Xenophrys tongbiguanensis Wu, Yu, Chen & Che, 2025

Xenophrys tongbiguanensis Wu, Yu, Chen & Che sp. nov.

Figs 3 View Figure 3 , 4 View Figure 4 , Table 3 View Table 3

Chresonymy.

Xenophrys sp. , Wu et al. 2024.

Type material.

Holotype • KIZ 058786 View Materials , an adult male collected from Tongbiguan Provincial Nature Reserve , Yingjiang County, Yunnan, China ( 24.562476°N, 97.642761°E; elevation 1500 m a. s. l.), collected by Shen-Pin Yang, Jia-Sheng Liu, and Shen-Quan Liu on 13 August 2024 GoogleMaps .

Paratypes • KIZ 058785 View Materials and KIZ 058786 View Materials , two adult males, collected at the same locality with the same collection information as the holotype GoogleMaps • KIZ 058838 View Materials , an adult female, from Tongbiguan Provincial Nature Reserve , Yingjiang County, Yunnan, China ( 97.675177°N, 24.781519°E; elevation 1452 m a. s. l.), collected by Shen-Pin Yang, Jia-Sheng Liu, and Shen-Quan Liu on 19 August 2024 • KIZ 058840 View Materials , an adult female, from Tongbiguan Provincial Nature Reserve , Yingjiang County, Yunnan, China ( 97.830888°N, 25.124331°E; elevation 1563 m a. s. l.), collected by Shen-Pin Yang, Jia-Sheng Liu, and Shen-Quan Liu on 20 August 2024 .

Etymology.

The specific epithet “tongbiguanen” is a Latinized adjective derived from the name of Tongbiguan Provincial Nature Reserve, Yunnan Province, China, where the new species occurs. We propose the English common name “Tongbiguanen horned toad” and the Chinese common name “Tóng Bì Guān Jiǎo Chán (铜壁关角蟾). ”

Diagnosis.

Xenophrys tongbiguanensis sp. nov. can be distinguished from its congeners by the following combination of morphological characters: (1) body size medium, SVL 43.5–44.2 mm in three adult males and 54.8–57.6 mm in two adult females; (2) head length almost equal to width; (3) vomerine teeth prominent; (4) eye diameter less than twice as long as maximum tympanum diameter; (5) tympanum distinct, upper margin concealed by supratympanic fold; (6) tongue oval-shaped, slightly notched posteriorly; (7) tibio-tarsal articulation of straightened limb reaching between nostrils and tip of snout; (8) the heels slightly overlapping; (9) relative finger length: I <II <IV <III; (10) metacarpal tubercle absent; (11) toes with rudimentary webbing; (12) throat, chest, and anterior half of abdomen yellowish-brown with dense orange flecking and three longitudinal dark-brown stripes that one located in the middle of the throat and the other two located below the pectoral glands; (12) male with single internal vocal sac; and (13) nuptial pads in males absent.

Description of holotype.

(measurements in Table 3 View Table 3 ): KIZ 058786 , mature male, sized medium body ( SVL 44.2 mm); head slightly longer than wide ( HL / HW = 1.02); snout bluntly pointed in dorsal view, obtusely protruding in lateral view, notably projecting beyond lower jaw; triangular in dorsal view; top of head flat; loreal region vertical and concave; canthus rostralis distinct, sharp (Fig. 3 A View Figure 3 ); pupil diamond-shaped, vertical (Fig. 3 B View Figure 3 ); eyes large ( ED / HDL 29.0 %), eye diameter less than twice as long as maximum tympanum diameter ( TD / ED 52.9 %) and shorter than snout length ( SNT 6.1 mm, ED / SNT 83.6 %); nares oval, laterally orientated, located much closer to eye than tip of snout ( SN 3.4 mm, DNE 2.7 mm); eye-tympanum distance larger than maximum tympanum diameter ( TEY / TD 114.9 %); tympanum distinct, oval-shaped, relatively small ( TD / HDL 15.3 %), with upper ~ 10 % concealed by supratympanic ridge; internarial distance almost equal to interorbital distance ( IND / IOD 101.8 %), and larger than width of upper eyelid ( IND / UEW 131.8 %); tongue oval-shaped, slightly notched posteriorly; maxillary teeth present; vomerine teeth prominent, in two oblique series, positioned between choanae; pineal ocellus absent; single internal vocal sac, with a sac slit opening on floor of mouth at each corner (Fig. 3 A, B View Figure 3 ).

