Data from: Cenozoic evolution of beta diversity and a Pleistocene emergence for modern mammal faunas in China

Aim Historical changes in community structure underlie modern spatial diversity patterns, but few empirical studies have focused on the variation in the community composition of fossil assemblages at large spatiotemporal scales. We wanted to investigat how the spatial differentiation of mammal communities changed in China throughout the Cenozoic in response to tectonic uplift and paleoclimatic changes and explore the timing of the emergence of the modern spatially structured faunas. Location China Time period Cenozoic (from 65 Ma to the present) Major taxa studied Terrestrial mammals
Methods We used a compiled database of the distributions of fossil and extant mammals to compare the multiple-site beta diversity among families and genera within six time intervals of the Cenozoic using Sørensen dissimilarity (βsor) and Simpson dissimilarity (βsim). To investigate the timing of the emergence of the modern spatially structured faunas, we applied hierarchical clustering and non-metric multidimensional scaling ordination based on pairwise βsim among seven zoogeographical regions within each time slice. Results The multiple-site beta diversity at the family level displayed hump-shaped changes during the Cenozoic, and it peaked in the Eocene and gradually decreased towards the present. However, the genus-level multiple-site beta diversity remained rather constant throughout the Cenozoic. Pronounced variations in the relationships among the zoogeographical regions were revealed in both the cluster analyses and ordinations. The modern spatial structure of mammal faunas at the family level was broadly similar to those observed in the Pliocene and Pleistocene. Main conclusions The spatial differentiation of mammal faunas in China dates back to the Eocene and pre-dates the formation of modern topography and climate. Throughout the Cenozoic, the spatial structure of mammal faunas was reorganized by an interplay of the uplift of the Tibetan Plateau, the emergence of the monsoon system and global macroevolutionary processes. The modern relationships among zoogeographical regions at the family level were established in the Pleistocene.

研究目的：群落结构的历史演变是现代空间多样性格局形成的基础，但目前鲜有实证研究聚焦于大时空尺度下化石组合的群落组成变异。本研究旨在探究新生代以来中国哺乳动物群落的空间分异如何响应构造隆升与古气候变化，并解析现代空间结构化动物群的形成时间。
研究区域：中国
研究时段：新生代（距今65 Ma至今）
研究类群：陆生哺乳动物（Terrestrial mammals）
研究方法：本研究整合了化石与现生哺乳动物的分布数据库，采用索伦森相异性指数（Sørensen dissimilarity，βsor）与辛普森相异性指数（Simpson dissimilarity，βsim），对比新生代六个时间区间内科级与属级类群的多位点beta多样性（multiple-site beta diversity）。为解析现代空间结构化动物群的形成时间，本研究基于各时间切片内七个动物地理区之间的成对βsim值，分别应用层级聚类（hierarchical clustering）与非度量多维标度排序（non-metric multidimensional scaling ordination）开展分析。
研究结果：科级水平的多位点beta多样性在新生代呈现驼峰式变化趋势，于始新世（Eocene）达到峰值，并逐渐向现代阶段递减。然而，属级水平的多位点beta多样性在整个新生代期间基本保持稳定。聚类分析与排序分析均揭示，各动物地理区之间的关联存在显著差异。科级水平的哺乳动物群现代空间结构与上新世（Pliocene）及更新世（Pleistocene）的结构大体相似。
主要结论：中国哺乳动物群的空间分异始于始新世，早于现代地形与气候系统的形成。在整个新生代期间，哺乳动物群的空间结构受青藏高原隆升、季风系统形成与全球宏观演化过程的共同作用而持续重构。科级水平下动物地理区间的现代关联模式于更新世得以确立。