![. Measurements of specimens of Tylototriton examined (means ± SD of SVL [in mm] and medians of ratios of characters [R: %SVL] and VTW/VTL, with range in parentheses). H: holotype, P: paratype, T: topotype. M: male; F: female. For character abbreviations, refer to text.](https://www.researchgate.net/profile/Kanto-Nishikawa/publication/267810165/figure/tbl2/AS:669280429428766@1536580297655/Measurements-of-specimens-of-Tylototriton-examined-means-SD-of-SVL-in-mm-and_Q320.jpg)
![Photograph of specimens of Tylototriton verrucosus verrucosus from Myanmar (A and B: dorsal and ventral views of CAS 230940 [male]; C: dorsal view of CAS 230933 [female]), dorsal view of male topotype of T. verrucosus verrucosus (D), and dorsal view of male holotype of T. uyenoi (E). Scale bar = 20 mm.](https://www.researchgate.net/profile/Kanto-Nishikawa/publication/267810165/figure/fig2/AS:669280425218070@1536580296997/Photograph-of-specimens-of-Tylototriton-verrucosus-verrucosus-from-Myanmar-A-and-B_Q320.jpg)
![Photograph of dorsal head of specimens of Tylototriton verrucosus verrucosus from Myanmar (A: CAS 230940 [male]; B: CAS 230933 [female]), male topotype of T. v. verrucosus (C), and male holotype of T. uyenoi (D). Scale bar = 10 mm.](https://www.researchgate.net/profile/Kanto-Nishikawa/publication/267810165/figure/fig3/AS:669280429412371@1536580297399/Photograph-of-dorsal-head-of-specimens-of-Tylototriton-verrucosus-verrucosus-from-Myanmar_Q320.jpg)
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A new species of Tylototriton (Amphibia: Urodela: Salamandridae) from Central Myanmar
Abstract and Figures
We describe a new species of Tylototriton from Taunggyi, Shan State, central Myanmar, based on molecular and morphological evidence. The new species, Tylototriton shanorum, is classified as a member of the subgenus Tylototriton. The species differs morphologically from all known congeners by having the combination of dull-colored markings, weakly protruding dorsolateral bony ridges on head, narrow and weakly segmented vertebral ridge, and narrow vomerine tooth series. The taxonomic relationship between T. verrucosus and T. shanjing is briefly discussed based on the molecular phylogeny obtained in this study.
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... For morphological comparisons, the data for the other related species were taken from the related literatures (Fang and Chang 1932;Liu 1950;Nussbaum et al. 1995;Böhme et al. 2005;Hou et al. 2012;Nishikawa et al. 2013aNishikawa et al. , 2014Khatiwada et al. 2015;Le et al. 2015;Phimmachak et al. 2015;Grismer et al. 2018Grismer et al. , 2019Zaw et al. 2019;Pomchote et al. 2020aPomchote et al. , 2020b. ...
... The relationships of all morphometric characters were examined using principal component analysis (PCA). Note that the vent length of the one T. uyenoi female (THNHM 13869) was excluded from the morphological comparison because this parameter is much longer in males than in females [RVL 7.4 vs 1.7 and 1.9; 9.3 vs 4.0 in T. uyenoi, data from Nishikawa et al. (2014) and the present study, respectively]. All statistical analyses were performed using the SPSS v. 22 for Windows. ...
We describe a new species of the newt genus Tylototriton from Umphang Wildlife Sanctuary, Tak Province , western Thailand based on molecular and morphological evidence and named here as Tylototriton umphangensis sp. nov. The new species is assigned to the subgenus Tylototriton and differs from other species in having dark-brown to blackish-brown body and limbs, truncate snout, prominent antero-medial ends of the expansion of the dentary bones, laterally protruding quadrate regions, indistinct and small rib nodules, a well-segmented vertebral ridge, and rough dorsolateral bony ridges, which are steeper anterior, and curved medially at the posterior ends. The molecular data show that Tylototriton umphangensis sp. nov. differs from T. uyenoi sensu stricto by a 5% genetic sequence divergence of the mitochondrial NADH dehydrogenase subunit 2 region gene. The new species and T. uyenoi are both endemic to Thailand, distributed along the Northwest Thai (Dawna) Uplands of Indochina. To clarify the species boundary between Tylototriton umphangensis sp. nov. and T. uyenoi, additional field research is needed in adjacent areas. Tylototriton umphangensis sp. nov. is restricted to evergreen hill forests in Umphang Wildlife Sanctuary. We suggest that the new species should be classified as Endangered (EN) in the IUCN Red List.
