SYS a001973, adult male, collected by Run-Lin Li on 13 December 2012 from Mt. Yinping, Xiegang County (22°54'17.20"N, 114°13'23.88"E; 132 m a.s.l.), Dongguan City, Guangdong Province, China.

SYS a002007, adult male, collected on 17 March 2013 by Run-Lin Li from Mt. Yinping, Qingxi County (22°53'26.21"N, 114°10'14.82"E; 277 m a.s.l.), Dongguan City, China; adult males, SYS a001971/CIB110006, SYS a001972, 1974–1975, collected on 12–13 December 2012, SYS a001492–1495, collected on 23 December 2012 by Run-Lin Li from the same locality as the holotype (100–300 m a.s.l.).

(1) Body size small to moderate, SVL 30.2–39.3 mm in 11 adult male specimens; (2) head width slightly larger than head length, HDW/HDL ratio 1.04–1.09; (3) snout pointed in dorsal view; (4) tympanum distinct, moderate-sized, TD/ED ratio 0.42–0.60; (5) strong vomerine ridge bearing vomerine teeth; (6) margin of tongue not notched behind; (7) hindlimbs short, heels not meeting, tibio-tarsal articulation reaching the region between tympanum and eye; (8) presence of subarticular tubercles and absence of lateral fringes on fingers, relative finger lengths II < I ≤ IV < III; (9) toes with rudiment of webbing at their bases and without lateral fringes, subarticular tubercles only present at the base of each toe; (10) numerous granules present on dorsal surface of body, several large tubercles present on surface of flanks; (11) presence of a barely visible reddish horn-like tubercle at the edge of the upper eyelid; (12) supratympanic fold distinct, whitish; (13) yellowish brown dorsally, with an incomplete dark triangular marking between eyes and usually an X-shaped marking on back of trunk; (14) ventral surface black brown, with white spots on posterior surface of abandon; (15) males with a single subgular vocal sac; (16) presence of nuptial pads with darker nuptial spines on dorsal surface of the first and second fingers in adult males during breeding season, respectively.

Comparative data of Megophrys dongguanensis sp. nov. with M. feii and the 33 recognized members of Megophrys s.l. allocated to the subgenus Panophrys are listed in Table 5.

With significantly smaller body size, SVL 30.2–39.3 mm in males, Megophrys dongguanensis sp. nov. differs from the eight members with larger SVL values: M. baolongensis (42.0–45.0 mm in males), M. binlingensis (45.1–51.0 mm in males), M. caudoprocta (81.3 mm in male), M. jingdongensis (53.0–56.5 mm in males), M. omeimontis (56.0–59.5 mm in males), M. sangzhiensis (54.7 mm in single male), M. spinata (47.2–54.4 mm in males) and M. shuichengensis (102.0–118.3 mm in males).

Megophrys dongguanensis sp. nov. differs from 12 species occurring in eastern and southern China (M. acuta, M. brachykolos, M. boettgeri, M. cheni, M. huangshanensis, M. insularis, M. jinggangensis, M. kuatunensis, M. lini, M. lishuiensis, M. obesa and M. ombrophila) by the following combination of characters: presence of vomerine teeth (vs. absent in M. acuta, M. boettgeri, M. brachykolos, M. cheni, M. huangshanensis, M. kuatunensis, M. lini, M. lishuiensis, M. obesa and M. ombrophila), margin of tongue not notched posteriorly (vs. notched in M. boettgeri, M. cheni, M. huangshanensis, M. insularis and M. kuatunensis), absence of lateral fringes on toes (vs. presence of narrow lateral fringes on toes in M. acuta, M. jinggangensis and M. kuatunensis; presence of wide lateral fringes on toes in M. boettgeri, M. cheni and M. lini), toes with rudimentary webbing (vs. toes without webbing in M. lishuiensis, M. kuatunensis and M. ombrophila), hindlimbs short, with heels not meeting when the flexed hindlimbs are held at right angles to the body axis (vs. hindlimbs comparatively longer, with heels meeting or overlapping in M. cheni, M. boettgeri, M. kuatunensis, M. jinggangensis and M. lini), tibio-tarsal articulation reaching the region between tympanum and eye when hindlimb is stretched along the side of the body (vs. reaching forward to the shoulder in M. brachykolos and to the posterior edge of tympanum in M. insularis).

From the remaining 10 species occurring in China, Megophrys dongguanensis sp. nov. can be distinguished by the presence of vomerine teeth (vs. absent in M. binchuanensis, M. leishanensis, M. minor, M. tuberogranulatus, M. wuliangshanensis and M. wushanensis), by the unnotched tongue (vs. tongue notched in M. daweimontis, M. liboensis, M. minor and M. rubrimera), by the absence of lateral fringes on toes (vs. wide in M. binchuanensis, M. liboensis, M. palpebralespinosa and M. wushanensis (in males); narrow in M. rubrimera), by the rudimentary webbing on toes (vs. toes without webbing in M. rubrimera and M. wuliangshanensis; at least one-fourth webbed in M. palpebralespinosa), by the heels not meeting when the flexed hindlimbs are held at right angles to the body axis (vs. heels meeting in M. binchuanensis and M. tuberogranulatus; heels meeting or overlapping in M. minor and M. wushanensis; heels overlapping in M. leishanensis, M. liboensis, M. palpebralespinosa and M. wuliangshanensis).

Megophrys dongguanensis sp. nov. differs from the remaining species, M. fansipanensis, M. hoanglienensis and M. latidactyla, by the small horn-like tubercle at edge of upper eyelid (vs. slightly large in M. latidactyla), by the unnotched tongue (vs. tongue notched in M. fansipanensis, M. hoanglienensis and M. latidactyla), by the absence of lateral fringes on toes (vs. wide in M. latidactyla), by the presence of rudimentary webbing on toes (vs. webbing indistinct or absent in M. fansipanensis and M. hoanglienensis).