Forelimbs moderately long and slender ( HL / SVL 29.0 %; FHL / SVL 53.6 %); forearm not enlarged, its length shorter than the hand length ( FAL / HL 70.3 %); fingers long and narrow, not flattened dorsoventrally; lateral fringes on fingers absent; finger length from shortest to longest: I <II <IV <III; tips of all fingers rounded, slightly dilated relative to digit widths, with circular pads, terminal grooves absent; no webbing between fingers; subarticular tubercle absent; supernumerary tubercle absent; inner metacarpal tubercle and outer metacarpal tubercle indistinct; nuptial pads absent (Fig. 3 E View Figure 3 ).

Hindlimbs long and robust, thigh length shorter than the tibia length ( THL / TL 96.6 %) but greater than the foot length ( THL / FL 108.5 %); tibia length 53.6 % of SVL; foot length 47.7 % of SVL; tibio-tarsal articulation of straightened limb reaching between nostrils and tip of snout when adpressed along body; the heels slightly overlapping when the tibias are perpendicular to the body axis; toes long and slightly dorsoventrally flattened, toe length from shortest to longest: I <II <V <III <IV; tips of all toes rounded, slightly dilated, terminal grooves absent; notably expanded relative to digit widths, forming circular pads; terminal grooves absent; lateral dermal fringes on toes weak, narrow; rudimentary webbing present between all toes; subarticular tubercle absent, replaced by indistinct callous dermal ridges; supernumerary tubercle absent; inner metatarsal tubercle indistinct, oval-shaped, outer metatarsal tubercle absent (Fig. 3 F View Figure 3 ).

Skin of dorsal surfaces of body, limbs, and dorsal and lateral surfaces of head primarily smooth, with scattered weakly granular; flanks with several large distinct warts (Fig. 3 A View Figure 3 ); a small pointed horn-like tubercle present on the outer edge of the upper eyelid (Fig. 3 B View Figure 3 ); supratympanic fold distinct, narrow anteriorly, slightly widening posteriorly, curves down broadly through upper tympanum, terminating above forelimbs; dorsolateral fold absent; a distinct narrow ‘ \ / ’ - shaped parietoscapular ridge present, its two sides extending posteriorly from above tympanum, terminating beyond level of axilla (Fig. 3 A View Figure 3 ); dorsal surface with distinct and irregular transverse ridges; ventral surface smooth; pectoral glands small, rounded, slightly raised, positioned on level with axilla; femoral gland distinct, located on the rear of each thigh at midpoint between knee and cloacal opening; pectoral glands slightly larger than femoral gland (Fig. 3 D, F View Figure 3 ).

Coloration in life.

Dorsum reddish brown, with a complete dark brown inverted triangle marking between the eyes, border of marking with a light edge; distinct dark brown X-shaped marking on dorsum; three to four dark brown vertical bars present on upper lips, the one below eye largest; lower lip black with four white bars, symmetrically distributed; canthus rostralis, supratympanic fold, to upper eyelid with a light edge; temporal region under supratympanic ridge dark brown, with a light edge; tubercles dark brown with cream-white tips; dorsal surface of forelimbs, hindlimbs, and fingers with dark crossbars; throat, chest, and anterior half of abdomen yellowish-brown with dense orange flecking and three longitudinal dark-brown stripes that one located in the middle of the throat and the other two located below the pectoral glands; posterior half of abdomen white with scattered orange flecking; ventral surface of thighs white, scattered small grey blotches; ventral surface of feet and shanks brown-black; pectoral and femoral glands cream-white; iris copper-brown with tiny radiating dark lines; pupil black, outlined in yellowish-brown; metatarsal tubercle, tips of finger, and toe orange-red.

Coloration in preservative.

After seven months of preservation in ethanol, the dorsal surface of head, back, and limbs fading to greyish-brown; a solid darker brown triangular marking between eyes; dark brown crossbars on dorsal surface of forelimbs, hindlimbs, and fingers still clear; throat, chest, and abdomen faded to pale grey-white, with greyish-brown flecking; three longitudinal stripes of the venter still clear, dark brown; metatarsal tubercle, tips of fingers and toes faded greyish-brown; pectoral and femoral glands white; toe webbing dark brown (Fig. 4 View Figure 4 ).

Sexual dimorphism.

Adult female specimens have larger body sizes than adult male specimens ( SVL 54.8–57.6 mm vs. 43.5–44.2 mm, Table 3 View Table 3 ). Male with a single internal vocal sac, with a sac slit opening on floor of the mouth at each corner.

