Microhyla malcolmi Cochran 1927

Microhyla malcolmi Cochran, 1927 Figures 6 C – D, 7 B, 10 B, 11, 12, 13; Tables 3, 6, S 2 Suggested common name. Malcolm’s narrow-mouthed frog. Synonymy and chresonymy. Microhyla malcolmi Cochran, 1927: 182. Holotype: USNM 72172 (Fig. 11). Type locality: “ Pak Jong, Siam ”, now Pak Chong District, Nakhon Ratchasima Province, Thailand — Parker (1928: 473–499); Barbour and Loveridge (1929: 235); Bourret (1942: 509); Li et al. (2019: 568). Microhyla fowleri Taylor, 1934: 284. Holotype: ANSP 19903 (Fig. 12). Type locality: “ Chieng Mai, Siam ”, now Chiang Mai Province, Thailand — Dubois (1987: 3); Bourret (1942: 509); Taylor (1962: 560); Fei (1999: 292–293); Yang and Rao (2008: 124); Fei et al. (2009: 890–894); Fei et al. (2010: 481); Matsui (2011: 33–49); Matsui et al. (2011: 168, 171, 174, in part); Fei et al. (2012: 567); Poyarkov et al. (2014: 89–148); Pradana et al. (2017: 70-90); Li et al. (2019: 568). Microhyla (Microhyla) fowleri — Dubois (1987: 3). Microhyla berdmorei — Bourret (1942: 509, in part); Parker (1928: 473–499, in part); Barbour and Loveridge (1929: 235); Parker (1934: 127, in part); Taylor (1962: 560, in part); Heyer (1971: 64–66, in part); Berry (1975: 118–119, in part); Dubois (1987: 3, in part); Stuart (1999: 49, in part); Orlov et al. (2002: 99, in part); Ohler et al. (2002: 465–481, in part); Chan-ard (2003: 102, in part); Teynié et al. (2004: 35, in part); Nguyen et al. (2005: 44, in part); Stuart (2005: 35); Devi and Shamungou (2006: 317–324, in part); Grismer et al. (2006: 63, in part); Stuart and Emmett (2006: 6); Das and Yaakob (2007: 68, in part); Grismer and Aun (2008: 277, in part); Neang and Holden, (2008: 63, in part); Wogan et al. (2008: 88, in part); Chan et al. (2009: 278, in part); Nguyen et al. (2009: 97, in part); Chan-ard et al. (2011: 131, in part); Thong-aree et al. (2011: 99–106, in part); Grismer et al. (2004: 18, in part); Manthey and Denzer (2014: 3–21, in part); Poyarkov et al. (2014: 89–148, in part); Sumarli et al. (2015: 8, in part); Vassilieva et al. (2016: 72–73, in part); Do et al. (2017: 88–89, in part); Mulcahy et al. (2018: 95, in part); Nguyen et al. (2019: 549-580, in part); Geissler et al. (2019: 40–63); Niyomwan et al. (2019: 222–223, in part); Garg et al. (2019: 15, in part); Poyarkov et al. (2020 b: 136 –163, in part); Gorin et al. (2020: 1–47, in part); Makchai et al. (2020: 116, in part); Poyarkov et al. (2021: 40, in part); Gorin et al. (2021: 97, in part); Zug (2022: 30, in part); Hoang et al. (2022: 35, in part); Frost (2024: page “ Microhyla berdmorei ” in part). Holotype. USNM 72172 (adult female), by original designation (not physically examined by us, but see Fig. 11). Type locality: “ Pak Jong, Siam ”, now Pak Chong District, Nakhon Ratchasima Province, Thailand (see Fig. 9). Revised diagnosis. Microhyla malcolmi is characterized by the following combination of morphological attributes: (1) large body size (SVL 33.2-41.8 mm in males, 36.0- 43.8 mm in females), with slender and triangular body habitus; (2) head longer than wide; (3) skin on dorsum slightly shagreened, laterally with sparse tiny tubercles; (4) snout obtusely pointed in dorsal, ventral, and lateral views; (5) first finger shorter than half of second finger length; (6) finger tips with weak disks lacking dorsomedial grooves; (7) toes with well-developed disks lacking or bearing rudimentary dorsomedial grooves; (8) tibiotarsal articulation of an adpressed limb extends far beyond snout; (9) toe webbing complete, reaching disks on all toes; webbing formula: i 1-1 ii 1 - 1 iii 1 - 1 iv 1 - 1 v; (10) throat and chin dark-gray to almost black in males; belly bluish-gray anteriorly, yellowish posteriorly; (11) dorsal surfaces of fore- and hind limbs with wide dark crossbars, up to 3–4 crossbars on thighs; (12) brown patch above cloacal opening of variable shape and indistinct edges; (13) dark-brown dorsal “ teddy-bear ” - pattern distinct, usually edged with light-brown or beige anteriorly; (14) black spots and blotches of irregular shape on body flanks; (15) broad grayish-brown lateral band lateral stripe extending from armpit to groin; (16) light postocular stripe beige with black edging; (17) reddish spots on dorsum and dorsal surfaces of hindlimbs absent; (18) iris with black stripe below the pupil. Material examined. In this study, we used morphological data from 52 specimens of M. malcolmi from Thailand, Laos, and Vietnam (see Table S 2 for details). Description of the specimen ZMMU A-7973 (Fig. 13). An adult male specimen in a very good state of preservation. Body size large (SVL 37.1 mm; other measurements are presented in Table S 2). Body habitus slender, triangular, dorsoventrally flattened (Fig. 13 E). Head triangular in dorsal view; longer than wide (HW / HL ratio 0.94). Snout comparatively long and protruding (SL / HL ratio 0.34), obtusely pointed in dorsal view (Fig. 13 A), gently obtusely pointed in profile, and noticeably extending beyond the edge