Holotype • ZMKU R 01068, adult male (Figs 4, 5B, 6) from Thailand, Sa Kaeo Province, Khlong Hat District, Khlong Hat Subdistrict, Tham (= cave) Phet Pho Thong (13°25.116'N, 102°19.690'E, 246 m elevation), collected on 28 July 2022 by Attapol Rujirawan. Paratypes. Five paratypes (three adults and two sub-adults) • Two adult males (ZMKU R 01067, ZMKU R 01069) and one adult female (ZMKU R 01070), same data as holotype • One sub-adult female (ZMKU R 01071), same data as holotype • One sub-adult male (ZMKU R 01072), same data as holotype, except from Khlong Kai Thuean Subdistrict, Tham Nam Khao Phra Siwa (13°19.258'N, 102°19.661'E, 178 m elevation), collected on 29 July 2022.

Cyrtodactyluskhlonghatensis sp. nov. can be distinguished from all other species of the intermedius group by having the following combination of characters: (1) SVL of 76.5–82.8 mm (mean 80.5 ± 3.5 mm, n = 3) in adult males and 88.5 mm in an adult female (n = 1); (2) eight supralabial and nine infralabial scales; (3) 30–32 paravertebral tubercles; (4) 20 or 21 longitudinal rows of dorsal tubercles; (5) 43 or 44 ventral scales; (6) seven or eight expanded subdigital lamellae on the 4^th toe; (7) 12 unmodified subdigital lamellae on the 4^th toe; (8) 19 or 20 total subdigital lamellae on the 4^th toe; (9) 31 or 32 total number of enlarged femoral scales; (10) enlarged femoral and precloacal scales continuous; (11) 6–8 pore-bearing precloacal scales in males; (12) three or four rows of enlarged post-precloacal scales; (13) 1–3 postcloacal tubercles; (14) proximal femoral scales < 1/2 the size of distal femoral scales; (15) absence of interdigital pocketing between digits of forefeet and hindfeet; and (16) posterior border of the nuchal loop rounded.

Adult male in good state of preservation with 82.8 mm SVL; head relatively moderate in length (HL/SVL 0.30), wide (HW/HL 0.64), slightly flattened (HD/HL 0.36), distinct from the neck, and triangular in dorsal profile; lores concave anteriorly, inflated posteriorly; frontal region flattened, prefrontal region concave; canthus rostralis rounded; snout rather elongate (ES/HL 0.40), rounded in the rostral region, eye to snout distance slightly greater than head depth; eye large (ED/HL 0.21), eyeball slightly protuberant, pupil vertical, the eye to ear distance greater than eye diameter; ear opening elliptical, obliquely oriented, moderate in size (EL/HL 0.07); rostral large, subrectangular, wider (3.3 mm) than high (1.8 mm), partially divided by a dorsal furrow, posteriorly bordered by left and right supranasals and smaller three internasal scales, laterodorsally bordered by nostril opening and 1^st supralabial; external nares anteriorly bordered by rostral, dorsally by large supranasal, posteriorly by two small postnasals, ventrally bordered by 1^st supralabial; 8L/8R subrectangular supralabials extending to below the center of the eye, 10L/10R to the posterior margin of the eyeball, subrectangular anteriorly, elliptical shape posteriorly; 2^nd to 6^th supralabials slightly larger than 1^st suprabial; 6L/6R infralabials extending to below center of the eye, 9L/9R to below the posterior margin of the eyeball, larger than supralabials, tapering smoothly posteriorly; scales of frontonasal, prefrontal and lores small, domed, relatively raise, slightly larger than granular scales on top of head and occiput; scales of occiput and top of head intermixed with scattered, distinct, enlarged tubercles, more prominent tubercles between occiput and ear opening; dorsal supraciliaries smooth, not elongate; mental large, triangular, 3.2 mm in width, 2.4 mm in length, laterally bordered by 1^st infralabial and posteriorly by large, left and right trapezoidal postmentals which contact medially for 50% of their length posterior to mental; one row of slightly enlarged, elongate sub-labials extending posteriorly to 7^th infralabials for both side; and gular and throat scales small, granular, grading posteriorly into larger, smooth, flat, imbricate, pectoral and ventral scales.