Megophrys dongguanensis sp. nov. further differs from M. feii, for which molecular data are lacking and cannot be allocated to any subgenus base on morphology only (Yang et al. 2018) by the larger body size, SVL 30.2–39.3 mm in males (VS. 24.3–25.1 mm in males), presence of nuptial pad with nuptial spines in males during breeding season (vs. absent), presence of vomerine teeth (vs. absent), unnotched tongue (vs. slightly notched), absence of lateral fringes on toes (vs. moderate or wide), heels not meeting when the flexed hindlimbs are held at right angles to the body axis (vs. heels overlapping).

Adult male. Body moderate-sized, SVL 38.0 mm; head width slightly larger than head length, HWD/HDL 1.09; snout pointed in dorsal view, projecting, sloping backward to mouth in profile, protruding well beyond margin of lower jaw; top of head flat; eye large, ED/HDL 0.40, pupil vertical; nostril oblique ovoid; canthus rostralis well developed, forming the beginning of a fleshy, protruding ridge, that continues over the upper eyelid, and transitions into a supratympanic fold that terminates in the scapular region; loreal region slightly oblique; internasal distance slightly larger than interorbital distance; tympanum distinct, moderate-sized, TD/ED 0.54; large ovoid choanae at the base of the maxilla; presence of vomerine ridge bearing vomerine teeth; margin of tongue not notched posteriorly; internal vocal slits present near the rear of the lower mandible.

Radioulna length and hand length 0.24 of SVL; fingers without webbing and lateral fringes, relative finger length II < I < IV < III; tips of fingers slightly dilated, round; presence of subarticular tubercles on finger III, and one subarticular tubercle at the bases of each finger; outer metacarpal tubercles indistinct, inner metacarpal tubercles distinct and observably enlarged. Hindlimbs short, tibio-tarsal articulation reaching the region between tympanum and eye when hindlimb is stretched along the side of the body; heels not meeting when the flexed hindlimbs are held at right angles to the body axis; tibia length 0.41 of SVL and foot length 0.61 of SVL; relative toe length I < II < V < III < IV; tips of toes round and slightly dilated; presence of rudimentary webbing on toes but absence of lateral fringes and tarsal folds; one subarticular tubercle at the bases of each toe; presence of a long ovoid inner metatarsal tubercle and absence of outer metatarsal tubercle.

Dorsal skin texture rough with dense granules; granules forming discontinuous X-shaped ridge with two discontinuous dorsolateral ridges on both sides at the central trunk; several large tubercles present on dorsal surface of flanks, thighs, shanks and forearms; four small tubercles present on the edge of upper eyelid, one of which is more prominent; distinct narrow supratympanic fold curving posteroventrally from posterior corner of eye to a level above insertion of arm; ventral skin texture smooth, several granules present on surface of abandon, ventral and posterior surface of thighs; pectoral gland small, closer to axilla; single femoral gland on rear of thigh.

SVL 38.0, HDL 12.0, HDW 13.1, SNT 4.5, IND 3.9, IOD 3.6, ED 4.8, TD 2.6, TED 2.1, HND 9.1, RAD 9.2, FTL 23.2, TIB 15.6.

(Fig. 3A–E) Yellowish brown dorsally, with a dark triangular marking between eyes. A wide oblique black band present on forearm. Dorsal surface of fingers and hindlimbs with dark grey transverse bands. Point of snout dark brown, presence of a vertical dark brown band below the eye. Tubercles on the edge of upper eyelid reddish. Supratympanic fold whitish tan. Ventral surface dark brown, with a black longitudinal band on surface of throat, several white spots present on ventral surface of limbs. Digits, inner and outer metacarpal tubercles greyish white, inner metatarsal tubercle greyish brown. Pectoral glands and femoral glands white. Iris yellowish brown.

Figure 3. 

Megophrys dongguanensis sp. nov. in life: A–E SYS a001973, the male holotype F SYS a001492, a male paratype with more distinct skin ridges, granules and tubercles on dorsal surface of body.

Yellowish brown fades to greyish brown dorsally. Triangular marking between eyes, oblique bands on dorsal forearms, transverse bands on dorsal fingers and hindlimbs become indistinct. Color of ventral surface fades, all bands and spots become indistinct.

Measurements of type series are listed in Table 4. All paratypes are very similar to holotype in morphology and color pattern. However, one male (SYS a001492) has more distinct skin ridges, granules and tubercles on dorsal surface of body (Fig. 3, F).

The specific epithet “dongguanensis” is in reference to the type locality, Dongguan City of the new species. We propose the common English name “Dongguan Horned Toad” and Chinese name “Dong Guan Jiao Chan (东莞角蟾)”.

Currently, Megophrys dongguanensis sp. nov. is only known from Mt. Yinping, Guangdong Province, China. It inhabits flowing montane streams and the nearby forest floor and leaf litter at elevations between 100–300 m. Advertisement calls of males were noticed from mid-December until April of the next year just before the rainy season. Males were found calling on rocks in the flowing streams. Tadpoles could be found in this period.

SYS a004498, adult male, collected by Jian Wang and Hai-Long He on 20 October 2015 from Mt. Nankun (23°38'19"N, 113°53'24"E; 400 m a.s.l.), Longmen County, Huizhou City, Guangdong Province, China.

Adult females, SYS a004506–4507, collected by Jian Wang and Hai-Long He on 20 October 2015; adult males, SYS a002023, 2032–2033, collected by Run-Lin Li on 20 March 2013, SYS a004499–4504, SYS a004505/CIB110007, collected by Jian Wang and Hai-Long He on 20 October 2015, all from Mt. Nankun at elevations between 300–650 m.

