Oligodon lungshenensis Zheng & Huang in Huang, Zheng and Fang 1978

Figs 9, 10, 11, 12, Suppl. material 1: table S 4

Vernacular name.

Longsheng Kukri Snake / 龙胜小头蛇 (Pinyin: Lo ́ ng She ̀ ng Xia ̌ o To ́ u She ́)

Synonymy.

Oligodon guizhouensis – Li in Wu, Li, Xu, Dong and Liu (1979): 104.

Partial chresonymy.

Oligodon ornatus (in part) – Zhao et al. (1986: 157); Zhao and Yang (1997: 238 –239); Zhao (2002: 171); Li et al. (2020); Wu et al. (2023); Lee et al. (2024).

Type material.

Holotype. • FNU 64099 (or NHMG 64099; see notes about holotype) (immature male), collector and collection date unknown. Type locality: Longsheng County, Guilin City, Guangxi Zhuang Autonomous Region, China.

Paratype. • NHMG 64100 (immature male), sharing the same collection data as the holotype, deposited in the NHMG.

Notes about holotype.

In the original description, Huang et al. (1978) explicitly stated the holotype was deposited in Fujian Normal University and the paratype in the Natural History Museum of Guangxi Zhuang Autonomous Region (NHMG). However, both specimens were assigned NHMG catalogue numbers (Huang et al. 1978: 92). We made inquiries to the relevant institutions. At present, no archival records of O. lungshenensis or O. ornatus collected during the 20 th century are retained in the collections of FNU; therefore, the holotype of O. lungshenensis was most likely lost.

Specimens examined

(N = 11). China. Guangxi Zhuang Autonomous Region. • QHU R 2024050 (Field NO. LFR 2024180; adult male), from Guilin City (approx. 25.275°N, 110.296°E), collected on 20 October 2024 by Y. H. Xu; • SYS r 001529 (adult male), from Pinggui District, Hezhou Prefecture (24.293°N, 111.556°E, 345 m asl.), collected on 16 July 2016 by the team of Y. Y. Wang. Guizhou Province. • CIB F.201109039 (Field NO. TH 1962; adult male), from Leigongshan, Leishan County, Qiandongnan Miao, and Dong Autonomous Prefecture (approx. 26.37°N, 108.16°E), collected on 24 September 2011 by the team of J. P. Jiang; • CIB 9963 (adult male), collected in August 1976, share the same locality as CIB F.201109039; • ANU ZR 24115 (adult female), from Fangxiang Town, Leishan County, Qiandongnan Miao, and Dong Autonomous Prefecture (26.4192°N, 108.2367°E, 1098 m asl.), collected in August 2024 by T. R. Zhang; • QHU R 2025048 (Field NO. LFR 2025226; adult female), collected on 26 September 2025 by the team of L. F. Peng, shares the same locality as ANU ZR 24115. Hunan Province. • QHU R 2024048 (Field NO. LFR 2024098; adult male), from Yongzhou City (approx. 26.45°N, 111.39°E), collected on 10 July 2024 by the team of L. F. Peng; • QHU R 2025057 (Field NO. LFR 2025109; adult male), collected on 09 June 2025 by the team of L. F. Peng, shares the same locality as QHU R 2024048; • ANU ZR 24103 (adult female) and • ANU ZR 240104 (adult male), from Longshan Forest Park, Lianyuan City, Loudi City (27.5033°N, 111.7465°E, 1046 m asl.), collected in 2024 by T. R. Zhang; • QHU R 2025049 (Field NO. LFR 2025227; adult male), from Longshan forest park, Lianyuan City, Loudi City (27.5033°N, 111.7465°E, 1046 m asl.), collected on 12 September 2025 by the team of L. F. Peng.

