Gloydius hazarensis sp. nov.

Proposed common names.

Hazara Pitviper (English), हज ़ ा र ा प ि ट व ा इपर (Hazārā Pi ṭ Vāipar; Hindi) and ہزارہ گڑھے والا سانپ (Hazara gaday wali afee; Urdu).

Type material.

Holotype. • UF 70652 (field no. SRT 4283), an adult female from Naran town, Mansehra District, Khyber Pakhtunkhwa, Pakistan, 34.9061°N, 73.6494°E, 2375 m altitude, collected on 11 July 1975 by Sam Rountree Telford Jr. (Fig. 18). Paratypes. • NHMW 17078: 1, adult male from Murree, Murree District, Punjab Province, collected in 1878 by the Moravian-Austrian zoologist Ferdinand Stoliczka; UF 70656–70657 (field nos. SRT 5162 –5163), adult females, other data as for the holotype; UF 82634, adult female from Nathia Gali, Abbottabad District, Khyber Pakhtunkhwa, Pakistan, 34°04'N, 73°23'E, ~ 2400 m altitude, collected on 14 July 1986 by Walter Auffenberg.

Description of the holotype.

Adult female, indicated by the absence of hemipenes; 1 / 1 loreal, as high as wide; nasal partially divided below naris; 3 / 3 elongated preoculars, the lowest is the narrowest; 1 / 1 supraocular; 2 / 2 postoculars, upper reaching onto top of head and touching the parietal, the lower can be described as postsubocular, because it extends under the eye, up to the level of the posterior border of the third supralabial; rostral scale wider than high; two internasals wider than long; two prefrontals, wider than long; a small oval scale between posterior end of prefrontal suture and frontal; frontal trapezoidal, as long as wide, anterior edge wider than posterior; 2 / 3 anterior temporals, upper significantly smaller than the lower one, and 3 / 2 posterior temporals, the lower one slightly larger than upper and in contact with the second last supralabial; supralabials 7 / 7, second last two and a half times higher than the previous one, in contact with lower posterior temporal, 3 rd / 3 rd in contact with the eye; pit opening shorter than horizontal diameter of eye and encircled by 3 / 3 scales; 15 circum-pileus scales; 10 / 10 sublabials, first four in contact with anterior submaxillars; two pairs of submaxillars, anterior nearly twice as wide and 50 % longer than posterior; followed by four rows of paired gular scales, increasing in size posteriorly; dorsal scales in 21-20 - 17 rows, strongly keeled, except the outer row, which is only very slightly keeled, paired apical pits on some dorsals, very weakly developed; three preventrals; 163 ventrals; cloacal plate entire; 40 / 41 paired subcaudal scales. Body compact, subcylindrical; tail short (TaL / TL 0.123); SVL 400 mm; TaL 56 mm, head length measured from tip of snout to posterior border of parietals 13.7 mm, head length measured from tip of snout to posterior edge of mandible 20.3 mm, head width 11.3 mm.

Dorsal scale reduction formula.

Dentition.

Maxillary bone with two posteriorly curved fangs on each side. On both sides the medial fang is not connected to the maxilla. Behind the main fangs are 5 / 6 replacement fangs at different growth stages. Main fang 3.98 mm in length, i. e., 24.1 % of skull length. Discharge orifice 0.76 mm in length, i. e., 19.1 % of fang length. Palatine bone with 4 / 3 posteriorly curved teeth slightly decreasing in size posteriorly. Teeth one and three loose on left, all teeth loose on right side. Lateral to each palatine tooth is a single replacement tooth at different growth stages. Pterygoid bone with 9 / 9 posteriorly curved teeth, shorter than the palatine tooth, all nearly the same size. Teeth II, V, VII and IX loose on left side. Teeth I, II, IV, VI and VIII loose on right side. The posterior 60.8 % of the pterygoid bone is without teeth. Mandibular bone with 12 / 12 posteriorly curved teeth gradually decreasing in size posteriorly. The first two teeth closer together than the rest. Medial to each mandibular tooth are up to two replacement teeth in different growth stages. Teeth I, III, V, VII, IX, XI and XII loose on left side. Teeth I, III, V, VII, IX and XI loose on right side. Splenial and angular bones are fused. The total length of splenial-angular complex spans 27.0 % of the mandibular bone. The dental is 36.4 % as long as the mandibular bone. The complete skull of the holotype UF 70652 is presented in Fig. 19.