... Many new species of crocodile newts have been described recently, based on a combination of morphological and molecular investigations (e.g. Nishikawa et al. (2013Nishikawa et al. ( , 2014; Le et al. (2015); Phimmachak et al. (2015); Khatiwada et al. (2015); Grismer et al. (2018Grismer et al. ( , 2019; Zaw et al. (2019); Bernardes et al. (2020); Li et al. (2020); Pomchote et al. (2020aPomchote et al. ( , 2021; Poyarkov et al. (2021b); Dufresnes and Hernandez (2022); Phung et al. (2023)). ...
An integrative taxonomic analysis combining molecular and morphological lines of evidence revealed a new cryptic species in the Tylototriton verrucosus species group from Manipur, northeastern India. The new species was previously confused with T. hima-layanus and T. verrucosus. Tylototriton zaimeng sp. nov. can be distinguished from its congeners by medium body size, head massive and wide with rounded snout and very wide and protruding supratemporal bony ridges and a well-developed sagittal ridge, short limbs not overlapping when adpressed along body, wide and not segmented vertebral ridge distinct, 13-14 pairs of rib nodules, brown colouration with dull orange to yellowish-brown markings on head, vertebral ridge, rib nodules, palms, soles, vent and ventral tail ridge and by vomerine teeth organised in two distinctly curved bell-shaped series. Phylogenetic analysis of the ND2 and 16S rRNA mtDNA genes confirmed the placement of the new species to the Clade I of the subgenus Tylototriton and suggested it is a sister species of T. panwaensis and T. houi (p-distance 3.0% in ND2 gene). The range of the new species is restricted to the Khongtheng Mountain Range and is isolated from the range of T. panwaensis and T. houi in northern Myanmar and southern China, respectively. We suggest the new species to be considered as Vulnerable (VU) in the IUCN Red List.
... Nonetheless, several key specimens included in phylogenetic studies of Tylototriton and Echinotriton originated from street markets in Asia, collected by locals to be eventually used for medicine or as animal curiosities (Fei et al., 2012;Hou et al., 2012;Nishikawa et al., 2014). Within our extensive dataset, we listed 26 such specimens, representative of no less than eight species, mostly of Chinese origin (T. ...
Crocodile newts (genera Echinotriton and Tylototriton) symbolize the outstanding biodiversity of Southeast Asia. In this study, we provide an exhaustive account of their evolution and diversity with an extensive phylogeography based on unprecedented mitochondrial (16.2kb) and nuclear sequence (3.2kb) alignments, combining barcoding information from nearly 1200 specimens collected over ~180 localities representative of all lineages known to date. While nuclear data lacked resolution, the mitochondrial tree of life highlighted an extreme dynamic of allopatric speciation that intimately followed climate cooling within the last 10 million years, a pattern shared with many other tropical and subtropical amphibians. In Crocodile newts, this dynamic implies weak dispersal and local adaptation as contributing factors of isolation, and was accompanied by macro- and micro-evolutionary changes in reproductive behaviors. Specifically, our resolved phylogeny of Tylototriton allowed tracing a major shift from conserved habits of terrestrial clutch spawning towards more plastic strategies involving both aquatic and land spawning of single eggs. Exploiting our framework, we then completed the taxonomy of crocodile newts by describing a new subgenus and two new species. Our study provides a checkpoint to guide future phylogeographic, speciation and conservation research in these iconic amphibians, which would greatly benefit from genomic resources.