(1) Body size small, SVL 29.9–34.9 mm in 11 adult males, 39.4–41.9 mm in two adult females; (2) head width slightly larger than head length, HDW/HDL ratio 1.00–1.20; (3) snout rounded in dorsal view, tip of snout slightly sharpened; (4) tympanum distinct, moderate-sized, TD/ED ratio 0.43–0.61; (5) strong vomerine ridge bearing vomerine teeth; (6) margin of tongue not notched behind; (7) shanks short, heels not meeting when the flexed hindlimbs are held at right angles to the body axis; tibia-tarsal articulation reaching forward to the region between tympanum and eye when hindlimb is stretched along the side of the body; (8) TIB/SVL ratio 0.35–0.42, FTL/SVL ratio 0.53–0.62; (9) absence of lateral fringes on fingers, presence of an indistinct subarticular tubercle on the bases of each finger, relative finger lengths II < I < IV < III; (10) toes with rudimentary webbing at their bases and without lateral fringes, subarticular tubercles only present on the bases of each toes; (11) dorsal surface with dense granules, surface of flanks and dorsal surface of limbs with large tubercles; (12) edge of eye lid with a small reddish horn-like tubercle; (13) supratympanic fold distinct, forming a depressed supraaxillary gland above insertion of arm; (14) dorsum beige to dark brown, with indistinct light brown patches, with an incomplete dark triangular marking between eyes; (15) males with a single subgular vocal sac, and dense dark villiform nuptial spines present on dorsal surface of first and second fingers during breeding season, respectively; (16) gravid females bear creamy yellow oocytes.

Comparative data of Megophrys nankunensis sp. nov. with M. dongduanensis sp. nov., M. feii and the 33 recognized members of Megophrys s.l. allocated to the subgenus Panophrys are listed in Table 5.

In the ML and BI phylogenetic trees (Fig. 2), Megophrys nankunensis sp. nov. is a sister taxon to M. dongguanensis sp. nov. (p=4.6–5.0%) with high node-supporting value (0.1 in BI, 100% in ML%), and differs from the later by the snout rounded in dorsal view, tip of snout slightly sharpened (vs. snout pointed in dorsal view, tip of snout not sharpened), supratympanic fold forming a depressed supraaxillary gland above insertion of arm (vs. supraaxillary gland absent).

With significantly smaller body size, SVL 29.9–34.9 mm in males and 39.4–41.9 mm in females, Megophrys nankunensis sp. nov. differs from the 12 members with larger SVL values: M. baolongensis (42.0–45.0 mm in males), M. binlingensis (45.1–51.0 mm in males), M. caudoprocta (81.3 mm in single male), M. hoanglienensis (37.4–47.6 mm in males), M. jingdongensis (53.0–56.5 mm in males, 63.5 mm in single female), M. latidactyla (38.9 mm in single male), M. omeimontis (56.0–59.5 mm in males, 68.0–72.5 mm in females), M. palpebralespinosa (36.2–38.0 mm in males), M. sangzhiensis (54.7 mm in single male), M. shuichengensis (102.0–118.3 mm in males, 99.8–115.6 mm in females), M. spinata (47.2–54.4 mm in males, 54.0–55.0 mm in females) and M. tuberogranulatus (50.5 in single female).

Megophrys nankunensis sp. nov. differs from 12 species occurring in eastern and southern China (M. acuta, M. brachykolos, M. boettgeri, M. cheni, M. huangshanensis, M. insularis, M. jinggangensis, M. kuatunensis, M. lini, M. lishuiensis, M. obesa and M. ombrophila) by the following combination of characters: presence of vomerine teeth (vs. absent in M. acuta, M. boettgeri, M. brachykolos, M. cheni, M. huangshanensis, M. kuatunensis, M. lini, M. lishuiensis, M. obesa and M. ombrophila), absence of lateral fringes on toes (vs. presence of narrow lateral fringes on toes in M. acuta, M. jinggangensis and M. kuatunensis; presence of wide lateral fringes on toes in M. boettgeri, M. cheni and M. lini), toes with rudimentary webbing (vs. toes without webbing in M. lishuiensis, M. kuatunensis and M. ombrophila), hindlimbs short, with heels not meeting when the flexed hindlimbs are held at right angles to the body axis (vs. hindlimbs comparatively longer, with heels meeting or overlapping in M. cheni, M. boettgeri, M. kuatunensis, M. jinggangensis and M. lini), tibio-tarsal articulation reaching forward to the region between tympanum and eye when hindlimb is stretched along the side of the body (vs. reaching forward to the shoulder in M. brachykolos and to the posterior edge of tympanum in M. insularis), relative finger lengths II < I < IV < III (vs. IV < I < II < III in M. brachykolos and I < II < IV < III in M. obesa and M. ombrophila); supratympanic fold forming a depressed supraaxillary gland above insertion of arm (vs. supraaxillary gland swollen in M. insularis; absent in other 11 species).

Megophrys nankunensis sp. nov. differs from the remaining nine members of the Megophrys s.l. allocated to the subgenus Panophrys which share a moderate or small body size, by the by the small horn-like tubercle at edge of upper eyelid (vs. horn-like tubercle indistinct or absent in M. binchuanensis, M. minor, M. wuliangshanensis and M. wushanensis; long point in M. liboensis), presence of vomerine teeth (vs. absent in M. binchuanensis, M. leishanensis, M. minor, M. wuliangshanensis and M. wushanensis), absence of lateral fringes on toes (vs. wide in M. binchuanensis, M. liboensis, M. wushanensis (wide in males); narrow in M. rubrimera), toes with rudimentary webbing (vs. toes without webbing in M. daweimontis, M. rubrimera, M. wuliangshanensis and M. wushanensis (in females); webbing indistinct or absent in M. fansipanensis), tibio-tarsal articulation reaching forward to the region between tympanum and eye when hindlimb is stretched along the side of the body (vs. reaching forward to the tip of snout in M. daweimontis), finger II shortest (vs. finger I shortest in M. liboensis), presence of an indistinct subarticular tubercle on the bases of each finger (vs. subarticular tubercle absent in M. fansipanensis), heels not meeting when the flexed hindlimbs are held at right angles to the body axis (heels meeting in M. binchuanensis; heels meeting or overlapping in M. minor and M. wushanensis; heels overlapping in M. leishanensis, M. liboensis and M. wuliangshanensis).