Colouration and pattern.

Colouration after ~ 50 years preservation in ~ 70 % ethanol was recorded as follows: dorsal ground colour Pale Neutral Gray (Colour 296), with 34 Olive-Brown (278) coloured dorsolateral roundish blotches that are 4–6 dorsal scales wide and show a light Pale Neutral Gray (296) centre; most blotches open vertebrally and ventrolaterally or the lower outer edges disintegrate and form a ventrolateral row of small spots; below that a row of small, irregular Olive-Brown (278) coloured spots runs along the outer edge of the ventrals; dorsal tail with five irregular blotches in the same colouration as on the body; dorsal head Pale Neutral Gray (296) coloured and densely Olive-Brown (278) mottled; loreal and upper temporal region of head Pale Neutral Gray (296) with dense Olive-Brown (278) mottling; a wide Light Neutral Gray (297) postocular stripe from the posterior border of the eye to the posterior edge of the mandible, whose lower edge is bordered by a Dark Grayish Brown (284), wavy narrow line; lower parts of posterior supralabials Cream White (52) with Sepia (279) speckles; lower labials with Sepia (279) coloured markings on their sutures; venter with a colour gradient that becomes darker towards the tail; throat Pale Neutral Gray (296) coloured with dense Sepia (279) mottling; in the further course, venter ground colour changes gradually to Medium Neutral Gray (298) and shows a very dense Sepia (279) mottling; tail tip Drab-Gray (256) coloured. Examples of variation in the colouration and pattern of live individuals; see Fig. 20.

Variation.

The paratypes and other examined material agree well with the holotype in general appearance. For differences based on sexual dimorphism, morphometrics and scalation we refer to Tables 3, 4, 7.

Sum formula of dorsal scale reduction in males.

Sum formula of dorsal scale reduction in females.

Variation in dentition.

Maxillary bone with two posteriorly curved fangs on each side. Main fang 3.98–5.99 mm in length, i. e., 24.1–29.2 % of skull length. Discharge orifice 0.76–1.17 mm in length, i. e., 14.7–22.3 % of fang length. Palatine bone with 3–5 posteriorly curved teeth slightly decreasing in size posteriorly. Pterygoid bone with 8–11 posteriorly curved teeth, shorter than the palatine tooth, all nearly the same size. The posterior 56.3–61.6 % of the pterygoid bone is without teeth. Mandibular bone with 11 or 12 posteriorly curved teeth gradually decreasing in size posteriorly. The first two teeth closer together than the rest. Splenial either 94.3 % of length of angular or fused. The total length of splenial-angular complex spans 24.2–27.2 % of the mandibular bone. The dental is 34.6–37.3 % as long as the mandibular bone.

Variation in colouration and pattern.

Dorsal ground colour can darken considerably into Sepia (279) during preservation, so that the dorsal pattern elements of the head and body are no longer recognisable; number of dorsolateral blotches can vary from 29–34 on body and from 5–7 on tail.

Etymology.

The specific epithet hazarensis is a latinised adjective referring to the Hazara region of northeastern Pakistan, where the new species was discovered, where its type locality lies, and where it is currently known to occur. This region lies between the Indus River to the west, the foothills of the western Himalaya to the east, and the Karakoram to the north, which together create natural barriers. It includes the Pakistani districts of Abbottabad, Mansehra, Haripur, Battagram, Torghar, Kohistan (east of the Indus River) in Khyber Pakhtunkhwa Province, and is characterised by rugged montane landscapes, river valleys, and rich temperate forests. The name highlights the geographic origin of the species and reflects the ecological distinctiveness of this transitional zone between the Indo-Gangetic Plains and the western Himalayan biodiversity corridor (Khan 2006). The term should not be confused with the ethnically defined " Hazara " region of central Afghanistan (Hindu Kush), as the two are geographically and culturally distinct. The name was previously used for example for the endemic frog of the region, Rana (Paa) hazarensis Dubois & Khan, 1979 (today Nanorana hazarensis) or for an invalid subspecies of the Black-spined toad, Bufo melanostictus hazarensis Khan, 2001, today in the synonymy of Duttaphrynus melanostictus (Schneider, 1799).

Distribution.

