taxonID	type	description	language	source
CB89E7D293A0506CAD2E70828E40EEA5.taxon	description	Table 1, Figs 3, 4, 5 В, C, Suppl. material 1: fig. S 3 A	en	Grassby-Lewis, Rupert J., Brakels, Peter, Maury, Nathanaël, Sitthivong, Saly, Frohlich, David, Pawangkhanant, Parinya, Idiiatullina, Sabira S., Nguyen, Tan Van, Poyarkov, Nikolay A. (2025): A new endemic karst-associated species of lance-headed pit viper (Squamata, Viperidae, Protobothrops) from Laos. Herpetozoa 38: 43-60, DOI: 10.3897/herpetozoa.38.e146004
CB89E7D293A0506CAD2E70828E40EEA5.taxon	etymology	Etymology. The specific name “ flavirostris ” is a Latin adjective in the nominative singular, masculine gender, derived from Latin words “ flāvus ” for “ yellow ” and “ rostrum ” for “ snout ” or “ beak ” and is given in reference to the characteristic yellowish colouration of the snout in the new species. We suggest the following common names for the new species: “ Vang Vieng lance-headed pit viper ” (in English), “ Ngu Phao Ka Ba Khor Kop ” (“ ງ ູ ເພ ົ າກະບາຄ ໍ ກ ົ ບ ”, in Lao) and “ Laosskiy habu ” (“ Лаосский хабу ”, in Russian). Furthermore, the new species is well-known to the Hmong people living in village communities around Vang Vieng and their local name for this species is “ nan jaow ka, ” which is roughly translated as “ a snake that can open its mouth very wide ” or “ big-mouthed snake ”.	en	Grassby-Lewis, Rupert J., Brakels, Peter, Maury, Nathanaël, Sitthivong, Saly, Frohlich, David, Pawangkhanant, Parinya, Idiiatullina, Sabira S., Nguyen, Tan Van, Poyarkov, Nikolay A. (2025): A new endemic karst-associated species of lance-headed pit viper (Squamata, Viperidae, Protobothrops) from Laos. Herpetozoa 38: 43-60, DOI: 10.3897/herpetozoa.38.e146004
CB89E7D293A0506CAD2E70828E40EEA5.taxon	diagnosis	Diagnosis. The new species Protobothrops flavirostris sp. nov. differs from other members of the genus Protobothrops by the following combination of the morphological characters: dorsal scales in 23 – 21 – 17 rows, all keeled; ventral scales 215; subcaudal scales 79, all paired; supralabials 7 – 8; infralabials 10; horn-like projection on supraocular absent; head triangular with a typical lance-shaped pattern on dorsal surface; three faint dark vertical stripes on snout; head blackish-brown with rostral, nasals, preoculars, loreals and the two anterior supralabials, as well as the anterior parts of supraoculars yellow-orange; dorsal surfaces of body and tail brown or greyish-brown, dorsum with large dark reddish-brown cross-shaped blotches, edged with black, somewhat fused together forming an interrupted zigzag line; and a row of large brown ventrolateral blotches on each side.	en	Grassby-Lewis, Rupert J., Brakels, Peter, Maury, Nathanaël, Sitthivong, Saly, Frohlich, David, Pawangkhanant, Parinya, Idiiatullina, Sabira S., Nguyen, Tan Van, Poyarkov, Nikolay A. (2025): A new endemic karst-associated species of lance-headed pit viper (Squamata, Viperidae, Protobothrops) from Laos. Herpetozoa 38: 43-60, DOI: 10.3897/herpetozoa.38.e146004
CB89E7D293A0506CAD2E70828E40EEA5.taxon	description	Description of the holotype. Adult female (Figs 3, 4), specimen in a good state of preservation. Body elongate, thin and slightly compressed (SVL 688 mm, TaL 137 mm, TL 825 mm; TaL / TL ratio 0.17) (Fig. 3 A, B). Head triangular in dorsal view (Fig. 3 E), elongated, clearly distinct from the neck (HL 25.4 mm, HW 16.2 mm, HD 10.2 mm; HW / HL ratio 0.64); covered with small, convex and irregularly-shaped scales (Fig. 3 E). Snout elongate, dorsally flattened and rounded in dorsal view (Fig. 3 E), rather rectangular in lateral view (Fig. 3 C, D), with a distinct and sharp canthus rostralis (SnL 7.9 mm, IN 5.4 mm, NL 3.0 mm). Eyes medium-sized (ED 3.5 mm, EN 5.7 mm; ED / EN ratio 0.61). Rostral triangular, barely visible in dorsal aspect (Fig. 3 E). Pupil vertically elliptical. Loreal pit present, large, triangular in shape, located closer to eye than to nostril (Fig. 3 C, D). Nostril vertical, elliptical, completely enclosed in nasal scale, with a short complete suture dividing the ventral part of nasal just below nostril (Fig. 3 C, D). Nasal scale separated from first supralabial by a complete suture (Fig. 3 C, D). Subocular long, thin, crescent-like, separated from the fourth supralabial by a single scale and separated from the fifth supralabial by 2 / 2 scales (Fig. 3 C, D). Three preoculars on each side of the head; two upper preoculars located dorsally of the loreal pit; first preocular short, rectangular; second preocular elongated, bordering the dorsal margin of loreal pit; the first upper preocular in contact with the posterior loreal; the second upper preoculars in contact with the anterior and posterior loreals, which separate it