Distribution and ecology.

Currently, Xenophrys tongbiguanensis sp. nov. is known only from the type locality, Tongbiguan Provincial Nature Reserve, Yingjiang County, Yunnan Province, China (Fig. 1 View Figure 1 ). This frog inhabits flowing montane streams and the nearby forest floor in subtropical evergreen broad-leaved forests (Fig. 5 View Figure 5 ). The frog usually perches on cardamom leaves at night, but it can be found among piles of dead leaves by the roadside on rainy days. Advertisement calls of males were heard in August. However, the breeding season is currently unclear. The sympatric species Leptobrachella ventripunctata , Zhangixalus smaragdinus , Rhacophorus rhodopus , and Limnonectes longchuanensis were also recorded.

Comparison.

We compared Xenophrys tongbiguanensis sp. nov. with other congeneric species ( Ohler et al. 2002; Stuart et al. 2006; Mahony 2011; Mahony et al. 2011, 2013, 2018, 2020; Che et al. 2020; Luong et al. 2022; Lyu et al. 2023; Shu et al. 2023; Saikia et al. 2024; Wu et al. 2024).

Xenophrys tongbiguanensis sp. nov. is clearly distinct from its four sympatrically distributed congeners ( X. periosa , X. dehongensis , X. glandulosa , and X. yingjiangensis ). It differs from X. periosa by a smaller body size, SVL 43.5–44.2 mm in three adult males and 54.8–57.6 mm in two adult females (vs. 71.3–93.8 mm in 12 adult males and 112.0 mm in one adult female), outer metacarpal tubercle absent (vs. outer metacarpal tubercle weakly developed), iris copper-brown (vs. iris very dark orange), and nuptial pads in males absent (vs. present); from X. dehongensis by a larger body size, SVL 43.5–44.2 mm in three adult males and 54.8–57.6 mm in two adult females (vs. 34.8–36.7 mm in five adult males and 45.7–46.8 mm in two adult females), nuptial spines in males absent (vs. dense black nuptial spines on dorsal bases of fingers I and II), and tibio-tarsal articulation of straightened limb reaching between nostrils and tip of snout (vs. reaching posterior corner of eye); from X. glandulosa by a smaller body size, 43.5–44.2 mm in three adult males (vs. SVL 77.0–81.0 mm in three adult males), nuptial pads in males absent (vs. present), and lateral dermal fringes on toes distinct, narrow (vs. moderately wide lateral fringes present on all toes); from X. yingjiangensis by inner metatarsal tubercle indistinct, oval-shaped (vs. inner metatarsal tubercle large, elongate), relative finger lengths: I <II <IV <III (vs. II <IV <I <III), nuptial pads in males absent (vs. present), dorsal surface of limbs with dark crossbars (vs. absent), and three to four dark brown vertical bars below eye (vs. absent).

