Veerappan Deepak

Western Melanesia sits at the junction of three major tectonic plates, characterised by dynamic plate interactions and geological diversity. Tectonic activity in this region has given rise to modern New Guinea, a relatively young island with extreme topographic heterogeneity and evolutionarily complex biota. New Guinea—particularly the East Papuan Composite Terrane (EPCT)—supports exceptional frog diversity; however, evolutionary histories of many frogs of the EPCT are poorly understood. The microhylid frog genus Mantophryne currently includes five described species ( M. axanthogaster , M. insignis , M. louisiadensis , M. menziesi and M. lateralis ), with the first four confined to small portions of the EPCT and the last distributed across the eastern half of New Guinea. The biogeographic history of these frogs remained incompletely resolved at the time of our study. We estimate that Mantophryne diverged from other microhylid genera approximately 14.4 million years ago (MYA) and began to speciate ca. 8.5 MYA. We recover eight distinct lineages within frogs assigned to M. lateralis , which started to diverge ca. 5.5 MYA. Dispersal of Mantophryne out of the EPCT occurred in the late Pliocene, around the time the Central Highlands expanded eastward to connect with the EPCT. Six pairs of sister lineages arose during a time of significant climate reorganisation in the Late Pliocene—Early Pleistocene when it is possible that areas to the north of the Central Highlands experienced increased precipitation, while areas south of the Central Highlands experienced lower rainfall, resulting in contraction of rainforests and expansion of savannahs. We did not identify any significant differences in habitus between lineages, other than M. louisiadensis which is much larger than all other Mantophryne, and has exceptionally high sexual‐size dimorphism. While an interrogation of the putative cryptic species complex within the M. lateralis clade is beyond the scope of our study, we find that a combination of tectonic rearrangement and climatic history are likely responsible for most of the diversity within the genus that we see today.

The genus Ptyctolaemus (Peters, 1864) has a restricted distribution in northeast India, Indo-Burma and Indochina region. Ptyctolaemus currently includes six nominal species. Previous molecular studies suggested the presence of a genetically distinct lineage from northern Myanmar. I studied a historic series of Ptyctolaemus specimens collected from Myanmar housed at the Natural History Museum in London (n=29) and the California Academy of Sciences (n=17) in the USA. The specimens collected from Kachin State in northern Myanmar are morphologically distinct from the currently recognised species and are described here as a new species. The addition of another new species of Ptyctolaemus highlights the underestimated diversity of agamid lizards in the Indo-Burma biodiversity hotspot. An identification key to the species in the genus Ptyctolaemus is provided herein.

The diversity of lizards in the northeast Indian biodiversity hotspot is underestimated, as evidenced by many new species recorded in recent years. Here, we describe a new species of Takydromus from Ultapani, Kokrajhar District, Assam, India. This newly identified species is distinguished from its relatives in its distinctive morphological features and significant genetic variation in the mitochondrial 12S rRNA and COI genes. We have also added the missing molecular data for T. sikkimensis and T. khasiensis. In the light of these new data, we discuss the phylogenetic relationships of Takydromus species from the Indian subcontinent with their congeners.

Aim: The aim of this study was to elucidate the phylogenetic and evolutionary history of the colubrid genus Platyceps . Location: Saharo–Arabian biogeographic realm. Taxon: Genus Platyceps , Colubridae, Squamata. Methods: We sequenced four mitochondrial (12S rRNA, cytb , ND4 + tRNA, COI ) and two nuclear ( c‐mos , NT3) markers of 19 species (115 newly analysed tissue samples) of the genus Platyceps , covering the entire distribution of the genus, to build both Maximum Likelihood (IQ‐Tree) and Bayesian inference (BEAST) trees. Furthermore, for the first time, we reconstructed the historical biogeography of this genus based on a time‐calibrated tree using the BioGeoBEARS package in R. Results: Our results confirmed Platyceps to be monophyletic and that it is divided into four main groups ( plinii , ventromaculatus , karelini , and florulentus ). The genus diverged in the Early Miocene (around 19.9 million years ago) when the ancestor of the plinii group split. This was followed by the separation of the three main groups ( ventromaculatus , karelini , and florulentus ) around 18.6 million years ago. The genus's representatives then spread from their most probable place of origin in South Asia to the entire Saharo‐Arabian biogeographic realm. Main Conclusions: The genus originated most likely in South Asia from where it expanded three independent times through the Arabian Peninsula to northeastern Africa. The dispersal events were likely enabled by the existence of temporary land bridges between Africa and Arabia. Considering that many of the Platyceps species are well adapted to arid conditions, the distribution was also affected by the Miocene climatic changes and the increasing aridification of the North African and Arabian arid belt.

