Megophrys yeae, Shi & Zhang & Xie & Jiang & Liu & Li Ding & Luan & Wang, 2020

Shi, Shengchao, Zhang, Meihua, Xie, Feng, Jiang, Jianping, Liu, Wulin, Li Ding,, Luan, Li & Wang, Bin, 2020, Multiple data revealed two new species of the Asian horned toad Megophrys Kuhl & Van Hasselt, 1822 (Anura, Megophryidae) from the eastern corner of the Himalayas, ZooKeys 977, pp. 101-161 : 101

Megophrys yeae sp. nov. Figs 3E, J, O, T, Y , 4C, F, I, L , 5E, J , 6D, H, L, P , 9 , 10A, C, G , Suppl. material 2: Figs S4, S5A, S5B, S5E, S5F; Tables 1 , 2, 3, 4, Suppl. material 1: Tables S1-S3, S5

Holotype.

(Figs 3E, J, O, T, Y , 4C, F, I, L , 9 ). CIB201706MT02, adult male, collected in Beibeng village, Medog County, Tibet Autonomous Region, China (29.24292°N, 95.18561°E, 870 m), at 1:40 h on 15 June 2017 by SC Shi and L Ding.

Paratypes.

Thirteen specimens (eleven males and two females) from Medog County, Tibet Autonomous Region, China. Four adult males (CIB201706MT01, CIB022017061102, CIB022017061103, and CIB022017061104) collected in Didong village (29.22508°N, 95.12463°E, 670 m) on 11 June 2017 by SC Shi and L Ding. One adult female (CIB201706MT03) collected on 13 June 2017 in Medog urban neighborhood (29.32213°N, 95.31324°E, 907 m) by SC Shi and L Ding. One adult female (CIBMTXC-201701-043) and one adult male (CIBMTXC-201701-044) collected on 28 May 2017 in Medog City neighborhood by F Xie and DW Yang. Two adult males (CIB022017061606 and CIB022017061407) collected in the same location of holotype by SC Shi and L Ding. One male (CIB022017061804) collected in Bari village (29.32947°N, 95.36016°E, 1780 m) at 21:01 18 June 2017 by S.C. Shi. Two adult males (CIBMT171065 and CIBMT171066) collected on 10 and 24 October 2017 in Yarang village (29.29485°N, 95.28126°E, 795 m) by F Xie and DW Yang. One adult male (CIBMT171064) collected at 23:54, 25 October 2017 in Yadong village in the vicinity of Medog city suburb (29.32654°N, 95. 34397°E, 1073 m) by SC Shi and B Wang.

Etymology.

The specific name yeae is in honor of Professor Ye Chang-Yuan, for her contribution to Chinese amphibian research and inspiration for younger generations of Chinese herpetologists.

Suggested vernacular name.

Ye’s horned toad (English), Ye Shi Jiao Chan (叶氏角蟾, Chinese).

Diagnoses.

Megophrys yeae sp. nov. is assigned to the genus Megophrys sensu lato based on molecular phylogenetic analyses and the following morphological characters: canthus rostralis well-developed; a tiny horn’ -like tubercle at edge of upper eyelid present; supratympanic fold distinct; axillary glands small and tit-like, on sides of the breast; oral disc of tadpoles funnel-like; mouth of tadpoles lacking transverse rows of teeth; head length more than 25% of body size; upper jaw protruding beyond the margin of the lower jaw; no skin fold on back of head; maxillary teeth present; tympanum distinct; hind legs long and thin.

Megophrys yeae sp. nov. is distinguished from its congeners by a combination of following characters: body relatively small (males 23.8-29.1 mm, n = 12; females 27.9-31.3 mm, n = 2); vomerine ridge weak, vomerine teeth absent; base of first finger weak, size equal to the base of second finger, tips of fingers II-IV flat, expand to small pad; foot of males shorter (FOL 10.8-12.6 mm, n = 12); dorsal skin being relatively smooth; protuberance beyond cloaca small, not visible from ventral view, not swollen; nuptial pad absent; skull weakly ossified, wider than long; premaxillary and maxillary teeth weak, separated from others by gaps; texture of sphenethmoid smooth, without curves and pits; anterior fontanelle opening large, sagittal suture occlusive; advertisement call short and fast (duration 99-212 ms, repetition rate 1.9-4.1 call/s, intervals, n = 6), and dominant frequency high (4.4-5.2 kHz, n = 6).

