Xenophrys yingjiangensis Wu, Yu, Chen & Che, 2024

Wu, Yun-He, Yu, Zhong-Bin, Chen, Jin-Min, Kilunda, Felista Kasyoka, Zhang, Ding-Can, Zuo, Chang-Sheng, Zuo, An-Ru, Duan, Zheng-Pan & Che, Jing, 2024, A field survey on the genus Xenophrys (Amphibia, Megophryidae) confirms underestimated diversity in the Gaoligong Mountains, with the description of a new species, Zoosystematics and Evolution 100 (3), pp. 1041-1052 : 1041-1052

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

Figs 3 , 4 , Table 2

Chresonymy.

Megophrys sp 17., Chen et al. 2017.

Type material.

Holotype: KIZ 053848 , an adult male collected from Tongbiguan Provincial Nature Reserve , Yingjiang County, Yunnan, China (24.563 ° N, 97.639 ° E; elevation 1478 m a. s. l.), collected by Zhong-Bin Yu, Dong An, Tian-En Chen, and Xian-Kun Huang on 12 August 2023.

Paratypes: KIZ 048503 – KIZ 048505 , three adult males, from Tongbiguan Provincial Nature Reserve , Yingjiang County, Yunnan, China (24.546 ° N, 97.759 ° E; elevation 809 m a. s. l.), collected by Jin-Min Chen and Mian Hou on 11 August 2013 ; KIZ 053828 , one adult male, collected at the same locality and with the same collection information as the holotype .

Etymology.

The specific epithet “ yingjiang ” is a Latinized adjective derived from the name of Yingjiang County, Yunnan Province, China, where the new species occurs. We propose the English common name “ Yingjiang horned toad ” and the Chinese common name “ Yíng Jiāng Jiǎo Chán (盈江角蟾) ”.

Diagnosis.

Xenophrys yingjiangensis sp. nov. differs from its congeners by a combination of the following morphological characters: (1) medium adult size, adult male SVL 44.6–49.8 mm (N = 5); (2) head slightly longer than wide; (3) tympanum distinct, narrow anteriorly, slightly widening posteriorly; (4) pupil vertically elliptical; (5) vomerine ridges and vomerine teeth present; (6) tongue large, oval-shaped, feebly notched posteriorly; (7) relative finger lengths: II < IV <I < III; (8) the heels slightly overlapping when the tibias are positioned at right angles to the body axis; (9) tibio-tarsal articulation of straightened limb reaching the nostril; (10) lateral dermal fringes on toes distinct, narrow; (11) toes with rudimentary webbing; (12) inner metatarsal tubercle large, elongate; (13) a distinct narrow ‘ \ / ’ - shaped parietoscapular ridge present; (14) flesh pink ventral surface of thighs.

Description of the holotype

(measurements in Table 2 ). KIZ 053848, mature male, sized medium body (SVL 45.0 mm); head moderate (HDL / SVL 39.6 %, HDW / SVL 38.9 %), slightly longer than wide (HDW / HDL 98.3 %); snout obtusely rounded in dorsal view, obtusely projecting beyond the lower jaw in profile, without rostral appendage; triangular in dorsal view; top of head flat; loreal region vertical and concave; canthus rostralis angular; eyes large (ED / HDL 31.5 %); eye less than twice as long as maximum tympanum diameter (ED / TD 207.4 %) and shorter than snout length (SNT 6.8 mm, ED / SNT 82.4 %); tympanum distinct, circular in shape, relatively small (TD / HDL 15.2 %), with upper border concealed by supratympanic ridge; eye-tympanum distance (TYE 3.3 mm) longer than tympanum diameter (TD 2.7 mm); nostril rounded, laterally positioned, nostril closer to the tip of snout than to the anterior corner of the eye (SN / DNE 81.6 %); internarial distance greater than interorbital distance (IND / IOD 109.4 %) and width of upper eyelid (IND / UEW 126.1 %); pineal ocellus absent; vomerine teeth in two oblique series, positioned between choanae, separated from each other by distance equal to distance from choanae; maxillary teeth present; choanae oval; tongue large, oval-shaped, feebly notched posteriorly; single internal vocal sac, with a sac slit opening on floor of mouth at each corner; pupil vertically elliptical (Fig. 3 B ).