Bush frogs currently in the genera Raorchestes and Philautus are poorly documented from northeast India when compared to the Western Ghats of southwestern India. They are morphologically cryptic, but variable in their acoustic repertoire and genetic divergence. We present a long-overdue revision of the bush frogs of northeast India by sampling 81 localities in eight Indian States (including nine type localities of known species) and by comparing historical (especially, type) material. Using an integrative approach that combines levels of divergence in mitochondrial DNA, a nuclear-encoded gene and comparing morphological and bioacoustic data, we demonstrate the existence of 13 new species, which are formally described here. In addition, based on the evidence from molecular and morphological data we synonymise four previously described species from this region. We resolve the taxonomic identities of three other frog species found in northeast India. After extensive survey across northeast India, we did not find a single specimen of the genus Philautus . The only species in this genus with ambiguous generic identity is P. dubius which requires further taxonomic investigation.

The genus Ptyctolaemus Peters, 1864 is currently represented by three species; P. gularis , P. collicristatus and P. chindwinensis . Previous molecular phylogenetic studies have highlighted additional lineages within P. gularis. Phylogenetic analysis using the ND2 mitochondrial gene recovered three distinct lineages in India. Multivariate analyses using morphological data placed the type specimen of P. gularis (ZMB 5004) with the samples collected from Meghalaya. We assign this lineage as P. gularis and describe the other two lineages as new species. Ptyctolaemus siangensis sp. nov. found west of Siang River in Arunachal Pradesh and Ptyctolaemus namdaphaensis sp. nov. found in Namdapha, Changlang district of Arunachal Pradesh. Although phenotypically similar the two new species differ from its congeners in gular colouration and subtle morphological differences.

The kukri snake Oligodon albocinctus (Cantor, 1839) is a widespread element of the Indo–Himalayan and Indo-Burmese snake fauna with two distinct color patterns. The first and more typical morphotype has light bands with black edges, while individuals of the second morphotype have brown blotches or narrow crossbars. The polychromatic nature of this species has led to considerable taxonomic confusion between O. albocinctus and members of Oligodon occurring in sympatry or parapatry. In this study, we investigate patterns of genetic and morphological variation in O. albocinctus and explore whether its color morphotypes correspond with genetic structure recovered in earlier studies. Additionally, we re-assess the status of two taxa that have been confused with O. albocinctus in the past—Oligodon juglandifer (Wall, 1909) and the recently synonymized Oligodon lipipengi Jiang, Wang, Li, Ding, Ding & Che in Che, Jiang, Yan & Zhang, 2020. Our results suggest both the banded and blotched morphotypes of O. albocinctus are genetically identical and lack phylogenetic signal. We recover three divergent clades separated by pairwise distances of 5.8–9.8% based on cytochrome b gene fragments and 1.7–4.2% based on 12s16s ribosomal RNA fragments. One of these clades is geographically restricted to southwest Myanmar (Burma) and was recovered as sister to all other populations of O. albocinctus. This lineage was supported as a cryptic yet evolutionarily independent lineage by species delimitation analyses, a partial lack of haplotype sharing based on nuclear DNA sequences (recombination activation gene 1), and subtle differences in morphology. To reflect these results, we resurrect the name Simotes amabilis Günther, 1868 from synonymy (as Oligodon amabilis comb. nov.) for the southwest Myanmar clade. Despite moderately high genetic divergence, morphological support for recognizing O. juglandifer and O. lipipengi was inconclusive and both names are considered junior synonyms of O. albocinctus sensu stricto until additional sampling can be conducted. We present detailed redescriptions of O. albocinctus and O. amabilis comb. nov. and outline diagnostic characters that distinguish each species from chromatically similar congeners.

A new species of the snake genus Xylophis is described from the Wayanad region in the Western Ghats of India. The new species, X. chenkaruppan sp. nov., is described based on six specimens collected from Vellarimala and Kurichyarmala Hills. Molecular genetic analysis based on three mitochondrial (16s, cytb & nd4) and one nuclear (cmos) marker recovered this lineage as sister to X. perroteti. Although also phenotypically generally similar to X. perroteti from Nilgiri Hills (north of the lowland Palghat Gap), the ventral head morphology of X. chenkaruppan sp. nov. differs from the former in that the posterior genial shields are in midline contact, a condition found also in X. mosaicus occurring only south of the Palghat Gap. An updated key to the identification of the species of the genus Xylophis is provided herein.

We describe a new species of Riopa from the Eastern Ghats in Andhra Pradesh and Telangana states, India. The new species is diagnosed by the following suite of characters: lower eyelid with a semi-transparent disk, 108–109 paravertebral scale rows, 8 or 9 lamellae on the 4th toe, dorsum with 16 distinct longitudinal lines, five fingers and five toes, preanal scales not enlarged, and ear opening covered by scales. Our mitochondrial molecular data supports the placement of the species in the genus Riopa and the new species is 4.1–9.2 % divergent from genetically sampled congeners. This study adds in understanding the cryptic diversity of lizard fauna in the Eastern Ghats in peninsular India. Based on our findings we provide a dichotomous key to the genus Riopa.