Xenophrys tongbiguanensis sp. nov. is different from other congeneric species. The new species differs from X. ancrae by pupil diamond-shaped, vertical (vs. pupil oval, horizontally orientated), iris copper-brown (vs. iris metallic mid-brown), and nuptial spines in males absent (vs. present); from X. apatani by tongue oval-shaped, slightly notched posteriorly (vs. tongue entire and rounded), relative finger length: I <II <IV <III (vs. I <II = IV <III), a smaller body size, 43.5–44.2 mm in three adult males (vs. SVL 54.0 mm in one adult male), eye diameter less than twice as long as maximum tympanum diameter (vs. eye diameter twice the diameter of tympanum), and head length almost equal to wide (vs. head moderately large, wider than long); from X. auralensis by a smaller body size, 43.5–44.2 mm in three adult males (vs. SVL 71.0– 76.9 mm in nine adult males), tongue oval-shaped, slightly notched posteriorly (vs. tongue entire and oval), vomerine teeth prominent (vs. absent), and inner metatarsal tubercle indistinct, oval-shaped (vs. distinct and long); from X. awuh by vomerine teeth prominent (vs. absent), lateral dermal fringes on toes distinct, narrow (vs. absent), metacarpal tubercle absent (vs. thenar and outer metacarpal tubercles weak), nuptial pads in males absent (vs. present), and tympanum distinct, upper margin concealed by supratympanic fold (vs. tympanum distinctly oval shaped, upper border not concealed by supratympanic ridge); from X. damrei by a smaller body size, SVL 43.5–44.2 mm in three adult males and 54.8–57.6 mm in two adult females (vs. 57.1 mm in one adult male and 69.1 mm in one adult female), nuptial pads in males absent (vs. present), head length almost equal to wide (vs. head considerably wider than long), and male with single internal vocal sac (vs. external vocal sac indistinct); from X. dzukou by a larger body size, SVL 43.5–44.2 mm in three adult males (vs. 34.2–35.3 mm in four adult males), eye diameter less than twice as long as maximum tympanum diameter (vs. eye length more than twice maximum tympanum diameter), tympanum distinct, upper margin concealed by supratympanic fold (vs. tympanum circular, upper border not concealed by supratympanic ridge), and toes with rudimentary webbing (vs. webbing absent); from X. flavipunctata by a smaller body size, SVL 43.5–44.2 mm in three adult males and 54.8–57.6 mm in two adult females (vs. 56.9–68.4 mm in four adult males and 68.0– 74.6 mm in three adult females), tongue oval-shaped, slightly notched posteriorly (vs. tongue moderately large, deeply notched posteriorly), and eye diameter less than twice as long as maximum tympanum diameter (vs. eye diameter 2.5 times maximum diameter of visible portion of tympanum); from X. himalayana by a smaller body size, SVL 43.5–44.2 mm in three adult males (vs. SVL 68.0– 73.5 mm in six adult males), eye diameter less than twice as long as maximum tympanum diameter (vs. eye diameter more than twice maximum diameter of visible portion of tympanum), and relative finger length: I <II <IV <III (vs. IV <II <I <III); from X. lancangica by a smaller body size, SVL 43.5–44.2 mm in three adult males and 54.8–57.6 mm in two adult females (vs. 64.0– 65.4 mm in three adult males and 75.0– 88.6 mm in three adult females), relative finger length: I <II <IV <III (vs. II <IV <I <III), and nuptial pads in males absent (vs. brown nuptial pads on dorsal bases of fingers I and II in adult males); from X. lekaguli by a smaller body size, SVL 43.5–44.2 mm in three adult males and 54.8–57.6 mm in two adult females (vs. 56.6–66.6 mm in eight adult males and 71.8–94.0 mm in four adult females), relative finger length: I <II <IV <III (vs. IV <II <I <III), and tongue oval-shaped, slightly notched posteriorly (vs. tongue unnotched); from X. major by a smaller body size, SVL 43.5–44.2 mm in three adult males and 54.8–57.6 mm in two adult females (vs. 75.0– 87.5 mm in 12 adult males and 85.6–98.2 mm in three adult females), nuptial pads in males absent (vs. present), male with single internal vocal sac (vs. external vocal sac indistinct), and eye diameter less than twice as long as maximum tympanum diameter (vs. eye diameter 2.5 times maximum diameter of visible portion of tympanum); from X. mangshanensis by a smaller body size, SVL 43.5–44.2 mm in three adult males and 54.8–57.6 mm in two adult females (vs. 60.4–71.6 mm in ten adult males and 62.0– 77.9 mm in three adult females), relative finger length: I <II <IV <III (vs. II <I <IV <III), tibio-tarsal articulation of straightened limb reaching between nostrils and tip of snout (vs. reaching center of eye), toes with rudimentary webbing (vs. absent), and nuptial spines in males absent (vs. dense brown nuptial spines on dorsal bases of fingers I and II in adult males); from X. maosonensis by a smaller body size, SVL 43.5–44.2 mm in three adult males and 54.8–57.6 mm in two adult females (vs. 66.2 mm in one adult male and 76.9 mm in one adult female), nuptial pads in males absent (vs. black nuptial pads on dorsal bases of fingers I and II in adult male), and tibio-tarsal articulation of straightened limb reaching between nostrils and tip of snout (vs. reaching center of eye); from