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Abstract: Based on a combination of six mitochondrial gene fragments (12S RNA, cyt b, ND1, ND2, ND4 and CO1) and one nuclear gene (c-mos) from 22 genera we infer phylogenetic relationships among natricine snakes and examine the date and area of origin of these snakes. Our phylogenetic results indicate: (1) the subfamily Natricinae is strongly supported as monophyletic including a majority of extant genera, and a poorly known and previously unassigned species Trachischium monticola, (2) two main clades are inferred within Natricinae, one containing solely taxa from the Old World (OW) and the other comprising taxa from a monophyletic New World (NW) group with a small number of OW relatives. Within the first clade, the genera Xenochrophis and Amphiesma are apparently not monophyletic. Divergence dating and ancestral area estimation indicate that the natricines originated in tropical Asia during the later Eocene or the Oligocene. We recover two major dispersals events out of Asia, the first to Africa in the Oligocene (28Ma) and the second to the Western Palearctic and the New World at 27Ma. This date is consistent with the dispersal of numerous other OW groups into the NW. [Copyright &y& Elsevier]

• 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]

Abstract: We investigated phylogenetic structure and morphological variation in Asian mountain pitvipers of the genus Ovophis (comprising 3–4 species some of which are considered polytypic) by sequencing four mitochondrial markers (cytochrome b, NADH dehydrogenase subunit 4, 12S and 16S rRNA) from 72 specimens, and analysed them in a Bayesian framework together with another 26 sequences from closely related genera. We reconstructed the region of origin and direction of dispersal of the major clades, and of Ovophis as a whole, using likelihood framework analysis. We also defined morphogroups from 280 specimens from across the range of Ovophis to allow the geographic extent of the major clades to be determined, as well as to allow inclusion of specimens lacking sequence data. Phylogenetic analyses confirmed the monophyly of Ovophis as currently defined, and revealed that it contains two major lineages, eastern (mainly Chinese) and western, with both occurring in southwestern China, central and northern Viet Nam. The most likely origin of the genus, and of individual lineages, coincides with the northeastern boundary of the Indomalayan hotspot. Major diversification in this species group likely corresponded to major climatic changes arising from the uplift of the Tibetan Plateau in the early to mid Miocene. With reference to the defined morphogroups, we suggest that at least five species are present and provide appropriate names. With a few exceptions, the newly defined species boundaries do not correspond to the existing taxonomy. [Copyright &y& Elsevier]

[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]