Microhyla sundaica Trofimets, Dufresnes, Pawangkhanant, Bragin, Gorin, Hasan, Lalremsanga, Muin, Le, Nguyen, Suwannapoom & Poyarkov, 2024, sp. nov.

Microhyla sundaica sp. nov. Figures 6 E – F, 7 C, 10 C, 14, 15 C – D; Tables 2, 3, 6 Suggested common name. Sundaic narrow-mouthed frog. Chresonymy. Microhyla berdmorei — Inger (1966: 149–151, in part); Grandison (1972: 59, in part); Dring (1979: 194, in part); Malkmus et al. (2002: 130–131, in part); Grismer et al. (2004: 18, in part); Das and Yaakob (2007: 68, in part); Grismer and Aun (2008: 277, in part); Chan et al. (2010: 203, in part); Teynié et al. (2010: 8); Matsui (2011: 35, 39); Matsui et al. (2011: 168, 171, 174, in part); Pradana et al. (2017: 70–90, in part); Firdaus et al. (2018: 1–6, in part); Haas et al. (2018: 89–114); Chan et al. (2019: 1057, in part); Nguyen et al. (2019: 549–580, in part); Gorin et al. (2020: 1–47, in part); Gorin et al. (2021: 97, in part); Poyarkov et al. (2021: 40, in part); Haas et al. (2022: 304–305); Badli-Sham et a l. (2023: 49, 82, in part); Frost (2024: page “ Microhyla berdmorei ” in part). Holotype. ZMMU A-8011, adult female from environs of Sungai Tua Recreational Forest, Selangor State, Malaysia (approximate coordinates: 3.32 ° N, 101.70 ° E), collected on January 27, 2003, by A. T. Aful. Paratypes (n = 5). Two adult males: ZMMU A-8012 and ZMMU A-8014 and two adult females: ZMMU A-8010, ZMMU A-8013, all collection data are the same as for the holotype. One adult male: ZMMU A-6158 from Kuala Tahan District, Pahang State, Malaysia (approximate coordinates: 3.96 ° N, 102.44 ° E) collected on January 18, 2003, by A. T. Aful. Diagnosis. Microhyla sundaica sp. nov. is characterized by a combination of the following morphological features: (1) medium body size (27.5-27.9 mm in males, 28.3-31.4 mm in females), with moderately stocky and triangular body habitus; (2) head wider than long; (3) dorsal skin shagreened with numerous small tubercles; (4) snout pointed in dorsal and ventral views, bluntly rounded in lateral view; (5) first finger notably longer than half the length of second finger; (6) finger tips with well-developed disks bearing wide and deep dorsomedial grooves; (7) toes dilated in wide disks, each with complete and deep dorsomedial groove, separating the toe disk into a pair of scale-like pads; (8) tibiotarsal articulation of the adpressed limb extending far beyond the snout tip; (9) toe webbing reaching to the disks on all toes; webbing formula: i 1-1 ii 1 - 2 iii 1 - 1 iv 1 - 1 v; (10) throat and chin dark-gray in males, beige in females; belly bright yellow in life; (11) dorsal surfaces of forelimbs without prominent crossbars, hindlimbs with 2–3 dark-brown crossbars on thighs and shanks; (12) two black blotches above cloacal opening edged with beige; (13) gray-brown dorsal “ teddy-bear ” - pattern distinct, edged with beige or white, anteriorly connecting with the dark interorbital bar; (13) dark spots and blotches on body flanks absent or scarce; (15) grayish lateral band with irregular edges extending from armpit to groin; (16) light postocular stripe absent; (17) reddish spots on dorsum and dorsal surfaces of hindlimbs absent; (18) iris uniform grayish-bronze, no black stripe below the pupil. Description of the holotype (Fig. 14). An adult female specimen in a very good state of preservation. Body size medium (SVL 31.4 mm; other measurements are presented in Table 2). Body habitus stocky, triangular, and significantly dorsoventrally flattened (Fig. 14 E). Head triangular in dorsal view; wider than long (HW / HL ratio 1.16). Snout comparatively short and protruding (SL / HL ratio 0.45), appearing pointed in dorsal and ventral views (Fig. 14 E), smoothly rounded in profile, and slightly extending beyond the edge of the lower jaw (Fig. 14 E). Eyes comparatively small, slightly protruding in lateral view, not protruding in dorsal view, significantly shorter than the snout (EL / SL ratio 0.76), and slightly shorter than the interorbital distance (IOD / EL ratio 1.03). Canthus rostralis distinct, rounded; loreal area slightly concave. Nostrils oval-shaped, with dorso-lateral orientation, situated almost on the canthus rostralis, closer to tip of snout than to eye. Interorbital distance broader than the internarial distance (IND / IOD ratio 0.77). Upper eyelid length narrower than the interorbital distance (UEW / IOD ratio 0.66). Tympanum concealed, supratympanic fold absent (Fig. 14 E). Tongue slender, rounded, free for the posterior four-fifths of its length; vomerine teeth absent. Eggs seen through the incision on the left lateral side of belly small, rounded, ca. 1.0– 1.1 mm in diameter, pigmented. Forelimbs short and slender (Fig. 14 A); lower arm elongated and thin (LAL / FLL ratio 0.83), hand less than half of forelimb length (HAL / FLL ratio 0.47). Fingers slender and elongated, webbing or skin fringes on fingers absent. First finger well-developed, notably longer than half of the second finger length (Fig. 14 D); the