... However, to understand evolutionary processes future studies especially on the ecology of the enigmatic crocodile newts are needed. Numerous species were just recently identified based on molecular data leading to an enormous increase in species numbers over the last decade (Stuart et al., 2010, Shen et al., 2012, Nishikawa et al., 2013a, Nishikawa et al., 2013b, Hou et al., 2014, Nishikawa et al., 2014, Khatiwada et al., 2015, Le et al., 2015, Phimmachak et al., 2015a, Qian et al., 2017, Grismer et al., 2018, Grismer et al., 2019, Zaw et al., 2019, Bernardes et al., 2020, Pomchote et al., 2020, Poyarkov et al., 2021. However morphological distinct characters are hard to identify and often appear somehow descriptive summarising differences of particular body part proportions based on a few specimens without any accounting for SD. ...
Sexual dimorphism (SD) is a main source of intraspecific morphological variation, however sexual shape dimorphism (SShD) was long time neglected in evolutionary research. Especially in cold-blooded animal groups only subtle shape differences are expressed between males and females and the selective forces behind it are poorly understood. Crocodile newts of the genera Echinotriton and Tylototriton are highly polymorphic in their reproductive ecology and hence, are a highly suitable model system to investigate potential evolutionary forces leading to SShD differences. We applied 3D geometric morphometrics to the cranial and humerus morphology of nine species of crocodile newts to investigate patterns of SShD in relation to the different mating modes. Trajectories of shape differences between males and females differ in both, cranium and humerus but mating mode does explain differences in SShD trajectories between species only in cranial morphology. Nevertheless, cranial morphology shape differed between the amplecting and circle dancing species. Hence, other selective forces must act here. Variable interspecific allometric trajectories are a potential source of shape differences whereas these trajectories are quite stable for the sexes irrespective of the species.
A new species of the genus Tylototriton is described from Ngoc Linh Mountain, Kon Tum Province, in the Central Highlands of Vietnam based on integrative taxonomy, namely by combining molecular and morphological evidence. Tylototriton ngoclinhensis sp. nov. differs from all other congeners based on morphological data, allopatric distribution, and molecular divergence. In terms of genetic divergence, Tylototriton ngoclinhensis sp. nov. distinctly differs from the sister species T. panhai (6.77%) and from T. ngarsuensis (12.36%) based on the mitochondrial NADH dehydrogenase subunit 2 (ND2) gene. Tylototriton ngoclinhensis sp. nov. is a moderate sized and robust salamander species with large cephalic edges, parotoids, and vertebral ridge orange in coloration. The new taxon differs from its congeners by a combination of the following morphological characteristics: size medium (SVL 60.8–66.5 mm, TL 57.6–61.8 mm in males, and SVL 72.5–75.6 mm, TL 62.9–67.9 mm in females); head longer than wide; parotoids very prominent and enlarged, projecting backwards; tail length shorter than snout-vent length; vertebral ridge large, high and glandular in appearance; 14 large and distinct dorsolateral glandular warts; gular fold present; tips of fore and hind limbs overlapping when adpressed along the body; tips of fingers reaching between eye and nostril when foreleg is laid forward; dorsal surface and lateral sides of the head, upper and lower lips, dorsolateral glandular warts, vertebral ridge, the peripheral area of the cloaca and the ventral edge of the tail orange in coloration; the presence of a distinct black line extending from the posterior end of the eye towards the shoulder. Tylototriton ngoclinhensis sp. nov. is restricted to evergreen montane forests near water bodies on Ngoc Linh Mountain. We suggest that the new species should be classified as Endangered (EN) in the IUCN Red List. This new important discovery represents the eighth Tylototriton taxon described from Vietnam, and at the same time constitutes the southernmost distributional record for the whole genus in Asia.
