Cyrtodactylus sanook, Pauwels, Olivier S. G., Sumontha, Montri, Latinne, Alice & Grismer, L. Lee, 2013

Pauwels, Olivier S. G., Sumontha, Montri, Latinne, Alice & Grismer, L. Lee, 2013, Cyrtodactylus sanook (Squamata: Gekkonidae), a new cave-dwelling gecko from Chumphon Province, southern Thailand, Zootaxa 3635 (3), pp. 275-285: 276-280

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Cyrtodactylus sanook

sp. nov.

Cyrtodactylus sanook  sp. nov.

( Figs. 1–6View FIGURE 1View FIGURE 2View FIGURE 3View FIGURE 4View FIGURE 5View FIGURE 6)

Holotype. Adult male (THNHM 22541) collected on 1 st November 2012 by Montri Sumontha from Wat (= Temple) Tham Sanook  and its cave Tham Sanook  , Banna Subdistrict, Muang District, Chumphon Province, southern Thailand.

Paratypes. Two adult males (PSUZC-RT 2012.4 and QSMI 1165), same locality, date and collector as holotype.

Diagnosis. Cyrtodactylus sanook  sp. nov. is distinguished from all other Sunda Shelf Cyrtodactylus  by having the unique combination of a maximum SVL of 79.5 mm; 18–20 longitudinal rows of dorsal tubercles at midbody; a continuous series of enlarged femoral and precloacal scales, no femoral pores, three or four precloacal pores in males (no pores in females), no precloacal groove nor depression; 19–20 subdigital lamellae on 4 th toe; transversally enlarged subcaudal plates; and six or seven irregular pale narrow dorsal bands between limb insertions.

Description of the holotype. SVL 73.8 mm. Head large, moderate in length (HL/SVL 0.30) and wide (HW/ HL 0.62), somewhat flattened (HD/HL 0.37), distinct from neck, and triangular in dorsal profile. Lores concave; frontal and prefrontal regions deeply concave; canthus rostralis rounded; snout elongate (ES/HL 0.42), rounded in dorsal profile. Eye of moderate size (ED/HL 0.21). Ear opening elliptical, very small (EL/HL 0.06), obliquely oriented. Eye to ear distance larger than diameter of eye. Rostral rectangular, deeply divided dorsally, bordered posteriorly by left and right supranasals and internasal, bordered laterally by first supralabials. Nares bordered anteriorly by rostral, dorsally by 2 / 2 supranasals, posteriorly by 4 / 4 granular scales, ventrally by first supralabials; 13 / 14 supralabials, rectangular, extending to just beyond upturn of labial margins, tapering abruptly below midpoint of eye, 1 st supralabial tallest; 10 / 10 infralabials; scales on rostrum and lores larger than granular scales on top of head and occiput, those on canthus rostralis largest; occipital scales intermixed with enlarged tubercles; large, boney frontal ridges bordering orbit confluent with boney, transverse, parietal ridge. Dorsal supraciliaries elongate and smooth. Mental triangular, bordered laterally by 1 st infralabials and posteriorly by left and right trapezoidal postmentals which contact medially for approximately half their length; one row of slightly enlarged, elongate sublabials extending to 5 th infralabial; small, granular, gular scales, abruptly transitioning on throat into large, flat, smooth, imbricate, pectoral and ventral scales.

Body relatively short (AG/SVL 0.45) with moderately defined, atuberculate, ventrolateral folds. Dorsal scales small, granular, interspersed with large, trihedral, regularly arranged, keeled tubercles separated by no more than three granular scales at their base; tubercles extend from occiput to anterior part of tail. Tubercles on occiput and nape relatively small, those on body and anterior part of tail largest; approximately 20 rows of tubercles at midbody; approximately 30 paravertebral tubercles; 27 flat, imbricate, ventral scale rows between ventrolateral body folds, increasing in size towards midline of venter; ventral scales much larger than the dorsal scales. Precloacal scales large, smooth. No precloacal groove. Right hemipenis everted during specimen preservation preparation. Forelimbs moderately robust, relatively short (FL/SVL 0.17). No granular scales on dorsal surface of forelimbs, but slightly keeled, larger, scales. Palmar scales rounded. Digits well-developed, inflected at basal, interphalangeal joints. Subdigital lamellae nearly square proximal to joint inflection, only slightly expanded distal to inflection. Digits more narrow distal to joints. Claws well-developed, sheathed by a dorsal and ventral scale. Hind limbs more robust than forelimbs, moderate in length (TBL/SVL 0.20). Dorsal surface of hind limbs showing granular scales interspersed with large, keeled, trihedral tubercles. Ventral thigh and tibial scales flat, imbricate, smooth. One row of enlarged, flat, imbricate femoral scales extends from knee to knee through precloacal region where it is continuous with enlarged, precloacal scales. The row of enlarged femoro-precloacal scales is V-shaped and includes 15 poreless scales (left leg) + two pored scales + one poreless scale + two pored scales (precloacal region) + 14 poreless scales (right leg), thus a total of 34 femoro-precloacal scales and four precloacal pores. Enlarged femoral scales directly bordered anteriorly by smaller, imbricate, smooth scales, and posteriorly by granular scales. Plantar scales low, slightly rounded. Toes well-developed, inflected at basal, interphalangeal joints; subdigital lamellae proximal to joint inflection nearly square, only slightly expanded distal to inflection. Toes more narrow distal to joints. Claws well-developed, sheathed by a dorsal and ventral scale; 20 / 20 subdigital lamellae on 4 th toe.

