Data from: Rodent phylogeny and a timescale for the evolution of Glires: evidence from an extensive taxon sampling using three nuclear genes.

Rodentia is the largest order of placental mammals, with approximately 2,050 species divided into 28 families. It is also one of the most controversial with respect to its monophyly, relationships between families, and divergence dates. Here, we have analyzed and compared the performance of three nuclear genes (von Willebrand Factor, interphotoreceptor retinoid-binding protein, and Alpha 2B adrenergic receptor) for a large taxonomic sampling, covering the whole rodent and placental diversity. The phylogenetic results significantly support rodent monophyly, the association of Rodentia with Lagomorpha (the Glires clade), and a Glires + Euarchonta (Primates, Dermoptera, and Scandentia) clade. The resolution of relationships among rodents is also greatly improved. The currently recognized families are divided here into seven well-defined clades (Anomaluromorpha, Castoridae, Ctenohystrica, Geomyoidea, Gliridae, Myodonta, and Sciuroidea) that can be grouped into three major clades: Ctenohystrica, Gliridae + Sciuroidea, and a mouse-related clade (Anomaluromorpha, Castoridae + Geomyoidea, and Myodonta). Molecular datings based on these three genes suggest that the rodent radiation took place at the transition between Paleocene and Eocene. The divergence between rodents and lagomorphs is placed just at the K-T boundary and the first splits among placentals in the Late Cretaceous. Our results thus tend to reconcile molecular and morphological-paleontological insights.

啮齿目（Rodentia）是有胎盘哺乳动物（placental mammals）中最大的目，现存约2050个物种，隶属于28个科。该类群在单系性（monophyly）、科间亲缘关系以及分化时间方面始终存在较大争议。本研究针对覆盖全啮齿类及有胎盘类多样性的大规模分类取样，分析并比较了三个核基因——血管假性血友病因子（von Willebrand Factor）、光感受器间类视黄醇结合蛋白（interphotoreceptor retinoid-binding protein）以及α2B肾上腺素能受体（Alpha 2B adrenergic receptor）的系统发育性能。系统发育分析结果显著支持啮齿目的单系性，以及啮齿目与兔形目（Lagomorpha）构成啮兔演化支（Glires clade）的亲缘关系，同时支持啮兔演化支与真统兽总目（Euarchonta，包含灵长目Primates、皮翼目Dermoptera和树鼩目Scandentia）构成更大的演化支。本研究对啮齿类内部亲缘关系的解析度也得到大幅提升。当前已确立的啮齿类科被划分为7个界定清晰的演化支：鳞尾松鼠下目（Anomaluromorpha）、河狸科（Castoridae）、豪猪下目（Ctenohystrica）、囊鼠总科（Geomyoidea）、睡鼠科（Gliridae）、鼠下目（Myodonta）以及松鼠总科（Sciuroidea），这7个演化支可进一步归为3个主干演化支：豪猪下目（Ctenohystrica）、睡鼠科+松鼠总科演化支，以及与鼠类相关的演化支（包含鳞尾松鼠下目、河狸科+囊鼠总科以及鼠下目）。基于这三个核基因的分子定年结果显示，啮齿类的辐射演化发生在古新世（Paleocene）与始新世（Eocene）的过渡时期。啮齿类与兔形类的分化时间恰好处于白垩纪-古近纪界线（K-T boundary）附近，而有胎盘类内部的首次分化则发生在晚白垩世（Late Cretaceous）。综上，本研究结果有助于调和分子生物学与形态学-古生物学研究的相关结论。