Description of holotype.

(Figs 3E, J, O, T, Y , 4C, F, I, L , 9 ). Measurements in mm. Adult male. Body small and slender (SVL 27.5); protuberance beyond cloaca small, not visible from ventral view, not swollen.

Head moderate, wider slightly than long (HW 9.8, HL 9.0, IFE 5.1, IBE 8.7); snout rounded in dorsal view, slightly projecting in profile, protruding beyond lower jaw, rostral appendage absent (SL 3.6); loreal region vertical and concave; canthus rostralis blunt; dorsal surface of snout slight concave; nostrils oval, nearly in the middle of distance from snout to eye(SN 1.9, EN 2.0); distance between nostrils (IN 3.2) almost equal with the shortest distance between upper eyelids (IUE 3.1); tympanum small, rounded, diameter (TYD 1.6) less than half of eye length (EL 3.8 mm), upper one third of tympanum anulus merge with supratympanic fold (Figure 5C ); eye-tympanum distance (TYE 1.6) equal to tympanum diameter; pupil near oval, with a gap at lower edge; visible pineal ocellus absent; vomerine ridges weak, interval longer than its length, vomerine teeth absent; tongue feebly notched behind, hardly visible, with no medial lingual process.

Forearm long and slim, forearm length (FAL 7.0) 25% of body length, slightly shorter than hand (HAL 8.3), not enlarged relative to the upper arm; relative finger lengths I <II <IV <III; base of first finger weak, size equal to the base of second finger; tips of finger I rounded, slightly swollen, tips of fingers II-IV flat and expanded, forming small oval pads (FIIIW 1.2, FIVW 1.3), pads without grooves and distinctively larger than terminal phalanges; fingers rudimentary webbed, with ventral callous ridges and narrow lateral fringes; subarticular and supernumerary tubercles absent, palmar tubercles indistinct.

Hindlimbs long and thin, tibio-tarsal articulation reaches area between nostril and eye; heels meet when thighs are positioned at right angles to the body, shank (SHL 14.1) slightly longer than thigh (TL 12.3) and feet (FOL 12.5, TFOL 19.7); toes thin, rudimentary webbed, with ventral callous ridges and narrow fringes; relatively toes lengths I <II <V <III <IV; tips of toes flat and slightly dilated, without grooves, slightly larger than terminal phalanges; inner metatarsal tubercle weak (IMT 1.9) and elliptical, outer metatarsal tubercle, subarticular and supernumerary tubercles absent.

Dorsal body and head relatively smooth, with tiny tubercles scattered on dorsal part of body and limbs; tiny tubercles on most of dorsum form a large “W” skin ridge from behind supratympanic fold curve to ca. one third distance left of groin, a “V” between shoulders ahead of “W”, and a triangle between eyes; edges of snout, eyelids, especially supratympanic fold and flanks scattered with larger tubercles; supratympanic fold thin, extend from rear of eyelid, curves down above tympanum to shoulder; small tubercles on dorsal thigh and shank arranged in several transversal rows. Ventral surface of body smooth; a granular line present on ventrolateral side of belly, interrupted on left side; several small glandular tubercles present around cloaca; pectoral glands small, as large as tips of finger II, raised slightly, close to axilla; single femoral gland on ventral thigh small and slightly raised, closer to knee than cloaca.

Coloration of holotype in life.