Forelimbs moderately long and thin; forearm not enlarged relative to the upper arm, its length shorter than the hand length (FAL / HL 86.4 %); fingers long and narrow, lateral fringes on fingers absent, relative finger lengths: II < IV <I < III; tips of all fingers rounded, slightly expanded relative to digit widths, with subcircular pads, terminal grooves absent; no webbing between fingers; subarticular tubercle absent; supernumerary tubercle absent; metacarpal tubercle absent (Fig. 3 E ).

Hindlimbs relatively long and thin, thigh length (THL 22.3 mm) shorter than the tibia length (TL 23.8 mm) but slightly longer than the foot length (FL 21.4 mm); the heels slightly overlapping when the tibias are positioned at right angles to the body axis; tibio-tarsal articulation of straightened limb reaching the nostril; toes long and thin, relative toe lengths: I < II < V < III < IV; tips of all toes rounded, slightly dilated, terminal grooves absent; notably expanded relative to digit widths forming circular pads; lateral dermal fringes on toes distinct, narrow; toes with rudimentary webbing; tarsal fold absent; subarticular tubercle, supernumerary tubercle, and outer metatarsal tubercle absent; inner metatarsal tubercle large, elongate, ca. one and a half times longer than wide (Fig. 3 F ).

Skin of dorsal surfaces of head, body and limbs relatively smooth, with very small granules; posterior back densely-distributed with numerous small to medium sized granules and tubercles; flanks with small scattered tubercles (Fig. 3 A ); supratympanic fold distinct, narrow anteriorly, slightly widening posteriorly, extending from the posterior corner of the eye to a level above the insertion of the arm; tympanum skin smooth, tympanic rim slightly elevated relative to skin of temporal region (Fig. 3 B ); two opposing “ V ” - shaped parietoscapular ridge present on dorsum joined by a ca. 10 mm long dorsomedial fold in a hourglass-shape; dorsolateral fold absent; a distinct narrow ‘ \ / ’ - shaped parietoscapular ridge present, its two sides extending posteriorly from above tympanum, terminating beyond level of axilla; dorsal surface of thighs, shanks and upper forearms with distinct transverse ridges (Fig. 3 A, C ); ventral surfaces of limbs, throat, chest, and abdomen smooth; pectoral glands small, rounded, slightly raised, closer to the axilla than to the mid-ventral line; femoral gland distinct, extend longitudinally, positioned equidistant from the knee and cloacal opening on rear of each thigh.

Coloration in life.

For the coloration of the holotype in life, see Fig. 3 . Dorsal surface reddish brown, with a complete inverted triangle bordered with a light edge present between eyes; lateral surface of trunk of body and anterior surface of the thighs near the groin pinkish; throat purplish grey with white flecking; chest and anterior half of abdomen purplish grey with yellowish flecking and grey-brown blotches; posterior half of abdomen white with irregular lighter greyish blotches; ventral surface of thighs pinkish; ventral surface of feet and shanks brown-black; brown nuptial pads present on the base of first and second finger; supratympanic fold, light colored, bordered by a black lower margin; iris copper-brown, with tiny dark reticulations spreading from pupil; pectoral and femoral glands creamy white; inner metatarsal tubercle off-white.

Coloration in preservative.

