Phylogenetic analyses of distantly related clades of bent-toed geckos (genus Cyrtodactylus) reveal an unprecedented amount of cryptic diversity in northern and western Thailand

Abstract

Cyrtodactylus species are the most diverse of the geckos and are widely distributed in Southeast Asia, including Thailand. However, their patterns of distribution, especially in northern and western parts of Thailand, remain unknown because few Cyrtodactylus species in these regions have been described. Thus, a data set of mitochondrial NADH dehydrogenase 2 (ND2) gene and flanking tRNAs from Cyrtodactylus found in northern and western Thailand, including contiguous areas, was assembled to elucidate phylogenetic relationships and identify the distribution patterns of these geckos. The results showed four well-supported clades, a northwestern clade (A), a northern clade (B), a western clade (C), and a special clade characterized by specific morphological features (D). Clades A–C were grouped with strong support by the geography of their localities from northern Thailand (Mae Hong Son and Chiang Mai Provinces) along the Tenasserim mountain ranges to Phang-Nga Province, Thailand. Clade D is a distinct clade of Cyrtodactylus species characterized by a tuberculate and prehensile tail and distributed widely in mainland Southeast Asia. Overall, the results suggest a pattern of geographic separation and distribution of Cyrtodactylus in northern and western Thailand. Additionally, this study provides evidence of a hidden biodiversity of Cyrtodactylus in these regions.

An integrative taxonomic revision of slug-eating snakes (Squamata: Pareidae: Pareineae) reveals unprecedented diversity in Indochina

“…Our work further highlights the importance of the Indochinese region, including the territories of Vietnam, Laos, Cambodia, and Thailand, as one of the key biodiversity hotspots with high levels of herpetofaunal diversity and endemism ( Bain & Hurley, 2011 ; Geissler et al, 2015 ; Duong et al, 2018 ; Nguyen et al, 2018 , 2019 , 2020b , 2020c ; Poyarkov et al, 2018b , 2019 , 2021 ; Grismer et al, 2019 , 2021a , 2021b ; Chomdej et al, 2021 ; Uetz, Freed & Hošek, 2021 ). This area is facing many pressures with major habitat loss by deforestation due to logging, the growing human population density and infrastructure development, agricultural extension, forest fires, and tourism development ( Lang, 2001 ; Meyfroidt & Lambin, 2009 ).…”

A new cryptic arboreal species of the Cyrtodactylus brevipalmatus group (Squamata: Gekkonidae) from the uplands of western Thailand

“…Smith's (1935) report of C. brevipalmatus from Ban Pa Che, Raheang (Umphang in Ellis and Pauwels 2012) Tak Province in western Thailand (not listed by Taylor 1963) was based on material he did not examine and his account merely re-described his specimens from the type locality at Khao Luang, Nakon Sri Thammarat Province (Smith 1923(Smith , 1930. Ban Pa Che is the same locality as Chao Doi Waterfall, Mae Moei National Park, Tha Song Yang District from where Chomdej et al (2021) report sp.10. and it is highly likely this is the species reported by Smith (1935) as C. brevipalmatus.…”

“…1) and partially webbed digits and spend most of their time above ground level-often in dense vegetation, beneath exfoliating bark, in root tangles, or within tree trunk crevices (Smith 1923;Ulber 1993;Grismer 2011;Nurngsomsri et al 2014;Grismer et al 2021b). The group currently contains four nominal species and at least three undescribed species (Chomdej et al 2021;Grismer et al 2021a) that range from northwestern Vietnam, Laos and Thailand, then southward along the Thai-Malay Peninsula to southern Peninsular Malaysia (Fig. 1).…”

“…Chomdej et al (2021) reported an undescribed species (sp. 9) in their phylogeny from Thong Pha Phum National Park, Thong Pha Phum District, Kanchanaburi Province, Thailand and government reports fromNabhitabhata et al (2004) andNabhitabhata and Chan-ard (2005) list C. interdigitalis from Huai Kha Khaeng, Uthai Province.…”

Hidden tribe: A new species of Stream Toad of the genus Ansonia Stoliczka, 1870 (Anura: Bufonidae) from the poorly explored mountainous borderlands of western Thailand

“…The northern Tenasserim Mountain region is nota ble for the recent discoveries of endemic amphibians and reptiles (Matsui 2006;Sumontha et al 2012Sumontha et al , 2017Wilkinson et al 2012;Connette et al 2017;Grismer et al 2016Grismer et al , 2020aGrismer et al , 2020bGrismer et al , 2020cMatsui et al 2018;Pawangkhanant et al 2018;Suwannapoom et al 2018;Lee et al 2019;Chomdej et al 2020Chomdej et al , 2021Poyarkov et al, 2020). The mountains of northern Tenasserim are recognized as one of multiple local centers of amphib ian diversity and endemism in Indochina .…”