceous, largely in agreement with the KTR. Habitat shift and ecological niche divergence resulted in the subsequent disjunctions between Asia and western North America. These findings suggest that the interplay of range expansion and niche divergence-driven vicariance might have shaped Cretaceous biogeographic patterns of angiosperms with Papaveraceae-like ecological requirements and dispersal abilities in the Northern Hemisphere, hence contributing to the knowledge on the geographic expansion of angiosperms during the KTR.
摘要：
被子植物,白垩纪陆地革命(KTR)的导火索,经历了快速扩张，并在上白垩纪中段占据了所有环境。然而，北半球被子植物多样性分布的白垩纪生物地理格局和过程仍然鲜为人知。这里,我们阐明了被子植物科罂粟科的生物地理多样性，一种古老的北半球进化枝，其特征是传播能力差和高度的区域特有性。基于质体和多位点数据集，我们重建了一个强大的时间校准系统发育，其中包括该家族的所有目前公认的45属。在时间校准的系统发育框架内，我们通过测试区域划界不确定度的敏感性进行了72次生物地理分析，maxarea约束，和模型的参数，即，j(描述跳跃-分散事件)和w(修改分散乘数矩阵)，祖先范围估计。我们还推断了祖先的栖息地和生态位。系统发育分析强烈支持罂粟科为单系。蕨类植物被大力支持为Hypcoideae-Fumarioideae的姐妹。我们的结果表明，j参数和预定义区域的数量强烈影响祖先范围估计，产生可疑的祖先范围，而maxarea约束和w参数没有影响，提高了模型拟合。在考虑了这些不确定性之后，我们的结果表明，罂粟科在下白垩纪期间在亚洲湿林中分化，随后占领了亚洲和北美西部的干旱和开放地区。在白垩纪中上游发生了三次从亚洲通过白令陆桥扩散到北美西部，在很大程度上与KTR一致。生境转移和生态位差异导致亚洲和北美西部之间随后的分离。这些发现表明，范围扩展和生态位发散驱动的代位权的相互作用可能已经塑造了北半球具有罂粟科样生态要求和扩散能力的被子植物的白垩纪生物地理模式，因此有助于了解KTR期间被子植物的地理扩展。