For coloration of the holotype in preservative, see Fig. 4 . After eight months of storage in ethanol, dorsal and lateral surfaces of head and body fading to greyish-brown; slightly darker brown triangular marking between the eyes; two opposing “ V ” - shaped parietoscapular ridges present on two sides of dorsum becoming less distinct; the ‘ \ / ’ - shaped parietoscapular ridge present dorsum still clear; lateral surfaces of head below supratympanic ridges and canthus rostralis dark brown; supratympanic ridges whitish-cream; dorsal surfaces of forelimbs and hindlimbs primarily light greyish-brown; granules and tubercles on posterior half of back and flanks more distinct; throat and chest faded greyish-brown with several scattered white dots; ventral thighs and shank faded to pale yellow, with several dark brown blotches on the anterior thigh and shank; pectoral and femoral glands white; inner metatarsal tubercle still off-white.

Sexual dimorphism.

All adult males with nuptial pads covering most of the dorsal surface of the bases of fingers I and II; male with single internal vocal sac (Fig. 5 ), with a sac slit opening on floor of mouth at each corner.

Distribution and ecology.

Xenophrys yingjiangensis sp. nov. is only known from the Tongbiguan Provincial Nature Reserve, Tongbiguan Town, Yingjiang County, Yunnan, China, and Myitkyina, Myanmar (Fig. 1 ). All individuals were discovered in a mountainous area surrounded by shrubland at elevations of approximately 800–1200 m (Fig. 6 ). This species is in sympatric distribution with X. periosa , X. dehongensis , X. glandulosa , and Xenophrys sp. of congeners. In addition, other frog species also found at the site include Leptobrachella yingjingensis , Jingophrys feii , and Kurixalus yangi .

Comparison.

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

Xenophrys yingjiangensis sp. nov. is obviously different from its four most phylogenetically close congeners ( X. dehongensis , X. auralensis , X. lekaguli , and X. takensis ). It differs from X. dehongensis by adult male SVL 44.6–49.8 mm, n = 5 (vs. adult male SVL 34.8–36.7 mm, n = 5), metacarpal tubercle absent (vs. two metacarpal tubercles indistinct), tibio-tarsal articulation of straightened limb reaching the nostril (vs. tibio-tarsal articulation reaching posterior corner of eye), inner metatarsal tubercle large, elongate, ca. one and a half times longer than wide (vs. inner metatarsal tubercle indistinct), relative finger lengths: II < IV <I < III (vs. II <I < IV < III); from X. auralensis by medium adult size, adult male SVL 44.6–49.8 mm, n = 5 (vs. large sized species, adult male SVL 71.0– 76.9 mm, n = 9), head longer than wide (vs. head wider than long), internarial distance greater than interorbital distance and width of upper eyelid (vs. interorbital distance larger than internarial distance and width of upper eyelid), relative finger lengths: II < IV <I < III (vs. II <I < IV < III), transverse crossbar in hindlimbs absent (vs. forelimb, dorsal parts of thigh, tibia and foot greyish brown with darker brown bands); from X. lekaguli by adult male SVL 44.6–49.8 mm, n = 5 (vs. adult male SVL 55.6–66.6 mm, n = 8), head longer than wide (vs. head slightly wider than long), relative finger lengths: II < IV <I < III (vs. IV < II <I < III); tongue feebly notched posteriorly (vs. tongue unnotched), vertical bar below eye absent (vs. wide, dark vertical bar below eye), transverse crossbar in limbs absent (vs. limbs with narrow dark brown crossbars); from X. takensis by head longer than wide (vs head wider than long), tongue large, oval-shaped, feebly notched posteriorly (vs. tongue oval, not notched posteriorly), relative finger lengths: II < IV <I < III (vs. IV ≤ II <I < III or IV = I < II < III), lateral dermal fringes on toes distinct, narrow (vs. absent).