According to the data presented here, the western range limit of the species is likely defined by the Upper Indus Valley, which separates the Hindu Kush from the western Himalaya (Fig. 9). The northern boundary is probably formed by the Karakoram Range, while the southern limit appears to be the Indus Plains, south of Murree in Punjab Province, Pakistan. The eastern distribution remains unclear. Gloydius hazarensis sp. nov. is so far only reported from northern Pakistan. Records are known from the districts of Kolai Palas, Mansehra, and Abbottabad in the Khyber Pakhtunkhwa Province, from the districts of Murree and Rawalpindi in the Punjab Province and from the districts of Neelam, Poonch and Bagh of the Azad Jammu and Kashmir, Pakistan-administered region (own data and Blanford 1878; Unwin in Lawrence 1895; Fenton 1910; Telford 1980; Khan and Tasnim 1986; Gloyd and Conant 1990; Showler 1998; Masroor 2017; Shabir 2022; Hadi and Junaid 2024; see also Fig. 9 and Suppl. material 1: table SS 3). The species is likely present around the Kashmir Valley; however, more extensive sampling and DNA barcoding are required to delineate the range limits between G. hazarensis sp. nov. and G. chambensis in the area. We estimate the total range of the species to be ca 27,500 km 2.

Habitat and ecology.

Little is known about the habitat and ecology of the species, as it was previously classified under G. himalayanus (see Khan and Tasnim 1986; Khan 2006; Masroor 2012). Based on verified locality data, the species occurs at elevations ranging from approximately 1630 m to 2900 m. This elevational range places G. hazarensis sp. nov. within montane to subalpine ecological zones, where climatic conditions are generally cool to cold, with seasonal snowfall and a pronounced monsoon period (see Fig. 20). For example, in Murree hills and surrounding Himalayan foothill regions of Punjab, Pakistan it can be found in moderate to steep slopes, rocky terrain, and a mosaic of forest patches interspersed with grassy clearings and human-altered landscapes in the subtropical pine forest, found between 1000–2000 m. Such habitat is characterised by Pinus roxburghii, which forms the dominant canopy, with an understory comprising Dodonaea viscosa, Carissa opaca, and various grasses, e. g., Cymbopogon jwarancusa. At higher elevations (up to ~ 2900 m), G. hazarensis sp. nov. is found in temperate forests, which are cooler and moister and include a mix of coniferous (Pinus wallichiana, Cedrus deodara, Abies pindrow) and broad-leaved trees (Quercus incana, Aesculus hippocastanum). These forests offer greater structural complexity, higher humidity, and abundant prey, making them ecologically ideal for G. hazarensis sp. nov. Telford (1980) described the species (classified as Agkistrodon himalayanus) from the Kaghan Valley as common on wooded slopes (a large flat granite slab), observed basking in the morning sun. Some encountered specimens seem to be sluggish and docile when disturbed, others try to escape under rocks or into surrounding undergrowth. Showler (1998) reports on specimens referable to the Hazara Pitviper from the Palas Valley and describes sites between 2400 and 2750 m elevation where he found the pitvipers mostly on southern slopes. The slopes consisted mostly of scree and were covered with herbaceous vegetation, grass banks of Ephedra gerardiana and Viburnum cottonifolium shrubs. One specimen he observed near Satoe was in woodland dominated by Picea smithiana with Cedrus deodara, Pinus wallichiana and Acer sp. with sparse ground flora consisting of Viola sp., Galium sp., Fragaria nubicola, Polygonum sp. and ferns. Little is known about the food spectrum of the Hazara Pitviper. Only recently, Hadi and Junaid (2024) reported how they observed this pitviper (classified as G. himalayanus) on a Himalayan white pine (Pinus wallichiana) capturing a small passerine bird, the Rufous-bellied Niltava (Niltava sundara), and devouring it within four minutes. Reproductive data are only reported by Telford (1980) for three gravid females which gave birth to five to six neonates in captivity between the end of August and the beginning of September. At birth, the neonates had an average snout-vent length of 146.9 mm and an average tail length of 24.3 mm. Further research focusing on populations now assigned to G. hazarensis sp. nov. is necessary to better understand its ecological requirements across the species range.

Conservation.

The species is currently unprotected. Existing legal protection applies only to populations previously classified under G. himalayanus. The species is frequently killed by residents (Fig. 20 D).