Rana hainan Wang, Qiu, Song, Qi, Wang, Li & Wang 2026, sp. nov.

Rana hainan Wang, Qiu, Song, Qi, Wang, Li & Wang sp. nov. Table 6; Figs 4, 5 Chresonymy. Rana nigrotympanica – Wang et al. (2007). Rana johnsi – Shi et al. (2011, in part). Type material. Holotype: China • 1 ♂; Hainan Province, Wanning City, Sangengluo Town, Shangxi Provincial Nature Reserve, 18.795246°N, 110.162373°E; altitude 350 m a. s. l.; collected by MHH on 16 January 2026; HNU 260411. Paratypes (n = 11): China • 2 ♂; same locality as holotype; collected by MHH on 09 October 2025 and 12 April 2026; SYS a 009638, HNU 260412 • 5 ♀; same locality as holotype; collected by MHH on 04 September 2025 and 12 April 2026, and by MHH and PPL on 11 January 2024; HNU 250901, SYS a 009526, SYS a 009527 (Field NO. SYNU 900774), HNU 260413 –14 • 4 ♀; Hainan Province, Lingshui County, Mt. Diaoluo, 18.7248115°N, 109.8770934°E; altitude 950 m a. s. l.; collected by CXL and DED on 19 April 2026; SYS a 009746, HNU 260407 –09. Diagnosis. Rana hainan sp. nov. is distinguished by the following morphological characteristics: (1) body medium-sized, SVL 44.4–45.4 (44.9 ± 0.5, n = 3) mm in adult males, 45.4–57.5 (51.2 ± 4.2, n = 9) mm in adult females; (2) head length significantly larger than head width; (3) a distinct triangular black patch on the temporal region; (4) dorsolateral fold distinct and thin, extending straight from posterior margin of upper eyelid to above groin; (5) internarial distances larger than interorbital distances; (6) eyes relatively small; (7) tympanum diameter significantly smaller than eye diameter; (8) fingers without lateroventral grooves, unwebbed, relative finger lengths II <I <IV <III; (9) presence of supernumerary tubercles below the bases of each finger, presence of three separated metacarpal tubercles; (10) toe tips slightly expanded into small discs, lateroventral grooves present on all toe tips, connected at the anterior margin, toes webbing formula: I 0–1 / 2 II 0–1 / 2 III 1 - – 1 / 2 IV 1 - – 0 V, relative toe lengths I <II <III <V <IV; (11) tibio-tarsal articulation reaching forward beyond tip of snout; (12) heels overlapping; (13) dorsal skin smooth, flanks smooth with few granules; (14) presence of vocal sacs in males; (15) breeding males possessing a grayish-white nuptial pad forming a continuous patch on finger I, extending from the tip of the finger to the posterior margin of the inner metacarpal tubercle, and densely covered with tiny hoary nuptial spines. Description of the holotype (Fig. 4). Adult male. Moderate body size, SVL 44.8 mm; head length larger than head width, HDW / HDL 0.91; snout slightly pointed in dorsal view, projecting, sloping backward to mouth in profile, protruding well beyond margin of lower jaw; top of head flat; eyes moderate in size, ED / HDL 0.27, pupil oval and horizontal; nostril oblique-ovoid; canthus rostralis well developed; loreal region slightly oblique; internasal distance larger than interorbital distance, IND / IOD 1.09; tympanum boundary clear, tympanic rim feebly elevated, ED / TYD 1.23; a skin fold present posterior to tympanum, disconnected with dorsolateral fold, swollen near shoulder; large ovoid choanae at the base of the maxilla; vomerine teeth in two short rows, oblique and separated by a distance about one row of teeth; maxillary teeth present; tongue deeply notched posteriorly; a pair of internal subgular vocal sacs present, openings slit like, small, positioned at on inner mandible near the corners of mouth. Forearms 0.19 of SVL and hand 0.24 of SVL; fingers slender, without web but with narrow fringe; tip of fingers rounded, not expanded, without lateroventral grooves; relative finger lengths II <I <IV <III; subarticular tubercles significantly prominent, rounded, formula 1, 1, 2, 2; distinct, small, rounded supernumerary tubercles below the bases of each finger; inner metacarpal tubercle indistinct, ovoid, partly covered by nuptial pad; two outer metacarpal tubercles distinctly separated, slightly larger, long elliptic; nuptial pad with tiny spines on the finger I, extending from the tip of the finger to the posterior margin of the inner metacarpal tubercle. Hindlimbs long, tibia 0.60 of SVL and length of foot and tarsus 0.79 ratio of SVL; thigh shorter than tibia, heels overlap when hindlimbs flexed at right angles to axis of body; tibio-tarsal articulation reaching far beyond snout when hindlimb stretched forward along body; toe tips slightly expanded into small discs with lateroventral grooves present and connected at middle of front edge; inner edge of toe I and outer edge of toe V with narrow lateral fringe, relative toe lengths I <II <III <V <IV, toes webbing formula: I 0–1 / 2 II 0–1 / 2 III 1 - – 1 / 2 IV 1 - – 0 V; subarticular tubercles prominent and oval, formula 1, 1, 2, 3, 2; supernumerary tubercles absent; inner metatarsal tubercle oval and prominent, outer metatarsal tubercle rounded, indistinct. Dorsal skin smooth, supratympanic fold absent; dorsum with a distinct chevron-shaped skin