Xenophrys yingjiangensis sp. nov. is different from other congeneric species. The new species differs from X. ancrae by inner metatarsal tubercle large, elongate, ca. one and a half times longer than wide (vs. inner metatarsal tubercle very weak), pupil horizontally orientated (vs. pupil vertically elliptical), relative finger lengths: II < IV <I < III (vs. I < II < IV < III), lateral dermal fringes on toes distinct, narrow (vs. absent); from X. awuh by adult male SVL 44.6–49.8 mm, n = 5 (vs. adult male SVL 35.7–41.1 mm, n = 4), nostril closer to the tip of snout than to the anterior corner of the eye (vs. nostril closer to eye than to snout), vomerine teeth present (vs. absent), inner metatarsal tubercle large, elongate, ca. one and a half times longer than wide (vs. inner metatarsal tubercle indistinct), lateral dermal fringes on toes distinct, narrow (vs. absent); from X. damrei by adult male SVL 44.6–49.8 mm, n = 5 (vs. adult male SVL 57.1 mm, n = 1), head longer than wide (vs head wider than long), nostril closer to the tip of snout than to the anterior corner of the eye (vs. nostril closer to eye than snout), lateral dermal fringes on toes distinct, narrow (vs. absent), male with single internal vocal sac (vs. external vocal sac indistinct); from X. dzukou by adult male SVL 44.6–49.8 mm, n = 5 (vs. adult male SVL 34.2–35.3 mm, n = 4), nostril closer to the tip of snout than to the anterior corner of the eye (vs. nostril closer to eye than snout), inner metatarsal tubercle large, elongate, ca. one and a half times longer than wide (vs. inner metatarsal tubercle indistinct), toes with rudimentary webbing (vs. webbing absent); from X. flavipunctata by adult male SVL 44.6–49.8 mm, n = 5 (vs. adult male SVL 56.9–68.4 mm, n = 4), head longer than wide (vs head wider than long), tongue large, oval-shaped, feebly notched posteriorly (vs. tongue moderately large, deeply notched posteriorly), inner metatarsal tubercle large, elongate, ca. one and a half times longer than wide (vs. inner metatarsal tubercle indistinct), transverse crossbar in hindlimbs absent (vs. dorsal surfaces of hindlimbs with distinct mid brown transverse crossbars); from X. himalayana by adult male SVL 44.6–49.8 mm, n = 5 (vs. adult male SVL 68.0– 73.5 mm, n = 6), lateral dermal fringes on toes distinct, narrow (vs. absent), outer metacarpal tubercle absent (vs. outer metacarpal tubercle weakly developed), transverse crossbar in hindlimbs absent (vs. dorsal surfaces of thighs and shanks with distinct dark brown transverse crossbars); from X. megacephala by the heels slightly overlapping when the tibias positioned at right angles to the body axis (vs. not meeting), inner metatarsal tubercle large, elongate, ca. one and a half times longer than wide (vs. inner metatarsal tubercle indistinct), relative finger lengths: II < IV <I < III (vs. IV < II <I < III); dorsal surface of thighs, shanks and upper forearms with distinct transverse ridges (vs. absent), transverse crossbar in limbs absent (vs. dorsal surface of the fore and hind limbs with faint dark cross bars); from X. numhbumaeng by adult male SVL 44.6–49.8 mm, n = 5 (vs. adult male SVL 33.8–34.6 mm, n = 2), pupil vertically elliptical (vs. pupil horizontally orientated), inner metatarsal tubercle large, elongate, ca. one and a half times longer than wide (vs. inner metatarsal tubercle weak), lateral dermal fringes on toes distinct, narrow (vs. absent); from X. oreocrypta by lateral dermal fringes on toes distinct, narrow (vs. absent), pupil vertically elliptical (vs. pupil horizontally orientated), inner metatarsal tubercle large, elongate, ca. one and a half times longer than wide (vs. inner metatarsal tubercle very weak), relative finger lengths: II < IV <I < III (vs. I < II < IV < III); from