Megophrys pachyproctus Huang, 1981

Shi, Shengchao, Zhang, Meihua, Xie, Feng, Jiang, Jianping, Liu, Wulin, Li Ding,, Luan, Li & Wang, Bin, 2020, Multiple data revealed two new species of the Asian horned toad Megophrys Kuhl & Van Hasselt, 1822 (Anura, Megophryidae) from the eastern corner of the Himalayas, ZooKeys 977, pp. 101-161 : 101

Megophrys pachyproctus Huang, 1981 Figs 3A, F, K, P, U , 5A, F , Suppl. material 2: Fig. S5C; Tables 1 , Suppl. material 1: Tables S1, S2, S5

Megophrys pachyproctus Huang, 1981* in Huang & Fei, 1981: 211-212. Holotype: NWIPB 770650, by original designation. Type locality: Gelin, Medog (29°11'N, 95°10'E), Xizang, China; altitude 1530 m, China.

Specimens examined.

Holotype: adult male NWIPB 770650.

Description of holotype.

(Fig. 3A, F, K, P, U ; Suppl. material 1: Table S1). Measurements in mm. Adult male. Body moderate, SVL 35.7; a large swollen arc-shaped protuberance present on vent beyond cloaca and visible on both dorsal and lateral view, its length 6.8 (measured dorsally), width 4.7, and thickness 2.7.

Head wider than long (HW/HL 1.13); snout blunt in dorsal view, obtusely protruding beyond mandible in lateral view; rostral appendage absent; canthus rostralis well developed, loreal region concave; dorsal surface of snout slightly concave; nostril oval, slightly closer to snout than eye (EN/SN 1.04); eyes lager than twice tympanum (EL/TYD 2.24); eye-tympanum distance smaller than tympanum diameter (TYE/TYD 0.86); tympanum oval, obliquely orientated, upper 1/3 concealed with supratympanic ridge; interorbital space flat, wider than upper eyelids (UEW/IUE 0.89); pineal ocellus not visible; vomerine ridges well developed, acutely angled, enlarged at ends where bearing several vomerine teeth; maxillary teeth present; tongue notched posteriorly, medial lingual process absent.

Forearm moderately long and wide; fingers long and thin, without webbing and lateral fringes; subarticular tubercles absent; inner and outer metacarpal tubercles small and oval, weakly connected at lower half; finger relative lengths I <II <IV <III; base of finger I strong, larger than base of finger II; tips of fingers slightly swollen and rounded (FIIIW 0.8), without pads.

Hindlimbs relatively thin and long; thighs ca. equal length of shanks and feet; toes long and thin, relative lengths I <II <V <III <IV; tips of toes rounded; toes rudimentary webbed; lateral fringes narrow; continuous dermal ridges present under toes; outer metatarsal, and subarticular tubercles absent; inner metatarsal tubercle distinct, rounded, separate from base of toe I at a distance nearly twice its diameter; tips of toes rounded.

Dorsal surface of head and body relativity rough, densely scattered with small granules; temporal region and upper corner of mandible scattered small granules; tympanum border slightly raised; upper eyelid without pointed edge; supratympanic ridges extend from posterior upper eyelid border to region above forearm insertions, not curving above tympanum, rear part thicker than front; flanks densely covered with small granules and scattered several larger tubercles; two longitudinal ridges on dorsolateral body distinct, nearly parallel, extending from above shoulder to nearby groin; parietoscapular-sacral ridges forming a "> <" configuration, composed by rows of small tubercles, dorsal surface of forearm thighs and shanks with several rows of small tubercles transversely arranged; dorsal upper arm and other dorsal surfaces of hindlimbs covered with dense small granules; ventral surface of body and limbs smooth; pectoral glands small (diameter 0.8) and rounded, close to axilla on chest; femoral glands small (diameter 1.0) and rounded, closer to outer edge of knee than to cloaca.

Coloration of holotype in preservative.

