Data from: Genetics, morphology, advertisement calls, and historical records distinguish six new polyploid species of African clawed frog (Xenopus, Pipidae) from West and Central Africa

African clawed frogs, genus Xenopus, are extraordinary among vertebrates in the diversity of their polyploid species and the high number of independent polyploidization events that occurred during their diversification. Here we update current understanding of the evolutionary history of this group and describe six new species from west and central sub-Saharan Africa, including four tetraploids and two dodecaploids. We provide information on molecular variation, morphology, karyotypes, vocalizations, and estimated geographic ranges, which support the distinctiveness of these new species. We resurrect Xenopus calcaratus from synonymy of Xenopus tropicalis and refer populations from Bioko Island and coastal Cameroon (near Mt. Cameroon) to this species. To facilitate comparisons to the new species, we also provide comments on the type specimens, morphology, and distributions of X. epitropicalis, X. tropicalis, and X. fraseri. This includes significantly restricted application of the names X. fraseri and X. epitropicalis, the first of which we argue is known definitively only from type specimens and possibly one other specimen. Inferring the evolutionary histories of these new species allows refinement of species groups within Xenopus and leads to our recognition of two subgenera (Xenopus and Silurana) and three species groups within the subgenus Xenopus (amieti, laevis, and muelleri species groups).

爪蟾属（Xenopus）的非洲爪蟾类群，在脊椎动物中以其多倍体物种的丰富多样性，以及辐射演化过程中发生的多次独立多倍化事件而极具研究特殊性。本研究更新了学界对该类群演化历史的现有认知，描述了来自撒哈拉以南非洲西部与中部的6个新物种，其中包含4个四倍体物种及2个十二倍体物种。我们提供了支撑这些新物种独立性的分子变异、形态学特征、核型、鸣声特征以及推测地理分布范围等多维度信息。本研究将原本归入热带爪蟾（Xenopus tropicalis）同物异名的克氏爪蟾（Xenopus calcaratus）恢复为有效物种，并将比奥科岛及喀麦隆沿海（喀麦隆山附近）的种群归入该物种。为便于与新物种开展对比研究，我们还对近热带爪蟾（X. epitropicalis）、热带爪蟾（X. tropicalis）以及弗雷泽爪蟾（X. fraseri）的模式标本、形态特征与分布范围进行了系统说明。其中包括严格限定X. fraseri与X. epitropicalis两个学名的应用范畴——我们认为，X. fraseri目前仅确定以模式标本为唯一有效依据，可能仅另有一份标本可佐证其有效性。通过推断这些新物种的演化历史，我们得以优化爪蟾属内的类群划分框架，并确认该属包含2个亚属：爪蟾亚属（Xenopus）与Silurana亚属；其中爪蟾亚属内设有3个种组，分别为amieti种组、laevis种组与muelleri种组。