taxonID	type	description	language	source
03A98786FF88FFF295E0FEF0FB81F86B.taxon	description	Figs. 3 – 7, Tables 1 – 2.	en	Xu, Yuhao, Zhang, Tierui, Nguyen, Tan Van, Sun, Fanyue, Vogel, Gernot, Deng, Jundong, Poyarkov, Nikolay A., Peng, Lifang (2026): Redescription and range extension of Pareas dulongjiangensis Liu, Yang, Rao, Guo & Rao, 2023 (Squamata: Pareidae). Zootaxa 5845 (3): 523-544, DOI: 10.11646/zootaxa.5845.3.5, URL: https://doi.org/10.11646/zootaxa.5845.3.5
03A98786FF88FFF295E0FEF0FB81F86B.taxon	vernacular_names	Dulongjiang slug-eating snake / ḇḭȗlj 头º (Pinyin: dú lóng jiāng dùn tóu shé)	en	Xu, Yuhao, Zhang, Tierui, Nguyen, Tan Van, Sun, Fanyue, Vogel, Gernot, Deng, Jundong, Poyarkov, Nikolay A., Peng, Lifang (2026): Redescription and range extension of Pareas dulongjiangensis Liu, Yang, Rao, Guo & Rao, 2023 (Squamata: Pareidae). Zootaxa 5845 (3): 523-544, DOI: 10.11646/zootaxa.5845.3.5, URL: https://doi.org/10.11646/zootaxa.5845.3.5
03A98786FF88FFF295E0FEF0FB81F86B.taxon	materials_examined	Holotype. KIZ R 201607 (adult female), collected on September 9, 2015 by D. Q. Rao from Kongdang Village, Dulongjiang Township, Gongshan Dulong and Nu Autonomous County (Gongshan County), Nujiang Lisu Autonomous Prefecture (Nujiang Prefecture), Yunnan Province, China (27.8378 ° N, 98.3250 ° E; elevation 1,460 m a. s. l.). Specimens examined (N = 5). China. Yunnan Province: QHU R 2024059 (field no. LFR 2024153, subadult male), collected on 3 October 2024; QHU R 2025063 (field no. LFR 2025286, adult male), collected on 27 October 2025; ANU ZR 24101 (adult male), collected on 13 August 2024; and ANU ZR 25057 (adult male), collected on 2 October 2025, all collected by J. D. Deng from Maku Village, Dulongjiang Township, Gongshan County, Nujiang Prefecture (27.6761 ° N, 98.3048 ° E; elevation 1,620 m a. s. l.). Myanmar. Kachin State: CAS 224415 (adult female), collected on 1 April 2002, by K. S. Lwin, M. Kyaw, A. Sin, and A. Di, from montane evergreen forest in Lon Nut Village, Hkakabo Razi NP, Nagmung Township, Putao District (27.768286 ° N, 97.818992 ° E; elevation 1,010 m a. s. l.).	en	Xu, Yuhao, Zhang, Tierui, Nguyen, Tan Van, Sun, Fanyue, Vogel, Gernot, Deng, Jundong, Poyarkov, Nikolay A., Peng, Lifang (2026): Redescription and range extension of Pareas dulongjiangensis Liu, Yang, Rao, Guo & Rao, 2023 (Squamata: Pareidae). Zootaxa 5845 (3): 523-544, DOI: 10.11646/zootaxa.5845.3.5, URL: https://doi.org/10.11646/zootaxa.5845.3.5
03A98786FF88FFF295E0FEF0FB81F86B.taxon	diagnosis	Revised diagnosis. Pareas dulongjiangensis differs from other congeners by the following combination of characters: (1) maximum SVL 390 mm in males and 377 mm in females; (2) dorsal scales in 15 - 15 - 15 rows, 5 – 9 median rows at midbody weakly keeled, and 1 – 3 vertebral scale rows slightly enlarged; (3) anterior pair of chin shields longer than broad; (4) a single, broad prefrontal in contact with the eye; (5) frontal subpentagonal, anterior margin rounded and slightly projecting, lateral sides converging posteriorly; (6) loreal entering or not entering the orbit; (7) preocular 0 or 1, postocular 0 or 1; (8) subocular 1, sometimes fused with the postocular; (9) temporals 2 + 2 or 2 + 3; (10) supralabials 6 – 7, none entering the orbit; (11) infralabials 7 – 9, with the first 3 – 5 contacting the anterior pair of chin shields; (12) ventrals 178 – 182 in males, and 182 in females; (13) subcaudals 77 – 83 pairs in males, and 71 – 76 pairs in females; (14) in life, dorsum yellowish brown with a prominent dark blotch on the head and 52 – 64 irregular dark transverse bands on the body; (15) venter pale yellow to light yellowish brown, densely mottled with dark speckles (based on Vogel et al. 2021, Liu et al. 2023 a, and this study).	en	Xu, Yuhao, Zhang, Tierui, Nguyen, Tan Van, Sun, Fanyue, Vogel, Gernot, Deng, Jundong, Poyarkov, Nikolay A., Peng, Lifang (2026): Redescription and range extension of Pareas dulongjiangensis Liu, Yang, Rao, Guo & Rao, 2023 (Squamata: Pareidae). Zootaxa 5845 (3): 523-544, DOI: 10.11646/zootaxa.5845.3.5, URL: https://doi.org/10.11646/zootaxa.5845.3.5