Megophrys nankunensis sp. nov. further differs from M. feii, for which molecular data are lacking and cannot be allocated to any subgenus base on morphology only (Yang et al. 2018) by the larger body size, SVL 29.9–34.9 mm in males and 39.4–41.9 mm in females (VS. 24.3–25.1 mm in males, 28.2–28.9 mm in females), presence of nuptial pad with nuptial spines in males during breeding season (vs. absent), presence of vomerine teeth (vs. absent), absence of lateral fringes on toes (vs. moderate or wide), heels not meeting when the flexed hindlimbs are held at right angles to the body axis (vs. heels overlapping).

Adult male. Habitus small, SVL 31.3 mm; head width slightly larger than head length, HDW/HDL 1.12; snout rounded in dorsal view, tip of snout slightly sharpened, sloping backward to mouth in profile, protruding well beyond margin of lower jaw; top of head flat; eye large, ED/HDL 0.38; nostril oblique ovoid; pupil vertical; canthus rostralis well developed, forming the beginning of a fleshy, protruding ridge, that continues over the upper eyelid, and transitions into a supratympanic fold that terminates in the scapular region; loreal region vertical; internasal distance slightly larger than interorbital distance; tympanum distinct, moderate-sized, TD/ED 0.44; large ovoid choanae at the base of the maxilla; strong vomerine ridge bearing vomerine teeth; margin of tongue weakly notched posteriorly; internal vocal slits present near the rear of the lower mandible.

RAD/SVL 0.22, HND/SVL 0.22; absence of lateral fringes and webbing on fingers, relative finger lengths II < I < IV < III; tip of finger rounded, slightly swollen; presence of a distinct subarticular tubercle on the base of each finger; outer metacarpal tubercles indistinct, inner metacarpal tubercles distinct and observably enlarged. Hindlimbs short, tibio-tarsal articulation reaching forward the anterior margin of tympanum when hindlimb is stretched along the side of the body; heels not meeting when the flexed hindlimbs are held at right angles to the body axis; TIB/SVL 0.37 and FTL/SVL 0.55; relative toe lengths I < II < V < III < IV; tips of toes round and slightly dilated; presence of rudimentary webbing on toes but absence of lateral fringes and tarsal folds; presence of a subarticular tubercle only at the bases of each toes; presence of a long ovoid inner metatarsal tubercle and absence of outer metatarsal tubercle.

Dorsal skin texture smooth with dense granules, some of which forming a weak X-shaped skin ridge on center of trunk; surface of flanks with large tubercles; presence of a small horn-like tubercle at the edge of eyelid; distinct supratympanic fold curving posteroventrally from posterior corner of eye to a level above insertion of arm, forming a swollen supraaxillary gland above insertion of arm; ventral skin texture smooth with granules on the surface of abdomen; pectoral gland large, equal size to tip of fingers, closer to axilla; single large femoral gland on rear of thigh.

SVL 31.3, HDL 9.6, HDW 10.8, SNT 3.4, IND 3.4, IOD 2.4, ED 3.7, TD 1.6, TED 1.0, HND 6.9, RAD 7.0, FTL 17.3, TIB 11.6.

(Fig. 4A–D) Dorsal surface beige with obscure darker patches, with a distinct and incomplete dark triangular marking between eyes, unconnected with an incomplete X-shaped marking on center of trunk. Forearm with dark bands dorsally; hindlimb with broad black transverse bands. Tip of snout dark brown. A dark brown vertical band below the eye. Supratympanic fold white. Horn-like tubercle at the edge of the upper eyelid orange. Surface of throat and chest dark brown, with scarlet spots. Posterior region of abdomen white, with dark brown and scarlet spots. Ventral surface of limbs white with brown patches. Ventral surface of hand and foot light brown, subarticular tubercle at the base of each fingers and toes, outer metacarpal tubercle, inner metatarsal tubercle and inner metacarpal tubercle pink. Pectoral and femoral glands white. Iris white.

Figure 4. 

Megophrys nankunensis sp. nov. in life: A–D SYS a004498, the male holotype E–F SYS a004507, the female paratype.

On dorsal surface the beige fades to dark grey. Dark interorbital triangular marking becomes more indistinct. Ventral surface pale in color, grey-brownish grounding, markings and mottling more distinct, all scarlet spots absent.

Measurements and body proportions of type series are given in Table 4.

All paratype specimens were very similar in morphology and color pattern. However, the holotype has the dorsal surface beige (vs. reddish brown in paratypes SYS a002033, 4501, and dark brown in paratypes SYS a004502–4506, 4507 (Fig. 4E–F)), dorsal skin texture smooth, granules and tubercles weak (vs. dorsal skin texture relatively rough with more distinct granules and tubercles in paratypes SYS a004502, 4504–4507), and ventral surface of hand and foot light brown (vs. ventral surface of hand and foot grey white in paratypes SYS a004502–4504).

The specific epithet “nankunensis” is in reference to the type locality of the new species: Mt. Nankun. We propose the common English name “Nankunshan Horned Toad” and Chinese name “Nan Kun Shan Jiao Chan (南昆山角蟾)”.

Currently, Megophrys nankunensis sp. nov. is known only from the type locality, Mt. Nankun in Longmen County, Guangdong Province, China. It inhabits forest floor, leaf litter and the nearby undergrowth rocky mountainous streams (2–3 m wide) surrounded by moist subtropical evergreen broadleaved forests at elevations between 300–600 m. Breeding season of M. nankunensis sp. nov. is from October to the following March, males were found calling under the leaf litter or rocks (Fig. 5A) on the ground in the flowing streams, besides, a pair were observed exposed on the floor in a flowing stream, about 2.5 m wide, prior to amplexus (Fig. 5B) at 20:09 P.M. on 20 October 2015. Tadpoles were not observed in this period.

Figure 5. 

Ecology and behavior of Megophrys nankunensis sp. nov. A an adult male observed under the rock in the flowing stream B pair of M. nankunensis sp. nov. observed exposed on leave litters in a flowing stream, about 2.5 m wide, prior to amplexus.

