Hughes Lily C, Bloom Devin D, Piller Kyle R, Lang Nicholas, Mayden Richard L
Department of Marine, Earth, and Atmospheric Sciences, North Carolina State University, Raleigh, NC 27606, USA.
North Carolina Museum of Natural Sciences, Raleigh, NC 27601, USA.
Proc Biol Sci. 2025 Jan;292(2038):20242101. doi: 10.1098/rspb.2024.2101. Epub 2025 Jan 8.
Jawless vertebrates once dominated Palaeozoic waters, but just two lineages have persisted to the present day: lampreys and hagfishes. Living lampreys are a relatively small clade, with just over 50 species described, but knowledge of their evolutionary relationships has always been based on either a few mitochondrial genes or a small number of taxa. Biogeographers have noted the disjunct antitropical distribution of living lamprey families. Here, we present a comprehensive phylogenomic analysis of living and fossil lampreys, sampling 36 species with phylogenomic data and 46 in total with genetic data. We present new divergence time estimates based on comprehensive nuclear data and analysis of their diversification dynamics. Our analysis indicates a central role for extreme global warming during the Late Cretaceous Cenomanian-Turonian Boundary Event as a likely cause for the antitropical distribution of living lampreys, and a notable increase in lineage diversification in Northern Hemisphere lampreys during the Miocene corresponding with a period of global cooling.
无颌脊椎动物曾在古生代的水域中占据主导地位，但至今仅存两个谱系：七鳃鳗和盲鳗。现存的七鳃鳗是一个相对较小的进化枝，已描述的物种仅有50多种，但对它们进化关系的了解一直基于少数线粒体基因或少量分类单元。生物地理学家已经注意到现存七鳃鳗科的间断反热带分布。在此，我们对现存和化石七鳃鳗进行了全面的系统基因组分析，对36个物种进行了系统基因组数据采样，总共对46个物种进行了遗传数据采样。我们基于全面的核数据提出了新的分歧时间估计，并分析了它们的多样化动态。我们的分析表明，晚白垩世森诺曼阶-土伦阶边界事件期间的极端全球变暖在现存七鳃鳗反热带分布中可能起到了核心作用，并且中新世期间北半球七鳃鳗谱系多样化显著增加，这与全球变冷时期相对应。