Other reported specimens

(N = 24). China. Chongqing Municipality. • CTS 20090624 (adult female), from Shuishi Township, Qianjiang District (29.2348°N, 108.6873°E; 1000 m asl.), collected on 24 June 2009 by Zhishen Fei, reported by Luo et al. (2010). • KIZ YPX 18635, sex and collection data unknown, from Qianjiang District (approx. 29.53°N, 108.77°E), reported by Wu et al. (2023). Guizhou Province. • ZMU 7600060 (adult male), the holotype of O. guizhouensis, from Yongle Town, Leishan County, Qiandongnan Miao, and Dong Autonomous Prefecture (26.2257°N, 108.2211°E; 630 m asl.); • ZMU 770272 (adult male), • ZMU 770273 (adult male), • ZMU 770275 (adult male), • ZMU 750159 (adult female), • ZMU 770274 (adult female), and • ZMU 770271 (adult female), from Chishui City, Zunyi City (approx. 28.36°N, 105.78°E); and • ZMU 7610418 (adult female), • ZMU 7610419 (juvenile female), • ZMU 7610421 (juvenile female), and • ZMU 770364 (juvenile female), from Leishan County, Qiandongnan Miao and Dong Autonomous Prefecture (approx. 26.37°N, 108.16°E), all of which are designated as paratypes of O. guizhouensis. These 11 specimens were reported by Wu et al. (1979). • TRU U R 201107001 (adult female), from Fodingshan Nature Reserve, Shiqian County, Tongren City (27.3371°N, 108.1601°E; 619 m asl.), collected on 07 July 2011, reported by Ran et al. (2012). Hubei Province. • XDSNR 0011 (adult male), from Xingdoushan Nature Reserve, Enshi City (30.067°N, 109.233°E; 1179 m asl.), collected on 12 August 2022, reported by Dong et al. (2023). Hunan Province. • CWNU unnumbered (adult male), from Mangshan National Nature Reserve, Chenzhou City (24.967°N, 112.867°E, 1000 m asl.), collected July 2008, reported by Yuan et al. (2010). • HNNU 920897 (adult female), from Shimen County, Changde City (approx. 29.58°N, 111.38°E); • HNNU 810732 (adult female), • HNNU 810731 (juvenile male), • HNNU 590046 (juvenile male) from Dayong, Zhangjiajie City (approx. 29.12°N, 110.48°E); • HNNU 590014 (adult female), from Jiangyong County, Yongzhou City (approx. 25.27°N, 111.34°E); • HNNU 590046 (adult female), from Cili County, Zhangjiajie City (approx. 29.43°N, 111.13°E). These 6 specimens were reported by Shen et al. (2014). • HS 11016 (now ANU HS 11016), sex and collection data unknown, from Yongzhou City (approx. 26.45°N, 111.39°E), reported by Li et al. (2020). Sichuan Province. • YBU 240279 (adult female), from Xianlong Village, Xiantan Town, Hejiang County, Luzhou City (106.2758°N, 28.6517°E; 696 m asl.), collected 22 June 2023, reported by Liu et al. (2025). Literature data from reported specimens are mentioned in the description. For electronic records, refer to Suppl. material 1.

Revised diagnosis.

A medium sized Oligodon, tail moderately long (TailLR 0.106 –0.147; in males 0.114 –0.147; in females 0.106 –0.133). Dorsal scales in 15–15 – 15 rows, all smooth, no reductions. Ventral scales 163–186, no dimorphism (163–185 in males, and 167–186 in females), no keeling. Cloacal plate divided. Subcaudals 31–40 (31–40 in males, 31–35 in females), paired. Total body scales 198–218 (198–215 in males, 201–218 in females). Subcaudal ratio 0.142 –0.188, no dimorphism (in males 0.148 –0.188, in females 0.142 –0.172). Maxillary teeth 8, posterior three teeth slightly enlarged and blade-like. Internasals absent, fused with prefrontals. Loreal absent, preocular 1, presubocular absent, postoculars 2 (rarely 1), temporals 2 + 2 (rarely 2 + 1). Temporolabial scale present. Supralabials 6 (rarely 5), 3 rd – 4 th in contact with the eye (rarely 2 nd – 3 rd in contact). Infralabials 6–7 (rarely 5), first 1–4 in contact with anterior chin shields (rarely 1–3). Dorsal surface light brown or grayish brown with a broad brown paravertebral stripe and a narrower lateral stripe on either side of body, both extending from nape to tail. Middorsal line between paravertebral stripes, same color as remaining body. A total of 9–14 irregular dorsal bands present (7–11 on body, and 1–3 on tail), some specimens exhibiting secondary bands or spots concentrated along the middorsal or paravertebral regions. Median portions of each band brown, edges normally dark brown or black. Head markings include ocular bar, temporal bar, and nuchal chevron. Ventral surface white with lateral series of black alternating rectangular blotches on ventral scales and a broad red midventral stripe in life. Hemipenis unilobed, simple sulcus spermaticus, spines gradually decreasing in size by midpoint of organ, and absent on distal one-fifth of organ and apical surface.

