Diploderma crypticum Liu, Wang, Hou, Zeng, Zhang & Rao, 2026, sp. nov.

Diploderma crypticum sp. nov. Figs 3, 4 A, B, 5 A, B Type material. Holotype. KIZ 20201011, adult male, collected on 26 August 2020 by JiShan Wang from the valley of the Yuqu River, a tributary of the Nujiang River, in Wabu Village, Chawalong Township, Chayu County, Linzhi City, Xizang Autonomous Region, China (28°41'12"N, 98°26'14"E, 2500 m elevation). Paratypes. KIZ 20201009 – KIZ 20201010 and KIZ 20201012 – KIZ 20201013, four adult males, and KIZ 20201014 – KIZ 20201015, two adult females; collecting data the same as the holotype. Etymology. The specific epithet is a Latin adjective in the neuter gender, derived from the Greek kryptos, meaning hidden, named for the cryptic status of this species, and given in reference to the morphology similarity of the new species to Diploderma laeviventre and D. yangi. Diagnosis. Diploderma crypticum sp. nov. can be diagnosed from other species of the genus by a combination of the following characters: SVL 54.8–69.6 mm in males, 57.8–62.9 mm in females; TAL / SVL 1.95–2.10 in males, 1.91–1.95 in females; HL / SVL 0.30–0.32 in males, 0.30–0.31 in females; HW / HL 0.72–0.77 in males, 0.69–0.74 in females; SEL / HL 0.35 in males, 0.33 in females; FLL / SVL 0.44–0.47 in males, 0.46–0.47 in females; HLL / SVL 0.71–0.76 in males, 0.74 in females; T 4 L / SVL 0.17–0.18 in males, 0.18 in females; MD 50–56; VT 57–69; F 4 S 16–18, T 4 S 20–24; NSL mostly 1, rarely 2; tympanum concealed; nuchal and dorsal crest undeveloped; distinct transverse gular fold present; anterior ventral head scales smooth or feebly keeled, posterior ventral head scales strongly keeled; ventral body scales strongly keeled; dorsolateral stripes smooth edged and yellowish white in males; gular spot present in both sexes, yellowish green in males and yellowish green or light yellow in females; and oral cavity and inner lips light pink, tongue pink. Description of holotype. Adult male, body size moderate, SVL 65.0 mm; tail long, TAL 128.2 mm, TAL / SVL 1.97; limbs moderate, FLL 30.0 mm, FLL / SVL 0.46, HLL 47.7 mm, HLL / SVL 0.73. Head moderately long, HL / SVL 0.31, HW / HL 0.72; snout relatively short, SEL / HL 0.35. Rostral transversely elongated, bordered by ten scales, including two first supralabials; dorsal head scales heterogeneous in size and shape, all keeled; Y-shaped ridge present on dorsal snout. Nasal oval, separated from first supralabial by one row of scales on each side, separated from rostral by two small scales on each side; loreals small, keeled; three rows of scales between supralabials and orbit circle on each side, keeled; canthus rostralis elongated, greatly overlapping with each other; three enlarged, strongly keeled scales forming a ridge from posteroinferior eye to posterosuperior tympanum on each side; tympanum concealed under small scales; supralabials seven on each side, smooth. Mental approximately hexagonal, bordered by six scales, including two first infralabials; infralabials nine on each side, smooth; enlarged chin shields 11 on each side, smooth, first one connected to mental and first infralabial on each side, remaining ones separated from infralabials by one to three rows of scales on each side; ventral head scales heterogeneous in size, anterior and middle ones larger, posterior and side ones smaller, anterior ones smooth or feebly keeled, posterior ones strongly keeled; transverse gular fold present; gular pouch moderately developed. Dorsal body scales heterogeneous in size and shape, all keeled, tip pointing backward; shoulder fold present; axillary scales much smaller than remaining dorsals; enlarged dorsal scales forming two intermittent longitudinal rows, one just above upper edge of dorsolateral stripe, another along lower edge of dorsolateral stripe on each side, remaining enlarged dorsal scales irregularly scattered on each side of body. Nuchal and dorsal crests undeveloped, continuous, no obvious erected skin fold under nuchal and dorsal crests; middorsal crest scales 51. Dorsal limb scales strongly keeled, almost homogeneous in size on forelimbs and heterogeneous in size on hind limbs; subdigital lamellae on fourth finger 16 on each side, subdigital lamellae on fourth toe 21 on left side and 20 on right side. Ventral body scales approximately parallel, almost homogeneous, all strongly keeled, ventral scales 66. Ventral limb scales all strongly keeled, smaller on upper arms and thighs and larger on forearms and crus. Tail scales all strongly keeled, ventral tail scales larger than dorsal tail scales. Coloration of holotype in life. Dorsal surface of head light brown with some indistinct black transverse stripes. Lateral surface of head light grayish brown, several indistinct radial black stripes around eye. Ventral surface of head white with many small black spots, gular spot yellowish green. Oral cavity and inner lips light pink, tongue pink. Dorsal surface of body dark brown. Dorsolateral stripe yellowish white, edges