Tail original, 104.2 mm in length, 7.2 mm width at base, tapering to a point. Postcloacal scales flat, large, imbricate. Median row of subcaudal scales transversely enlarged. One poorly-developed, lateral postcloacal spur at the base of the hemipenial swelling on the left side, no spur on the right side. Additional morphometrical data on the holotype are provided in Table 1.

Coloration in life. Ground color of body, head, limbs and tail dark brown; dark irregularly shaped markings on rostrum and top of head; wide dark band extending from postnasal region through eye onto occiput and onto the postnasal region on the other side of the head, on the nape this band is bordered above and below by thin contrasting yellow stripes; six irregular thin yellow transversal bands between limb insertions, three more such stripes above sacrum and anterior part of tail, followed by 10 white annuli not completely encircling the tail. Narrow dorsal yellow bands do not extend below mid-flank level; roundish yellow spots are irregularly disposed on the lower part of flanks. Upper surfaces of limbs bear smaller, irregularly arranged, yellow spots. Iris greenish bronze. Underside of head, venter, limbs and palms uniformly whitish; underside of tail marbled with yellow, white and black color.

Variation. The paratypes resemble the holotype in most aspects of morphology and coloration. PSUZC-RT 2012.4 shows a continuous series of enlarged femoro-precloacal scales, including 15 poreless scales (left leg) + two pored scales + two poreless scales + one pored scale (precloacal region) + 13 poreless scales (right leg), thus a total of 33 femoro-precloacal scales and three precloacal pores. QSMI 1165 shows a continuous series of enlarged femoro-precloacal scales, including 13 poreless scales (left leg) + two pored scales + one poreless scale + two pored scales (precloacal region) + 14 poreless scales (right leg), thus a total of 32 femoro-precloacal scales and four precloacal pores ( Fig. 4View FIGURE 4). PSUZC-RT 2012.4 and QSMI 1165 show respectively three and two well-developed spurs on each side of the hemipenial swelling. Meristic and morphometric data of the paratypes are presented in Table 1. Two adult females, photographed in situ and released, were examined; they show a similar color pattern to males; both show a continuous series of enlarged femoro-precloacal scales, like males, but without precloacal pores ( Fig. 5View FIGURE 5). Dorsal surface of regenerated part of tails of paratypes lack bands, but bear a poorly contrasted marbling pattern of grayish and whitish. Underside of regenerated part of tail in QSMI 1165 is uniformly grayish.

Distribution. The species is so far known only from its type locality, and it is possibly endemic to Tham Sanook  , Chumphon Province, Thailand.

Natural history. Fifteen individuals of the new species, including the type series, were encountered between 2000 and 2200 hrs, and it can thus be regarded as locally common. All were adults, except four subadults; no juveniles were encountered. They were found at the entrance of the cave and up to about 100 meters from the cave entrance, but always on or along the karst cliffs and boulders. The cave is surrounded by secondary forest with numerous lianas ( Fig. 7View FIGURE 7). The individuals were all actively foraging on the leaf litter, on tree trunks and stumps, on large leaves, boulders, on karst cliff and on the temple cement walls ( Fig. 4View FIGURE 4), at maximum one meter above the ground. One adult female was gravid with two eggs. The new species was found in strict syntopy with Gehyra lacerata (Wiegmann)  (several individuals observed on the karst cliff), Gekko gecko (Linnaeus)  (several hatched egg clutches found in holes within the karst cliff) ( Gekkonidae  ) and a subadult Trimeresurus venustus  Vo g e l ( Viperidae  ) (the latter representing a major range extension northwards for that pitviper species). Specimens of the new species are slow and easy to approach and catch. They generally do not bite when handled unless they are manipulated too long.

Etymology. The specific epithet is a noun in apposition referring to the species’ type locality. In Thai language, sanook  means ‘(having) fun’ and as such, the specific epithet is also a reference to the enormous pleasure that the authors take in discovering amazing reptiles and other animal diversity in Thailand and in making it known to others. We suggest the following common names: Tuk kai sanook  ( Thai), Sanook  Bent-toed Gecko  (English), Cyrtodactyle sanouk (French).

TABLE 1. Morphometric and meristic data for the type series of Cyrtodactylus sanook sp. nov. Paired meristic characters are given left / right. Measurements (in mm) are given for the left side. For the abbreviations, see Material and methods.

  Holotype THNHM 22541 Male    
Contact of posterior thigh scales abrupt No. of enlarged femoral and precloacal scales No. of femoro-precloacal pores Precloacal groove Precloacal depression Patch of enlarged precloacal scales