Description and variation.

The main morphological characteristics of O. lungshenensis are summarized in Suppl. material 1: table S 4, based on newly examined specimens in this study (N = 11) and previous reports by Huang et al. (1978), Wu et al. (1979), Zhao et al. (1986), Yuan et al. (2010), Luo et al. (2010), Ran et al. (2012), Dong et al. (2023), and Liu et al. (2025) (N = 17).

Body slender, subcylindrical. Head oblong, slightly distinct from neck. Snout elongate, narrowing in width in dorsal profile, slightly truncate in lateral profile. Eyes moderate relative to head, pupil round. Nostrils small, subelliptical, pointed laterally. Tail short to moderate, tapering gradually to sharp pointed tip. Largest specimen an adult female (ANU ZR 24115) measuring 612 mm SVL and 79 mm TailL. Largest male (uncatalogued specimen reported by Zhao et al. 1986) 550 mm SVL, 95 mm TailL. Head measurements (N = 11 unless noted otherwise) as follows: HeadL 12.8–17.3 mm (N = 12), HeadW 8.0– 10.9 mm (N = 12), SnoutL 4.1–6.1, EyeD 2.0– 3.1 mm, IOD 5.5–6.7 mm (N = 10), IND 3.6–4.9 mm, FrontalL 3.9–5.9 mm, FrontalW 3.5–5.1 mm. TailLR 0.106 –0.147 (x ̅ = 0.126 ± 0.012; N = 28), in males 0.114 –0.147 (x ̅ = 0.132 ± 0.012; N = 14), in females 0.106 –0.133 (x ̅ = 0.120 ± 0.009; N = 14), sexual dimorphism present (Student’s t-test P = 0.00468). HeadW / HeadL 0.52–0.76 (N = 12), SnoutL / HeadL 0.27–0.41 (N = 11), EyeD / SnoutL 0.36–0.51 (N = 11), EyeD / HeadL 0.13–0.21 (N = 11), FrontalL / FrontalW 1.02–1.30 (N = 11).

Body scalation. Dorsal scales in 15–15 – 15 rows, all smooth with no reductions. Ventral scales 163–186 (x ̅ = 171.0 ± 5.3; N = 28), in males 163–185 (x ̅ = 169.7 ± 5.0; N = 14), in females 167–186 (x ̅ = 172.4 ± 5.5; N = 14), no keeling. Cloacal plate divided. Subcaudal scales 31–40 (x ̅ = 34.0 ± 2.5; N = 28), in males 31–40 (x ̅ = 34.8 ± 2.9; N = 14), in females 31–35 (x ̅ = 32.6 ± 1.4; N = 14), paired. Total body scales 198–218 (x ̅ = 206.4 ± 5.5; N = 28), in males 198–215 (x ̅ = 205.9 ± 5.1; N = 14), in females 201–218 (x ̅ = 207.1 ± 5.9; N = 14). Subcaudal ratio 0.142 –0.188 (x ̅ = 0.163 ± 0.011; N = 28), in males 0.148 –0.188 (x ̅ = 0.169 ± 0.012; N = 14), in females 0.142 –0.172 (x ̅ = 0.157 ± 0.008; N = 14). Sexual dimorphism detected for subcaudal scales (Student’s t-test P = 0.01358) and subcaudal ratio (Student’s t-test P = 0.00609).

