Cyrtodactylus nagalandensis, Agarwal & Mahony & Giri & Chaitanya & Bauer, 2018

Agarwal, Ishan, Mahony, Stephen, Giri, Varad B., Chaitanya, R. & Bauer, Aaron M., 2018, Six new Cyrtodactylus (Squamata: Gekkonidae) from northeast India, Zootaxa 4524 (5), pp. 501-535 : 528-531

Cyrtodactylus nagalandensis sp. nov.

Figs. 9 and 18–20 .

Holotype. Adult female ( BNHS 2253 , field number CES09/1233) collected from near Khonoma village , Kohima district, Nagaland state, India (25.65818°N, 94.02142°E, 1450 m asl.) by Ishan Agarwal on 23 October 2009.

Paratype. Adult female ( BNHS 2254 ) bears the same collection information as holotype .

Etymology. This is the first endemic gecko from Nagaland, and the specific epithet is a toponym for the state.

Diagnosis. Cyrtodactylus nagalandensis sp. nov. can be distinguished from all congeners by its moderate body size (SVL to at least 72.0 mm); 10–12 supralabials; 8–10 infralabials; 16–18 longitudinal rows of rounded, conical, feebly keeled dorsal tubercles; tubercles extending posteriorly to third tail segment; 35–37 paravertebral tubercles; 34 or 35 ventral scales between ventrolateral folds; no precloacal groove; six depressions in precloacal series but no precloacal or femoral pores on females, male condition unknown; 16 total subdigital lamellae beneath toe IV of pes; subcaudal scalation of original tail with paired enlarged subcaudals not forming median plates; dorsal pattern of indistinct light and dark blotches forming longitudinal markings on neck and forebody; tail with alternating dark and lighter bands.

Description of holotype. Holotype in good preservation condition: tail tip removed for tissue voucher, tail curved towards left, with folds of skin along either side of ventrolateral aspect; constriction around midbody due to overzealous tag tying, toes on left and right pes recurved; all artifacts of preservation. Adult female, SVL 72.0 mm. Head long (HL/SVL 0.30), slightly wide (HW/HL 0.70), dorsoventrally depressed (HD/HW 0.59), distinct from neck; loreal region inflated, interorbital region flat, canthus rostralis not prominent; snout short (SE/HL 0.40), twice as long as orbital diameter (ED/SE 0.50); scales on snout and canthus rostralis granular, juxtaposed, homogenous in shape, with scales on snout being slightly larger; scales on interorbital region, forehead and occipital region slightly smaller, granular, juxtaposed; forehead and occipital region interspersed with larger tubercles that are rounded, smooth and two to four times the size of adjacent granules; enlarged tubercles smallest on anterior and central parietal regions, increasing in size laterally and posteriorly. Eye small (ED/HL 0.20); pupil vertical with crenulated margins; supraciliaries roughly triangular, pointed, decreasing in size towards posterior and anterior ends of orbit, largest about one-third the way from anterior edge of orbit; dorsal surface of eyelid primarily covered with small granular scales except a single row of granular scales bordering anterior supraciliaries are enlarged relative to adjacent granular scales. Ear opening oval, obliquely oriented; eye to ear distance almost twice diameter of eye (ED/EE 0.60). Rostral wider (2.7 mm) than deep (1.8 mm), partially divided dorsally by a weakly developed rostral groove; single enlarged rounded supranasals on either side, separated by a smaller, roughly hexagonal internasal scale which is about three times size of granules on snout; rostral in contact with supralabials I, nostrils, supranasals and a single internasal; nostrils oval, laterally oriented, posterior half covered by a conspicuous nasal pad, each in broad contact with rostral and surrounded by supranasal, supralabial I, and four smaller granular postnasal scales; one to three rows of granular scales separate orbit from supralabials; mental wider (3.1 mm) than long (1.8 mm), triangular, two pairs of well-developed postmentals on either side, inner pair in broad contact (0.9 mm) with each other posteriorly behind mental, inner pair larger (1.8 mm) than and separating outer pair (1.2); each inner postmental bordered by mental, infralabial I, outer postmental and a row of four or five gular scales of similar size to other gulars; outer postmentals each bordered by inner postmental, infralabials I and II, a large, roughly hexagonal scale posteriorly and four or five gular scales; eight supralabials to midorbital position and 10 to angle of jaw on each side, bordered by a row of flat, somewhat elongated scales slightly larger than their adjacent granules; infralabials, 10 on right side and eight on left side, infralabials II to V bordered by a row of enlarged scales, anteriormost largest.

Body slender (BW/TRL 0.4), short (TRL/SVL 0.50); dorsal scales heterogeneous with mostly rounded granules, intermixed with irregularly arranged enlarged tubercles, rounded, conical, feebly keeled, decreasing in size towards vertebral region; tubercles extend anteriorly to interorbital region; tubercles on nape smaller than those of dorsum; dorsal tubercles in 16 or 17 longitudinal rows at mid-dorsum; 35 paravertebral tubercles; a distinct ventrolateral fold on either side covered by a series of slightly enlarged, flat, granular scales; ventral scales much larger than dorsals, smooth, cycloid, subimbricate; a row of enlarged subimbricate scales along posterior border of precloacal pores; 36 ventral scales between ventrolateral folds; gular region with much smaller, granular scales throughout except for one or two rows originating from posterior margin of outer postmentals bordering infralabials, which are larger, flat and juxtaposed. A continuous series of six enlarged precloacal scales each with a shallow depression, precloacal and femoral pores absent, no precloacal groove.