(Fig. 3A, F, K, P, U ). Dorsal and lateral surface of body, dorsal surface of head mostly tan; a brown triangle present between eyes, little lighter in center, anterior corners reach to near out edge of upper eyelids; indistinct “X” -shaped markings on dorsum, with small tubercles in center; darker brown stripe along with dorsolateral ridges; tubercles on flanks white, edged with dark patches; lateral surface of head tan with brown stripes radiating from orbit to upper mandible and upper eyelid; iris dark brown; a brown stripe extending from posterior corner of orbit under former half supratympanic ridges to behind tympanum, a clear thin dark stripe under edges of supratympanic ridges after tympanum, no long white stripe present on upper lip; dorsal and lateral surface of limbs mostly tan, two broad brown transverse bands on forearms, and four thin indistinct transverse bands on dorsal thighs and shanks; dorsal tarsal pale gray with three indistinct transverse bands, outer three fingers with tan blotches; gular region and chest dusty tan with a short longitudinal brown stripe in middle of throat; two light patches on edges of jaw corresponding anterior corners of eyes and front edge of brown stripe at posterior end of jaw; and one brown stripe extending from posterior end of jaws to base of forearms on both sides; abdomen dusty tan, with a dozen darker patches on middle and upper abdomen, large longitudinal dark patches present on ventral lateral abdomen hardly present; ventral surface of forelimbs and hindlimbs dusty tan mottled with light patches; pectoral and femoral glands light tan.

Coloration of holotype in life.

According to Huang and Fei (1981): dorsum brown or dark brown; two to four dark colored transverse bands present on forearms; and four to five dark colored transverse bands present on thighs and shanks; places around cloaca, groin, and anterior, posterior, ventral thigh orange; tips of fingers and toes light red; ventral surfaces of tarsi, metatarsus, and toes grayish brown or black-brown; lateral and ventral surface with lots of grayish black spots; a longitudinal short grayish black stripe present on middle throat; granules on dorsal surface of body and limbs light red.

Skull.

(Fig. 5A, F ). Description based on scan of the holotype. Skull weakly ossified, width 1.12 × of length; maxillary overlapping with the quadratojugal; premaxillary and maxillary teeth strong, most tooth closely positioned with others, 9/9 teeth present on left/right premaxillary, no teeth present on mandible; vomerine ridge well developed, two vomerine teeth present on enlarged posterior end of each vomerine ridge; nasal process of premaxilla protruding beyond skull; nasal bones separated from each other, inner edge mostly contact with sphenethmoid; sphenethmoid relatively smooth with few small pits on both dorsal and ventral surface, the middle one third of front edge not contacting nasal bones and truncate, separated from premaxilla; frontoparietal divided by a distinctly opening sagittal suture, sagittal suture slightly wider posteriorly; anterior fontanelle small, only slightly wider than sagittal suture; front and rear part of frontoparietal almost equally wide; posterior edge of exoccipitals posterior to the line connecting conjunctions of quadratojugal and mandible; pterygoid moderate; anterior process of squamosal slender and sharp, tip closer to the junction of pterygoid and quadratojugal than its base, posterior process present; prootic relatively smooth, separated from exoccipitals; anterior process of parasphenoid in shape of fusiform, anterior part not raised above sphenethmoid, conjunction of parasphenoid anterior process meet with sphenethmoid moderate, width ca. three quarters of the constriction near its base; columella auris short.

Variations.

See for morphometric variation within the three types (two adult males and one adult female) in Suppl. material 1: Table S1. According to the photo of dorsal view of the only adult male paratype NPIB 770651 presented by Fei and Yei (2016), the adult male paratype resemble the holotype in general, also has a distinct swollen arc-shaped protuberance present on end of body beyond cloaca, but different in color on dorsal body darker, and not having distinguishable “X” -shaped markings on dorsum. The adult female allotype NPIB 770652 do not have a distinct projection on vent, and the coloration on dorsal and ventral surface of body lighter than males.

Secondary sexual characters.

Male with gray nuptial pad on inner side of the first finger, spines on nuptial pad dense and small; single subgular vocal sac; vocal sac opening small, slit like; a distinct fatty swollen rounded projection present on the end of body beyond cloaca.

Distribution and natural history.

According to Huang and Fei (1981), this species was first collected at elevation 1530 m in the type locality, Gelin, Medog, Xizang, China; two adult males were found on shrubs emitting continuous calls sounds like “gazhi...gazhi...gazhi...” to the human ear; the female was found on the road near a brook.

Comparisons.

