Data from: Diversity dynamics of Phanerozoic terrestrial tetrapods at the local-community scale

The fossil record provides one of the strongest tests of the hypothesis that diversity within local communities is constrained over geological timescales. Constraints to diversity are particularly controversial in modern terrestrial ecosystems, yet long-term patterns are poorly understood. Here we document patterns of local richness in Phanerozoic terrestrial tetrapods using a global data set comprising 145,332 taxon occurrences from 27,531 collections. We show that the local richness of non-flying terrestrial tetrapods has risen asymptotically since their initial colonization of land, increasing at most threefold over the last 300 million years. Statistical comparisons support phase-shift models, with most increases in local richness occurring: (1) during the colonization of land by vertebrates, concluding by the late Carboniferous; and (2) across the Cretaceous/Paleogene boundary. Individual groups, such as mammals, lepidosaurs and dinosaurs also experienced early increases followed by periods of stasis often lasting tens of millions of years. Mammal local richness abruptly tripled across the Cretaceous/Paleogene boundary, but did not increase over the next 66 million years. These patterns are consistent with the hypothesis that diversity is constrained at the local-community scale.

Usage Notes
code-for-close-et-al-diversity-dynamics-of-phanerozoic-terrestrial-tetrapods-at-the-local-scaleAll analysis code (R scripts) and data (CSV files downloaded from the Paleobiology Database at www.paleobiodb.org).

化石记录是检验局域群落（local community）内多样性在地质时间尺度上受约束这一假说的最有力佐证之一。多样性约束在现代陆生生态系统中极具争议，而人们对其长期格局的认知亦十分匮乏。本研究依托包含来自27531个标本馆藏的145332条分类单元出现记录的全球数据集，梳理了显生宙（Phanerozoic）陆生四足类（terrestrial tetrapods）的局域丰富度格局。研究表明，自陆生四足类首次登陆以来，非飞行类陆生四足类的局域丰富度呈渐近式增长，在过去3亿年间至多增长至原有水平的3倍。统计比对结果支持阶段转变模型（phase-shift models），局域丰富度的主要增长阶段发生在：(1) 脊椎动物登陆期间，至晚石炭世结束；(2) 跨越白垩纪/古近纪（Cretaceous/Paleogene）界线之时。诸如哺乳类、鳞龙类（lepidosaurs）和恐龙等类群也均经历了早期增长，随后进入通常持续数千万年的停滞期。哺乳类的局域丰富度在白垩纪/古近纪界线处骤然增至原有3倍，但在随后的6600万年间未出现增长。上述格局与局域群落尺度下多样性受约束的假说相一致。

【使用说明】
code-for-close-et-al-diversity-dynamics-of-phanerozoic-terrestrial-tetrapods-at-the-local-scale
本研究的所有分析代码（R脚本）与数据均从古生物数据库（Paleobiology Database）下载，格式为CSV文件，来源网址为www.paleobiodb.org。