smooth. Ventral surface of body grayish white. Dorsal surfaces of limbs light grayish brown with several brownish black transverse stripes. Ventral surfaces of limbs grayish white with small grayish black spots. Dorsal surface of tail light grayish brown with some transverse brownish-black bands. Ventral surface of tail grayish white. Variations. The paratypes are similar to the holotype in morphometric and pholidosis characteristics (Table 2). The coloration of the paratypes is also similar to that of the holotype except that the females have a relatively paler dorsal body color, grayish white discontinuous dorsolateral stripes, and a yellowish green or light yellow gular spot. Comparisons. Diploderma crypticum sp. nov. is phylogenetically closely related and most similar in morphological characteristics to D. laeviventre and D. yangi. However, Diploderma crypticum sp. nov. can be differentiated from D. laeviventre by having strongly keeled ventral body scales (vs smooth), a different coloration of the gular spot in life (yellowish green vs orange in males and yellowish green or light yellow vs orange or light orange in females) (Figs 4, 5), a relatively longer tail in females (TAL / SVL 1.91–1.95 vs 1.69–1.84), a relatively longer and wider head in females (HL / SVL 0.30–0.31 vs 0.28–0.29, HW / HL 0.69–0.74 vs 0.67–0.68), and fewer middorsal crest scales in both sexes (MD 50–56 vs 57–59); and can be differentiated from D. yangi by having a different coloration of the dorsolateral stripes in males in life (yellowish white vs green or bluish green), a different coloration of gular spot in life (yellowish green vs greenish blue in males and yellowish green or light yellow vs greenish blue or light blue in females) (Figs 4, 5), a relatively shorter tail in females (TAL / SVL 1.91–1.95 vs 1.97–2.09), a relatively shorter Toe IV in males (T 4 L / SVL 0.17–0.18 vs 0.20–0.21), and a relatively shorter snout in both sexes (SEL / HL 0.33–0.35 vs 0.38–0.45). Diploderma crypticum sp. nov. differs from D. brevipes (Gressitt, 1936), D. chapaense (Bourret, 1937), D. hamptoni (Smith, 1935), D. luei (Ota, Chen & Shang, 1998), D. makii (Ota, 1989), D. menghaiense Liu, Hou, Wang, Ananjeva & Rao, 2020, D. micangshanense (Song, 1987), D. nangunhe Liu, Li, Yang, Hou, Rao & Ananjeva, 2024, D. ngoclinense (Ananjeva, Orlov & Nguyen, 2017), D. polygonatum Hallowell, 1861, D. swinhonis (Günther, 1864), and D. yunnanense (Anderson, 1878) by the presence of a transverse gular fold (vs absence); and differs from D. dymondi (Boulenger, 1906), D. panlong Wang, Che & Siler, 2020, D. slowinskii, D. swild Wang, Wu, Jiang, Chen, Miao, Siler & Che, 2019, and D. varcoae (Boulenger, 1918) by having concealed tympana (vs exposed). Diploderma crypticum sp. nov. differs from D. bifluviale Liu, Wu, Zhang, Yang, Liu, Chen, Chang, Xie & Cai, 2025, D. daduense Cai, Liu, Liang, Hou, Zhou, Zhong, Li & Chang, 2024, D. danbaense Liu, Hou, Ananjeva & Rao, 2023, D. drukdaypo (Wang, Ren, Jiang, Zou, Wu, Che & Siler, 2019), D. fasciatum (Mertens, 1926), D. flaviceps (Barbour & Dunn, 1919), D. qiaojiaense Liu, Hou & Rao, 2024, D. shuoquense Liu, Hou, Rao & Ananjeva, 2022, and D. vela (Wang, Jiang & Che, 2015) by the presence of a colorful gular spot in life (vs absence). Diploderma crypticum sp. nov. differs from D. angustelinea Wang, Ren, Wu, Che & Siler, 2020, D. aorun Wang, Jiang, Zheng, Xie, Che & Siler, 2020, D. batangense (Li, Deng, Wu & Wang, 2001), D. bowoense Wang, Gao, Wu, Siler & Che, 2021, D. brevicauda (Manthey, Denzer, Hou & Wang, 2012), D. daochengense Cai, Zhang, Li, Du, Xie, Hou, Zhou & Jiang, 2022, D. donglangense Liu, Hou, Ananjeva & Rao, 2023, D. flavilabre Wang, Che & Siler, 2020, D. formosgulae Wang, Gao, Wu, Dong, Shi, Qi, Siler & Che, 2021, D. iadinum (Wang, Jiang, Siler & Che, 2016), D. jiulongense Liu, Hou, Ananjeva & Rao, 2023, D. limingensis Liu, Hou, Rao & Ananjeva, 2022, D. panchi Wang, Zheng, Xie, Che & Siler, 2020, D. qilin Wang, Ren, Che & Siler, 2020, D. tachengense Liu, Hou, Ananjeva & Rao, 2023, D. xinlongense Cai, Zhang, Li, Du, Xie, Hou, Zhou & Jiang, 2022, and D. yulongense (Manthey, Denzer, Hou & Wang, 2012) by having a distinctly different coloration of the gular spot in males in life (yellowish green vs yellow, orange, blue, bluish green, sulfur, yellowish white, or pinkish red). Diploderma crypticum sp. nov. differs from D. grahami (Stejneger, 1924) by having a much longer tail (TAL / SVL 1.91–2.10 vs. 1.64), having a distinct transverse gular fold (vs feeble), and the presence of dorsolateral stripes (vs absence); differs from D. hutiao Wang, Dong, Gao & Che, 2026 by having a different coloration of the ventrolateral body in males in life (white vs green) and the edges of the dorsolateral stripes being smooth in males (vs jagged); differs from D. kangdingense Cai, Zhang, Li, Du, Xie, Hou, Zhou & Jiang, 2022 by having a yellowish green gular spot in males in life (vs yellow or absent) and having a different coloration of the ventrolateral body in males in