relative finger lengths as follows: I <II <IV <III. Fingertips rounded, expanded into well-developed disks narrower than the basal phalanges of the respective fingers. Finger tips with peripheral grooves, dorsally with a wide and deep dorsomedial notch (Fig. 6 F). Finger tips almost equal in width, with the first fingertip slightly narrower. Subarticular tubercles on fingers distinct, large, rounded, and protruding; edges of the distal subarticular tubercle on the fourth finger less distinct. Subarticular tubercle formula: 1, 1, 2, 2 (Fig. 14 D). Two metacarpal tubercles: inner metacarpal tubercle distinct, protruding, rounded in shape; outer metacarpal tubercle rounded, flattened, its diameter much less than the diameter of inner metacarpal tubercle (OPTL / IPTL ratio 1.40). Hindlimbs long, slender, almost four times longer than the forelimbs (HLL / FLL ratio 3.96). Thighs robust and muscular (Fig. 14 B), shanks notably elongated and slender, comprising approximately one-third the length of the hindlimb (TL / HLL ratio 0.35). When the limbs are held the right angle to the body, the heels significantly overlap. Tibiotarsal articulation of the adpressed limb extends well beyond the tip of the snout. The foot length is more than one-third of the hindlimb length and significantly shorter than shanks (FL / HLL ratio 0.29; TL / FL ratio 1.21). The relative toe lengths as follows: I <II <V ≤ III <IV. Shanks smooth, with the inner tarsal fold absent. The tips of all toes distinctly widened into wide heart-shaped disks, almost twice as wide as finger disks (4 TDD / 3 FDD ratio 1.77). Toe webbing fully developed, reaching the disks of all toes; webbing formula: i 1-1 ii 1 - 2 iii 1 - 1 iv 1 - 1 v (Figs 6 E, 14 C). Toe subarticular tubercles distinct, rounded, slightly protruding, subarticular tubercle formula: 1, 1, 2, 3, 2. The 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 0.31). Outer metatarsal tubercle small but distinct, rounded, prominent with well-defined margins, slightly larger than the inner metatarsal tubercle (OMTL / IMTL ratio 1.45). Skin on the dorsum slightly tuberculated with numerous small tubercles covering both the middle and the lateral parts of the dorsum (Fig. 7 C). Dorsal surfaces of forelimbs smooth. Dorsal surface of hindlimbs with numerous sparse tubercles scattered across thighs and shanks; the tubercles on the hindlimbs notably smaller than those on dorsum (Fig. 14 A). Upper eyelid smooth. Body flanks smooth. Numerous small warts present around the tympanal region. Ventral surfaces of body and limbs smooth (Fig. 14 B). Cloacal opening unmodified, directed posteriorly. Coloration in life. The dorsal background coloration in life was gray-bronze with a light-gray tint on the sides of the dorsum, with a faint gray-brown “ teddy-bear ” - pattern in the middle of the dorsum (Fig. 7 C). The “ teddy-bear ” - pattern has regular light edging, which becomes less distinct posteriorly. A pronounced gray-brown interorbital band in the shape of an inverted triangle with irregular borders runs across the head between the posterior parts of the upper eyelids, and is posteriorly connected with the “ teddy-bear ” - pattern on the dorsum. The lateral sides of the dorsum are lighter and have a light grayish-brown tint. A pair of black spots, edged with beige, located above the cloacal opening. Body flanks and head lateral sides slightly lighter than the dorsum. Bronze blotches on both sides of the head on canthus rostralis; snout uniformly dark olive-brown. Upper jaw bronze-brown with a few irregular gray or white spots below the eye. Light postocular stripe or other markings in tympanal area or around axilla absent. On forelimbs, no conspicuous stripes or spots; two grayish-brown crossbars with indistinct border present on thighs and shanks. Dorsal surfaces of fingers and toes uniformly gray, lacking transverse stripes or dark spots. Belly and chest bright yellow, with a few irregular grayish spots on throat and chin, covered with sparse dark-gray spotting (Fig. 7 C). This coloration becomes notably darker along the edges of the mandible and the mouth corners. Ventral surfaces of the limbs yellow to grayish-yellow with rare gray spots and mottling. Ventral surfaces of arms (Fig. 14 D) and feet (Fig. 14 C) with irregular brownish-black blotches. Iris light grayish-bronze without dark reticulations and lacking the dark vertical stripe below the pupil. Pupil round, black, outlined with a thin bronze circle. Coloration in preservative. After 21 years in preservative, the pattern described above generally remained unchanged, but bright yellow and light-brown colors faded to off-white and gray. The dorsal pattern became less prominent, but all the dark markings on dorsum remain discernible. The dark transverse crossbands and spots on fore- and hindlimbs became less distinct. The gray markings on the chin were still visible as faint gray mottling. Variation. The examined members of the type series are overall quite similar