Body slender, relatively short (AG/SVL 0.41), with poorly-defined ventrolateral folds posteriorly; dorsal scales small, homogenous, granular, interspersed with relatively large, conical, semi-regularly arranged, slightly prominent trihedral keeled tubercles; tubercles extending from occipital region onto base of tail but end at regenerated tail, smaller at the anterior portion of body and increasing in size posteriorly; tubercles on occiput, nape and upper body at the level above shoulder smaller, subconical; mid-dorsally, on the posterior section of the body and tail larger, more dense, slightly more prominently keeled, semi-regularly arranged; approximately 21 longitudinal rows of dorsal tubercles between ventrolateral body folds at midbody; 32 paravertebral tubercles; 44 longitudinal rows of flat, imbricate smooth ventral scales between ventrolateral body fold much larger than dorsal scales; one row of 16L/15R enlarged femoral scales continuous with enlarged precloacal scales, enlarged femoral scales extending along 2/3 of the femora; proximal femoral scales < 1/2 size of distal femoral scales; femoral pores absent; seven enlarged, pore-bearing precloacal scales, smooth, approximately twice the size of femoral scales; precloacal groove or depression absent; three rows of enlarged post-precloacal scales.

Forelimbs rather slender, relatively short (FL/SVL 0.14); granular scales on forearm slightly larger than those on body, interspersed with enlarged, subconical smooth tubercles; dorsal scales of wrist and palm slightly rounded, flat, smooth, imbricate, slightly raise; ventral scales of palm flat, weakly rounded, smaller than those on body, slightly raised; 18L/18R total subdigital lamellae on 4^th finger; 7L/7R proximal subdigital lamellae rectangular with rounded, wide, transversely expanded proximal to joint inflection on 4^th finger, 11L/11R unmodified lamellae distal to inflection, gradually more expanded near the claw; digits narrower distal to inflections; interdigital pocketing absent on the forefeet; claws well-developed, relatively short, claw base sheathed by a dorsal and ventral scales; hindlimbs more robust than forelimbs, moderate in length (TBL/SVL 0.17); dorsal scales slightly rounded, granular, subconical, interspersed with enlarged subconical, smooth tubercles, and anteriorly by flat, slightly larger scales; ventral scales of femora flat, imbricate, smooth, larger than dorsals; ventral scales of tibia and subtibia flat, smooth, imbricate; 20L/20R total subdigital lamellae on 4^th toe, 8L/8R proximal subdigital lamellae, rectangular with rounded, wide, transversely expanded proximal to joint inflection on 4^th toe, 12L/12R unmodified lamellae distal to inflection, gradually more expanded near the claw; digits narrower distal to inflections; interdigital pocketing absent on the hindfeet; claws well-developed, short, claw base sheathed by a dorsal and ventral scales.

Tail regenerated, 100.5 mm in length, longer than SVL (TL/SVL 1.21), moderate in proportions, cylindrical, segmented, wide anteriorly, 7.7 mm in width at the base, tapering to a point, becoming slender toward the tip; dorsal scales of the original portion of tail small, flat, squared; dorsal scales of tail base granular, rounded, regenerated portion covered by small, smooth subcircular scales, grading posteriorly into larger, flatter; trihedral keeled tubercles forming paravertebral rows on tail base extending to posterior margin of 1/2 of tail; subcaudal scale rows enlarge, smooth; median row of transversely expanded subcaudal scales present, significantly larger than dorsal caudal scales; well-defined narrow ventrolateral subcaudal furrow present; tail base bearing hemipenial swellings; 3L/3R smooth, conical, flat, imbricate postcloacal tubercles on either side of hemipenial swellings; and postcloacal tubercles approximately equal in size.

