Megophrys zhoui, 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 zhoui sp. nov. Figs 3D, I, N, S, X , 5D, I , 8 , 10D, J , Suppl. material 2: Figs S3, S5B; Tables 1 , 3, Suppl. material 1: Tables S1, S5

Holotype.

(Figs 3D, I, N, S, X , 8 ). Adult male CIBMT171053, collected from vicinity of Renqingbeng Temple, Medog County, Tibet Autonomous Region, China (29.304832°N, 95.361682°E, 2003 m) by SC Shi on 26 October 2017.

Paratypes.

(Suppl. material 2: Fig. S3). Two adult gravid females CIBMT171060 and CIBMT171062, collected along with the holotype.

Etymology.

The specific name is in honor of Professor Zhou Kai-Ya, for his contribution to Chinese amphibian research.

Suggested vernacular name.

Zhou’s horned toad (English), Zhou Shi Jiao Chan (周氏角蟾, Chinese).

Diagnoses.

Megophrys zhoui sp. nov. is assigned to the genus Megophrys sensu lato based upon molecular phylogenetic analyses and the following morphological characters: canthus rostralis well-developed; supratympanic fold distinct; axillary glands small and tit-like, on sides of the breast; 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 zhoui sp. nov. is distinguished from its congeners by a combination of following characters: body small (male 23.0, n = 1; females 23.5-23.9, n = 2); vomerine ridge weak, vomerine teeth absent; tympanum present, moderate; base of finger I in similar size with finger II, relative finger lengths I <II <IV <III, fingertips not expanded into small pads; toes with narrow lateral fringes or absent; inner metatarsal tubercle long oval, positioned on base of toe I; dorsal skin relatively smooth; protuberance beyond cloaca indistinct, barely visible from ventral view, not swollen; skull weakly ossified, premaxillary and maxillary teeth weak; skull wider slightly than long; nasal bones not contact with sphenethmoid.

Holotype description.

(Figs 3D, I, N, S, X , 8 ). Measurements in mm. Adult male, with well-developed testes; body slender, extremely small (SVL 23.0); protuberance beyond cloaca small, not visible from ventral view, not swollen.

Head moderate, longer than wide (HW 7.8, HL 8.3, IFE 4.5, IBE 7.2); snout near rounded in dorsal view, slightly protruding beyond lower jaw; rostral appendage absent (SL 3.6); canthus rostralis blunt; loreal region slightly concave, dorsal surface of snout slightly concave; nostril oval, closer to eye than tip of snout (SN 1.8, EN 1.4); distance between nostrils approximate distance between upper eyelids (IN 3.0, IUE 2.7); eyes twice size of tympanum (EL 2.7, TYD 1.3); pupils diamond, inferior angle slightly concave; eye-tympanum distance subequal with tympanum diameter (TYE 1.1); tympanum rounded, upper 1/3 conceal with supratympanic ridge; interorbital space flat, wider than upper eyelids (UEW 2.3); pineal ocellus not visible; two arcuate vomerine ridges present, orientation of two ridges acutely angled, not enlarged at posterior ends, shortest distance between two ridges equal to length of vomerine ridges; vomerine teeth absent; maxillary teeth present; tongue weakly notched behind, medial lingual process absent.

Forearm slender, not wider than upper arms, shorter than hand (FAL 5.2, HAL 7.1); fingers thin, without rudimentary webbing; subarticular tubercles absent; inner and outer metacarpal tubercles indistinct; base of finger I equal wide with base of finger II; finger relative length I <II <IV <III; tips of fingers slightly swollen, without pads (FIIIW 0.5).

Hindlimbs thin and long, tibio-tarsal articulation reaches middle eye; thighs shorter than shanks but longer than feet (TL 11.5, SHL 12.5, FOL10.9, TFOL 16.7); toes slender, relative length I <II <V <III <IV, rudimentary webbed, without lateral fringes, tips slightly swollen, no dermal ridges on ventral surface; subarticular tubercles absent; outer metatarsal tubercle absent; inner metatarsal tubercle long oval (IMT 1.1), positioned on base of toe I.

Dorsal surface of head and body basically smooth, with skin ridges formed by small disconnected granules; lateral surface of head smooth, tympanum ring not raised; two small granules on out edges of upper eyelid; supratympanic ridges nearly straight, extend from behind upper eyelids to above forearm insertions, rear part not thicker than the front; flanks smoother than dorsum, with several small tubercles one or two × size of nostril; skin on head scattered with tiny granules, some lager granules form a triangle between eyes; a “Y” -shaped skin ridges present between shoulders, but posterior part connected the middle of a “W” -shaped skin ridge on dorsum; several larger granules on rear dorsum behind the “W”; dorsal surface of arm smooth, scattered with tiny granules; dorsal hand and feet smooth; dorsal thighs and shanks smooth, with several larger granules; ventral surface of body and limbs smooth; pectoral glands tiny, barely visible, close to axilla on chest; pectoral glands small and rounded, slightly larger than fingertips; closer to outer edge of knee than to cloaca.

