A new species of the genus Tylototriton (Urodela, Salamandridae) from western Thailand

Abstract

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 umphangensissp. 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 umphangensissp. 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 umphangensissp. nov. and T. uyenoi, additional field research is needed in adjacent areas. Tylototriton umphangensissp. 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.

Southbound – the southernmost record of Tylototriton (Amphibia, Caudata, Salamandridae) from the Central Highlands of Vietnam represents a new species

“…A total of 12 new species has been recorded during the last three years alone, from China, Thailand and northern Vietnam ( Bernardes et al 2020 ; Li et al 2020 ; Li et al 2022 ; Luo et al 2022 ; Lyu et al 2021 ; Pomchote et al 2021 ; Poyarkov et al 2021a ; Dufresnes and Hernandez 2022 ; Rao 2022 ; Wang et al 2022 ). Most recent descriptions were due to the separation of species complexes, that were previously masked by phenotypic similarities ( Bernardes et al 2020 ; Li et al 2020 ; Lyu et al 2021 ; Pomchote et al 2021 ; Poyarkov et al 2021a ; Luo et al 2022 ). There certainly is high potential to continue uncovering new species by applying integrative taxonomic analyses ( Dufresnes and Hernandez 2022 ).…”

“…Morphological comparisons between the new taxon and its congeners were based on the specimens examination and the following literature: Fei et al (1984) , Nussbaum et al (1995) , Böhme et al (2005) , Chen et al (2010) , Stuart et al (2010) , Hou et al (2012) , Shen et al (2012) , Nishikawa et al (2013a , b ), Nishikawa et al (2014) , Yang et al (2014) , Khatiwada et al (2015) , Le et al (2015) , Phimmachak et al (2015) , Fei and Ye (2016) , Hernandez (2016) , Qian et al (2017) , Grismer et al (2018 , 2019 ), Zaw et al (2019) , Bernardes et al (2017a , 2020 ), Pomchote et al (2020 , 2021 ), Lyu et al (2021) , Poyarkov et al (2021a) , Li et al (2022) , and Luo et al (2022) .…”

“…Remarkably, 15 new species have been described in the past five years ( Hernandez 2016 ; Dufresnes and Hernandez 2022 ; Frost 2023 ). The genus was subdivided into three subgenera, Tylototriton , Yaotriton , and Liangshantriton (e.g., Dubois and Raffaëlli 2009 ; Nishikawa et al 2013a ; Bernardes et al 2020 ; Pomchote et al 2021 ) and includes several, as yet, unnamed taxa, which contain cryptic species that are morphologically difficult to distinguish, especially in their southern range of distribution ( Hernandez 2016 ; Pomchote et al 2021 ; Poyarkov et al 2021b ). Most of the new discoveries derived from the splitting of widely distributed Tylototriton taxa through the efforts of integrative taxonomy, namely the combination of morphological and phylogenetic analyses.…”