03A98786FF88FFF295E0FEF0FB81F86B.taxon	description	Redescription of the Myanmar specimen CAS 224415 (Fig. 3, Table 1). An adult female in good condition. Body slender and distinctly laterally compressed; SVL 377 mm, TAL 100 mm, TL 477 mm; TAL / SVL ratio 0.27; TAL / TL ratio 0.21. Head relatively large and clearly distinct from the neck. Eye relatively large with vertically elliptical pupil. Nostril oval, situated approximately at the center of the nasal scale. Head scalation. Rostral not visible from above. Nasal single, undivided; internasals 2, distinctly wider than long; anteriorly in contact with rostral, laterally contacting nasal and loreal, posteriorly contacting prefrontal. Prefrontal single, large and broad, slightly curved posteriorly, with both anterior and posterior margins smoothly rounded; entering the orbit. Frontal single, anterior margin rounded and slightly protruding anteriorly, giving it a somewhat subhexagonal shape; lateral margins converging posteriorly. Loreal single, narrowly contacting the eye, dorsally contacting the preocular, prefrontal, and internasal, anteriorly contacting the nasal, ventrally contacting the 2 nd supralabial and subocular. Supraocular 1; preocular 1; subocular 1; postocular 1. Temporals 2 + 3 / 2 + 3. Supralabials 7 / 7, none entering the orbit; first supralabial smallest, and seventh largest. Infralabials 7 / 7; the first pair in contact medially and bordering the mental; first 5 contacting the first pair of chin shields. Chin shields 3 / 3, arranged in an interlaced pattern; the first pair relatively large, distinctly longer than broad; the posterior two pairs much broader than long. Body scalation. Dorsal scales in 15 - 15 - 15 rows, 5 scale rows slightly keeled at midbody, without apical pits, and 1 vertebral scale row slightly enlarged. Ventrals 182 (+ 1 preventral), lateral keels absent. Subcaudals 71. Cloacal plate single. Coloration in preservative. In preservative, the dorsal background color of the head and body is light brown. A large, irregularly edged dark brown blotch occupies most of the dorsal surface of the head; anteriorly it reaches the anterior portion of the prefrontal, and posteriorly extends beyond the parietals. From the posterior margin of this blotch, a pair of thick dark brown longitudinal streaks extends backward and connects with the dark markings on the neck. Surrounding the blotch, including the internasals and lateral surfaces of the head, numerous small dark speckles are present. The eyes are grayish black. Between the posterior margin of the eye and the corner of the mouth, two large, irregular, teardrop-shaped dark blotches are present. A large black blotch occurs on each side of the neck. Posterior to the neck, the dorsum bears approximately 60 irregular dark brown transverse bands of unequal spacing; these bands are interrupted along the vertebral region and do not extend onto the venter. Toward the posterior part of the body, the bands become increasingly irregular, and on the dorsal surface of the tail they are indistinct and difficult to count. The ventral surfaces of the head and body are creamy white, scattered with dark brown speckles of varying size and shape. Description and variation of the species. The main morphological characteristics of P. dulongjiangensis are summarized