Cryptic species, taxonomic inflation, or a bit of both? New species phenomenon in Sri Lanka as suggested by a phylogeny of dwarf geckos (Reptilia, Squamata, Gekkonidae, Cnemaspis)

We evaluated the status of 16 of 22 recognized Sri Lankan Cnemaspis Strauch species, and flagged overlooked diversity with two mitochondrial (cyt b & ND2) and two nuclear markers (RAG1 & PDC) totalling 2829 base pairs. A fossil-calibrated timetree and sampling of other South Asian Cnemaspis provide insights into the diversification of the genus in peninsular India and Sri Lanka. Phylogenetic analyses consistently inferred two broad clades within South Asian Cnemaspis, with Sri Lankan species in two clades, which we call the podihuna and kandiana clades. Each Sri Lankan clade as a whole is sister to Indian taxa and nested within Indian lineages. Cnemaspis modigliani Das from Indonesia is a member of the kandiana clade. This suggests a minimum of two dispersal events between India and Sri Lanka and one between Sri Lanka/India and South-east Asia. South Asian Cnemaspis date back to at least the Eocene, in Sri Lanka to the early Miocene, with late Miocene diversification in the kandiana clade. All but one of the named species we sampled is likely to be valid, and 10 divergent unnamed lineages may warrant specific recognition. A resolution of Sri Lankan Cnemaspis taxonomy will require thorough sampling and the use of both morphological and molecular data.本研究对22个已确认的斯里兰卡疣鳞虎属（Cnemaspis Strauch）物种中的16个开展了分类地位评估，并借助2个线粒体标记（mitochondrial marker，包含细胞色素b基因cyt b与ND2基因）和2个核标记（nuclear marker，包含RAG1与PDC），总序列长度达2829个碱基对（base pair），以此揭示了该类群中被忽视的物种多样性。本研究构建的化石校准时间树（fossil-calibrated timetree）以及对其他南亚疣鳞虎属类群的采样分析，为厘清印度半岛与斯里兰卡地区该属的物种分化历程提供了重要视角。系统发育分析一致推断，南亚疣鳞虎属可分为两大演化支（clade），其中斯里兰卡物种分别隶属于两个演化支，本研究将其命名为podihuna演化支与kandiana演化支。两个斯里兰卡演化支整体上均与印度类群构成姊妹群（sister taxon），且嵌套于印度演化支系之中。产自印度尼西亚的Modigliani疣鳞虎（Cnemaspis modigliani Das）隶属于kandiana演化支。这一结果表明，印度与斯里兰卡之间至少发生过两次物种扩散事件（dispersal event），而斯里兰卡/印度与东南亚之间则至少发生过一次物种扩散事件。南亚疣鳞虎属的起源时间至少可追溯至始新世（Eocene），斯里兰卡本地类群的起源则可至早中新世（Miocene），而kandiana演化支的物种分化发生于晚中新世时期。本研究采样的已命名物种中，除1个物种外其余均大概率为有效物种；另有10个分化显著的未命名演化支，具备被正式描述为独立物种的潜力。要厘清斯里兰卡疣鳞虎属的分类学（taxonomy）问题，需要开展更为全面的类群采样，并结合形态学与分子生物学数据进行综合分析。