Coloration of holotype in preservative.

(Fig. 3D, I, N, S, X ). Dorsal surface of body and limbs covered with dense gray pigments; larger granules on body and limbs light colored; a brown triangle present between eyes on head; markings on dorsum, and larger granules on dorsal thighs and shanks with brown fringes around; one broad brown transverse bands present on finger II, III and IV; two narrow transverse short bands present on lower arms; one or two faint brown transverse bands on dorsal toes. Lateral side of head pale gray mostly; skin on upper jaw between nostril and below eyes colored lighter; eyes dark with silver dense fiber around pupils and radiate on iris; supratympanic ridge light colored; chest, ventral surface of head, arms and shanks and feet covered with dense smoky gray pigments; abdomen ivory stained with smoky pigments, and scattered with several dark dots; several small ivory patches present on ventral margin of mandible; a darker brown patches with light colored inner edges extend from posterior end of jaws to ventral surface of upper arms on both sides; ventral surface hand mostly with smoky gray pigments, but base of finger I and II ivory; a brown stripe present on ventrolateral body; ventral surface of thighs smoky gray; tips of digits light colored; pectoral and femoral glands ivory.

Coloration of holotype in life.

(Fig. 8 ). Dorsal body and limbs orange-brown, granules on body orange-red; markings on dorsal body as described above; lateral head basically brown; supratympanic ridge orange; temporal region under supratympanic ridge dark brown; upper lips and canthus rostralis stained with orange; dark patches present on upper lips under eyes; iris orange-red, brighter around pupils. Flanks with several larger orange dots, ventrolateral trunk with white pigments and larger white dots. Throat, chest, arms orange-brown, mottled with dense white pigments; chin stained with orange, several small white patches present on lower lips; brown patches from posterior end of jaws to ventral surface of upper arms edged with white at inner side; upper abdomen orange-brown, stained with several faint orange dots; lower abdomen white, scattered with several clean orange dots; both lateral sides of abdomen with broad brown strips; ventral surface of thighs and shanks flesh brown, with several white tiny granules around cloaca; ventral hand with dense gray-brown pigments, base of finger I and II fleshy; inner and outer metacarpal tubercle, and tips of fingers light orange; ventral feet brown; inner metatarsal tubercle, tips of toes light orange.

Skull.

(Fig. 5D, J ). Skull weakly ossified, width equal to length; maxillary overlapping with the quadratojugal; premaxillary and maxillary teeth weak, barely visible; teeth absent on mandible; vomerine ridge weak, vomerine teeth absent; nasal process of premaxilla protruding beyond skull; nasal bones separated from each other, completely disconnected with sphenethmoid; sphenethmoid relatively smooth with several small pits on dorsal surface and ventral surface, the front edge of sphenethmoid rounded and protruding forward, separated from premaxilla; frontoparietal partially divided by a narrowly opening sagittal suture; anterior fontanelle almost occlusive; 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 in the middle of the distance from the base to the junction of pterygoid and quadratojugal, 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 ca. two thirds of the constriction near the base; columella auris short.

Variation.

(Suppl. material 2: Fig. S3). Paratypes resemble the holotype in general but with following differences: for CIBMT171060, narrow fringes present on toes, tympanum slightly larger than half eyes, orange granules on dorsum form an “X” -shaped skin ridge and a pair of nearly parallel ridges on dorsolateral trunk, and ventral surface less brown and more orange; for CIBMT171060, a broad “X” pattern present on dorsum, and parallel skin ridges on dorsolateral trunk do not make contact with skin ridges between the left parallel ridge.

Secondary sexual characters.

Male with single subgular vocal sac; nuptial pad not observed in October; lineae musculinae absent.

Distribution and natural history.

The species is currently only discovered from type locality Renqingbeng Temple area at elevation 2003 m in Medog County, Tibet Autonomous Region, China, inhabits small streams in subtropical forests (Fig. 10D, J ; Suppl. material 1: Table S5B). All three individuals were found on short herds or ferns beside small mountain stream at a distance shorter than 0.5 m to the ground (Fig. 10J ). Females were found to be gravid during October, but eggs not well developed. Advertisement calls not head in October. Several gravid females of Megophrys cf. pachyproctus were collected from the same small stream with types of Megophrys zhoui sp. nov. on the same night. Theloderma sp. and Amolops nyingchiensis Jiang, Wang, Xie, Jiang, and Che, 2016 were recorded at the same habitat.