Fore and hind limbs slender; forearm (FL/SVL 0.20) and tibia (CL/SVL 0.20) short; digits short, strongly inflected at each joint, all bearing robust recurved claws that are slightly longer than their associated claw sheath; five subdigital lamellae in basal series and seven in distal series with four non-lamellar granules at inflection (digit IV, right manus); five basal and 11 distal lamellae with one non-lamellar granule at inflection (digit IV, right pes); slight inter-digital webbing between toes I–III, absent between fingers; relative length of digits: I <II <V <III <IV (right manus) and I <II <V <III <IV (right pes); scales on palms and soles smooth, flat, juxtaposed, with those on soles being slightly larger; scales on fore limbs heterogeneous, composed of large, rounded, granular, juxtaposed scales becoming flatter, smooth and subimbricate anteriorly; granules of upper arms larger than those on forearms, sparsely interspersed with slightly enlarged rounded tubercles; ventral portion of fore limbs covered mostly with flat, granular, juxtaposed scales; scales on hind limbs heterogeneous, dorsal part of thighs and shanks with small, rounded, granular scales, scattered densely with rounded, enlarged, feebly keeled tubercles; ventral aspect of hind limbs with enlarged, smooth, subimbricate scales.

Tail original with tip removed, somewhat rounded, slender, tapering, divided into indistinct segments; eight rows of enlarged, sub-trihedral, strongly keeled tubercles on tail base; approximately four rounded, flattened tubercles form a transverse row at posterior border of each of first three segments; remaining dorsal caudal scales smooth, rounded, subimbricate, similar in size dorsally getting slightly larger on lateral aspect; subcaudal scales larger, smooth, imbricate; a distinct mid-ventral series comprising of two large scales; enlarged smooth post cloacal spurs, three on left side and two on right side.

Colouration in life ( Fig. 18 ). Dorsal ground colour of head, body, limbs and tail buff-brown; top of head with numerous dark spots; labials strongly suffused with yellow; a dark postorbital streak that extends beyond ear opening; neck and back with black spots that form longitudinal markings on neck and forebody; limbs with indistinct darker bars and spots; 11 dark and 10 light caudal bands, dark bands more than twice as wide as light bands; rest of ventral surfaces immaculate; iris green-grey with dark reticulations, pupil bordered by orange-red

Colouration in preservative ( Figs. 19 & 20 ). Dorsal ground colour of head, body, limbs and tail buff-brown; top of head with numerous dark spots; labials suffused with lighter markings; a dark postorbital streak that extends beyond ear opening; neck and back with black spots that form longitudinal markings on neck and forebody; limbs with indistinct darker bars and spots; 11 dark and 10 light caudal bands, dark bands more than twice as wide as light bands; rest of ventral surfaces immaculate except some mottling toward flanks.

Variation ( Fig 9 ). Female paratype (BNHS 2254) similar to holotype in general colouration but with less distinct longitudinal markings on neck; 10 dark bands on tail. Refer to Table 4 for further variation.

Distribution and Natural History. Cyrtodactylus nagalandensis sp. nov. is known only from the vicinity of Khonoma village, in the Naga Hills. The type series was collected from a road cutting after dark. We only saw two specimens of this species in two nights of searching. The surrounding forest habitats were mainly secondary forest.

Comparisons. Cyrtodactylus nagalandensis sp. nov. is a member of the mountain clade and is poorly supported as sister to the other Indian species in this clade, with uncorrected p- distance between the new species and other members of the clade 18.0–21.7%. Cyrtodactylus nagalandensis sp. nov. can be diagnosed by the number of ventral scales (36 or 37 MVSR) from C. brevidactylus (45 MVSR), and Cyrtodactylus jaintiaensis sp. nov. (40–42 MVSR); by having fewer dorsal tubercle rows (16–18) from C. gansi (20–25 DTR) and Cyrtodactylus montanus sp. nov. (21–23 DTR); by its irregular dorsal colour pattern from C. chrysopylos (dorsal pattern of alternating brown and white bands). Major diagnostic characters for the new species and regional congeners are summarized in Table 3.

Figures

FIGURE 9. Paratypes of the new species described in this paper. From left to right, top panel: Cyrtodactylus kazirangaensis sp. nov. (BNHS 2147, 2149), Cyrtodactylus jaintiaensis sp. nov. (BNHS 2246), Cyrtodactylus montanus sp. nov. (BNHS 2234), and Cyrtodactylus jaintiaensis sp. nov. (BNHS 2247); bottom panel: Cyrtodactylus nagalandensis sp. nov. (BNHS 2254), Cyrtodactylus septentrionalis sp. nov. (BNHS 1989), and Cyrtodactylus montanus sp. nov. (BNHS 2231–2233).

FIGURE 18. Cyrtodactylus nagalandensis sp. nov. in life (adult female holotype, BNHS 2253).

FIGURE 19. Dorsal view (A), ventral view (B), and details of dorsal pholidosis (C) of adult female holotype (BNHS 2253) of Cyrtodactylus nagalandensis sp. nov. Scale bars 10 mm.

FIGURE 20. Head of Cyrtodactylus nagalandensis sp. nov. (adult female holotype, BNHS 2253), dorsal (A), lateral (B), and ventral (C) view. Scale bars 10 mm.