X. medogensis by a smaller body size, SVL 43.5–44.2 mm in three adult males and 54.8–57.6 mm in two adult females (vs. 56.1–62.4 mm in six adult males and 73.8–79.6 mm in one adult females), relative finger length: I <II <IV <III (vs. II <I <IV <III), and nuptial spines in males absent (vs. dense black nuptial spines on dorsal bases of fingers I and II in adult males); from X. megacephala by the heels slightly overlapping when the tibias positioned at right angles to the body axis (vs. not meeting), relative finger length: I <II <IV <III (vs. IV <II <I <III), tongue oval-shaped, slightly notched posteriorly (vs. tongue long and narrow, without notch posteriorly), and nuptial pads in males absent (vs. present); from X. monticola by nuptial spines in males absent (vs. present), male with single internal vocal sac (vs. large subgular external vocal sac distinct), eye diameter less than twice as long as maximum tympanum diameter (vs. eye diameter more than twice as long as maximum diameter of visible portion of tympanum), and pupil vertically elliptical (vs. pupil horizontally orientated); from X. numhbumaeng by a larger body size, SVL 43.5–44.2 mm in three adult males (vs. 33.8–34.6 mm in two adult males), pupil vertically elliptical (vs. pupil horizontally orientated), eye diameter less than twice as long as maximum tympanum diameter (vs. eye length more than two times longer than maximum tympanum diameter), single internal vocal sac (vs. external vocal sac indistinct), and nuptial pads in males absent (vs. present); from X. oreocrypta by a smaller body size, 54.8–57.6 mm in two adult females (vs. 94.9 mm in one adult female), throat, chest, and anterior half of abdomen yellowish-brown with dense orange flecking and three longitudinal dark-brown stripes, posterior half of abdomen white with scattered orange flecking (vs. ventral surface of throat and chest primarily pale grey with dark orange speckling, speckling more dense on lateral stripes of throat, and ventrolaterally on anterior abdomen), and relative finger length: I <II <IV <III (vs. IV <II <I <III); from X. oropedion by a larger body size, SVL 43.5–44.2 mm in three adult males and 54.8–57.6 mm in two adult females (vs. 32.8–39.2 mm in seven adult males and 44.1–48.7 mm in two adult females), and tympanum distinct, upper margin concealed by supratympanic fold (vs. tympanum slightly oval, vertically orientated, not concealed by supratympanic ridge); from X. pangdaensis by a larger body size, SVL 43.5–44.2 mm in three adult males and 54.8–57.6 mm in two adult females (vs. 17.9–22.2 mm in six adult males and 23.4 mm in one adult female), and single internal vocal sac (vs. external vocal sac indistinct); from X. parva by relative finger length: I <II <IV <III (vs. II <IV <I <III), tibio-tarsal articulation of straightened limb reaching between nostrils and tip of snout (vs. tibiotarsal articulation reaching anterior corner of eye), nuptial spines in males absent (vs. dense black nuptial spines on dorsal bases of fingers I and II in adult males), and throat, chest, and anterior half of abdomen yellowish-brown with dense orange flecking (vs. throat and chest purplish); from X. robusta by a smaller body size, SVL 43.5–44.2 mm in three adult males and 54.8–57.6 mm in two adult females (vs. 73.5–83.1 mm in six adult males and 81.3–108.3 mm in four adult females), nuptial pads in males absent (vs. present), single internal vocal sac (vs. external vocal sac indistinct), and vomerine teeth prominent (vs. absent); from X. serchhipii by relative finger length: I <II <IV <III (vs. IV <I = II <III), nuptial pads in males absent (vs. present), and single internal vocal sac (vs. external vocal sac distinct); from X. takensis by head length almost equal to wide (vs. head wider than long), tongue oval-shaped, slightly notched posteriorly (vs. tongue oval, not notched posteriorly), nuptial pads in males absent (vs. present), relative finger lengths: I <II <IV <III (vs. IV ≤ II <I <III or IV = I <II <III) and single internal vocal sac (vs. external vocal sac indistinct); from X. truongsonensis by a smaller body size, SVL 43.5–44.2 mm in three adult males and 54.8–57.6 mm in two adult females (vs. 58.8–71.4 mm in 20 adult males and 65.6–87.3 mm in five adult females), and nostril closer to eye than tip of snout (vs. nostril closer to the tip of snout than to the eye); from X. zhangi by rudimentary webbing present between all toes (vs. toes without webbing), tibio-tarsal articulation of straightened limb reaching between nostrils and tip of snout (vs. reaching anterior corner of eye), and nuptial spines in males absent (vs. dense grey nuptial spines on dorsal bases of fingers I and II in adult males); from X. zunhebotoensis by a larger body size, SVL 43.5–44.2 mm in three adult males and 54.8–57.6 mm in two adult females (vs. 28.4–33.9 mm in 22 adult males and 37.0– 39.5 mm in three adult females), vomerine teeth prominent (vs. absent), tympanum distinct, upper margin concealed by supratympanic fold (vs. tympanum circular, not concealed by supratympanic ridge), single internal vocal sac (vs. external vocal sac distinct), and nuptial spines in males absent (vs. present).