Tracing the patterns of non-marine turtle richness from Triassic–Palaeogene: from origin through global spread

Turtles are key components of modern vertebrate faunas and it is predicted that their diversity and distributions will be affected by anthropogenic climate change. Despite this, few studies have attempted to provide baseline data on turtle taxonomic richness through time or assess their past responses to global environmental change. We used the extensive Triassic–Palaeogene (252–23 Ma) fossil record of terrestrial and freshwater turtles to investigate diversity patterns, finding substantial variation in richness through time and between continents. Subsampled turtle richness was low globally from their Triassic origin until the Late Jurassic. There is strong evidence for high richness in the earliest Cretaceous of Europe. Richness was especially high following the Cretaceous Thermal Maximum and declined in all continents by the end-Cretaceous. At the K-Pg boundary, South American richness levels changed little while North American richness increased. Subsampled North American turtle ric...

龟类是现代脊椎动物群落的关键组成部分，现有研究预测其多样性与分布格局将受到人为气候变化的影响。尽管如此，目前鲜有研究尝试构建龟类随时间变化的分类丰富度基线数据，或是评估其过去对全球环境变化的响应。我们依托覆盖三叠纪至古近纪（2.52亿至2300万年前）的海量陆生与淡水龟类化石记录，对其多样性格局展开研究，发现其丰富度随时间推移以及不同大陆间均存在显著差异。从龟类起源于三叠纪直至晚侏罗世，全球经抽样校正的龟类丰富度始终处于较低水平。有充分证据表明，欧洲在早白垩世早期便拥有极高的龟类丰富度。白垩纪热极事件后，龟类丰富度显著升高，而至白垩纪末期，所有大陆的丰富度均出现下降。在白垩纪-古近纪（K-Pg）界线处，南美洲的龟类丰富度几乎未发生变化，而北美洲的丰富度反而有所提升。经抽样校正的北美龟类丰富度……