Boulenophrys yangchunensis, Zhao & Lin & Li & Lyu & Zheng & Zeng & Borzée & Wang, 2025

Zhao, Yi-Yang, Lin, Shi-Shi, Li, Yuan-Hang, Lyu, Zhi-Tong, Zheng, Ke, Zeng, Zhao-Chi, Borzée, Amaël & Wang, Jian, 2025, A new species of Chinese horned toad (Anura, Megophryidae, Boulenophrys) from western Guangdong Province, China, with recommendations for extinction risk assessments for several related congeners, Herpetozoa 38, pp. 345-357 : 345-357

Boulenophrys yangchunensis sp. nov.

Figs 3 , 4 English name: Yangchun Horned Toad Chinese name: yáng chūn jiǎo chán (阳春角蟾 )

Type materials.

Holotype • ♂. GEP a 170 , collected by Jian Wang, Zhao-Chi Zeng, Hong-Hui Chen, Yuan-Hang Li, and Ke Zheng on 11 August 2023 from Guangdong Yangchun Ehuangzhang Provincial Nature Reserve ( 21.851912°N, 111.421553°E; ca. 1,060 m a. s. l.) in Yangchun City, Guangdong Province, China .

Paratypes. • 4 ♂: GEP a 168 –169, SYS a 009518 (field number: GEP a 172), and CIB 121751 (field number: GEP a 171), same collection data as holotype .

Etymology.

The specific epithet yangchunensis is in reference to the type locality, Yangchun City.

Diagnosis.

(1) small size ( SVL 27.6–28.7 mm in five adult males); (2) snout sharpened in dorsal view, canthus rostralis well developed, tongue not notched distally; (3) tympanum distinct; (4) vomerine ridges and vomerine teeth absent; (5) dorsal skin rough and highly granular, discontinuous X-shaped ridge on center of dorsum, discontinuous dorsolateral ridges present, sparse large tubercles on flanks, dorsal limbs with discontinuous transverse ridges and tubercles; (6) outer margin of upper eyelid with a small horn-like prominent tubercle, supratympanic fold distinct and narrow, curving posteroventrally to above arm; (7) two metacarpal tubercles distinct, inner one observably enlarged, relative finger lengths I <II <IV <III, distinct subarticular tubercle at base of each finger; (8) heels just meeting when hindlimbs folded, tibio-tarsal articulation reaching middle to anterior corner of eye; (9) toes without webbing and lateral fringes, inner metatarsal tubercle long ovoid, outer one absent, relative toe length I <II <V <III <IV; (10) dorsal surface yellowish-brown to dark brown, with indistinct irregular dark-brown patches and small orange dots; dark-brown triangular marking between eyes; dorsal limbs and digits light brown with dark-brown transverse bands; and (11) a single nuptial pad bearing dense nuptial spines on dorsal bases of fingers I and II in breeding adult males, subgular vocal sac present in males.

Comparisons.

Boulenophrys yangchunensis sp. nov. is phylogenetically most closely related to B. acuta and B. gaolanensis (Fig. 2 ). However, the new species distinctively differs from B. acuta by its heels meeting when hindlimbs are folded (vs. heels not meeting), absence of vomerine ridge (vs. presence of weak vomerine ridge), absence of webbing and lateral fringes on toes (vs. presence of rudimentary webbing and narrow lateral fringes on toes), presence of nuptial pads bearing dense nuptial spines on dorsal bases of fingers I and II in breeding adult males (vs. presence of weak nuptial pads not bearing nuptial spines on dorsal bases of fingers I and II in breeding adult males). The new species further differs from B. gaolanensis by its heels meeting when hindlimbs folded (vs. heels not meeting), sharpened snout in dorsal view (vs. rounded snout in dorsal view), presence of nuptial pad bearing dense nuptial spines on dorsal bases of fingers I and II in breeding adult males (vs. nuptial pad and nuptial spines invisible).

Boulenophrys yangchunensis sp. nov. can be easily distinguished from B. brachykolos , B. daoji , B. daweimontis , B. dongguanensis , B. fengshunensis , B. frigida , B. hungtai , B. hengshanensis , B. kuatunensis , B. lichun , B. lushanensis , B. nankunensis , B. puningensis , B. pepe , B. insularis , B. obesa , B. ombrophila , and B. wugongensis , by its heels meeting when hindlimbs folded (vs. heels not meeting); and from B. anlongensis , B. baishanzuensis , B. binlingensis , B. caudoprocta , B. cheni , B. changyangensis , B. congjiangensis , B. changyangensis , B. chishuiensis , B. daxuemontis , B. dalaolingensis , B. dupanglingensis , B. fanjingmontis , B. jiangi , B. jiulianensis , B. jingdongensis , B. jinggangensis , B. leishanensis , B. lushuiensis , B. liboensis , B. lini , B. lishuiensis , B. mirabilis , B. mufumontana , B. nanlingensis , B. omeimontis , B. palpebralespinosa , B. qianbeiensis , B. sangzhiensis , B. shunhuangensis , B. sanmingensis , B. shimentaina , B. spinata , B. tongboensis , B. tuberogranulata , B. xianjuensis , B. yangmingensis , B. yezhongensis , B. yingdeensis , B. yunkaiensis , and B. wuliangshanensis (vs. heels overlapping).