in Table 1, based on specimens examined in this study, Vogel et al. (2021), and Liu et al. (2023 a). A medium-sized species of Pareas with weak sexual dimorphism. Body slender and distinctly laterally compressed. Maximum total length 514 mm in males (ANU ZR 24101, SVL 390 mm, TAL 124 mm) and 488 mm in females (KIZ R 201607, holotype, SVL 373 mm, TAL 115 mm). Tail relatively slender and elongate; TAL / SVL ratio 0.31 – 0.33 in males and 0.27 – 0.31 in females; TAL / TL ratio 0.23 – 0.25 in males and 0.21 – 0.24 in females. Head relatively large and clearly distinct from the neck; HL 10.9 – 14.1 mm, HW 6.8 – 8.1 mm, HW / HL ratio 0.52 – 0.62. Eye relatively large, pupil vertically elliptical; ED 2.5 – 2.9 mm. Nostril oval, situated approximately in the center of the nasal scale. Head scalation (Fig. 4). Rostral not visible from above. Nasal single, undivided; internasals 2, distinctly wider than long. Prefrontal single, large and broad, slightly curved posteriorly, with both anterior and posterior margins smoothly rounded; in specimens QHU R 2025063 and ANU ZR 25057, the median portion of the posterior margin of the prefrontal is partially fused with the anterior margin of the frontal (see Remarks for details on the prefrontal condition in P. dulongjiangensis); entering the orbit. Frontal single, subpentagonal (Only the anterior portion of the frontal scale in specimen CAS 224415 is slightly protruding anteriorly, but the anterior apex remains bluntly rounded); anterior margin smoothly rounded and slightly protruding anteriorly; lateral margins converging posteriorly. Loreal single, entering or excluded from the orbit. Supraocular 1; preocular absent or 1; suboculars 1 – 3, with the subocular fused with the postocular in some individuals; postocular absent or 1. Temporals 2 + 2 or 3. Supralabials 6 – 7, separated from the eye by suboculars, none entering the orbit; first supralabial smallest, last supralabial largest. Infralabials 7 – 9; the first pair in contact medially and bordering the mental; first 3 – 5 infralabials contacting the first pair of chin shields. Chin shields 3 (rarely 2), arranged in an interlaced pattern; the first pair relatively large, distinctly longer than broad; the posterior two pairs much broader than long. Body scalation. Dorsal scales in 15 - 15 - 15 rows; 5 – 9 median rows at midbody slightly keeled; apical pits absent; and 1 – 3 vertebral scale rows slightly enlarged. Ventrals 178 – 182 (+ 1 preventral) in males, and 182 in both examined females; lateral keels absent. Subcaudals weakly sexually dimorphic, 77 – 83 in males, and 71 – 76 in females, all paired. Cloacal plate single. Dentition. In Liu et al. (2023 a), the maxillary teeth of the holotype (KIZ R 201607) were only counted (5 / 4), without further description. Hemipenis (Fig. 5). Description based on the fully everted left organ of adult male specimen QHU R 2025063. When fully everted, the hemipenis is slender and relatively short, reaching the 8 th subcaudal scale. Total length (HTL) 12.98 mm; total width (HTW) 4.52 mm. It is Y-shaped and bilaterally symmetrical; truncus length (HCL) 6.03 mm, with an HCL / HTL ratio of 0.46. The surface from the base to the point of bifurcation is smooth. Distal to the bifurcation, each branch bears nine distinct transverse folds. The proximal folds are widely spaced and clearly separated; distally, the spacing gradually decreases, and at approximately the distal half of each branch the folds become progressively confluent, forming a smooth-margined calyculate region. The calyces are more distinct on the inner surface of each branch, whereas on the outer surface they are weakly developed and barely discernible, appearing primarily