(Fig. 9 ). Dorsal head and body light brown, tiny tubercles scattered on dorsum and head orange-red; skin ridges edged with faint brown, forming a barely visible “X” pattern on dorsum and triangular on head; skin ridges on thigh edged with narrow black-brown; supratympanic fold orange-red; one short black vertical bar on each side of upper lips beneath the eyes; tympanum pale gray; a black streak under supratympanic fold; tubercles on flanks edged with small dark blotches; two thin ambiguous transverse dark band on dorsal forearms; fingers II-IV with transverse dark band on dorsal surface; dorsal surface of fingers and toes colored with orange-red; flanks light brown; throat pale dusty gray; chest mottled gray stained with light purple between axillary glands; two pale gray streaks from lower place of joins of jaws extend to half of ventral upper arm; abdomen ivory, mottled gray on upper part, several small dark dots scattered rear; a large dark streaks present on both lateral sides of abdomen, from behind axilla to near groin, bordering the creamy white ventrolateral granular line on belly; groin not colored with red; ventral surfaces of thighs light purple mottled with tiny smoky white pigments; small glandular tubercles around cloaca and ivory; ventral surface of shanks and arms with large dark patches; palm and ventral surfaces of foot purplish gray; tips of digits orange edges; pectoral glands and femoral glands creamy white; iris orange-bronze.

Coloration of holotype in preservative.

(Fig. 3E, J, O, T, Y ). Dorsal body gray, triangle on head and “X” pattern on dorsum barely visible; tubercles on dorsum, dorsal surface of head and limbs light gray; tympanum brown, a black streak under supratympanic fold; vertical bar beneath the eyes pale gray; tubercles on flanks edged with small black blotches; tubercles rows on dorsal thigh and shank with dark edges more or less; dorsal surface of forelimbs and hindlimbs dark gray with several ambiguous transverse dark bands; fingers II, III and IV with transverse dark band on dorsal surface; tips of digits light colored; throat, chest, and upper abdomen dusty gray, lower part of abdomen off-white; two dark streaks from lower place of joins of jaws extend to half of ventral upper arm; several small dark patches scattered on lower abdomen; two large dark streaks on lateral sides of abdomen; ventral surface of lower arm whitish, with a pale gray patches connected to hand; palm and ventral surface of foot dusty gray, with light colored fingertips; ventral surface of thigh dusty gray, femoral glands and glandular tubercles around cloaca white; ventral surface of shank dusty gray with several large pale gray patches; iris mottled copper.

Skull.

(Fig. 5E, J ). Skull rather small and weakly ossified, width 1.16 × of length; maxillary overlapping with the quadratojugal; premaxillary and maxillary teeth moderately developed, independent with each other, 10/7 teeth present on left/right premaxillary, teeth absent on mandible; vomerine ridge weak, vomerine teeth absent; nasal process of premaxilla protruding beyond skull; nasal bones separated, posterior edges completely contact with sphenethmoid; sphenethmoid smooth on both dorsal and ventral surface, without curves and pits, the front edge of sphenethmoid concave, in contact with premaxillary; frontoparietal not divided, sagittal suture occlusive; anterior fontanelle opening large, triangular, width approximately the same as nasal bones; the front and rear part of frontoparietal almost equally wide; posterior edge of exoccipitals posterior to the line connecting conjunctions of quadratojugal and mandible; pterygoid moderate; anterior process of squamosal slender and sharp, tip closer to the junction of pterygoid and quadratojugal than its base, posterior process present; prootic relatively smooth, separated from exoccipitals; anterior process of parasphenoid in shape of narrow trapezoid, anterior part not raised above sphenethmoid, conjunction of anterior process of parasphenoid with width approximately the same as the constriction near the base; columella auris short.

Variation

(Suppl. material 2: Fig. S4; Suppl. material 1: Table S1). Two female specimens with no lateral fringes on toes. A distinct brown “X” marking on dorsum and a clear triangular on head present on CIB022017061407, CIBMT171064. Abdomens of CIB201706MT01, CIB022017061103 with dark patches on both sides instead of two large streaks. Overall coloration of CIB022017061102, CIB022017061103, CIB022017061103, CIB201706MT01 lighter, without visible “X” marking on dorsum. The “W” skin ridges on dorsum of CIBMT171065 and CIBMT171066 shattered into short disconnected bars. The tympanum of CIBMT171065 not merged with supratympanic fold. The ventrolateral line varies among individuals, in some (e.g., CIB201706MT01) it is interrupted and short, in others (e.g., CIBMT171066) it is simply formed by two separated granules.