SYS a002112, adult male, collected by Yu-Long Li on 2 May 2013 from Daqiutian Protection Station (24°34'34.99"N, 114°26'28.53"E; 560 m a.s.l.) of Mt. Jiulian, Longnan County, Ganzhou City, Jiangxi Province, China.

SYS a002110, 2111, adult females, collected by Yu-Long Li on 3 May 2013 from Xiagongtang Protection Station (24°32'16.74"N, 114°27'56.82"E; 770 m a.s.l.) of Mt. Jiulian; SYS a001007, 1009, adult males, collected by Run-Lin Li on 23 July 2010 from Daqiutian Protection Station of Mt. Jiulian; SYS a002107–2109, 2113–2114, SYS a002115/CIB110008, adult males, collected by Yu-Long Li on 1–4 May 2013 from Xiagongtang Protection Station and Daqiutian Protection Station of Mt. Jiulian at elevations between 400–800 m a.s.l.; SYS a002031, adult male, collected by Run-Lin Li on 20 Marth 2013 from Mt. Nankun (23°38'21.94"N, 113°50'39.49"E; 610 m a.s.l.), Longmen County, Huizhou City, Guangdong Province, China.

(1) Body slender and small-sized, SVL 30.4–33.9 mm in nine adult males, 34.1–37.5 mm in two adult females; (2) head width slightly larger than head length, HDW/HDL ratio 1.04–1.06; (3) snout rounded in dorsal view; (4) eye large, tympanum distinct, moderate-sized, TD/ED ratio 0.50–0.59; (5) weak vomerine ridge bearing vomerine teeth; (6) tongue weakly notched posteriorly; (7) hindlimbs slender, heels overlapping when the flexed hindlimbs are held at right angles to the body axis, tibia-tarsal articulation reaching forward to the middle of eye when hindlimb is stretched along the side of the body; (8) absence of lateral fringes on fingers, presence of an indistinct subarticular tubercle on the bases of each finger, relative finger lengths II < I < IV < III; (9) toes with rudimentary webbing at their bases and without lateral fringes, subarticular tubercles only present at the base of toe I and II; (10) dorsal skin rough, presence of black spines on granules of dorsal skin, and occasionally present on canthus rostralis and margin of tympanum, presence of large tubercles on flanks, dorsal body and limbs; (11) four prominent parallel dorsolateral ridges with granules bearing black spines on back of trunk, the middle two ridges forming a X-shaped ridge occasionally; (12) a reddish horn-like tubercle bearing a black spine at its tip at the edge of eye lid; (13) distinct supratympanic fold bearing black spines; (14) beige to brownish red above, with an hollow dark triangle between eyes and a rectangular dark marking on the center of the back of trunk; (15) males with a single subgular vocal sac, and presence of nuptial pads bearing darker nuptial spines on dorsal surface of the first and second fingers in adult males during breeding season, respectively; (16) gravid females bear creamy yellow oocytes.

Comparative data of Megophrys jiulianensis sp. nov. with M. dongduanensis sp. nov., M. nankunensis sp. nov., M. feii and the 33 recognized members of the Megophrys s.l. allocated to the subgenus Panophrys are listed in Table 5.

Megophrys jiulianensis sp. nov. is sympatric with M. nankunensis sp. nov. in Mt. Nankun, but it can be easily distinguished from the later by heels overlapping when the flexed hindlimbs are held at right angles to the body axis (vs. heels not meeting), TIB/SVL ratio 0.61–0.68 (vs. TIB/SVL ratio 0.35–0.42), supratympanic fold not forming a supraaxillary gland above insertion of arm (vs. supratympanic fold forming a depressed supraaxillary gland), presence of black spines on dorsal skin (vs. absent); besides, M. jiulianensis sp. nov. differs from M. dongguanensis sp. nov. by the notched tongue vs. (not notched), heels overlapping when the flexed hindlimbs are held at right angles to the body axis (vs. heels not meeting), TIB/SVL ratio 0.61–0.68 (vs. TIB/SVL ratio 0.41–0.46).

With significantly smaller body size, SVL 30.4–33.9 mm in males and 34.1–37.5 mm in females, M. jiulianensis sp. nov. differs from the 17 members with larger SVL values: M. baolongensis (42.0–45.0 mm in males), M. binchuanensis (40.2–42.5 mm in females), M. binlingensis (45.1–51.0 mm in males), M. caudoprocta (81.3 mm in single male), M. daweimontis (40.0–46.0 mm in females), M. fansipanensis (41.7–42.5 mm in females), M. hoanglienensis (37.4–47.6 mm in males, 59.6 mm in single female), M. jingdongensis (53.0–56.5 mm in males, 63.5 mm in single female), M. liboensis (34.7–67.7 mm in males, 60.8–70.6 mm in females), M. minor (34.5–41.2 mm in males), M. omeimontis (56.0–59.5 mm in males, 68.0–72.5 mm in females), M. palpebralespinosa (36.2–38.0 mm in males), M. sangzhiensis (54.7 mm in single male), M. shuichengensis (102.0–118.3 mm in males, 99.8–115.6 mm in females), M. spinata (47.2–54.4 mm in males, 54.0–55.0 mm in females), M. tuberogranulatus (50.5 mm in single female) and M. wuliangshanensis (41.3 mm in single female).

Megophrys jiulianensis sp. nov. differs from 12 species occurring in eastern and southern China (M. acuta, M. brachykolos, M. boettgeri, M. cheni, M. huangshanensis, M. insularis, M. jinggangensis, M. kuatunensis, M. lini, M. lishuiensis, M. obesa and M. ombrophila) by the following combination of characters: presence of vomerine teeth (vs. absent in M. acuta, M. boettgeri, M. brachykolos, M. cheni, M. huangshanensis, M. jinggangensis, M. kuatunensis, M. lini, M. lishuiensis, M. obesa and M. ombrophila), tongue notched posteriorly (vs. not notched in M. acuta, M. brachykolos, M. jinggangensis, M. lini, M. lishuiensis, M. obesa and M. ombrophila), absence of lateral fringes on toes (vs. narrow in M. acuta, M. jinggangensis and M. kuatunensis; wide in M. boettgeri, M. cheni and M. lini), heels overlapping when the flexed hindlimbs are held at right angles to the body axis (vs. heels not meeting in M. acuta, M. brachykolos, M. insularis, M. obesa and M. ombrophila).