This book offers a comprehensive account of the current state of inland waters in tropical and subtropical East Asia, exploring a series of case studies of freshwater fish, reptiles, amphibians, birds, mammals and water bodies at particular risk. The book highlights the rich freshwater biodiversity of tropical East Asia and draws attention to the various threats it faces due to human activities and rapid environmental change. It addresses the question of whether the contributions of these animals and habitats, or biodiversity in general, to ecosystem functioning and service provision provide sufficient basis for arguments supporting nature conservation. Drawing on instances from the rivers and lakes of tropical East Asia, the book also asks whether the benefits accruing from intact ecosystems are likely to be enough to ensure their preservation. If the answer to either or both these questions is ʼno’, then what are the prospects for freshwater biodiversity in rapidly changing tropical East Asia? This book will be of interest to students and scholars of biodiversity, conservation, freshwater ecology, ecosystem services and Asian Studies.
A new species of the genus Tylototriton sensu lato from Tongzi County, Guizhou Province, China was described. Molecular phylogenetic analyses based on mitochondrial 16S and ND2 gene sequences indicated the new species as the most closely related species of T. dabienicus in Henan. The new species could be identified from its congeners by a combination of the following morphological characters: (1) body size medium (TOL 120.5–135.1 mm and SVL 61.1–65.9 mm in males, and TOL 123.5–127.6 mm and SVL 66.7–69.2 mm in females); (2) gular fold present; (3) the tail length shorter than the snout-vent length; (4) the distal ends and ventral surfaces of digits, peripheral area of cloaca, and the lower margin of tail orange; (5) the distal tips of the limbs greatly overlapping when the fore and hind limbs being pressed along the trunk; (6) fingertips reaching to the level beyond the snout when the forelimbs being stretched forward; (7) nodule-like warts on body sides continuous and no obvious. The new species is known only from the montane forests of Huanglian Nature Reserve, Tongzi County, Guizhou Province, China. We recommend the new species to be listed as Critically Endangered.
In this work, a new species of the genus Tylototriton is described from Guangdong, southern China. Tylototriton sini sp. nov. was recorded as T. asperrimus for decades, and was indicated to represent an independent lineage based on recent molecular phylogenetic analyses. After detailed molecular analysis and morphological comparisons, Tylototriton sini sp. nov. is recognized as a distinct species which can be clearly distinguished from all known congeners by a combination of morphological characteristics and the significant divergence in the mitochondrial gene. Because the genus Tylototriton is of high conservation concern and all formally described members are protected by law, we also provide first data on the conservation status and recommendations for IUCN categorization for Tylototriton sini sp. nov. A suggestion on the species groups division of the genus Tylototriton is also provided based on their morphological differences and phylogenetic relationships.
Herein, we provided a morphological description combined with a phylogenetic analysis of the northernmost Thai Tylototriton population, which was found in Doi Pha Hom Pok National Park (DPHPNP), Chiang Mai Province, northern Thailand. Three adult males were collected from a small breeding pond during our survey in July 2020. Based on molecular (two specimens) and morphological (three specimens) evidence, all three specimens from DPHPNP were identified as Tylototriton verrucosus Anderson, 1871, and were characterized by having a blackish background, orange to light orange-brown color markings, segmented vertebral ridge, prominent rib nodules ranging from 13–15 warts, and a rough skin with granules. Hence, this second record of T. verrucosus populations in Thailand confirms a range extension of this species in northern Indochina. Additionally, the morphological variation and conservation status are discussed for the populations from Thailand.
A new species of the salamandrid genus Tylototriton is described from Ha Giang and Cao Bang provinces, northern Vietnam, based on molecular and morphological data. The new species differs morphologically from all known congeners in the combination of blackish body coloration; medium-sized body; distinctly rough skin; tubercular vertebral ridge; knob-like rib nodules; large eye; and low, narrow tail. The distribution pattern of species of Tylototriton in Vietnam is briefly discussed.