Secondary sexual characters.

An internal single subgular vocal sac present in male. Vocal openings present at rear of part the mouth. Calling males without nuptial pad on finger.

Advertisement call.

(Fig. 4C, F, I, L ; Tables 4 ; Suppl. material 1: Table S3). A total of 19 call groups and 176 calls were analyzed. Megophrys yeae sp. nov. has a high dominant frequency (average 4.7 kHz, range 4.4-5.2 kHz). Calls frequent, average calls per seconds 3.0, vary from 1.9 to 4.1; average intercall interval 218 ms, vary from 649 ms to 119 ms when ambient temperatures vary from 17 °C to 25 °C. The number of calls in each call group average 68.9, range from 5 to 187. Calls short, duration average 139 ms, range from 89 ms to 246 ms. Pules per call average 9.2, vary from 7 to 12. To human ears, sound like cricket.

Tadpole.

(Fig. 6D, H, L, P ; Suppl. material 1: Table S2). Stages 28-35. Body length range from 10.2-11.4 mm, elongated and slender; oral disk funnel like; positioned anterior-dorsal, large, width average 1.4 (1.1-1.5) × of maximum body width, with five nearly parallel rows of oval submarginal papillae on middle lower lip, three rows of oval submarginal papillae on both sides of upper lips, both submarginal papillae rows on upper and lower lips rows pointing towards oral cavity, smaller outer sides; nares oval and are closer to the eye than to the snout (RN/NE average 2.2, 1.8-2.6); internarial distance average 69% (64-78%) of the interorbital distance; eyes positioned dorsolaterally, the pupils rounded; spiracle in right-handed helix from ventral view, spiracular tube not protruding beyond body wall, positioned 53% (47-57%) of the distance between tip of the snout and trunk-tail junction, and opens laterally; the tail makes up average 69% (67-72%) of the total body length; dorsal fin arise behind trunk-tail junction, average 35% (30-41%) of maximum body height; the basal tail width average 60% (48-65%) of the maximal trunk width; keratodonts absent.

Coloration of tadpoles in life: dorsal body brown with dense copper pigments; dorsal tail brown, scattered with copper pigments; lateral tail above lower fin mottled with copper patches; ventral surface of body, and lower fin semi-transparent; iris light brown. Coloration in preservative: dorsal body brown; dorsal tail light brown scattered with brown patches; lateral sides of body brown; lateral tail semitransparent brown, muscle scattered with a lot of distinct brown patches; fins semitransparent stained with little brown, no pigments on lower fin except latter 1/3; ventral body semitransparent white, with tiny gray pigments scattered on throat and chest; ventral tail off-white; lips semitransparent white, papillae brown.

Distribution and natural history.

This species is currently known from five localities in Medog County, Tibet Autonomous Region, China (Fig. 1 ). All calling males recorded on June and October were found on herb leaves near or upon small stream in tropical forest (Fig. 10A, C, G ; Suppl. material 2: Fig. S5A, B, E, F). Eggs in adult female (CIB201706MT03) are in two different development stage: pure yellow eggs with diameter of 1.1 mm, and semitransparent eggs with size half or less of the former. A total of 45 larger yellow eggs were counted, smaller semitransparent eggs more than 70. Thus, breeding season is suggested including June to October, and this species may lay eggs more than once during one season. The new species was recorded at elevation between 670 m to 1780 m. On 18 June 2017, four males of Megophrys pachyproctus (CIB201706MT04-CIB022016061806, CIB022017061807) were calling in the same stream where one male (CIB022017061804) of the new species was calling together at nearest distance ca. 3 meters in Bari Village (29.32947°N, 95.36016°E, 1780 m). From its habitat, other amphibians like Megophrys medogensis , Megophrys cf. pachyproctus , Odorrana zhaoi Li, Lu, and Rao, 2008, Amolops medogensis , and Huangixalus translineatus Wu, 1977 were also recorded.

Comparison.