of the lower jaw (Fig. 13 E). Eyes large, protruding in dorsal and lateral views, significantly shorter than the snout (EL / SL ratio 0.75), and longer than the interorbital distance (IOD / EL ratio 0.88). Canthus rostralis distinct, rounded; loreal area notably concave, smooth. Nostrils oval-shaped, with lateral orientation, located below the canthus rostralis; closer to eye than to the tip of snout. Interorbital distance broader than internarial distance (IND / IOD ratio 0.72). Upper eyelid smaller than interorbital distance (UEW / IOD ratio 0.69). Tympanum concealed, faintly developed glandular supratympanic fold extending from the posterior corner of eye to axilla (Fig. 13 E). At the level of mouth corner, supratympanic fold bends posteriorly and extends to the forelimb insertion. Tongue slender, rounded, free behind for half of its length; vomerine teeth absent; gular vocal sac present, single. Forelimbs short and slender (Fig. 13 A); lower arm elongated and thin (LAL / FLL ratio 0.75), hand less than half of forelimb length (HAL / FLL ratio 0.42). Fingers slender and elongated, webbing or skin fringes on fingers absent. First finger well-developed, subequal to half of the second finger length (Fig. 13 D); the relative finger length formula: I <II ≤ IV <III. Fingertips rounded, slightly expanded, noticeably narrower than the basal phalanges of the respective fingers. Finger tips lacking peripheral grooves, dorsomedial grooves absent, or present as a very shallow rudimentary medial notch (Fig. 6 D). Finger tips almost uniform in width, with the tip of the first finger being slightly narrower. Subarticular tubercles on fingers distinct, large, rounded, and protruding, with the distal subarticular tubercle on the fourth finger being less distinct. Subarticular tubercle formula: 1, 1, 2, 2. Nuptial pad absent (Fig. 13 D). Two metacarpal tubercles: inner metacarpal tubercle distinct, protruding, rounded in shape; outer metacarpal tubercle rounded, flattened, its diameter equal to the diameter of inner metacarpal tubercle (OPTL / IPTL ratio 1.0). Hindlimbs long and strong, slender, almost four times longer than the forelimbs (HLL / FLL ratio 3.66). Thighs robust and muscular (Fig. 13 B), shanks elongated and slender, comprising approximately one-third of the hindlimb length (TL / HLL ratio 0.37). When the limbs are held at the right angle to the body, the heels significantly overlap. Tibiotarsal articulation of the adpressed limb extends well beyond the tip of the snout. Foot length comprises more than one-third of the hindlimb length, being significantly shorter than tibia (FL / HLL ratio 0.27; TL / FL ratio 1.36). The relative toe lengths: I <II <V ≤ III <IV. Shanks smooth, inner tarsal fold absent. Tips of all toes distinctly widened into small round disks wider than finger tips (4 FDD / 3 FDD ratio 2.05). Dorsomedial longitudinal grooves absent on all toes or present as rudimentary median notch at the medial edge of toe disk (Fig. 6 C). The relative width of toes disks: I <V <II <III ≤ IV. Toe webbing fully developed, web reaching disks on all toes; webbing formula: i 1-1 ii 1 - 1 iii 1 - 1 iv 1 - 1 v (Fig. 6 C). Subarticular tubercles on toes distinct, rounded, slightly protruding, subarticular tubercle formula: 1, 1, 2, 3, 2. Internal metatarsal tubercle of moderate size, oval, slightly elongated, with indistinct margins, less than half the length of the first toe (IMTL / 1 TOEL ratio 0.45). Outer metatarsal tubercle small but very distinct, rounded, prominent with well-defined margins, slightly longer than inner metatarsal tubercle (OMTL / IMTL ratio 1.12, Fig. 13 C). Skin texture is generally similar to that described for M. berdmorei (see above, Fig. 7 A, B). Skin on dorsum slightly shagreened, with sparse small tubercles getting denser on the lateral sides of dorsum (Fig. 7 B). Dorsal surfaces of forelimbs almost smooth, few tiny tubercles present on forearms. Dorsal surfaces of hindlimbs with sparse tubercles scattered across thighs and shanks; these tubercles are noticeably smaller than those on dorsum (Fig. 13 A). Upper eyelid smooth. Body flanks smooth, numerous small warts present around the tympanal region. Ventral surfaces of body and limbs completely smooth (Fig. 13 B). Cloacal opening unmodified, with posterior orientation. Coloration in life. Dorsal background coloration gray-brown with a bronze tinge on the sides of the back, with a faint brown “ teddy-bear ” pattern medially (Fig. 7 B). “ Teddy-bear ” marking with more distinct borders and beige edging anteriorly; the pattern becoming less distinct posteriorly, beige edging not discernible posteriorly. Interorbital dark bar incomplete, present as two indistinct dark-brown blotches between posterior parts of upper eyelids. Indistinct gray-brown marking in the shape of an inverted triangle between interorbital blotches and the “ teddy-bear ” pattern on dorsum (Fig. 13 A). Posterior part of dorsum brownish with indistinct gray blotches. A wide beige light p