Megophrys jiulianensis sp. nov. differs from the remaining four members of the Megophrys s.l. allocated to the subgenus Panophrys which share a moderate or small body size, by the presence of vomerine teeth (vs. absent in M. leishanensis and M. wushanensis), tongue notched posteriorly (vs. not notched in M. leishanensis, M. wushanensis and M. latidactyla), absence of lateral fringes on toes (vs. narrow in M. rubrimera; wide in M. latidactyla and M. wushanensis (wide in females)), toe webbing rudimentary (vs. absence of webbing on toes in M. rubrimera).

Megophrys jiulianensis sp. nov. further differs from M. feii, for which molecular data are lacking and cannot be allocated to any subgenus base on morphology only (Yang et al. 2018) by the larger body size, SVL 30.4–33.9 mm in males and 34.1–37.5 mm in females (VS. 24.3–25.1 mm in males, 28.2–28.9 mm in females), presence of nuptial pad with nuptial spines in males during breeding season (vs. absent), presence of vomerine teeth (vs. absent), absence of lateral fringes on toes (vs. moderate or wide).

Adult male. Habitus slender and small, SVL 32.0 mm; head width slightly larger than head length, HDW/HWL 1.04; snout rounded in dorsal view, projecting, sloping backward to mouth in profile, protruding well beyond margin of lower jaw; top of head flat; eye large, ED/HDL 0.39; nostril oblique ovoid; pupil vertical; canthus rostralis well developed, forming the beginning of a fleshy, protruding ridge, that continues over the upper eyelid, and transitions into a supratympanic fold that terminates in the scapular region; loreal region vertical; internasal distance slightly larger than interorbital distance; tympanum distinct, moderate-sized, TD/ED 0.52; large ovoid choanae at the base of the maxilla; weak vomerine ridge bearing vomerine teeth; margin of tongue weakly notched posteriorly; internal vocal slits present near the rear of the lower mandible..

RAD/SVL 0.25; absence of lateral fringes and webbing on fingers, relative finger lengths II < I < IV < III; tip of finger rounded, slightly swollen; presence of an indistinct subarticular tubercle on the base of each finger; outer metacarpal tubercles indistinct, inner metacarpal tubercles distinct and observably enlarged. Hindlimbs long, tibio-tarsal articulation reaching forward to the middle of eye when hindlimb is stretched along the side of the body; heels overlapping when the flexed hindlimbs are held at right angles to the body axis; TIB/SVL 0.46 and FTL/SVL 0.62; relative toe lengths I < II < V < III < IV; tips of toes round and slightly dilated; presence of rudimentary webbing on toes but absence of lateral fringes and tarsal folds; presence of a subarticular tubercle only at the bases of the first and second toes; presence of a long ovoid inner metatarsal tubercle and absence of outer metatarsal tubercle.

Dorsum rough with dense granules bearing spines; canthus rostralis, margin of tympanum, supratympanic fold and upper lip with dense spines; presence of large tubercles bearing spines on dorsal surface of body, surface of flanks and dorsal and posterolateral surface of limbs; prominent parallel dorsolateral ridges with granules bearing spines on back of trunk; presence of a horn-like tubercle bearing a spine at its tip at the edge of eye lid; distinct supratympanic fold curving posteroventrally from posterior corner of eye to a level above insertion of arm; ventral skin texture smooth, the lower lip bears spines; sides of belly with large tubercles; ventral skin texture of thighs smooth with a few small tubercles, posterior surface and surface around anus with large tubercles bearing spines; surface of tibia-tarsal with a few tubercles bearing spines; presence of spines on lateral sides of fingers and toes; pectoral gland moderate-sized, closer to axilla; single femoral gland on rear of thigh, distinctly smaller than pectoral gland.

SVL 32.2, HDL 11.5, HDW 11.4, SNT 3.6, IND 3.5, IOD 3.3, ED 4.2, TD 2.3, TED 1.7, HND 8.0, RAD 8.1, FTL 20.5, TIB 14.7.

(Fig. 6A–D) Dorsal surface yellowish brown, with an incomplete dark triangular marking between eyes. Spines on dorsal surface, granules and tubercles black. Forearm with a distinct, black oblique band. Transverse bands on hindlimb indistinct. Tip of snout grayish brown. A grayish-brown vertical band below the eye. Tubercle at the edge of the upper eyelid red. Ventral surface yellow, scattered with dense dark gray spots and black scarlet blotches; ventral surface of limbs flesh colored with pink and black spots. Palms and soles dark brown, inner metatarsal tubercle, outer metacarpal tubercle and inner metacarpal tubercle orange red, tip of digits orange-red. Pectoral glands and femoral glands white. Iris white.

Figure 6. 

General life aspect in life of Megophrys jiulianensis sp. nov.: A–D SYS a002112, the male holotype E–F SYS a002111, the female paratype.

Dorsum yellowish brown fades to greyish brown, scattered with black spots. Greyish black triangular marking between the eyes become more distinct. Ventral surface paled in color, brown grounding, markings and mottling become more distinct.

Measurements and body proportions of type series are given in Table 6.

All paratype specimens were very similar in morphology and color pattern. However, dorsal skin texture is more rough with well-developed spines in the female specimen SYS a002111 (Fig. 6E–F), dorsal surface yellowish brown in the other female specimen SYS a002110, and the middle two ridges on dorsum forming an X-shape skin ridge in the male specimen SYS a002108.

The specific epithet “jiulianensis” is in reference to the known localities of the new species: Mt. Jiulian and Nankunshan Natuire Reserve located in the Jiulian Mountains range. We propose the common English name “Jiulianshan Horned Toad” and Chinese name “Jiu Lian Shan Jiao Chan (九连山角蟾)”.