Megophrys pachyproctus differs from all other known congeners except M. koui and M. caudoprocta by having a distinct protuberance above vent, and further differs from the latter two species in protuberance above vent being swollen and arc-shaped (vs. not). For comparisons with subsequent undescribed species covered in this paper, refer to relevant morphological comparison sections for those species.

Remarks.

Megophrys pachyproctus was originally described by Huang and Fei (1981) with description and figures of the holotype, measurements of types, secondary sexual characters, and brief natural history. And then were translated into English and measurements of snout length, internasal space, interorbital space, eyelid width, diameter of eye, tympanum, and tibia width were supplemented by Huang et al. (1998). Fei et al. (2009) provided illustration of the holotype. Fei et al. (2010) and Fei and Ye (2016) provided colored drawings of the holotype and the paratype (NPIB) 770651, and colored photos of dorsal and lateral views of one living topotype from Medog (photographs by Ke Jiang). The topotype possess expanded fingertips with small disk and two large longitudinal dark patches on ventral lateral abdomen (while the holotype of M. pachyproctus does not have these character), and not having a distinct swollen arc-shaped protuberance present above vent (while the holotype of M. pachyproctus possess). Li et al. (2010) provided similar photos of a living specimen and measurements of seven specimens from Maniwong and Yarang, Medog, under the name M. pachyproctus . The body length of these specimens ranges from 26.1 mm to 27.9 mm, and Li et al. (2010) cited the body length of the male types of M. pachyproctus as 25.3 mm to 36.2 mm, which should be 35.3 mm to 36.2 mm ( Huang and Fei 1981). These specimens with small body size, expanded fingertips with small disk, and two large longitudinal dark patches on ventral lateral abdomen turn out to be mostly similar with Megophrys yeae sp. nov. (see description of Megophrys yeae sp. nov.). We suggest reexamination of these specimens should be taken. Saikia and Sinha (2018) reported M. pachyproctus from Southern Xizang (27.547681°N, 93.897555°E, 1855 m), provided description, measurements (body length 37.8), and a photo of dorsal view of the single male voucher specimen V/A/NERC/1352. But the photo does not present an arc-shaped swelling above vent ( Saikia and Sinha 2018: fig. 3A) as the holotype. We suggest further examination should be made to confirm the identification of the specimen. This species was also reported new range in Lao Cai and Ha Tinh Province, Vietnam (Orlov et al. 2002; Nguyen et al. 2005). Since Megophrys inhibits astonishing cryptic species biodiversity, and species like M. pachyproctus thought to be widespread from Southwest China to Vietnam confirmed to be another species ( Chen et al. 2016; Tapley et al. 2017; Liu et al. 2018), records from Vietnam where more than 1000 km from type locality should be questioned and specimens should be reexamined.

Figures

Figure 3. Photos of specimens of Megophrys species in Medog. A-E dorsal views of adult male holotype NWIPB 770650 of M. pachyproctus, adult male topotype CIB 022017061406 of M. medogensis, adult male CIB 022017061805 of M. cf. pachyproctus, adult male holotype CIBMT 171053 of Megophrys zhoui sp. nov., and adult male holotype CIB 201706 MT 02 of Megophrys yeae sp. nov., respectively F-J ventral views of the specimens, respectively K-O lateral view of head of the specimens, respectively P-T ventral view of hand of the specimens, respectively U-Y ventral view of foot of the specimens, respectively. Scale bar for body view equal to 10 mm, and for partial view 5 mm.

Figure 5. Skull of Megophrys species in Medog. A-E dorsal views of adult male holotype NWIPB 770650 of M. pachyproctus, adult male topotype CIB 022017061406 of M. medogensis, adult male CIB 022017061805 of M. cf. pachyproctus, adult male holotype CIBMT 171053 of Megophrys zhoui sp. nov., and adult male holotype CIB 201706 MT 02 of Megophrys yeae sp. nov., respectively F-J ventral views of the specimens, respectively. Key to skull: 1 premaxillary; 2 maxillary; 3 nasal; 4 sphenethmoid; 5 anterior fontanelle; 6 frontoparietal; 7 sagittal suture; 8 pterygoid; 9 squamosal; 10 quadratojugal; 11 prootic; 12 exoccipital; 13 vomerine ridge; 14 mandible; 15 anterior process of parasphenoid; 16 columella auris. Scale bar equal to 5 mm.