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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]

Achalinus yangdatongiHou, Wang, Guo, Chen, Yuan & Che, 2021 was described based on single specimen. After morphological examination of recently collected specimens from the type locality and close region, several specimens (3 females and 1 male) were identified as this species. Genetic distances (p-distance) calculated from a fragment of the mtDNA gene, cytochrome c oxidase subunit I (COI) were less than 1.8% between the newly collected specimens and the type specimen. Achalinus yangdatongi is redescribed and several of its diagnostics are revised accordingly: dorsal body scales 23 rows throughout; ventrals 155–171; subcaudals 59–76, unpaired; maxillary teeth 24–26. [ABSTRACT FROM AUTHOR]

Integrative taxonomy based on multiple data sets plays an important role in species classification, especially in the case of cryptic species. Rhabdophis subminiatus is a colubrid snake with broadly geographical distribution, and two subspecies (Rhabdophis subminiatussubminiatus and Rhabdophis subminiatushelleri) are currently recognized within this species. Based on external morphological comparison, mitochondrial DNA (mtDNA)‐based phylogeny, single‐nucleotide polymorphism (SNP)‐based phylogeny, and population structure analysis, we explored the intraspecific taxonomy of R. subminiatus. Phylogenetic analysis based on mtDNA and SNPs consistently uncovered two highly supported lineages separated by a large genetic distance, with SNP‐based principal component analysis (PCA) and population structure analysis displaying similar results. Despite the fact that PCA based on morphological data did not show population differentiation, unlike the molecular data, we suggest that R. s. helleri should be elevated to the specific rank as Rhabdophishelleri based on all lines of evidence. The distributional boundary between the two species R. helleri and R. subminiatus is tentatively proposed. [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]