By body relatively smaller (males 23.8-29.1, n = 12; females 27.9-31.3, n = 2; measurements in mm), Megophrys yeae sp. nov. differs from M. pachyproctus (males 35.3-35.7, n = 2; female 35.8, n = 1), Megophrys cf. pachyproctus (males 33.6-36.6, n = 5; females 40.6-42.8, n = 4), M. medogensis (males 57.2-68.7, n = 21), M. baolongensis (males 41.8-45.0, n = 5), M. binchuanensis (males 32.0-36.0, n = 4), M. binlingensis (males 45.1-51.0, n = 3), M. boettgeri (males 34.5-37.8, n = 20), M. brachykolos (males 33.7-39.3, n = 5), M. caudoprocta (males 70.8-81.3, n = 4), M. daweimontis (males 34-37, n = 18), M. fansipanensis (males 30.9-44.3, n = 13), M. hoanglienensis (males 37.4-47.6, n = 11), M. insularis (males 36.8-41.2, n = 5), M. jingdongensis (males 53.0-56.5, n = 3), M. jinggangensis (males 35.1-36.7, n = 2), M. liboensis (males 61.6-62.9, n = 4), M. lini (males 34.1-39.7, n = 20), M. lishuiensis (males 30.7-34.7, n = 13), M. minor (males 34.5-41.2, n = 4), M. obesa (male 35.6, n = 1; females 37.5-41.2, n = 6), M. omeimontis (males 56.0-59.5, n = 10), M. palpebralespinosa (male 36, n = 1; female 41, n = 1), M. sangzhiensis (male 54.7, n = 1), M. shuichengensis (males 102.0-118.3, n = 7), M. spinata (males 47.2-54.4, n = 18), M. tuberogranulata (males 33.2-39.6, n = 9), M. wushanensis (males 30.4-35.5, n = 10), M. leishanensis (males 32.1-42.3, n = 10), M. dongguanensis (males 30.2-39.3, n = 9), M. nankunensis (males 29.9-34.9, n = 11), M. jiulianensis (males 30.4-33.9, n = 9), M. nanlingensis (males 30.5-37.3, n=10), M. wugongensis (males 31.0-34.1, n = 4), M. mufumontana (males 30.1-30.8, n = 2), M. aceras (males 55.8-62.4, n = 6); M. ancrae (males 39.1-45.3, n = 8), M. auralensis (males 76.7, n = 1), M. damrei (male 57.1, n = 1; female 69.1, n = 1), M. flavipunctata (males 56.9-68.4, n = 4), M. glandulosa (males 76.3-81.0, n = 10), M. himalayana (males 68.0-73.5, n = 6), M. huangshanensis (males 36.0-41.6, n = 4), M. katabhako (males 35.4-37.0, n = 3), M. lekaguli (males 55.6-66.6, n = 8), M. longipes (male 47, n = 1; female 65, n = 1), M. major (males 71.6-87.5, n = 12), M. mangshanensis (male 62.5, n = 1; female 73.0, n = 1), M. maosonensis (male 77, n = 1; female 94, n = 1), M. megacephala (males 45.9-53.4, n = 12), M. monticola (males 38.4-49.5, n = 17), M. periosa (males 71.3-93.8, n = 12), M. robusta (males 73.5-83.1, n = 6), M. longipes (male 47, n = 1; female 65, n = 1), M. oreocrypta (female 94.9, n = 1), M. oropedion (males 32.8-39.2, n = 7), M. parva (males 35.6-50.6, n = 5), M. periosa (males 71.3-93.8, n = 12), M. robusta (males 73.5-83.1, n = 6), M. sanu (males 39.0-46.7, n = 5), M. serchhipii (male 37.1, n = 1), M. takensis (males 47.3-53.0, n = 3), M. zhangi (males 32.5-37.2, n = 3), M. zunhebotoensis (male 30.0, n = 1; female 39.0, n = 1), M. angka (males 31.2-32.1, n = 2), M. shunhuangensis (males 30.3-33.7, n = 10), M. jiangi (males 34.4-39.2, n = 9), and M. xianjuensis (males 31.0-36.3, n = 7).

By tympanum distinct moderate, Megophrys yeae sp. nov. differs from M. gigantica , M. nankiangensis , M. shapingensis , and M. wawuensis (vs. absent, concealed or very small in the latter).