Currently, Megophrys jiulianensis sp. nov. is known from Mt. Nankun in Guangdong Province and the type locality, Jiulian Nature Reserve in Jiangxi Province, China. It inhabits forest floor, leaf litter and the nearby undergrowth mountainous streams surrounded by moist subtropical evergreen broadleaved forests at elevations between 500–800 m. Breeding season of M. jiulianensis sp. nov. is from March to July, males were usually found staying while calling on leaves (Fig. 7A), about 0.1–0.3 m above the ground. After the rain, numerous individuals can be easily found on the road, and a female individual from Mt. Nankun was observed feeding on an earthworm (Fig. 7B) on 20:45 p.m., 21 March 2016. Tadpoles could be found all year round.

Figure 7. 

Ecology and behavior of Megophrys jiulianensis sp. nov.: A The male paratype SYS a002031 observed calling on a leaf (showing subgular vocal sac) B a female individual observed feeding on an earthworm after rain, both from Mt. Nankun in Guangdong Province.

Megophrys jiulianensis sp. nov. is sympatric with M. nankunensis sp. nov. and M. mangshanensis at Mt. Nankun.

SYS a001964, adult male, collected by Run-Lin Li on 21 December 2012 from Nanling Nature Reserve (24°54'48.80"N, 113°01'12.34"E; 1008m a.s.l.), Ruyuan County, Shaoguan City, Guangdong Province, China.

SYS a001959–1962, SYS a001963/CIB110010, adult males, collected on 21 December 2012 by Run-Lin Li from the same stream as the holotype (1000–1300 m a.s.l.); SYS a002334, 2356–2358, collected on 1–3 October 2013 by Ying-Yong Wang and Zu-Yao Liu from Mt. Qiyun (25°52'22.84"N, 114°01'52.09"E; 691–1355m a.s.l.), Chongyi County, Ganzhou City, Jiangxi Province, China.

(1) Body small-sized, SVL 30.5–37.3 mm in 10 adult males; (2) snout rounded in dorsal view; (3) tympanum distinct, moderate-sized, TD/ED ratio 0.43–0.57; (4) vomerine ridge and vomerine teeth present; (5) tongue notched posteriorly; (6) absence of lateral fringes and webbing on fingers, presence of narrow lateral fringes and rudimentary webbing on toes; (7) presence of a subarticular tubercle at the base of each finger and toe; (8) hindlimbs slender, heels overlapping, tibio-tarsal articulation reaching between the posterior corner to the center of eye; (9) TIB/SVL ratio 0.45–0.51 and FTL/SVL ratio 0.61–0.73; (10) dense conical granules present on surface of temporal region, upper lip, and from loreal region to the tip of snout; (11) granules and tubercles on dorsal surface forming a discontinuous X-shaped ridge and a pair of discontinuous dorsolateral ridges on back of trunk; (12) supratympanic fold distinct, whitish tan; (13) brown dorsally, with a dark triangular marking with light yellow edge between eyes, and an X-shaped or V-shaped marking with light yellow edge on the center of the back of trunk; (14) presence of a single subgular vocal sac in males; (15) nuptial pads and nuptial spines invisible in males during breeding season.

Comparative data of Megophrys nanlingensis sp. nov. with M. dongduanensis sp. nov., M. nankunensis sp. nov., M. jiulianensis sp. nov., M. feii and the 33 recognized members of Megophrys s.l. allocated to the subgenus Panophrys are listed in Table 5.

Megophrys nanlingensis sp. nov. differs from M. dongguanensis sp. nov., M. nankunensis sp. nov. and M. jiulianensis sp. nov. by the heels overlapping when hindlimb is stretched along the side of the body (vs. heels not meeting in M. dongguanensis sp. nov. and M. nankunensis sp. nov.), presence of lateral fringes on toes (vs. absent in M. dongguanensis sp. nov., M. nankunensis sp. nov. and M. jiulianensis sp. nov.), tongue notched posteriorly (vs. not notched in M. dongguanensis sp. nov. and M. nankunensis sp. nov.), skin relatively smooth and lacking black horny spines (vs. skin rough with black horny spines in M . jiulianensis sp. nov.).

With the smaller body size, SVL 30.5–37.3 mm in males, Megophrys nanlingensis sp. nov. differs from the nine members with larger SVL values: M. baolongensis (42.0–45.0 mm in males), M. binlingensis (45.1–51.0 mm in males), M. caudoprocta (81.3 mm in single male), M. jingdongensis (53.0–56.5 mm in males), M. latidactyla (38.9 mm in single male), M. omeimontis (56.0–59.5 mm in males), M. sangzhiensis (54.7 mm in single male), M. shuichengensis (102.0–118.3 mm in males) and M. spinata (47.2–54.4 mm in males).

Megophrys nanlingensis sp. nov. differs from 12 species occurring in eastern and southern China (M. acuta, M. brachykolos, M. boettgeri, M. cheni, M. huangshanensis, M. insularis, M. jinggangensis, M. kuatunensis, M. lini, M. lishuiensis, M. obesa and M. ombrophila) by the following combination of characters: presence of vomerine teeth (vs. absent in M. acuta, M. boettgeri, M. brachykolos, M. cheni, M. huangshanensis, M. kuatunensis, M. lini, M. lishuiensis, M. obesa and M. ombrophila), margin of tongue notched posteriorly (vs. not notched in M. acuta, M. brachykolos, M. jinggangensis, M. lini, M. lishuiensis, M. obesa and M. ombrophila), toes with narrow lateral fringes (vs. wide in M. boettgeri, M. cheni and M. lini; absent in M. brachykolos, M. huangshanensis, M. insularis, M. lishuiensis, M. obesa and M. ombrophila), toes with rudimentary webbing (vs. toes without webbing in M. lishuiensis, M. kuatunensis and M. ombrophila), hindlimbs comparatively longer, with heels overlapping when the flexed hindlimbs are held at right angles to the body axis (vs. hindlimbs short, with heels not meeting in M. acuta, M. brachykolos, M. huangshanensis, M. insularis, M. obesa and M. ombrophila).

