Kukri snakes Oligodon Fitzinger, 1826 of the Western Palearctic with the resurrection of Contia transcaspica Nikolsky, 1902 (Reptilia, Squamata, Colubridae).

The kukri snakes of the genus Oligodon Fitzinger, 1826 reach the westernmost limits of their distribution in Middle and Southwest Asia (Afghanistan, Iran, and Turkmenistan), and the Palearctic portions of Pakistan. In this article, we review the systematics and distribution of the two species native to this region, Oligodon arnensis (Shaw, 1802) and Oligodon taeniolatus (Jerdon, 1853) based on an integrative approach combining morphological, molecular, and species distribution modeling (SDM) data. Phylogenetic analyses recover O. taeniolatus populations from Iran and Turkmenistan in a clade with the O. arnensis species complex, rendering the former species paraphyletic relative to O. taeniolatus sensu stricto on the Indian subcontinent. To correct this, we resurrect the name Contia transcaspica Nikolsky, 1902 from the synonymy of O. taeniolatus and assign it to populations in Middle-Southwest Asia. So far, Oligodon transcaspicus comb. et stat. nov. is known only from the Köpet-Dag Mountain Range of northeast Iran and southern Turkmenistan, but SDM mapping suggests it may have a wider range. Genetic samples of O. "arnensis" from northern Pakistan are nested in a clade sister to the recently described Oligodon churahensis Mirza, Bhardwaj & Patel, 2021, and are phylogenetically separate from O. arnensis sensu stricto in south India and Sri Lanka. Based on morphological similarity, the Afghanistan and Pakistan populations are assigned to Oligodon russelius (Daudin, 1803) and we synonymize O. churahensis with this species. Our investigation leads us to remove O. taeniolatus from the snake fauna of Afghanistan, Iran, and Turkmenistan, with the consequence that only Oligodon transcaspicus comb. et stat. nov. and O. russelius are present in these countries. Additional studies are needed to resolve the taxonomy of the O. taeniolatus and O. arnensis species complexes on the Indian subcontinent, and an updated key for both groups is provided.

A review of records of the Trimeresurus albolabris Gray, 1842 group from the Indian subcontinent: expanded description and range extension of Trimeresurus salazar, redescription of Trimeresurus septentrionalis and rediscovery of historical specimens of Trimeresurus davidi (Reptilia: Viperidae).

We revisit the identities of Trimeresurus albolabris records from India and Nepal, based on a re-examination of historically mentioned specimens. Based on morphological congruence, we identify an old specimen originally labeled as T. albolabris from Nagpur, Central Province as Trimeresurus salazar. We also provide new records of T. salazar based on molecular data from newly collected specimens in Central India. As the range of T. salazar is now known to approach that of its sister species Trimeresurus septentrionalis, we also redescribe T. septentrionalis based on the holotype and referred material. Finally, we examined two historical specimens from Madras collected during the Novara Expedition, which we identify as T. davidi, leading to a reassessment of their origin. Consequently, we remove T. albolabris from the list of Indian snake fauna.

A new species of Boiga (Serpentes: Colubridae) from the Southern Western Ghats of India with a molecular phylogeny and expanded characterisation of related species.

We conducted a molecular phylogenetic study on the Boiga ceylonensis group from the Western Ghats of India, building on a recent morphology-based study. Our analysis supports previous work in elucidating the phylogenetic position of B. nuchalis and B. beddomei s. str. (of Matheran, Western Ghats) as clustering closely with B. ceylonensis, while B. flaviviridis clustered with the Sri Lankan taxon close to B. ranawanei. Additionally, our phylogenetic study revealed the presence of an undescribed taxon in the Southern Western Ghats, more closely related to B. ceylonensis than to any other sampled taxon, including sympatric congeners. This new taxon is described here as a new species Boiga whitakeri sp. nov. from the Devar MalaiAnaimalai hill complex. Based on molecular and morphometric studies, we expand the description of the recently described B. thackerayi as inhabiting almost the entire stretch of the Western Ghats. We also complement the diagnoses of B. nuchalis and B. flaviviridis, and determine the phylogenetic position of B. thackerayi with molecular data.

Disentangling vines: a study of morphological crypsis and genetic divergence in vine snakes (Squamata: Colubridae: Ahaetulla) with the description of five new species from Peninsular India.

We carried out a taxonomic revision of Ahaetulla species inhabiting Peninsular India, using a multiple criteria approach (including genetics, morphology, and geography). Our work included populations of the A. nasuta complex (widespread across the entire region, including the Western Ghats), the A. pulverulenta complex (in the Western Ghats, within Peninsular India) and the A. dispar complex (endemic to the Southern Western Ghats) which all revealed undocumented cryptic diversity. Here, we describe five new species and effect nomenclatural changes to some recognised taxa. In the A. nasuta complex, we describe four species from several latitudinal blocks of the Western Ghats and make nomenclatural emendations to the plains populations in the Indian peninsula. We effect nomenclatural change in the A. pulverulenta population of the Western Ghats and describe a new species from the A. dispar group. Our study highlights the use of a multi-criteria approach in unraveling cryptic diversity. This study also reveals a striking case of discordance between morphological and genetic divergence, and the way this is reflected in previous taxonomic and nomenclatural treatments of these populations.

Discovery of a deeply divergent new lineage of vine snake (Colubridae: Ahaetuliinae: Proahaetulla gen. nov.) from the southern Western Ghats of Peninsular India with a revised key for Ahaetuliinae.

The Western Ghats are well known as a biodiversity hotspot, but the full extent of its snake diversity is yet to be uncovered. Here, we describe a new genus and species of vine snake Proahaetulla antiqua gen. et sp. nov., from the Agasthyamalai hills in the southern Western Ghats. It was found to be a member of the Ahaetuliinae clade, which currently comprises the arboreal snake genera Ahaetulla, Dryophiops, Dendrelaphis and Chrysopelea, distributed in South and Southeast Asia. Proahaetulla shows a sister relationship with all currently known taxa belonging to the genus Ahaetulla, and shares ancestry with Dryophiops. In addition to its phylogenetic position and significant genetic divergence, this new taxon is also different in morphology from members of Ahaetuliinae in a combination of characters, having 12-13 partially serrated keels on the dorsal scale rows, 20 maxillary teeth and 3 postocular scales. Divergence dating reveals that the new genus is ancient, dating back to the Mid-Oligocene, and is one of the oldest persisting monotypic lineages of snakes in the Western Ghats. This discovery adds to the growing list of ancient lineages endemic to the Agasthyamalai hills and underscores the biogeographic significance of this isolated massif in the southern Western Ghats.