By maxillary teeth present, Megophrys yeae sp. nov. differs from M. elfina , M. gerti , M. hansi , M. koui , M. microstoma , and M. synoria (vs. absent in the latter).

By hind limbs long and head not wide and flat, Megophrys yeae sp. nov. differs from M. carinense , M. chuannanensis , M. feae , M. intermedia , and M. popei (vs. head wide flat and hind limbs short in the latter).

By lacking a single, wide and flat palpebral projection on the edge of the upper eyelid, Megophrys yeae sp. nov. differs from M. lancip , M. montana , M. parallela , M. baluensis , M. edwardinae , M. kobayashii , M. ligayae , M. nasuta , and M. kalimantanensis (vs. present in the latter).

By lacking rostral appendage, Megophrys yeae sp. nov. differs from M. stejnegeri (vs. having less rostral appendage in the latter).

By lacking a distinct horn-like tubercle at edge of upper eyelid, Megophrys yeae sp. nov. differs from M. dringi (vs. present in the latter).

By vomerine ridge weak, Megophrys yeae sp. nov. differs from M. pachyproctus , M. medogensis , and Megophrys cf. pachyproctus (vs. stronger in the latter); differs from M. vegrandis , M. baolongensis , M. binchuanensis , M. boettgeri , M. kuatunensis , M. lishuiensis , M. wuliangshanensis , M. wushanensis , M. ombrophila , M. leishanensis , M. feii , M. huangshanensis , M. shunhuangensis , M. jiangi , and M. xianjuensis (vs. absent in the latter).

By vomerine teeth absent, Megophrys yeae sp. nov. differs from Megophrys cf. pachyproctus , M. pachyproctus , M. medogensis , M. caudoprocta , M. daweimontis , M. fansipanensis , M. hoanglienensis , M. insularis , M. jingdongensis , M. jinggangensis , M. liboensis , M. omeimontis , M. rubrimera , M. dongguanensis , M. nankunensis , M. jiulianensis , M. nanlingensis , M. aceras , M. ancrae , M. damrei , M. flavipunctata , M. glandulosa , M. himalayana , M. katabhako , M. lekaguli , M. longipes , M. major , M. mangshanensis , M. maosonensis , M. megacephala , M. monticola , M. oreocrypta , M. oropedion , M. parva , M. periosa , M. serchhipii , M. takensis , M. zhangi , and M. zunhebotoensis (vs. present in the latter).

By tips of fingers II-IV flat, expand to small pad, Megophrys yeae sp. nov. differs from Megophrys cf. pachyproctus , Megophrys zhoui sp. nov., M. pachyproctus , M. acuta , M. binlingensis , M. brachykolos , M. cheni , M. lini , M. minor , M. obesa , M. palpebralespinosa , M. sangzhiensis , M. shuichengensis , M. spinata , M. tuberogranulata , M. wugongensis , M. mufumontana , M. auralensis , and M. robusta (vs. expanded pads on fingertips absent in the latter).

By foot of males shorter (FOL 10.8-12.6 mm, n = 12), tympanum relatively smaller (males TD/EL 0.36-0.46, n = 12), and toes with narrow lateral fringes, Megophrys yeae sp. nov. further differs from M. vegrandis (vs. FOL 13.2-13.8 mm, n = 4, P <0.001; TYD/EL 0.44-0.56, n = 4, P <0.03; and fringes on toes wide in the latter).

By dorsal skin being relatively smooth, Megophrys yeae sp. nov. differs from M. feii (vs. dorsal skin rough in the latter).

Megophrys yeae sp. nov. differs from M. medogensis by the following characters: nuptial pad absent (vs. present in the latter); and base of first finger weak, size equal to the base of second finger, relative finger lengths I <II <IV <III (vs. base of finger I strong, larger than base of finger II, relative finger lengths II <I <IV <III in the latter).

