Ahaetulla laudankia, Deepak & Narayanan & Sarkar & Dutta & Mohapatra, 2019

Deepak, V., Narayanan, Surya, Sarkar, Vivek, Dutta, Sushil K. & Mohapatra, Pratyush P., 2019, A new species of Ahaetulla Link, 1807 (Serpentes: Colubridae: Ahaetullinae) from India, Journal of Natural History 53 (9), pp. 497-516 : 501-512

publication ID	https://doi.org/ 10.1080/00222933.2019.1589591
DOI	https://doi.org/10.5281/zenodo.3680418
persistent identifier	https://treatment.plazi.org/id/321C6834-FF84-3D3F-FE23-131BFD65FEC3
treatment provided by	Valdenar
scientific name	Ahaetulla laudankia
status	sp. nov.

Treatment

Ahaetulla laudankia sp. nov.

Dryophis mycterizans – Sclater (1891) [in part]

Ahaetulla nasuta isabellinus – Dutta et al. (2009)

Proposed standard English name: Laudankia vine snake

Holotype. ZSI-CZRC-6403, adult female, Bangriposi, Mayurbhanj district , Odisha state (22.142167N, 86.520025E), collected by Manoj V. Nair and S. K. Dutta, 15 June 2010. GoogleMaps

Paratypes (2). ZSI-CZRC-6404, adult male, Nilagiri, Balasore district, Odisha state (21.471232N, 86.634096E), collected by Vivek Sarkar, 15 March 2013 GoogleMaps ; ZSI-R-26412 ( Figure 4 View Figure 4 ), subadult male, Madhapur, along Khajuriakata-Madhapur road, Harabhanga Tehsil, Boudh District , Odisha state (20.442518N, 84.503152E), collected by Pratyush P GoogleMaps . Mohapatra on 5 May 2009.

Diagnosis

A medium-sized Ahaetulla (largest TL 1184 mm (male), 1237 mm (female)) with dermal appendage; 192 – 202 ventrals, 154 – 185 divided subcaudals; 8 teeth on maxilla and 9 on palatine; dorsal scale reduction from 15 to 13 rows occurs between ventrals 143 – 147; ochre brown/chestnut brown dorsum with black spots, paler supralabials, white lower lip, and light orange/brick red venter with a pair of whitish line on both sides of the mid venter.

Morphologically, Ahaetulla laudankia can be distinguished from all its congeners except Ahaetulla nasuta sensu lato (see discussion), A. pulverulenta and A. anomala in having a long dermal appendage (vs. snout without dermal appendage) ( Figure 5 View Figure 5 ).

Ahaetulla laudankia differs from A. nasuta sensu lato in having a higher number of ventrals: explicitly – 192 – 202 (vs. 168 – 184 in A. nasuta from Sri Lanka (both with long and short dermal appendages); vs. 171 – 181 in A. nasuta from India (both with long and short dermal appendages); 169 – 181 in A. nasuta cf isabellina (see discussion), and 168 ventrals in Wall ’ s type of Dryophis mycterizans isabellinus = A. nasuta isabellina ) ( Tables 2 View Table 2 , 3 View Table 3 and S4).

Ahaetulla laudankia can be distinguished from A. pulverulenta in having its dermal appendage formed by a single scale with mid-dorsal groove (vs. dermal appendage formed by multiple scales without mid-dorsal groove), and dermal appendage shorter than horizontal eye diameter (vs. dermal appendage longer than horizontal eye diameter).

Ahaetulla laudankia differs from A. anomala in having a higher number of ventral scales – 192 – 202 (vs. 170 – 189); dermal appendage formed by a single scale (vs. multiple scales) and coloration – adults of both sexes have a brown dorsum speckled with black and brick-red ventrals (vs. brown adult females and green adult males) and in having an un-patterned head (vs. head with a black rhomboidal pattern).