ridge; dorsolateral folds distinct, narrow, straight, extending from edge of upper eyelid to hip, not curve above tympanum; several small tubercles on flank; several tiny granules on the skin of loreal and temporal regions; ventral skin smooth, skins around cloaca with numerous flat tubercles; skin on limbs with transverse parallel bars; tarsal fold absent, and small tubercles present on the tarsus. Coloration in life. In life, dorsal surface overall reddish brown; a transverse stripe formed by black speckles present between the upper eyelids; loreal region dark brown, with white spots along the lower margin; a distinct triangular black patch present on temporal region, completely covering the tympanum, with its anterior margin edged by a pale border; iris bicolored, upper one-third pale yellowish brown and lower part darker, separated by a distinct horizontal boundary; pupil dark brown. Dorsal surfaces of limbs reddish brown, with several dark transverse bars; ventral surface of forelimb brown near the junction with posterior dorsal surface, gradually becoming paler toward anterior side; fingers grey; nuptial pad greyish white; toe webs dark brown to black; toe tips grey; ventral surface of tibia yellow; posterior surface of thigh orange brown. Ventral surface creamy white to pale yellow; throat and chest suffused with pale yellow. In preservative, dorsal surface greyish brown with dark brown mottling; limbs greyish brown with dark transverse bars; loreal and temporal regions dark grey; ventral surface creamy white, with grey mottling on throat and chest; ventral surfaces of limbs pale orange to beige, scattered with dark speckles; toe webs dark grey to black; nuptial pad dark grey. Variation. Measurements of type series specimens are given in Table 6. Dorsolateral folds are discontinuous in the female paratype SYS a 009527 (Field NO. SYNU 900774) (Fig. 5 B). The number of transverse bars ranges from 2–4 on forearms, 3–5 on thigh, and 3–6 on tibia. Sexual dimorphism. Breeding males possessing a grayish-white nuptial pad forming a continuous patch on finger I, extending from the tip of the finger to the posterior margin of the inner metacarpal tubercle, and densely covered with tiny hoary nuptial spines. Male with a pair of internal subgular vocal sacs. Etymology. The specific epithet “ hainan ” is a noun in apposition referring to the type locality of Hainan Province, China. The English common name “ Hainan Groove-toed Frog ” and formal Chinese name “ 海南趾沟蛙 ” (hǎi nán zhǐ gōu wā) are proposed. Comparison. Rana hainan sp. nov. is assigned to the R. johnsi group due to the presence of lateroventral grooves on the flattened tips of the toes, a distinct triangular black patch on the temporal region, and vocal sacs in males, distinguishing it from other species of the subgenus Rana. Within the R. johnsi group, Rana hainan sp. nov. differs from R. johnsi in mean values of SL, IOD, UEW, LW, THL, TW (Table 3), and by the smaller HDW / HDL in males (0.78–0.86 vs 0.93–1.03; Suppl. material 4); differs from R. sangzhiensis in mean values of HDL, SL, ED (Table 3), by the smaller HDW / HDL in males (0.78–0.86 vs 0.91–1.08; Suppl. material 4), by the toes webbing formula: I 0–1 / 2 II 0–1 / 2 III 1 - – 1 / 2 IV 1 - – 0 V (vs entirely webbing), and by the tibio-tarsal articulation reaching far beyond snout when hindlimb stretched forward along body (vs reaching the nostril or tip of the snout); differs from R. wuyiensis in mean values of HDL, SL, IOD, ED, TYD, THL, TL (Table 3), by the smaller HDW / HDL, ED / HDL and TYD / HDL in females (0.81–0.93 vs 0.97–1.26, 0.25–0.30 vs 0.36–0.44, and 0.18–0.22 vs 0.25–0.36, respectively; Suppl. material 4), by the tarsal fold absent (vs presence), by the connect lateroventral grooves on toes (vs unconnected), by the nuptial pad forming a continuous patch on finger I in males (vs divided into three parts), and by the toes webbing formula: I 0–1 / 2 II 0–1 / 2 III 1 - – 1 / 2 IV 1 - – 0 V (vs 1 1 / 3 –2 II 1 1 / 3 –2 1 / 3 III 1 ½ – 2 2 / 3 IV 3–1 1 / 3 V). Distribution and natural history. Rana hainan sp. nov. is currently known from Shangxi Provincial Nature Reserve in Wanning and the Diaoluo Mountain section of Hainan Tropical Rainforest National Park, Hainan, China. The population reported from Mt. Jianfengling, Ledong by Fei et al. (2009) was tentatively identified as Rana cf. johnsi prior to the collection of specimens (see Discussion below). Rana hainan sp. nov. inhabits tropical rainforest at elevations of 350–950 m, predominantly in evergreen broadleaf forests (Fig. 6). The understory is rich in ferns and shrubs, and streams are typically rocky. Breeding often occurs in seasonal pools and slow-flowing backwaters of these streams. Tadpoles were observed in November at microhabitats similar to that shown in Fig. 6 B (Li, pers. obs.). Male specimens collected from October to April consistently exhibited nuptial pads and nuptial spines, suggesting that the breeding season likely occurs during this period. Furt