Data from: Multi-locus phylogeny of the Afrotropical freshwater crab fauna reveals historical drainage connectivity and transoceanic dispersal since the Eocene

Phylogenetic reconstruction, divergence time estimations and ancestral range estimation were undertaken for 66% of the Afrotropical freshwater crab fauna (Potamonautidae) based on four partial DNA loci (12S rRNA, 16S rRNA, cytochrome oxidase one (COI) and the histone 3 gene). The present study represents the most comprehensive taxonomic sampling of any freshwater crab family globally, and explores the impact of paleodrainage interconnectivity on cladogenesis among freshwater crabs. Phylogenetic analyses of the total evidence data using maximum likelihood, maximum parsimony, and Bayesian inference produced a robust statistically well-supported multi-locus topology that reaffirmed the monophyly of the Afrotropical freshwater crab fauna. The estimated divergence times suggest that the Afrotropical Potamonautidae diverged during the Eocene. Cladogenesis within and among several genera occurred predominantly during the Miocene, which was associated with major tectonic and climatic ameliorations throughout the region. Paleodrainage connectivity was observed with specimens from the Nilo-Sudan and East African coast proving to be sister to specimens from the Upper Guinea Forests in West Africa. In addition, we observed strong sister taxon affinity between specimens from East Africa and the Congo basin, including specimens from Lake Tanganyika, while the southern African fauna was retrieved as sister to the Angolan taxa. Within the East African clade we observed two independent transoceanic dispersal events, one to the Seychelles Archipelago and a second to Madagascar, while we observe a single transoceanic dispersal event from West Africa to São Tomé. The ancestral area estimation suggested a West African / East African ancestral range for the family with multiple dispersal events between southern Africa and East Africa, and between East Africa and Central Africa. The taxonomic implications of our results are discussed in light of the widespread paraphyly evident among a number of genera.

本研究基于4个部分DNA基因座（12S rRNA、16S rRNA、细胞色素氧化酶亚基I（COI）以及组蛋白H3基因），对66%的非洲热带淡水蟹类群（Potamonautidae科）开展了系统发育重建、分歧时间估算与祖先分布区重建工作。本研究为目前全球范围内针对任一淡水蟹科类群的最全面分类学采样，并探讨了古水系连通性对淡水蟹支系发生的影响。通过最大似然法（maximum likelihood）、最大简约法（maximum parsimony）以及贝叶斯推断（Bayesian inference）对全证据数据进行系统发育分析，得到了统计学支持度优异的稳健多基因座拓扑结构，再次证实了非洲热带淡水蟹类群的单系性。估算所得分歧时间显示，非洲热带Potamonautidae科的支系分化始于始新世（Eocene）。多个属内及属间的支系发生主要集中于中新世（Miocene），这与区域内发生的重大构造运动与气候变迁事件紧密关联。古水系连通性特征表现为：尼罗-苏丹流域与东非海岸的标本，与西非上几内亚森林的标本构成姊妹群。此外，本研究还发现东非与刚果盆地（含坦噶尼喀湖（Lake Tanganyika）标本）的类群间存在极强的姊妹群亲缘关系，而南部非洲类群则与安哥拉类群互为姊妹群。在东非支系中，我们观测到两次独立的跨洋扩散事件：一次扩散至塞舌尔群岛（Seychelles Archipelago），另一次至马达加斯加（Madagascar）；而西非向圣多美岛（São Tomé）仅发生过一次跨洋扩散事件。祖先分布区重建结果表明，该科的祖先分布区为西非/东非区域，且南部非洲与东非之间、东非与中非之间存在多次扩散事件。最后，我们结合多个属中普遍存在的并系群现象，对本研究结果的分类学意义展开了讨论。