from the nasal; lower preocular triangular, elongated, forming the ventral margin of the loreal pit; lower preocular in contact with subocular, third and second supralabials (Fig. 3 C, D). A small elongated, rectangular scale between nasal and second supralabial, also in contact with anterior loreal and first supralabial (Fig. 3 C, D); 2 / 2 postoculars; 8 / 7 supralabials, third the largest (Fig. 3 C, D); 10 / 10 infralabials, those of the first pair in contact with each other behind the triangular mental; the first two pairs of infralabials in contact with the single pair of chin shields (Fig. 3 F). Four pairs of gulars aligned between the chin shields and the first preventral (Fig. 3 F). One pair of enlarged internasals, not in contact with rostral and separated from each other by two small scales (Fig. 3 E). One large supraocular, with 7 – 8 small scales along the transverse line between supraoculars (Fig. 3 E). Scales on snout and in the interorbital region smooth, irregular, subimbricate; temporal and occipital scales feebly keeled (Fig. 3 E, F). Dorsal scales in 23 – 21 – 17 rows, all of them narrow, pointed and strongly keeled in single and straight keels, including the first row. One preventral and 215 ventrals. Cloacal plate single; 79 subcaudals, all divided (Fig. 3 B).	en	Grassby-Lewis, Rupert J., Brakels, Peter, Maury, Nathanaël, Sitthivong, Saly, Frohlich, David, Pawangkhanant, Parinya, Idiiatullina, Sabira S., Nguyen, Tan Van, Poyarkov, Nikolay A. (2025): A new endemic karst-associated species of lance-headed pit viper (Squamata, Viperidae, Protobothrops) from Laos. Herpetozoa 38: 43-60, DOI: 10.3897/herpetozoa.38.e146004
CB89E7D293A0506CAD2E70828E40EEA5.taxon	distribution	Distribution and natural history notes. Currently, Protobothrops flavirostris sp. nov. is known only from three limestone caves within the Vang Vieng karstic massif (Fig. 5 A), namely Khan Kham Cave, Nang Oua Khiam Cave and Loup Caves, all located within the Vang Vieng District, Vientiane Province, Laos. Though at present the species can be considered microendemic to a narrow area in Vang Vieng karsts, its occurrence in the adjacent limestone karst formations in other provinces of north-western Laos, such as Xayabury, Luang Prabang and Xaysombom Provinces, cannot be excluded. Protobothrops flavirostris sp. nov. was recorded at low elevations (200 – 400 m a. s. l.) in limestone massifs covered by karst forest or within the caves. Protobothrops flavirostris sp. nov. is nocturnal; the holotype was collected at 21 h 15, although all individuals seen within caves were observed during the daytime hours. All four known observations of the new species are from within caves on limestone karst formations or at the base of limestone karst formations. All four individuals were observed climbing on limestone rocks, stalactites / stalagmites or cave walls. The holotype specimen would constantly anchor itself to anything possible using its tail and was very agile while climbing. Hereby, we identify the new species as a specialised limestone-dwelling rupicolous ecotype, spending most of its life climbing or resting amongst steep limestone rocks and hiding in their crevices. The diet of the new species is not reliably known, though it may include the local species of bats (Chiroptera), as the species was only recorded in the caves with remnant bat colonies. Bent-toed geckos (primarily Cyrtodactylus pageli Schneider, Nguyen, Schmitz, Kingsada, Auer & Ziegler) were abundant within these same caves and on the adjacent limestone karst formations, so it is possible that it also predates on geckos. Other species of amphibians and reptiles recorded at the same habitat in the type locality during our survey included Microhyla mukhlesuri Hasan, Islam, Kuramoto, Kurabayashi & Sumida, Micryletta cf. menglienica (Yang & Su), Kaloula pulchra Gray, Sylvirana cf. menglaensis (Fei, Ye & Xie), Polypedates megacephalus Hallowell, Gracixalus sp., Rhacophorus kio Ohler & Delorme, Acanthosaura cf. rubrilabris Liu, Rao, Hou, Orlov, Ananjeva & Zhang, Cyrtodactylus pageli, Gehyra mutilata (Wiegmann), Ahaetulla prasina (Boie), Lycodon davidi Vogel, Nguyen, Kingsada & Ziegler, L. davisonii (Blanford), L. neomaculatus Nguyen, Lee, Pauwels, Kennedy-Gold, Poyarkov, David & Vogel, Bungarus fasciatus (Schneider), Trimeresurus macrops Kramer and T. guoi Chen, Shi, Vogel & Ding.	en	Grassby-Lewis, Rupert J., Brakels, Peter, Maury, Nathanaël, Sitthivong, Saly, Frohlich, David, Pawangkhanant, Parinya, Idiiatullina, Sabira S., Nguyen, Tan Van, Poyarkov, Nikolay A. (2025): A new endemic karst-associated species of lance-headed pit viper (Squamata, Viperidae, Protobothrops) from Laos. Herpetozoa 38: 43-60, DOI: 10.3897/herpetozoa.38.e146004
