Data from: A revision of African helmeted terrapins (Testudines: Pelomedusidae: Pelomedusa), with descriptions of six new species

Using nearly range-wide sampling, we analyze up to 1848 bp of mitochondrial DNA of 183 helmeted terrapins and identify a minimum of 12 deeply divergent species-level clades. Uncorrected p distances of these clades equal or clearly exceed those between the currently recognized species of Pelusios, the genus most closely related to Pelomedusa. We correlate genetic discontinuities of Pelomedusa with data on morphology and endoparasites and describe six new Pelomedusa species. Moreover, we restrict the name Pelomedusa subrufa (Bonnaterre, 1789) to one genetic lineage and resurrect three further species from its synonymy, namely P. galeata (Schoepff, 1792), P. gehafie (Rüppell, 1835), and P. olivacea (Schweigger, 1812). In addition to these ten Pelomedusa species, we identify two further clades from Cameroon and Sudan with similar levels of genetic divergence that remain unnamed candidate species. We also note that some problematical terrapins from South Africa and Somalia may represent two additional candidate species. Some of the Pelomedusa species are morphologically distinctive, whilst others can only be identified by molecular markers and are therefore morphologically cryptic taxa.

本研究通过近乎全分布范围的采样，对183只盔龟的最长达1848个碱基对（base pair, bp）的线粒体DNA（mitochondrial DNA）片段进行分析，鉴定出至少12个深度分化的物种级演化支（clade）。上述演化支的未校正p距离（uncorrected p-distance），达到甚至显著超过了当前公认的、与Pelomedusa属亲缘关系最近的Pelusios属物种间的未校正p距离。本研究将Pelomedusa属的遗传间断特征与形态学及体内寄生虫数据进行关联，并描述了6个Pelomedusa属新物种。此外，本研究将Pelomedusa subrufa（Bonnaterre, 1789）这一学名限定于单个遗传谱系（genetic lineage），并从其同物异名（synonymy）中恢复了3个有效物种，分别为P. galeata（Schoepff, 1792）、P. gehafie（Rüppell, 1835）及P. olivacea（Schweigger, 1812）。除上述10个Pelomedusa属物种外，本研究还从喀麦隆与苏丹地区鉴定出另外2个演化支，其遗传分化水平与前述物种相当，目前暂未命名，属于候选物种。本研究同时指出，采自南非及索马里的部分存在分类争议的龟类，可能代表另外2个候选物种。部分Pelomedusa属物种在形态上具有显著辨识度，其余物种则仅能通过分子标记（molecular marker）进行鉴定，因此属于形态隐存类群（morphologically cryptic taxon）。