as transverse folds. The apical surface of each branch is flattened and smooth, with the margins expanded outward to form a circumferential fold. The sulcus spermaticus is bifurcate, running medially and extending to the apical margin of each branch. The sulcal lips are well developed and prominently raised, smooth, and lacking spinules. Coloration in life (Fig. 6). In life, the ground color of dorsal surface of the head and body yellowish brown. A large, irregularly edged black blotch occupies most of the dorsal surface of the head; anteriorly it reaches the anterior portion of the prefrontal, and posteriorly extends behind the parietals. From the posterior margin of this blotch, a pair of thick black longitudinal streaks extends backward and connects with the dark markings on the neck. Surrounding the blotch, including the internasals and lateral surfaces of the head, numerous small dark speckles are present. The eyes are orange to orange-brown. Between the posterior margin of the eye and the corner of the mouth, there are 2 – 3 large, irregular, teardrop-shaped dark blotches; in specimen QHU R 2025063, these postocular blotches are connected, forming a short oblique streak. A large black blotch is present on each side of the neck. Posterior to the neck, the dorsum bears 52 – 64 irregular dark transverse bands of unequal spacing; these bands are usually interrupted along the vertebral region and do not extend onto the venter. Toward the posterior part of the body the bands become increasingly irregular, and on the dorsal surface of the tail they are indistinct and difficult to count. The ventral surfaces of the head and body are creamy yellow to light yellowish brown, scattered with dark brown speckles of varying size and shape; the density of ventral blotches varies among individuals. Coloration in preservative. In preservative, the dorsal ground color fades to light brown or brown, and the ventral ground color becomes creamy white, while the dark markings remain clearly visible. The eyes turn dark gray to grayish black. Re-comparison between Pareas dulongjiangensis and P. kaduri. Both morphological and molecular evidence indicate that P. dulongjiangensis is most closely related to P. kaduri (Fig. 2; Table 2). Based on the revised results, P. dulongjiangensis can be distinguished from the latter by the following characters: (1) relatively longer tail, with TAL / SVL ratio 0.31 – 0.33, TAL / TL ratio 0.23 – 0.25 in males, and TAL / SVL ratio 0.27 – 0.31, TAL / TL ratio 0.21 – 0.24 in females (vs. TAL / SVL ratio 0.23 – 0.26, TAL / TL ratio 0.18 – 0.21 in males, and TAL / SVL ratio 0.23, TAL / TL ratio 0.19 in the single female); (2) PF 1 (vs. 2); (3) PO 0 or 1 (vs. 2); (4) KMD 5 in females (vs. 0 in the single female); (5) more VEN in females (182 vs. 171); and (6) more SC in both sexes, 77 – 83 in males and 71 – 76 in females (vs. 65 – 70 in males and 52 in females).	en	Xu, Yuhao, Zhang, Tierui, Nguyen, Tan Van, Sun, Fanyue, Vogel, Gernot, Deng, Jundong, Poyarkov, Nikolay A., Peng, Lifang (2026): Redescription and range extension of Pareas dulongjiangensis Liu, Yang, Rao, Guo & Rao, 2023 (Squamata: Pareidae). Zootaxa 5845 (3): 523-544, DOI: 10.11646/zootaxa.5845.3.5, URL: https://doi.org/10.11646/zootaxa.5845.3.5