By having following differences on skull morphology, Megophrys yeae sp. nov. differs from M. medogensis : skull weakly ossified, opening of anterior fontanelle large (vs. skull well ossified, opening of anterior fontanelle occlusive in the latter); premaxillary and maxillary teeth weak, separated from others by gaps (vs. strong, closely positioned with others in the latter); texture of sphenethmoid smooth, without curves and pits (vs. relatively smooth, with few pits in the latter); frontoparietal front equals rear (vs. distinctly wider in the latter); exoccipitals posterior to the line connecting conjunctions of quadratojugal and mandible (vs. anterior); and columella auris short (vs. long in the latter).

By having following differences on bioacoustics, Megophrys yeae sp. nov. differs from M. medogensis : dominant frequency significantly higher (4.4-5.2 kHz vs. 2.3-3.0 kHz in the latter; P <0.001); call significantly faster (repetition rate average 3.0, vary from 1.9 to 4.1 vs. average 1.2 vary from 0.6 to 2.2 in the latter); and call intervals significantly longer (493-720 ms vs. 153-254 ms in the latter; P <0.001).

By having the following characters, Megophrys yeae sp. nov. differs from M. pachyproctus : lacking a swollen protruding beyond cloaca (vs. present in the latter); nuptial pad absent (vs. present in the latter); and base of first finger weak, size equal to the base of second finger (vs. base of finger I strong, larger than base of finger II in the latter).

By having the following characters on skull morphology, Megophrys yeae sp. nov. differs from M. pachyproctus : premaxillary and maxillary teeth weak, separated from others by gaps (vs. strong, closely positioned with others in the latter); texture of sphenethmoid smooth, without curves and pits (vs. relatively smooth, with few pits in the latter); anterior fontanelle opening large (vs. occlusive in the latter); and sagittal suture occlusive (vs. distinctly open in the latter).

By having the following characters, Megophrys yeae sp. nov. differs from Megophrys cf. pachyproctus : nuptial pad absent (vs. present on finger I in the latter); and base of first finger weak, size equal to the base of second finger (vs. strong, larger than base of finger II in the latter).

By having following characters on skull morphology, Megophrys yeae sp. nov. differs from Megophrys cf. pachyproctus : texture of sphenethmoid smooth, without curves and pits (vs. rough, with curves and pits in the latter); anterior fontanelle opening large (vs. small, width equals sagittal suture in the latter); and sagittal suture occlusive (vs. distinctly open in the latter).

By having the following acoustical characters, Megophrys yeae sp. nov. differs from Megophrys cf. pachyproctus : call significantly shorter (99-212 ms, n = 6 vs. 491-889 ms, n = 3 in the latter; P <0.001); dominant frequency much higher (4.4-5.2 kHz, n = 6 vs. 3.2-3.3 kHz, n = 3 in the latter; P <0.001); call intervals significantly shorter (146-370 ms, n = 6, vs. 493-720 ms, n = 3 in the latter; P <0.001); and calls significantly faster (call repetition rate1.9-4.1 call/s, n = 6, vs. 0.7-1.1call/s, n = 3 in the latter; P <0.01).

By having following characters on skull morphology, Megophrys yeae sp. nov. differs from Megophrys zhoui sp. nov.: texture of sphenethmoid smooth, without curves and pits (vs. relatively smooth, with several small pits in the latter); and sagittal suture occlusive (vs. narrowly or wide open in the latter).

Figures

Figure 1. Distributional localities for specimens of the Megophrys species used in this study in Medog County, Tibet Autonomous Region, China. 1 80 k 2 Gedang village 3 vicinity of Medog urban area 4 Bari village 5 vicinity of Renqingbeng Temple 6 Beibeng village 7 Gelin village 8 Didong village 9 Yarang village. Species were denoted as different color.

Figure 3. Photos of specimens of Megophrys species in Medog. A-E dorsal views of adult male holotype NWIPB 770650 of M. pachyproctus, adult male topotype CIB 022017061406 of M. medogensis, adult male CIB 022017061805 of M. cf. pachyproctus, adult male holotype CIBMT 171053 of Megophrys zhoui sp. nov., and adult male holotype CIB 201706 MT 02 of Megophrys yeae sp. nov., respectively F-J ventral views of the specimens, respectively K-O lateral view of head of the specimens, respectively P-T ventral view of hand of the specimens, respectively U-Y ventral view of foot of the specimens, respectively. Scale bar for body view equal to 10 mm, and for partial view 5 mm.

