Lycodon latifasciatus Nguyen, Lee, Jiang, Ding, Chit, Poyarkov & Vogel, 2025, sp. nov.

Lycodon latifasciatus sp. nov. urn:lsid:zoobank.org:act: 1EBEF5EA-E5BA-4786-BB18-424D0358FFEC (Figs. 2–4, 5A–C, 6A–B, 7A, Appendix Fig. S1; Tables 1–3, Appendix Table S4) Lycodon cf. fasciatus — Che et al. (2020: 683–87). Lycodon sp. — Li et al. (2020: 11); Vogel et al. (2024: 120). Lycodon sp. 2 — Wu et al. (2023: in Appendix). Holotype. CAS 245367 (adult male) from Laung Nguk Village, Lahe Township, Khandi District, Sagaing Region, Myanmar (26.159833°N, 95.522527°E; altitude ca. 950 meters asl.) collected by M. Hlaing, S.L. Oo, Z.H. Aung, and Y.M. Win on 19 May 2009. Paratypes (n = 4). China: Xizang AR—CIB DL.2015.25.52 (one adult male), from Beibeng Township, Medog County collected by L. Ding; CIB DL.050, CIB DL.053 (two adult males) from Damu Township, Medog County collected by L. Ding. Myanmar: Sagaing Region — ZMMU Re- 16728 (one adult male; field ID NAP-09559) from Zalon Taung Mt., Ban Mauk District (24.51628°N, 95.81705°E; altitude 660 meters asl.) collected by N.A. Poyarkov, P. Pawangkhanant, V.A. Gorin, and May Thu Chit on 02 August 2019. Referred specimens (n = 2). China: Xizang AR — CIB. DL.2015.122.51 (subadult male), from Beibeng Township, Medog County collected by L. Ding. Myanmar: Sagaing Region — ZMMU Re-16729 (immature female; field ID NAP-09560) same collection data as ZMMU Re-16728 specimen. Diagnosis. A medium-sized species of Lycodon with a maximum total length of 871 mm; relative tail length 0.21–0.23; dorsal scale rows 17–17–15, first 5–9 upper dorsal scale rows keeled at midbody, remaining rows smooth; ventrals 206–216; subcaudals 90–96, paired; cloacal plate undivided; supralabials usually eight (rarely nine) with third to fifth scales in contact with eye; infralabials eight or nine (rarely seven), the first five (rarely four) in contact with anterior chin shields; preocular 1/1, blocking prefrontals from contacting eye; loreal usually in narrow contact with eye; postoculars 2/2; temporals 2+2 (rarely 2+3). Dorsum dark brown in life with 29–36 orange or orange brown light body crossbands and 13–21 tail crossbands; first light crossband starting between ventrals 4–11, 5–8 ventral scales long at base and 2–4 vertebral dorsal scales long; in life, head dark brown in adults, white spots present across most supralabials, underside of head white, scale sutures of chin and throat with dark brown mottling; venter with discrete light and dark crossbands, small irregular spots prevalent posteriorly. Description of holotype (Fig. 3). Specimen CAS 245367 in excellent condition, small ventral incision at midbody; right and left hemipenis both partially everted, but right organ more fully prepared than left (Fig. 7A). Body elongate, laterally compressed. Tail gracile, tapering to a blunt and enlarged terminal scute. Head ovate in dorsal profile, distinct from neck (Fig. 3E); temporal and parietal region slightly raised in lateral profile; snout relatively elongate, depressed downwards, upper jaw projecting further than lower jaw, no distinct canthus rostralis (Fig. 3C–D). Nostrils round, circular, positioned medially within nasal. Eyes moderate relative to head; pupil elliptical, vertical. Measurements. SVL 680 mm, TaL 191 mm, TL 871 mm, TaL/TL ratio 0.22, HeadL 18.8 mm, HeadW 11.0 mm, SnL 5.5 mm, SnW 3.8 mm, EyeD 2.5 mm, FrontalL 4.7 mm, FrontalW 4.4 mm, InterorbD 5.6 mm. Body scalation. Dorsal scales arranged in 17-17-15 rows; all dorsal scales smooth anteriorly, keeled at midbody and posteriorly except for the first four outermost rows on either side at midbody and the two outermost rows posteriorly, which are smooth; vertebral row of dorsal scales not enlarged; apical pits absent. Ventral scales 216, laterally angulate, forming a slight keel; subcaudals 96, paired, laterally angulate; total body scales 313; subcaudal ratio 0.31; cloacal plate undivided. Head scalation. Rostral subtriangular, wider than high, barely visible from above, its posterior edge bordering internasals forming a broad ‘gull-wing’ shaped obtuse angle (~147º) (Fig. 3E). Nasals vertically divided by indistinct suture above and below nostril, longer than high, in contact with internasal, loreal, prefrontal, rostral and first two supralabials. Each portion of nasal subhexagonal, anterior portion slightly smaller than posterior. Internasals paired, rectangular, anterior edges concave, 1.5 times wider than length of entire scale, 1.9 times wider than medial suture, each scale in contact with rostral, nasal and prefrontal. Prefrontals paired, 3.9 times larger than internasals, subrectangular, anterior edges straightened, 1.2 times longer than wide, medial suture 1.1 times longer than wide and 3.0 times longer than internasal suture, each prefrontal contacting internasals, nasals, loreal, and frontal. Supraoculars paired, subrectangular, posterior suture straightened, anterior suture concave, 1.5 times longer than wide, posterior edge 2.2 times wider than anterior edge, each supraocular