X. oropedion by adult male SVL 44.6–49.8 mm, n = 5 (vs. adult male SVL 32.8–39.6 mm, n = 7), lateral dermal fringes on toes distinct, narrow (vs. absent), inner metatarsal tubercle large, elongate, ca. one and a half times longer than wide (vs. inner metatarsal tubercle indistinct); from X. pangdaensis by adult male SVL 44.6–49.8 mm, n = 5 (vs. adult male SVL 17.9–22.2 mm, n = 6), tympanum distinct (vs. indistinct), inner metatarsal tubercle large, elongate, ca. one and a half times longer than wide (vs. inner metatarsal tubercle indistinct), transverse crossbar in limbs absent (vs. two dark transverse bands on each forearm, three dark transverse bands on anterior surface of thigh and shank), iris copper-brown (vs. iris orange-red); from X. periosa by medium adult size, adult male SVL 44.6–49.8 mm, n = 5 (vs. medium adult size, adult male SVL 71.3–93.8 mm, n = 12), outer metacarpal tubercle absent (vs. outer metacarpal tubercle weakly developed), inner metatarsal tubercle large, elongate, ca. one and a half times longer than wide (vs. inner metatarsal tubercle weakly defined), iris copper-brown (vs. iris very dark orange), transverse crossbar in hindlimbs absent (vs. hindlimbs with distinct transverse crossbars); from X. truongsonensis by adult male SVL 44.6–49.8 mm, n = 5 (vs. adult male SVL 58.8–71.4 mm, n = 14), internarial distance greater than interorbital distance and width of upper eyelid (vs. internarial distance narrower than interorbital distance but wider than upper eyelid), external vocal sac indistinct (vs. absent), upper lip dark brown (vs. upper lip with a continuous white stripe, running from the nostril to shoulder), hindlimbs (vs. dorsal surface of fore and hind limbs reddish brown with dark crossbars); from X. lancangica by adult male SVL 44.6–49.8 mm, n = 5 (vs. adult male SVL 64.0– 65.4 mm, n = 3), metacarpal tubercle absent (vs. two metacarpal tubercles indistinct), tibio-tarsal articulation of straightened limb reaching the nostril (vs. tibiotarsal articulation reaching region between nostril and tip of snout), inner metatarsal tubercle large, elongate, ca. one and a half times longer than wide (vs. inner metatarsal tubercle indistinct), transverse crossbar in limbs absent (vs. dorsal limbs with transverse bands), relative finger lengths: II < IV <I < III (vs. II < IV <I < III); from X. glandulosa by adult male SVL 44.6–49.8 mm, n = 5 (vs. adult male SVL 77.0–81.0 mm, n = 3), head longer than wide (vs head wider than long), tongue large, feebly notched posteriorly (vs. tongue distinctly notched posteriorly), lateral dermal fringes on toes distinct, narrow (vs. moderately wide lateral fringes present on all toes), transverse crossbar in limbs absent in preservative (vs. dorsal surfaces of hindlimbs with distinct brown transverse crossbars in preservative), sides of head smooth (vs. sides of head finely granular); from X. monticola by vomerine teeth present (vs. vomerine teeth absent), inner metatarsal tubercle large, elongate, ca. one and a half times longer than wide (vs. inner metatarsal tubercle indistinct), toes with rudimentary webbing (vs. absent), lateral dermal fringes on toes distinct, narrow (vs. absent), pupil vertically elliptical (vs. pupil horizontally orientated), tongue large, feebly notched posteriorly (vs. tongue large, appears rounded posteriorly without notch); from X. robusta by adult male SVL 44.6–49.8 mm, n = 5 (vs. adult male SVL 73.5–83.1 mm, n = 6), head longer than wide (vs head wider than long), vomerine teeth present (vs. absent), lateral dermal fringes on toes distinct, narrow (vs. absent); from X. medogensis by inner metacarpal tubercle absent (vs. distinct), toes with rudimentary webbing (vs. absent), lateral dermal fringes on toes distinct, narrow (vs. absent), relative