Megophrys nanlingensis sp. nov. differs from the remaining 12 members of the Megophrys s.l. allocated to the subgenus Panophrys which share a moderate or small body size, by the small horn-like tubercle at edge of the upper eyelid (vs. horn-like tubercle indistinct or absent in M. binchuanensis, M. minor, M. wuliangshanensis and M. wushanensis; slightly large in M. palpebralespinosa; long point in M. liboensis), presence of vomerine teeth (vs. absent in M. binchuanensis, M. leishanensis, M. minor, M. wuliangshanensis and M. wushanensis), tongue notched posteriorly (vs. tongue not notched in M. palpebralespinosa, M. tuberogranulatus and M. wushanensis), toes with narrow lateral fringes (vs. wide in M. binchuanensis, M. liboensis, M. palpebralespinosa and M. wushanensis (in males)); absent in M. daweimontis, M. leishanensis, M. minor, M. tuberogranulatus, M. wuliangshanensis, M. wushanensis (in females); indistinct or absent in M. hoanglienensis), toes webbing rudimentary (vs. toes without webbing in M. daweimontis, M. fansipanensis, M. rubrimera and M. wuliangshanensis; indistinct or absent in M. fansipanensis and M. hoanglienensis; at least one-fourth webbed in M. palpebralespinosa), subarticular tubercles present (vs. absent in M. palpebralespinosa and M. rubrimera).

Megophrys nanlingensis sp. nov. further differs from M. feii, for which molecular data are lacking and cannot be allocated to any subgenus based on morphology only (Yang et al. 2018) by the larger body size, SVL 30.5–37.3 mm in males (VS. 24.3–25.1 mm in males), presence of nuptial pad with nuptial spines in males during breeding season (vs. absent), presence of vomerine teeth (vs. absent), presence of narrow lateral fringes on toes (vs. moderate or wide).

Adult male. Body size small, SVL 32.5 mm; head length and head width almost isometric, HDW/HDL 0.99; snout rounded in dorsal view, projecting, sloping backward to mouth in profile, protruding well beyond margin of lower jaw; top of head flat; eye large, ED/HDL 0.37, pupil vertical; nostril oblique ovoid; canthus rostralis well developed; loreal region slightly oblique; internasal distance slightly larger than interorbital distance; tympanum distinct, moderate-sized, TD/ED 0.48; large ovoid choanae at the base of the maxilla; presence of vomerine ridge bearing vomerine teeth; margin of tongue notched posteriorly; internal vocal slits present near the rear of the lower mandible.

RAD/SVL 0.25, HND/SVL 0.24; fingers without webbing and lateral fringes, relative finger length II < I < IV < III; tips of fingers slightly dilated, round; one subarticular tubercle at the bases of each finger; outer and inner metacarpal tubercles distinct, and the inner one observably enlarged. Hindlimbs slender, tibio-tarsal articulation reaching forward to the center of the eye when hindlimb is stretched along the side of the body; heels overlapping when the flexed hindlimbs are held at right angles to the body axis; TIB/SVL 0.49 and FTL/SVL 0.69; relative toe length I < II < V < III < IV; tips of toes round and slightly dilated; toes with narrow lateral fringes, rudimentary webbing; one subarticular tubercle at the bases of each toes; presence of a long ovoid inner metatarsal tubercle and absence of outer metatarsal tubercle.

Dorsal skin texture rough; head surface rough, with small tapered granules densely covering from temporal region, upper lip, loreal region to tip of snout; granules forming discontinuous X-shaped ridge with two discontinuous dorsolateral ridges on both sides at the central trunk; large tubercles on flanks; a horn-like prominent tubercle on the edge of the upper eyelid; distinct supratympanic fold curving posteroventrally from posterior corner of eye to a level above insertion of arm; ventral skin texture smooth, with several large granules and tubercles on two sides; ventral skin texture of thighs smooth, with a few small tubercles; pectoral gland larger, closer to axilla; single femoral gland on rear of thigh.

SVL 32.5, HDL 11.5, HDW 11.4, SNT 3.7, IND 3.5, IOD 3.3, ED 4.2, TD 2.0, TED 1.7, HND 8.0, RAD 7.8, FTL 22.3, TIB 15.9.

(Fig. 8A–D) Brown dorsally, with a dark triangular marking with light yellow edge between eyes, and an X-shaped marking with light yellow edge on the center of the back of trunk. Dark brown transverse bands dorsally on lower arms and hindlimbs. Surface of snout brown. Black brown vertical band below the eye on each side. Temporal region brown, supratympanic fold white. Ventral surface pale grey, an indistinct longitudinal stripe on surface of throat. Scarlet spots on surface of chest. Belly whitish grey with dark brown marbling. A pair of black longitudinal stripes scattered with several white tubercles on surface of lateroventral flanks. Ventral surface of limbs light red and scattered with white spots. Ventral surface of hands and feet dark brown, tips of digits pale-grey. Metacarpal tubercle and metatarsal tubercle light red. Pectoral glands and femoral glands white. Iris reddish brown.

Figure 8. 

Megophrys nanlingensis sp. nov. in life: A–D SYS a001964, male holotype E, F SYS a001963, female paratype.

Coloration of dorsal and ventral surface turned pale; transverse bands on limbs, dark longitudinal stripe on surface of throat and black patches on surface of lateroventral flanks became more distinct; scarlet spots on surface of chest faded.

Measurement data of type series are listed in Table 7.

All paratypes are very similar to holotype in morphology and color pattern. However, the male specimen SYS a001963 (Fig. 8E, F) is obviously large in snout-vent length than other specimens, with lighter reddish-brown iris, yellowish brown background coloration and comparatively smooth skin. The heels are significantly overlapping in all specimens from Nanling Nature Reserve but slightly overlapping in specimens from Mt. Qiyun.