Figure 4. Visualization of advertisement calls of three Megophrys species from Medog. A-C visualizations of 60 seconds waveform of relative amplitude over time for M. medogensis (one unvouchered individual recorded in the vicinity of Medog urban area), M. cf. pachyproctus (CIB 022017061807), and Megophrys yeae sp. nov. (paratype CIB 022017061804), respectively D-F visualizations of 20 seconds waveform of relative amplitude over time G-I visualizations of two seconds waveform of relative amplitude for the species, respectively J-L visualizations of two seconds waveform of spectrogram for the species, respectively.

Figure 5. Skull of Megophrys species in Medog. A-E dorsal views of adult male holotype NWIPB 770650 of M. pachyproctus, adult male topotype CIB 022017061406 of M. medogensis, adult male CIB 022017061805 of M. cf. pachyproctus, adult male holotype CIBMT 171053 of Megophrys zhoui sp. nov., and adult male holotype CIB 201706 MT 02 of Megophrys yeae sp. nov., respectively F-J ventral views of the specimens, respectively. Key to skull: 1 premaxillary; 2 maxillary; 3 nasal; 4 sphenethmoid; 5 anterior fontanelle; 6 frontoparietal; 7 sagittal suture; 8 pterygoid; 9 squamosal; 10 quadratojugal; 11 prootic; 12 exoccipital; 13 vomerine ridge; 14 mandible; 15 anterior process of parasphenoid; 16 columella auris. Scale bar equal to 5 mm.

Figure 6. Tadpole specimens of four groups of three Megophrys species from Medog. A-D dorsal views of the low-middle-elevation tadpole CIBMT 20170621 of M. medogensis (Goser stage 35), the high-elevation tadpole CIBMT 171001 of M. medogensis (stage 27), tadpole CIBMT 20170611 of M. cf. pachyproctus (stage 25), tadpole CIBMT 170604 of Megophrys yeae sp. nov. (stage 35), respectively E-H lateral views of the tadpoles, respectively I - L ventral views of the tadpoles, respectively. M-P dorsal views of head of the tadpoles, respectively. Scale bar for body view equal to 10 mm, and for head view 2 mm.

Figure 9. The holotype adult male CIB 201706 MT 02 of Megophrys yeae sp. nov. in life. A dorsolateral view of body B ventral view of body C dorsolateral view of head D ventral view of hand E ventral view of foot.

Figure 10. Microhabitats of Megophrys toads in the field in Medog. A stream at elevation 850 m in Didong village, harboring the low-middle-elevation M. medogensis and Megophrys yeae sp. nov. B a stream at 1530 m in Gelin village, hosting the low-middle-elevation M. medogensis and M. pachyproctus C a stream at 1780 m in Bari village, harboring low-middle-elevation M. medogensis, M. cf. pachyproctus and Megophrys yeae sp. nov. D a stream at 2003 m in the vicinity of Renqingbeng Temple, hosting M. cf. pachyproctus and Megophrys zhoui sp. nov. E a stream at 2142 m in Gedang village, hosting M. medogensis F one adult male of low-middle-elevation M. medogensis calling on a dead leaf on the tropical forest ground nearby a stream in Didong village G the adult male paratype CIB 022017061102 of Megophrys yeae sp. nov. calling on a leaf of dense bushes under tropical forest, ca. 0.5 m above a stream in Didong village H the adult male CIB 022017061806 of M. cf. pachyproctus calling on a branch of dead bush, ca. 0.5 m above ground under subtropical forest in Bari village I the gravid female CIBMT 171054 of M. cf. pachyproctus precariously climbing up onto a stem of herb, ca. 0.3 m above a tiny stream under subtropical forest in Renqingbeng J the adult male holotype CIBMT 171053 of Megophrys zhoui sp. nov. sitting on a split of a fern leaf in a small stream under subtropical forest in the vicinity of Renqingbeng Temple.