in contact with upper preocular, upper postocular, frontal and parietal. Frontal small, hexagonal and shield shaped, 1.6 times longer than prefrontal suture, 1.1 times longer than wide; anterior edge of frontal straightened, positioned in-line with eyes in dorsal profile; posterior vertex of frontal bordering parietals acute angled (~81º). Parietals paired, subpentagonal, entire scale 1.9 times longer than wide, medial suture 1.1 times longer than wide and 1.1 times shorter than frontal; anterior edge of parietal straightened, its suture with frontal and supraoculars obtuse angled and directed laterally (~121º). A total of 11 scales behind the upper postoculars surround both parietals. Loreal 1/1, subrectangular, roughly 2.4 times longer than high, in narrow contact with eye on either side. Preocular 1/1, vertical and subrectangular. Presubocular and subocular scales absent. Postoculars 2/2, vertical and subrectangular, bottommost scale slightly larger. Temporals 2+2, lowermost anterior temporal largest. A single slightly enlarged paraparietal scale present behind posterior temporal row, each surrounded by 6/6 scales with 3/3 scales positioned immediately below. Supralabials 8/8, the first and second in contact with nasal, second and third in contact with loreal, third to fifth in contact with eye; sixth supralabial largest, first supralabial smallest. Infralabials 9/9, first to fifth in contact with anterior chin shields, fifth and sixth contacting posterior chin shields. Mental subtriangular, 1.8 times wider than long. Posterior chin shields roughly same length as anterior shields. Gular scales 3/3 (excluding two preventrals) behind posterior row of chin shields. Color of holotype in preservative. After 15 years in preservative, dorsal ground color dark brown with a series of 36 light crossbands on the body and 17 on the tail (Fig. 3A). First three anteriormost crossbands tan, each narrower than darker brown crossbands with inconspicuous light brown mottling within them. First light crossband starting at 7 th ventral scale, 8 ventral scales long at base, 2.5 vertebral dorsal scales long. Remaining light crossbands wider than dark bands after 7 th band, usually 4.0 vertebral dorsal scales in length, each with light brown mottling within them. Margins of dorsal crossbands tan at midbody; posteriormost crossbands with irregular, jagged edges that buffer the dark bands and cause them to narrow medially. Color of light tail crossbands same as body, except the last six bands are tan with less light brown pigmentation intruding inside. Head dark brown, mostly plain, edges of loreal, prefrontals and temporals with subdued light brown mottling. Light brown, indistinct mottling on rostral and anterior edges of internasals. A very subdued “Y” shaped nuchal collar present in parietal region (Fig. 3E), starting medially from the parietal suture, bifurcating posteriorly along the temporals and paraparietal before expanding posterolaterally to the nape. Bottommost half of nasal and first supralabial light brown. Bottom halves of supralabials 2–7 with distinct tan spots, rounded in shape. Underside of head tan, mental and infralabial sutures dark brown. Throat tan, plain, gular scales with scattered dark brown pigment along their edges. Ventral surface with alternating series of dark brown and tan colored bands, all rectangular in shape (Fig. 3B). Anteriorly, first three dark ventral bands are extremely diffuse, present only as small dark brown spots, whereas the remaining dark bands are bold. Posteriorly, ventral bands begin to intrude into each other along the ventral scales, occasionally forming irregular dark brown spots. Each dark ventral band 2–3 ventral scales wide, light bands 3–5 ventral scales wide. Arrangement and color of bands on tail underside same as posterior ventral surface. Color of holotype in life unknown. General description and variation (see Table 1 and Figs.: 4, 5A–C, 6A–B, 7A). Based on seven specimens (including holotype and paratypes). The holotype (adult male) is the longest specimen in terms of total length (TL 871 mm). The longest female is 670 mm long (SVL 513 mm, TaL 157 mm; CIB DL.053). Ratio TaL/TL 0.21– 0.23 (x̄ = 0.219±0.009; n = 8). In general habitus like holotype, elongate overall (Appendix Fig. S1). Tail gracile, terminal scute blunt ended. Head ovate, distinct from neck, temporal and parietal region slightly raised; snout elongate, depressed in lateral profile, no canthus rostralis. One of the paratypes (CIB DL.050) is partially crushed and as a result has a more flattened head and more rounded snout in lateral profile (Appendix Fig. S1A–B). Nostrils rounded, positioned medially. Eyes moderate, pupil elliptical. No sexual dimorphism was evident in body or head proportions. ......continued on the next page Body scalation. Dorsal scales in 17-17-15 rows. Three specimens (holotype + DL.050, DL.053) have entirely keeled scales at midbody and posteriorly, except for the outermost four rows (which are smooth). In one specimen