Head scalation (Fig. 9). Rostral enlarged, inflated, triangular in dorsal profile, curved onto upper surface of snout, in contact with first supralabial, nasal and prefrontals. Posterior suture of rostral obtuse angled, “ gull-wing ” shaped in dorsal profile. Condition of nasal variable, completely divided (in CIB F.201109039 and ANU ZR 24115), partially divided above (left side of head in QHU 2024050) or below nostril (4 / 11 specimens), or undivided (4 / 11 specimens + right side of head in QHU 2024050). Nostril positioned in the anterior edge of the nasal when completely divided; when partially divided, nostril positioned in the median part of the entire scale. Internasals absent, fused with prefrontals. Prefrontals subrectangular, paired, entire scale broad, 1.0–1.1 times wider than long. Anterior and posterior prefrontal sutures concave. Median prefrontal suture 2.2–2.5 times shorter than entire scale. Supraoculars longer than wide, narrower than prefrontals, posterior edge wider than anterior edge. Frontal large, pentagonal, shield shaped, longer than wide, 1.3–1.5 times longer than median parietal suture. Anterior frontal suture angled, positioned in front of eye sockets. Posterior vertex of frontal bordering parietal broad acute to weak obtuse angle (87–102 °). Parietals large, subrectangular, paired, in broad contact, entire scale 1.0–1.1 times longer than frontal. Parietal suture bordering supraocular and frontal weak obtuse angle (121–130 °), ray oriented posterolaterally. Parietals surrounded by 7–9 scales (N = 5; excluding postoculars). Loreal absent. Preocular 1 / 1, rectangular, higher than long. Presubocular absent. Postoculars 2 / 2 (19 / 28 specimens), rarely 1 / 1 (7 / 28 specimens) or 1 / 2 (2 / 28 specimens; in ANU ZR 24104 and QHU R 2025057), rectangular, higher than long, uppermost scale slightly larger. Temporals 2 + 2. In two specimens (QHU 2024048 and XDSNR 0011 fide. Dong et al. 2023) posterior temporals fused, resulting in scale formula of 2 + 1. Lower anterior temporal broad, diamond shaped, present as “ temporolabial ” scale leading to narrow contact between fifth and sixth supralabial. Supralabials 6 / 6, in one specimen 5 / 5 (YBU 240279 fide. Liu et al. 2025); first scale smallest, fifth and sixth largest. First supralabial contacts nasal, second contacts nasal, prefrontal and preocular, third contacts preocular, third + fourth contact orbit, fifth + sixth contact lower temporals. In two specimens the second + third supralabials contact orbit (YBU 240279 fide. Liu et al. 2025; ANU ZR 24115 on right side of head). Infralabials 7 / 7 (9 / 17 specimens) or 6 / 6 (8 / 17 specimens), rarely 7 / 6 (CIB F.201109039) or 5 / 6 (QHU R 2025048). First pair of infralabials in contact at midline, second scale smallest, fourth scale largest. First four infralabials contact anterior chin shields (8 / 11 specimens), exceptionally 3 / 4 (SYS r 001529), 4 / 3 (CIB F.201109039), or 3 / 3 (QHU R 2025048). Anterior chin shields subrectangular, larger than posterior. Posterior chin shields also subrectangular, in contact at midline for half their length, suture bordering gulars concave. Mental groove poorly defined, present between first infralabials and posterior chin shields.

Dentition. Maxillary teeth 8, enlarged and blade-like, increasing in size posteriorly (based on QHU R 2024048, R 2024050, R 2025057 and R 2025049). Wu et al. (1979) and Zhao (2006) recorded the same tooth counts in their material.

Coloration in life. In life (Fig. 10), dorsal surface light brown to grayish brown. A broad, paravertebral stripe present followed by narrower lateral stripe on each side of body, both brown, extending from nape to tail. Paravertebral stripes positioned on dorsal scale rows 6–7, each 2.0–2.5 scales wide; lateral stripe between dorsal scale rows 3–4, each 0.5–1.0 dorsal scales wide. One narrow middorsal line engulfed between paravertebral stripes, same color as remaining body. 7–11 transverse body bands (x ̅ = 8.7 ± 0.8; N = 26), 1–3 on tail (x ̅ = 2.4 ± 0.7; N = 26); total bands 9–14 (x ̅ = 11.3 ± 1.2; N = 28). Median portion of each band brown, lighter than the surrounding edges, which are typically dark brown or black. Some specimens exhibit secondary banding or spotting across body, concentrated middorsally or paravertebrally contributing to a more complex dorsal pattern (YBU 240279 fide. Liu et al. 2025: Fig. 1). Dorsal surface of the head light brown to grayish brown, marked by ocular bar, temporal streak and nuchal chevron. All three head markings brown or reddish brown, slightly paler medially, bordered by dark brown. Ocular bar has its apex positioned at the posterior edge of the rostral, extending across internasals, prefrontals, supraoculars, and anterior margin of frontal, descending through eye to partially covering first 2–3 supralabials. Apex of temporal streak arises near middle of head, extending obliquely across temporals to the posterior end of the head. Nuchal chevron arrow-shaped or heart-shaped, starting at median edge of parietals and extending onto nape. Ventral surface of head white, scattered with irregular black blotches. Underside of body also white, small subrectangular black blotches present across lateral edges of ventral scales. These ventral blotches are typically arranged at alternating intervals of 1–2 scales, though they can be continuous in some examples. One red midventral streak present between dark blotches extending from throat to cloaca. Underside of tail same coloration and pattern as body, though red midventral streak may become faint or absent, particularly near the tail tip.