finger lengths: II < IV <I < III (vs. I < II < IV < III); dark brown stripe in lower margin of the supratympanic folds absent (vs. lower margin of the supratympanic folds with dark brown stripe); from X. major by medium adult size, adult male SVL 44.6–49.8 mm, n = 5 (vs. large sized species, adult male SVL 75.0– 87.5 mm, n = 12), throat purplish grey with white flecking; chest and anterior half of abdomen purplish grey with yellowish flecking and grey-brown blotches (vs. light-edged wide dark brown stripe extending from posterior edge of mandible onto base of forearms), dorsolateral surface of forearms without blotch (vs. three dark brown blotches on dorsolateral surface of forearms); from X. maosonensis by adult male SVL 44.6–49.8 mm, n = 5 (vs. adult male SVL 66.2 mm, n = 1), metacarpal tubercle absent (vs. two metacarpal tubercles indistinct), relative finger lengths: II < IV <I < III (vs. I < II < IV < III), tibio-tarsal articulation of straightened limb reaching the nostril (vs. tibio-tarsal articulation reaching center of eye), inner metatarsal tubercle large, elongate, ca. one and a half times longer than wide (vs. inner metatarsal tubercle indistinct); from X. mangshanensis by adult male SVL 44.6–49.8 mm, n = 5 (vs. adult male SVL 60.4–71.6 mm, n = 10), metacarpal tubercle absent (vs. two metacarpal tubercles indistinct), relative finger lengths: II < IV <I < III (vs. II <I < IV < IIII), tibio-tarsal articulation of straightened limb reaching the nostril (vs. tibio-tarsal articulation reaching center of eye), lateral dermal fringes on toes distinct, narrow (vs. absent), toes with rudimentary webbing (vs. absent), inner metatarsal tubercle large, elongate, ca. one and a half times longer than wide (vs. inner metatarsal tubercle indistinct); from X. zhangi by adult male SVL 44.6–49.8 mm, n = 5 (vs. adult male SVL 32.5–40.0 mm, n = 7), metacarpal tubercle absent (vs. two metacarpal tubercles indistinct), relative finger lengths: II < IV <I < III (vs. I < II < IV < III), tibio-tarsal articulation of straightened limb reaching the nostril (vs. tibio-tarsal articulation reaching anterior corner of eye), toes with rudimentary webbing (vs. absent); from X. zunhebotoensis by adult male SVL 44.6–49.8 mm, n = 5 (vs. adult male SVL 28.4–33.9 mm, n = 23), vomerine teeth present (vs. absent), lateral dermal fringes on toes distinct, narrow (vs. absent), toes with rudimentary webbing (vs. absent), the heels slightly overlapping when the tibias positioned at right angles to the body axis (vs. meeting); absent (vs. dense orange speckling on chest and anterior abdomen); from X. serchhipii by lateral dermal fringes on toes distinct, narrow (vs. absent), relative finger lengths: II < IV <I < III (vs. IV <I = II < III), two opposing “ V ” - shaped parietoscapular ridge present on dorsum joined by a ca. 10 mm long dorsomedial fold in a hourglass-shape (vs. unconnected inverted “ V ” - shaped sacral ridge).

Figures

Figure 1. Known distribution of Xenophrys yingjiangensis sp. nov. The red pentagram indicates the type locality of Xenophrys yingjiangensis sp. nov.

Figure 3. Views of the Holotype KIZ 053848 in life. A. Lateral view; B. Lateral view of head; C. Dorsal view of hindlimbs; D. Ventral view; E. Ventral view of hand, and F. Ventral view of foot. Photos by Zhong-Bin Yu.

Figure 4. Views of the Holotype KIZ 053848 in preservative. A. Dorsal view; B. Ventral view; C. Lateral view; D. Lateral view of head; E. Ventral view of hand, and F. Ventral view of foot. Photos by Zhong-Bin Yu.

Figure 5. Advertisement calls for Paratype KIZ 048505. Photo by Jin-Min Chen.

Figure 6. Habitat of Xenophrys yingjiangensis sp. nov. at the type locality in Tongbiguan Provincial Nature Reserve, Yingjiang County, Yunnan, China. Photo by Zhong-Bin Yu.