Three morphological groups are found in a salamandrid newt Tylototriton shanjing from Thailand. We describe two of them as new species, one from northern and the other from northeastern Thailand, based on molecular and morphological data, however we could not make a taxonomic decision on the remaining one group because of the lack of voucher specimens and sufficient genetic data. The northern species differs morphologically from all known congeners by having the combination of orange to reddish brown markings, narrow and sharply protruding dorsolateral bony ridges on head, weakly segmented vertebral ridge, and long and high tail. The northeastern species is characterized by having the combination of yellow, orange, or reddish brown markings, wide and moderately protruding dorsolateral bony ridges on head, smooth vertebral ridge, black limbs, and black tail except for edges. Validity of taxonomic subdivision of the genus Tylototriton
is discussed.
Significance
Chytridiomycosis has resulted in the serious decline and extinction of >200 species of amphibians worldwide and poses the greatest threat to biodiversity of any known disease. This fungal disease is currently known to be caused by Batrachochytrium dendrobatidis , hitherto the only species within the entire phylum of the Chytridiomycota known to parasitize vertebrate hosts. We describe the discovery of a second highly divergent, chytrid pathogen, Batrachochytrium salamandrivorans sp. nov., that causes lethal skin infections in salamanders, which has resulted in steep declines in salamander populations in northwestern Europe. Our finding provides another explanation for the phenomenon of amphibian biodiversity loss that is emblematic of the current global biodiversity crisis.
The collision of India with Asia results in a rapidly changing stress pattern around both Himalayan syntaxes. The maximum compressive stress, which is north- south north of the indenter, fans radially through nearly 180° around the syntaxes to accommodate the necessary strike-slip motion on the edges of the indenter. Thus, the whole Indochina Peninsula was swept by the migrating stress and associated strain pattern as the eastern syntaxis moved to the north. As a result, the maximum horizontal component of the stress field is predicted to have been first oriented east-west, then north-south. We propose that this changing stress field controlled the opening of the sedimentary basins and of the South China Sea as well as the direction of motion of the major strike-slip faults.
The genus Oreolalax is reported from Vietnam for the first time and a new species is described based on morphological differences, molecular divergence, and phylogenetic placement. Morphologically, the new species is distinguishable from its congeners on the basis of a combination of the following diagnostic characters: size small; tympanum hidden; toes with webbing at base; dorsum with distinct, round, spiny warts; flanks with white, spiny spots; belly and lower surface of limbs smooth, with dark marbling; interorbital region without dark triangular pattern; upper surface of thigh with dark bars; male with black spines present on margin of lower lip, spinal patches on chest small with fine spines, nuptial spines on fingers small, and without vocal sacs. In phylogenetic analyses, the new species is unambiguously nested within the genus Oreolalax.
A new species in the morphologically conservative Tylototriton asperrimus group is described from Khammouan Province, Laos. Molecular phylogenetic analysis of mitochondrial DNA confirms its placement in the T. asperrimus group. Tylototriton notialis sp. nov. is diagnosable in mitochondrial DNA, nuclear DNA, and morphology from its congeners. The new species represents the first record of the genus from Laos, and is the southernmost known member of the T. asperrimus group.
A new species of the subgenus Vibrissaphora in the genus Leptobrachium is described from eastern Laos, on the basis of molecular and morphological evidence. The new species differs from all members of the subgenus by lack of spines on upper lip, small size with adult male SVL of 55.2 mm, indistinct tympanum, first finger longer than fourth, inner metatarsal tubercle smaller than first toe, 2⅓ phalanges of fifth toe unwebbed, dorsum nearly smooth and flanks with densely granulated skin, dorsum light brown with dark brown spots, flanks dark brown reticulated with cream spots, and abdomen cream with irregular brown markings. Classification of two subgenera in Leptobrachium is discussed.
A new species of the genus Tylototriton is described in this article based on morphological and genetic evidence. The new species is identified belonging to the T asperrimus group and is similar to T wenxianensis. The diagnostic characters of the new species are as follows: dorsal ridge broad and thick, its width approximately equal to eye diameter (P < 0.001); tail height greater than width at base of tail (P < 0.001); no villous genital papilla found inside the male anal fissure; nodule-like warts, along lateral margin of the trunk, bulge and forming tubercles, and thin and transverse striae present between the tubercles.