Boulenophrys yangchunensis sp. nov. further differs from B. angka , B. anlongensis , B. baishanzuensis , B. binlingensis , B. elongata , B. fansipanensis , B. hoanglienensis , B. minor , B. rubrimera , B. shuichengensis , B. xiangnanensis , B. yaoshanensis , and B. yezhongensis by its absence of vomerine ridge (vs. presence of vomerine ridge); from B. daiyunensis , B. elongata , B. fansipanensis , B. hoanglienensis , and B. rubrimera by its absence of vomerine teeth (vs. presence of vomerine teeth); and from B. baolongensis and B. boettgeri by its tongue not notched distally (vs. tongue notched). The new species differs from B. wushanensis and B. gutu by its absence of lateral fringes on toes (vs. presence of lateral fringes on toes); from B. yaoshanensis and B. caobangensis by its absence of webbing on toes (vs. presence of webbing on toes); from B. xuefengmontis by its tibiotarsal articulation reaching region between middle of eye to anterior corner of eye when legs are stretched forward (vs. between posterior margin of tympanum and posterior corner of eye), and the absence of granules on ventral skin (vs. presence of several granules on chest); from B. huangniushiensis by its presence of nuptial pads bearing nuptial spines in males (vs. absence of nuptial pads or nuptial spines).

Description of holotype.

Adult male. Body size small, SVL 27.9 mm. Head length almost equal to head width, HDW / HDL 1.00; snout sharpened in dorsal view, projecting, sloping backward to mouth in profile, protruding well beyond margin of lower jaw; top of head flat; eyes moderate in size, ED 0.40 of HDL, pupil vertical, near diamond-shaped; nostril obliquely ovoid; canthus rostralis well developed; loreal region slightly oblique; internasal distance slightly larger than interorbital distance; tympanic region oblique, tympanum distinct and visible in dorsal view; tympanum moderate in size, margin clear, upper margin in contact with supratympanic fold, lower margin in contact with upper lip, TD / ED 0.50; large ovoid choanae at base of maxilla; vomerine ridge and vomerine teeth absent, maxillary teeth present; margin of tongue rounded, not notched distally; presence of single subgular vocal sac.

Forearm length 0.20 of SVL, hand 0.30 of SVL; webbing absent between fingers, lateral fringes absent, relative finger length I <II <IV <III; tips of fingers slightly dilated, round; subarticular tubercles on base of fingers present, distinct; inner metacarpal tubercle observably enlarged, outer one slightly smaller; single nuptial pad bearing dense nuptial spines present on dorsal surface of first and second fingers, respectively. Hindlimbs moderate in length, tibio-tarsal articulation reaching forward to anterior corner of eye when hindlimb stretched along body; heels just meeting when flexed hindlimbs held at right angles to body axis; crus length 0.50 of SVL and foot length 0.70 of SVL; relative toe length I <II <V <III <IV; tips of toes round and slightly dilated; toes without lateral fringes and webbing; subarticular tubercles on base of toes present and distinct; inner metatarsal tubercle long ovoid and lacking outer metatarsal tubercle.

Dorsal skin rough and highly granular; dense large tubercles on flanks; single horn-like prominent tubercle on edge of upper eyelid; obvious supratympanic fold curving posteroventrally from posterior corner of eye to level above insertion of arm; discontinuous X-shaped ridge on center of dorsum, discontinuous dorsolateral ridges present; dorsal limbs with discontinuous transverse ridges and tubercles; ventral surface smooth; small and distinct pectoral gland closer to axilla; single femoral gland positioned on posterior surface of thigh at midpoint between knee and cloaca.

Coloration of holotype.

In life, dorsal surface of body yellowish-brown with indistinct irregular dark-brown patches and small orange dots, dark-brown triangular marking between eyes. A vertical dark-brown band present below eye. Tympanum light brown. Dorsal surface of limbs with dark-brown transverse bands. Tubercles on edge of upper eyelids orange. Supratympanic fold grey white. Iris coppery brown.

In preservative, dorsal surface of body greyish-brown, with markings and patches more distinct. Surface of chest, throat and limbs are yellowish brown, with distinct dark-brown markings and greyish-white patches. Pectoral glands and femoral glands greyish-white.

Variation.

Morphometric variations are listed in Table 2 . Most of the paratypes are similar to the holotype in morphology and color pattern, except for the following: tibio-tarsal articulation reaching forward to middle of eye when hindlimb stretched along body in the paratype GEP a 171 ; head width larger than head length in the paratype SYS a 009518 ; dorsal coloration yellowish-brown, greyish-brown to dark brown (Fig. 4 ).

Distribution and natural history.

Currently, Boulenophrys yangchunensis sp. nov. is only known from the type locality, Guangdong Yangchun Ehuangzhang Provincial Nature Reserve, western Guangdong, China. It inhabits flowing montane streams and the nearby forest floor and leaf litter. The habitat is surrounded by evergreen broad-leaved forest mixed with bamboo groves at elevations between 900 and 1,100 m (Fig. 5 ). Advertisement calls of males were heard from February to May. Males were found calling while perching on leaves that are 10–30 cm above the ground.

Figures

Figure 2. Maximum likelihood tree results from partial DNA sequences of the mitochondrial 16 S rRNA and COI gene. Numbers before slashes indicate bootstrap support (BS), and numbers after slashes indicate Bayesian posterior probabilities (BPP).

Figure 3. The holotype (GEP a 170) of Boulenophrys yangchunensis sp. nov. in preservative: dorsal view (A); ventral view (B); ventral view of hand (C); ventral view of foot (D). Photos by Jian Wang.

Figure 4. Life aspect of Boulenophrys yangchunensis sp. nov.: holotype GEP a 170 (A, B); paratype GEP a 168 (C); paratype GEP a 172 (D). Photos by Jian Wang.

Figure 5. Microhabitat of Boulenophrys yangchunensis sp. nov. in Guangdong Yangchun Ehuangzhang Provincial Nature Reserve, Yangchun City, Guangdong Province, China. Photos by Bin-Bin Zhan.