Search

Lycodon gammiei (Blanford, 1878), a rarely encountered species of Asian snake, is characterized by ambiguous systematics and biology. Based on a sole specimen of L. gammiei rediscovered in southeastern Xizang, China, we conduct a detailed morphological examination and description, and investigate the systematic position of this species. Morphologically, the newly collected specimen is closely aligned with specimens previously described. Mitochondrial DNA-based phylogenetic analyses reveal that L. gammiei constitutes an independent evolutionary lineage, forming a clade with L. fasciatus (Anderson, 1879), L. gongshan Vogel & Luo, 2011, L. butleri Boulenger, 1900, and L. cavernicolus Grismer, Quah, Anuar, Muin, Wood & Nor, 2014. The closest genetic distance between L. gammiei and its congeners was 10.2%. The discovery of L. gammiei in Medog County, China, signifies an eastward expansion of its known geographical distribution. [ABSTRACT FROM AUTHOR]

• The monophyly of Trimerodytes is strongly supported, with T. yapingi as the basal to the remaining species. • Trimerodytes likely originated in Hengduan Mountains (eastern Tibetan Plateau) in western China at 23.93 Ma (17.09–31.30). • The validity of T. yunnanensis is supported. The Asian water snake genus Trimerodytes (formerly Sinonatrix) is endemic to East and Southeast Asia. Although several species have been included in various phylogenetic studies previously, the evolution and relationships among members of this genus as a whole remain unexplored. In this study, we report the sequencing two protein-coding mitochondrial gene fragments (MTCYB and ND2) and three nuclear genes (c-mos , NT3 , and Rag1), reconstruct interspecific phylogeny, and explore biogeography for the genus Trimerodytes. Both Bayesian inference and maximum likelihood analyses consistently recover the monophyly of Trimerodytes with strong support, with T. yapingi the sister-group to the remaining species. The divergence date and ancestral area estimation suggest that Trimerodytes likely originated in Hengduan Mountains (eastern Tibetan Plateau) in western China at 23.93 Ma (95% HPD: 17.09–31.30), and intraspecific divergence began at about 4.23 Ma (95% HPD: 2.74–6.10). Analyses support the validity of T. yunnanensis. [ABSTRACT FROM AUTHOR]

The Asian pitviper genus Ovophis is a group of venomous snakes widely distributed in mid to high elevation mountains in Asia, and presently five species are recognised. However, its systematics, species diversity and species distribution boundaries remain poorly understood. We reconstructed the phylogenetic relationships and explored species diversity of Chinese Ovophis based on two mitochondrial fragments (Cyt b and ND4) and four nuclear genes (BACH1, c‐mos, Rag1, NT3) and also conducted a morphological comparison between focal species. Our results indicated that the species diversity had been underestimated within Ovophis and we described a population from southern Yunnan, China, as a new taxon, naming it as Ovophis malhotraesp.nov. Based on more extensive sampling, we redefined the distribution of O. monticola and O. makazayazaya in China. Divergence date estimation suggested that Ovophis originated at about 16.79 Ma in the middle Miocene. [ABSTRACT FROM AUTHOR]

[Display omitted] • All species of Rhabdophis nuchalis (sensu lato) complex did not form a monophyly, but each species was highly supported. • Incongruence was detected between nuclear and mtDNA phylogeny. • A new taxa has been described from southwestern China. • Geographic distribution boundary for each species within this species complex has been redefined. Stable taxonomy and robust phylogeny are essential for the evolution and conservation of organisms. The Rhabdophis nuchalis (sensu lato) complex presently contains three species (R. nuchalis , R. chiwen , R. pentasupralabialis). Although several studies have explored the diversity and phylogeography of this group, certain issues related to systematics and taxonomy remain unresolved. Here, based on genome-wide data, including single nucleotide polymorphisms (SNPs) generated from ddRAD-seq and mitochondrial DNA (mtDNA), we re-evaluated the phylogenetic relationships and cryptic diversity of this species group. Our results are generally consistent with previous studies but provide some new insights. Phylogenetic relationship reconstruction based on SNPs and mtDNA revealed that three species in the R. nuchalis (sensu lato) complex did not form a monophyly but each species is well supported as monophyletic lineage in SNP-based analyses. Population structure analyses showed genetic admixture between several species pairs. Additionally, the population in eastern Yunnan, China, was identified as a potential cryptic species and thus described as a new species based on morphological data. From our results and previous studies, we redefined the distribution boundary for each species in the R. nuchalis (sensu lato) species complex. [ABSTRACT FROM AUTHOR]

• A unified multilocus marker system for snake systematics was developed. • A comprehensive systematic framework of the snakes in China was constructed. • The marker system enables better understanding of the snake evolutionary histories. • The snake divergence times were estimated with the substantial new molecular data. Snakes are one of the most diverse groups of terrestrial vertebrates, with approximately 3500 extant species. A robust phylogeny and taxonomy of snakes is crucial for us to know, study and protect them. For a large group such as snakes, broad-scale phylogenetic reconstructions largely rely on data integration. Increasing the compatibility of the data from different researches is thus important, which can be facilitated by standardization of the loci used in systematic analyses. In this study, we proposed a unified multilocus marker system for snake systematics by conflating 5 mitochondrial markers, 19 vertebrate-universal nuclear protein coding (NPC) markers and 72 snake-specific noncoding intron markers. This marker system is an addition to the large squamate conserved locus set (SqCL) for studies preferring a medium-scale data set. We applied this marker system to over 440 snake samples and constructed the currently most comprehensive systematic framework of the snakes in China. Robust snake phylogenetic relationships were recovered at both deep and shallow evolutionary depths, demonstrating the usefulness of this multilocus marker system. Discordance was revealed by a parallel comparison between the snake tree based on the multilocus marker system and that based on only the mitochondrial loci, highlighting the necessity of using multiple types of markers to better understand the snake evolutionary histories. The divergence times of different snake groups were estimated with the nuclear data set. Our comprehensive snake tree not only confirms many important nodes inferred in previous studies but also contributes new insights into many snake phylogenetic relationships. Suggestions are made for the current Chinese snake taxonomy. [ABSTRACT FROM AUTHOR]