Microhyla nilphamariensis sp. nov. urn:lsid:zoobank.org:act: 11E1D35F-7FC1–43C1–8318– 747F9FC0C882 Etymology. The species name is derived from the name of the type locality Nilphamari, where the type specimens were collected. Holotype. Adult male, MZH-2362, collected from grass-field (25° 48 0 06.12"N, 88° 53 0 59.21"E), Koya Golahut, Saidpur, Nilphamari, Bangladesh; collected by M. S. A. Howlader, June 9, 2012. Paratopotypes. MZH-2360 (adult female), MZH-2361 (adult female), MZH-2363 (adult female), MZH-2364 (adult female), MZH-2365 (adult female), and MZH-2366 (adult female) collected from the same locality as the holotype; collected by M. S. A. Howlader and Abdur Razzaque, June 9, 2012. Diagnosis. Microhyla nilphamariensis sp. nov. is characterized by a combination of the following characters: HL 77% of HW, EN roughly six times greater than NS, IN roughly five times greater than NS, IOD two times greater than IN, MBE 15% of HL, small ovoid-shaped inner metacarpal tubercle, very small rounded outer metacarpal tubercle, toes with rudimentary webbing, absence of digital discs, inner metatarsal tubercle small and round, outer metatarsal tubercle ovoid-shaped, minute, and indistinct. Description of taxa Holotype (adult male). Small sized frog (SVL 17.36 mm). Head large, triangular, wider than long, HL 77% of HW, HW 27 % of SVL, HL 21 % of SVL, MFE 67 % of HL, MBE 15 % of HL. Snout nearly rounded in lateral view, SL 46% of HL; canthus rostralis indistinct, loreal region concave. Nostrils much closer to snout tip than to eyes, NS 16 % of EN; NS 1 % of SVL, EN 7 % of SVL; nostrils rounded and very small, NS 20 % of IN, MN 92 % HL. Eye large, EL 52 % of HL, EL 11 % of SVL; interorbital distance greater than maximum width of upper eyelid greater, UEW 41 % of IOD, UEW 44 % EL, UEW 4 % SVL. Interorbital space convex, IN 49 % of IOD. Tympanum is hidden. Arms moderately long, FAL 74% HAL, FAL 16% of SVL, HAL 22% SVL. Fingers small, free of webbing, tips are flattened. Relative length of fingers, shortest to longest: 1 0.05 in all pairwise comparisons) along the first PC-axis (Eigenvalue = 14.07; 82.8% variance explained), which correspond to variation in overall size (all traits loading positively and roughly equally on this axis), M. nilphamariensis sp. nov. being the smallest species (Fig. 5B). The second PC-axis (Eigenvalue = 1.48; 8.7% variance explained) captures shape differences, but in this axis M. nilphamariensis sp. nov differs significantly only from M. ornata (Tukey’ s HSD, P <0.05). Nevertheless, that the M. nilphamariensis sp. nov. is clearly differentiated from M. ornata and M. rubra can also be depicted from bivariate scatterplots (S2 Fig.) showing that it’ s diagnostic ratios (see above) do not overlap with those of M. ornata and M. rubra. doi:10.1371/journal.pone.0119825.t001 doi:10.1371/journal.pone.0119825.t002 Genetic divergence of M. nilphamariensis sp. nov. from all other species in the Southeast Asian clade is 10% to 13% (Fig. 3). Likewise, the new species is morphologically different from all known Southeast Asian species in comparison to the original descriptions [39 – 55]. Morphological characters of the other Southeast Asian species (M. berdmorei, M. borneensis, M. achatina, M. butleri, M. palmipes, M. annamensis, M. annectens, M. heymonsi, M. mantheyi, M. superciliaris, M. malang, M. chakrapanii, M. marmorata, M. nanapollexa, M. pulverata, M. arboricola, M. darevskii, M. minuta, M. pineticola, M. pulchella, M. perparva, M. mixtura, M. fowleri, M. maculifera, M. petrigena, M. orientalis) such as webbed toes with distinct digital discs, and leaf vain-type dorsal surface markings separate them from M. nilphamariensis sp. nov., which has reduced webbing, absent discs and irregular dorsal surface markings. M. sholigari also differs from M. nilphamariensis sp. nov. as it has discs on fingers (Fig. 4). Shovel-shaped inner metatarsal tubercle and a more rounded snout separate M. picta from M. nilphamariensis sp. nov. [56]. M. nilphamariensis sp. nov. lacks the minutely shagreened dorsum, mid-dorsal ridge, and deeply furrowed outer metacarpal tubercle of M. fusca [57]. M. nilphamariensis sp. nov. differs from M. pulchra [58] and M. erythropoda [59] in having a rounder snout, smaller body size, and rudimentary foot webbing (M. pulchra and M. erythropoda have obtuse or obtusely pointed snouts, larger body size and half-webbed toes). M. karunaratnei [60] and M. zeylanica [61] are two species endemic to Sri Lanka, and differ from M. nilphamariensis sp. nov. by extensive digital webbing, presence of digital discs, IOD 1.6 times greater than UEW (vs. rudimentary digital webbing, absence of digital discs, IOD 2.43 times greater than UEW). Absence of digital discs differentiates M. nilphamariensis sp. nov. from M. mukhlesuri, M. fissipes and M. mymensinghensis, in which digital discs are present.

Published as part of Howlader, Mohammad Sajid Ali, Nair, Abhilash, Gopalan, Sujith V. & Merilä, Juha, 2015, A New Species of Microhyla (Anurα: Microhylidαe) from Nilphαmαri, Bαnglαdesh, pp. 1-18 in PLoS ONE (e 0119825) (e 0119825) 10 (3) on pages 5-10, DOI: 10.1371/journal.pone.0119825, http://zenodo.org/record/12630525