03A98786FF88FFF295E0FEF0FB81F86B.taxon	distribution	Distribution and natural history notes. Pareas dulongjiangensis is currently known from two nearby localities in Dulongjiang Township, Gongshan County, Nujiang Prefecture, Yunnan Province, China (Kongdang Village [type locality] and Maku Village), as well as from Hkakabo Razi NP, Nagmung Township, Putao District, Kachin State, northern Myanmar (Fig. 1). Detailed ecological information on this species remains limited. The general habitat of this species consists of primary broad-leaved forests and secondary forests subject to some degree of anthropogenic disturbance, at elevations of approximately 1,010 – 1,620 m a. s. l. (Vogel et al. 2021; Liu et al. 2023 a; this study). The holotype (KIZ R 201607) was found on a road near Kongdang Village; the microhabitat comprised rocks, grasses, and plantains along both sides of the road. Four specimens from Maku Village were collected from shrubs along a mountain road and from Amomum tsaoko plantations cultivated by local residents. The Myanmar specimen (CAS 224415) was discovered on the ground near a mountain stream (Vogel et al. 2021). In Dulongjiang Township, other sympatric reptile species observed in the area include Elaphe carinata (Günther, 1864), Japalura sagittifera Smith, 1940, Lycodon gongshan Vogel & Luo, 2011, L. septentrionalis (Günther, 1875), L. zayuensis Jiang, Wang, Jin & Che, 2020, Ovophis zayuensis (Jiang, 1977), Protobothrops jerdonii (Günther, 1875), P. kaulbacki (Smith, 1940), P. mucrosquamatus (Cantor, 1839), Pseudocalotes bapoensis (Yang, Su & Li, 1979), Rhabdophis leonardi (Wall, 1923), and Sphenomorphus indicus (Gray, 1853) (Liu et al. 2023 a; this study).	en	Xu, Yuhao, Zhang, Tierui, Nguyen, Tan Van, Sun, Fanyue, Vogel, Gernot, Deng, Jundong, Poyarkov, Nikolay A., Peng, Lifang (2026): Redescription and range extension of Pareas dulongjiangensis Liu, Yang, Rao, Guo & Rao, 2023 (Squamata: Pareidae). Zootaxa 5845 (3): 523-544, DOI: 10.11646/zootaxa.5845.3.5, URL: https://doi.org/10.11646/zootaxa.5845.3.5
03A98786FF88FFF295E0FEF0FB81F86B.taxon	discussion	Remarks on the prefrontal condition. In the original descriptions by Vogel et al. (2021) and Liu et al. (2023 a), Pareas dulongjiangensis was reported to possess two prefrontal scales. However, examination of four newly collected specimens reveals that the species consistently bears a single, large prefrontal that is slightly curved posteriorly (Fig. 4). Re-examination of the Myanmar specimen CAS 224415 also confirms the presence of a single prefrontal (Fig. 3), indicating that this condition is not an abnormal individual variation. In other members of the P. hamptoni species group, the prefrontals are typically paired. In those species, the suture between the paired prefrontals is clearly visible, with the inner margins of the prefrontals distinctly narrowed, forming a pronounced anterior concavity in the median region of the paired prefrontals, whereas the frontal scale usually extends anteriorly into the suture between the prefrontals and possesses a distinctly projecting anterior margin, giving the scale a hexagonal shape. In contrast, the presence of a single prefrontal in P. dulongjiangensis alters the configuration of the frontal scale: its anterior margin becomes smoothly rounded and only weakly projecting, and the overall shape approaches a subpentagonal condition (Fig. 4). Based on the photographs of the holotype KIZ R 201607 provided in Liu et al. (2023 a), the observable configuration of the prefrontal and frontal scales closely matches that of the newly examined specimens. We therefore conclude that the holotype also possesses a single prefrontal. We suggest that the previously reported paired prefrontals most likely resulted from a misinterpretation of the scale sutures.	en	Xu, Yuhao, Zhang, Tierui, Nguyen, Tan Van, Sun, Fanyue, Vogel, Gernot, Deng, Jundong, Poyarkov, Nikolay A., Peng, Lifang (2026): Redescription and range extension of Pareas dulongjiangensis Liu, Yang, Rao, Guo & Rao, 2023 (Squamata: Pareidae). Zootaxa 5845 (3): 523-544, DOI: 10.11646/zootaxa.5845.3.5, URL: https://doi.org/10.11646/zootaxa.5845.3.5