Coloration in preservative (Fig. 11). In preservative, ground color fades to pale brown on the dorsum and creamy white on the venter. The red midventral streak is no longer visible, but the dark dorsal bans and ventral blotches remain distinct. In addition, the black ventral blotches in specimen CIB F.201109039 enlarge in the mid- to posterior body region and subsequently merge, causing the entire central portion of the ventral surface in this region to become uniformly black (Fig. 11 C).

Description of hemipenis. (Fig. 12). Description based on everted left organ of adult male specimen QHU R 2024050. When fully everted, hemipenis thin, short, and cylindrical, elliptical in cross-section, and extending to the 9 th subcaudal scale. Hemipenial total length 14.55 mm, maximum width 5.05 mm. Both sulcate and asulcate surfaces are densely covered with spines, which are arranged in approximately 15 faintly defined rows; basal hooks are absent. First sixth of hemipenis nude, followed immediately by large, keratinized spines restricted to proximal half. Width of hemipenis narrows slightly in a transverse manner past midpoint. Spines gradually decrease in size after midpoint and disappear completely at the distalmost fifth of the organ near the apex. The apical surface is predominately smooth with occasional scattered small papillae-shaped calyces. The sulcus spermaticus is simple and non-bifurcate, extending centripetally from the base to the apex. Sulcus lips well-developed, slightly raised, walls smooth.

Distribution and natural history.

This species is endemic to south to southwest China, where it is known from Chongqing Municipality, Guangdong Province, Guangxi Zhuang AR, Guizhou Province, Hunan Province, Hubei Province, and Sichuan Province (Huang et al. 1978; Wu et al. 1979; Zhao et al. 1986; Yuan et al. 2010; Luo et al. 2010; Ran et al. 2012; Dong et al. 2023; Liu et al. 2025; this study) (Fig. 1, Suppl. material 1: table SS 1). The record from Sichuan Province was first reported from Miyi County, Panzhihua City, and was identified as Oligodon ornatus (Zhao et al. 1986; Zhao and Yang 1997; Zhao 2002). However, the described specimen was noted to lack internasal scales, a diagnostic trait of O. lungshenensis. This observation is also consistent with the more westerly distribution of O. lungshenensis compared to O. ornatus. All known localities are situated at mid-to-high elevations (between 619–1500 m asl.) in habitats characterized by evergreen broadleaf forests (Huang et al. 1978; Wu et al. 1979; Zhao et al. 1986; Zhao 2006; Yuan et al. 2010; Luo et al. 2010; Ran et al. 2012; Dong et al. 2023; Liu et al. 2025; this study). Zhao (2006) reported a female specimen of Oligodon lungshenensis from Guizhou Province containing five eggs, confirming that the species is oviparous. The same study also noted that O. lungshenensis primarily feeds on reptile eggs, but no specific predator-prey observations have been documented. When threatened and unable to escape, O. lungshenensis exposes its vividly colored ventral surface by curling and raising its tail. This species also displays marked aggressiveness when handled and will simultaneously attempt to bite and use its tail tip to jab at perceived threats.

Etymology.

Named after the type locality in Longsheng County, Guilin City, Guangxi. Treated as a Latinized adjective in nominative case. Its Chinese common name is “ 龙胜小头蛇 ” (Pinyin: Lo ́ ng She ̀ ng Xia ̌ o To ́ u She ́). In addition, since this species has long lacked a formal English name, we propose the name “ Longsheng Kukri Snake ” based on its type locality and specific epithet.

Conservation status.

Oligodon lungshenensis was previously assessed as Near Threatened (NT) on the IUCN Red List (Zhou et al. 2012). Our updated and verified distributional data indicate that the species has a broader range than previously assumed. GeoCAT analysis yielded an EOO of 369,331.6 km 2 and an AOO of 42,500.0 km 2. Accordingly, we recommend that the conservation status of O. lungshenensis be revised to Least Concern (LC).