Based on scale reduction, Ahaetulla laudankia can be distinguished from A. nasuta sensu lato (both morphs with long or short dermal appendages from Sri Lanka as well as India), A. nasuta cf. isabellina and A. anomala . In A. laudankia scale reduction from 15 to 13 rows occurs between ventrals 143 – 147 in four out of five specimens examined by us ( Table 3 View Table 3 ) vs. 110 – 127 in A. nasuta with long dermal appendage and 121 – 137 in A. nasuta with a short dermal appendage from India; vs. 117 – 120 in A. nasuta with long dermal appendage and 119 – 132 in A. nasuta with short dermal appendage from Sri Lanka; vs. 110 – 128 in A. nasuta cf. isabellina and vs. 119 – 129 in A. anomala .

Description of holotype (ZSI-CZRC-6403). ( Figure 3 View Figure 3 ; Table 3 View Table 3 ). A medium sized snake (maximum recorded TL 1237 mm), ochre-brown dorsum speckled with black dots, brick-red ventral scales, tail 32.4% of the TL. Specimen partially dehydrated; 7 cm longitudinal ventral incision into coelom at 500 mm from snout tip. Body subtriangular, slightly flatten on venter, widest at midbody, gently tapering anteriorly and sharply tapering posteriorly; tail much more strongly tapered; head broader (11.9 mm) than tall (7.9 mm), distinctly wider than neck.

In dorsal view, head elongate and triangular anterior to eye, ends with an elongated dermal appendage; temporal region gently converging posteriorly; in lateral view, head steeply tapering downwards from eye to nostril; scales on top of head smooth, abutting along midline rather than imbricate/overlapping. Length of dermal appendage smaller (2.1 mm) than horizontal eye diameter (4.7 mm) and 6% of head length (HL 34.0 mm); canthus rostral is prominent; nostrils situated anteriorly to snout, closer to snout than eye (EN 7.1 mm, NS 6.2 mm); nasals elongate and roughly lanceolate (6.1 mm), nostril squarish located on posterior end of nasal scale; frontal rhomboidal, longer than wide, wider anteriorly (FL 7.9 mm, FW 4.5 mm); parietals longer than supraocular, smaller than frontal scale and longer than prefrontals (PAL 7.1 mm, SOL 6.1 mm); left supraocular tapering down completely touching first temporal, on the right supraocular not touching the first temporal; PrF length almost equal to IN (PrFL 4.9 mm, INL 5.1 mm). One preocular and two presuboculars, lower right presubocular smaller than postocular; left postocular smaller than both presuboculars.

Eight supralabials; 6th largest, 8th longest and 4th smallest; 1st, 2nd and 3rd SL subequal, small; 5th and 7th SL subequal but of different shapes; 1st SL touches rostral, nasal and internasal; 2nd touches internasal and prefrontals; 3rd contacts first two preoculars and prefrontals; 4th SL in contact with both preoculars while 5th touches orbit, postocular and anterior temporal; 6th contacts anterior and lower posterior temporal and 7th in touch with lower posterior temporal. Eye oval, pupil elongate (long horizontal axis); temporals 1 + 2 + 2; second pair upper temporal largest on both sides; parietals larger than other head scales; midline inter-parietal suture much longer than parietal projection behind suture, shorter than frontal; left parietal contacts frontal, supraocular, anterior, second and upper third temporal plus three other scales; right parietal contacts postocular and only two other scales instead of three. Mental small, subtriangular, wider than long; 8 asymmetric infralabials; first ILs touching each other; fifth largest; 2nd IL smallest and 5th longest. Two pairs of genials; first pair largest, longer than broad, touching each other; second pair not in contact; anterior genials contact 1st to 4th IL; posterior genials contact 4th and 5th IL. Six pre-ventrals; anteriormost ventral separated from posterior genials by 6 scales; separated from posteriormost infralabials by 8 scales. Anal scale divided, right overlapping left; 194 ventrals; 154 divided subcaudals, first pair notably smaller and less regular than second pair; terminal scute pointed, longer than wide. Dorsal scale rows 15-15-13. Scale reduction formula is as follows:

3 + 4 (145)

15(10)––––––- 13 (194)

4 + 5 (147)