Comparison.

By body relatively smaller (male 23.0, n = 1; females 23.5-23.9, n = 2 measurements in mm), Megophrys zhoui 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. acuta (males 27.1-33.0, n = 10), 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. cheni (males 26.2-29.5, n = 15), 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. kuatunensis (males 26.2-31.4, n = 18), 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. rubrimera (males 26.7-30.5 n = 8), 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. wuliangshanensis (males 27.3-31.6, n = 10), M. wushanensis (males 30.4-35.5, n = 10), M. ombrophila (males 27.4-34.5, n = 5), 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. feii (males 24.5-25.1, n = 4; female 28.2-28.9, n = 2), M. vegrandis (males 27.5-30.6, n = 4), 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 (males31.2-32.1, 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, larger than half eye diameter, Megophrys zhoui sp. nov. differs from M. gigantica , M. nankiangensis , M. shapingensis , and M. wawuensis (vs. tympanum absent, concealed or very small in the latter).

By maxillary teeth present, Megophrys zhoui 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 zhoui 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 zhoui 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 zhoui 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 zhoui sp. nov. differs from M. dringi (vs. present in the latter).

By vomerine ridge weak, Megophrys zhoui sp. nov. differs from M. pachyproctus , M. medogensis , and Megophrys cf. pachyproctus (vs. vomerine ridge 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 , and M. jiangi (vs. absent in the latter).

By vomerine teeth absent, Megophrys zhoui 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 toes with narrow lateral fringes or absent, Megophrys zhoui sp. nov. differs from M. binchuanensis , M. cheni , M. jingdongensis , M. lini , M. rubrimera , M. shuichengensis , M. spinata , M. feii , M. vegrandis , and M. glandulosa (vs. wide in the latter).

By dorsal skin relatively smooth, Megophrys zhoui sp. nov. differs from M. pachyproctus , Megophrys cf. pachyproctus , M. insularis , M. jinggangensis , M. tuberogranulata , M. wuliangshanensis , M. leishanensis , M. dongguanensis , M. jiulianensis , M. nanlingensis , M. wugongensis , M. mufumontana , and M. feii (vs. rough in the latter).

By tympanum moderate (TYD/EL 0.40-0.60, n = 9), Megophrys zhoui sp. nov. differs from species with large tympanum: M. brachykolos (0.70-0.75, n = 7); M. jinggangensis (0.73-0.88, n = 5), and M. takensis (0.71-0.77, n = 4).

By fingertips not expanded into small pads, Megophrys zhoui sp. nov. differs from M. vegrandis , M. ancrae , and M. feii (vs. fingertips with small pads in the latter).

By the following characters, Megophrys zhoui sp. nov. differs from M. pachyproctus : protuberance beyond cloaca small, not visible from ventral view, not swollen (vs. protuberance present on vent beyond cloaca large, swollen, arc-shaped, visible on both dorsal and lateral view in the latter); and inner metatarsal tubercle long oval, positioned on base of toe I (vs. inner metatarsal tubercle rounded, separate from base of toe I at a distance nearly twice its diameter in the latter).

By having following differences on skull morphology, Megophrys zhoui sp. nov. differs from M. pachyproctus : premaxillary and maxillary teeth weak, barely visible or separated from others by gaps (vs. strong, closely positioned with others in the latter); nasal bones not contact with sphenethmoid (vs. mostly in the latter); and middle front edge of sphenethmoid protruding (vs. truncate in the latter).

By base of finger I in similar size with finger II, relative finger lengths I <II <IV <III, Megophrys zhoui sp. nov. differs from M. medogensis (vs. base of finger I distinctly larger than finger II, relative finger lengths II <I <IV <III in the latter).

By having following differences on skull, Megophrys zhoui sp. nov. differs from M. medogensis : skull weakly ossified, opening of anterior fontanelle present, sagittal suture narrowly or wide open (vs. skull well ossified, opening of anterior fontanelle and sagittal suture occlusive in the latter); premaxillary and maxillary teeth weak, barely visible or separated from others by gaps (vs. strong, closely positioned with others 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 base of finger I similar in size with finger II, nasal bones not in contact with sphenethmoid, and texture of sphenethmoid relatively smooth with several small pits, Megophrys zhoui sp. nov. differs from Megophrys cf. pachyproctus (vs. base of finger I larger than the base of finger II, nasal bones mostly contact with sphenethmoid, and sphenethmoid rough with curves and pits in the latter).

Figures

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 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 8. The holotype adult male CIBMT 171053 of Megophrys zhoui 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.