(Figs 4, 5B). Dorsal ground color of head, body, and limbs light-brown; indistinct dark-brown markings on top of head; superciliary scales pale yellow anteriorly and posteriorly; iris brown with dark brown vermiculations; rostral and loreal regions dark brown; rostral, mental, supralabial and infralabial scales creamy-white with scattered dark brown pigment; dark brown nuchal loop with rounded posterior border extends from posterior margin of orbit to posterior margin of the other orbit; nuchal loop edged with thin, pale lines and creamy white tubercles; four similar dark brown body bands, edged in creamy white tubercles with slightly paler centers occur between limb insertion; first body band terminates at shoulders near anterior margin of forelimb insertion; second and third body bands terminate at dorsal to ventrolateral fold on flanks; fourth body band terminates at anterior margin of hindlimb insertion; limbs lighter brown; dorsal portion of forelimbs bearing scattered dark brown markings; dorsal portion of hindlimbs bearing pale yellow spots; four wide dark brown caudal bands encircling the original tail edged in creamy white tubercles; three wide pale caudal bands brown encircling tail; regenerated tail, uniformly brown with small, scattered creamy white markings dorsally; regenerated tail extending from posterior margin of 4^th dark caudal band.

Ventral surfaces of head, body, and limbs dull white to beige, stippled; ventral surfaces of fingers and toes with dark pigmentation; subdigital lamellae on fingers and toes off-white; palmar surface dark brown; hemipenial swelling dark brown with scattered pale yellow; subcaudal region darkened with fine mottling anteriorly.

(Fig. 6). Overall color pattern of head, body, limbs, flanks, and tail remains similar to that observed in life; dorsal ground color became pale brown in hue; all creamy white tubercles and scales on both dorsal and ventral surfaces faded to an off-white; dark body bands and dark caudal bands appear lighter than observed in life; entire ventral surfaces changed to greyish white with small, refined dark mottling; regenerated tail turned pale brown.

All paratypes closely resemble the holotype in coloration (Fig. 5). Morphometric, meristic and color pattern characters of the type series of C.khlonghatensis sp. nov. are presented in Tables 2, 3. ZMKU R 01067 (adult male), ZMKU R 01069 (adult male), ZMKU R 01070 (adult female), ZMKU R 01071 (subadult female), and ZMKU R 01072 (subadult male) bear dark brown blotches on the top of the head. The adult female (ZMKU R 01070) exhibits a pale-colored nuchal loop, body, and caudal bands edged with creamy white tubercles. All paratypes have regenerated tails, except for two subadult specimens (ZMKU R 01071–01072), which retain their original tails with a caudal band encircling the tail edge. Posterior portion of tail in juveniles (not collected) white.

Cyrtodactyluskhlonghatensis sp. nov. is currently known from only two localities: (1) Tham Phet Pho Thong (type locality) in Khlong Hat District, Sa Kaeo Province, Thailand; and (2) Tham Nam Khao Phra Siwa, Khlong Kai Thuean Subdistrict, Khlong Hat District, Sa Kaeo Province, Thailand, approximately 10 km from the type locality.

The type locality is an isolated karstic formation mountain surrounded by karstic outcrops in dry deciduous forest at an elevation of 246 m. The type series of C.khlonghatensis sp. nov. was found during both day (1400–1530 h) and night (1900–2000 h) in various microhabitats of the Tham Phet Pho Thong karstic area (Fig. 7), including karstic boulders, karstic wall, cracks, and crevices; shrubs; vines and other vegetations. The male holotype was found at night (1950 h), perched on a dry vine near a karstic wall, approximately 20 cm above the ground. The male paratype (ZMKU R 01067) was found during the day on a karstic wall in a cave, approximately 5 m from the entrance, with air temperatures of 26.3 °C and a relative humidity of 93.3%. Another male paratype (ZMKU R 01069) was found at night on a karstic wall in a cave. The female paratype (ZMKU R 01070) was found perched on a dry log along a trail in a karstic habitat. A subadult male (ZMKU R 01071) was found perched upside down on a shrub, approximately 50 cm above ground level. At Tham Nam Khao Phra Siwa, a subadult female (ZMKU R 01072) was found on crevices of a karstic wall near a cave entrance, approximately 50 cm above the ground. Cyrtodactyluskhlonghatensis sp. nov. is likely a nocturnal species that inhibits karstic environments. During the day, individuals were found to be inactive in shaded areas with cracks, while at night, they were active both on the karstic terrain and in vegetation. In this survey, the smaller nocturnal gekkonid Gehyramutilata (Wiegmann, 1834) was found in sympatry on karstic boulders, karstic outcrops and vegetations such as tree trunks and dry shrubs.

