A new species of miniaturised narrow-mouth frog of the genus Microhyla Tschudi, 1838 (Amphibia: Anura: Microhylidae) from northern Tenasserim, Thailand

An integrative taxonomic analysis recovered the new miniaturised species Microhyla tetrix sp. nov. of the M. superciliaris group as the sister species to M. superciliaris. The new species inhabits low-elevation to mid-elevation evergreen tropical forests of Ratchaburi, Phetchaburi, Prachuap Khiri Khan, Chumphon, Surat Thani and Krabi provinces of south-western Thailand. Additionally, our analysis supports the occurrence of M. superciliaris in Songkhla Province of southern Thailand. Our results underscore the important role of the Isthmus of Kra - a well-known biogeographic region of cladogenic turnover - in differentiation of the M. superciliaris species group. The description of Microhyla tetrix sp. nov. and the record of M. superciliaris brings the total number of species of Microhyla in Thailand to nine. Our work underlines the physiographic complexity of the Thai-Malay Peninsula and the need for intensified field surveys and integrative taxonomic studies for further exploration of its poorly understood herpetofauna.