(Suppl. materials 3, 4). Cyrtodactyluskhlonghatensis sp. nov. is differentiated from 13 recognized species of the intermedius group by having a unique combination of morphological characteristics and uncorrected pairwise sequence divergences of mtDNA (ND2) of 4.73–22.55%.

Cyrtodactyluskhlonghatensis sp. nov. is distinguished from C.auralensis by having a larger maximum SVL of 88.5 mm (vs 84.3 mm); 20 or 21 longitudinal rows of body tubercles (vs 17 or 18 rows); and 31 or 32 total number of enlarged femoral scales (vs 23–28 scales).

Cyrtodactyluskhlonghatensis sp. nov. is distinguished from C.bokorensis by having a smaller maximum SVL of 88.5 mm (vs 93.0 mm); 31 or 32 total number of enlarged femoral scales (vs 26–30 scales); and posterior border of the nuchal loop rounded (vs pointed).

Cyrtodactyluskhlonghatensis sp. nov. is distinguished from C.cardamomensis by having a larger maximum SVL of 88.5 mm (vs 84.1 mm); 7 or 8 expanded subdigital lamellae proximal to the digital inflection on the 4^th toe (vs 5 or 6 lamellae); 31 or 32 total number of enlarged femoral scales (vs 23–28 scales); 6–8 precloacal pores (vs 9 or 10 pores); proximal femoral scales < 1/2 size of distal femoral scales present (vs absent); and dark pigmented blotches on top of the head varies (vs absent).

Cyrtodactyluskhlonghatensis sp. nov. is distinguished from C.disjunctus by having a larger maximum SVL of 88.5 mm (vs 66.7 mm); 8 supralabial scales (vs 12 scales); 9 infralabial scales (vs 11 scales); 30–32 paravertebral tubercles between limb insertions (vs 41 tubercles); 20 or 21 longitudinal rows of body tubercles (vs 11 rows); 43 or 44 longitudinal rows of ventral scales (vs 36 rows); 12 unmodified subdigital lamellae distal to the digital inflection on the 4^th toe (vs 9 lamellae); 19 or 20 total number of subdigital lamellae beneath the 4^th toe (vs 17 lamellae); 31 or 32 total number of enlarged femoral scales (vs 21 scales); 6–8 precloacal scales (vs 10 scales); 6–8 precloacal pores (vs 9 pits); 3 or 4 rows of post-precloacal scales (vs 1 row); enlarged femoral and precloacal scales continuous (vs discontinuous); 4 body bands (vs 3 bands); and dark pigmented blotches on top of the head varies (vs absent).

Cyrtodactyluskhlonghatensis sp. nov. is distinguished from C.hontreensis by having 8 supralabial scales (vs 11–13 scales); 30–32 paravertebral tubercles between limb insertions (vs 20–24 tubercles); 20 or 21 longitudinal rows of body tubercles (vs 14 rows); 43 or 44 longitudinal rows of ventral scales (vs 40–42 rows); 31or 32 total number of enlarged femoral scales (vs 4–9 scales); enlarged femoral and precloacal scales continuous (vs discontinuous); and 4 body bands (vs 3 bands).

Cyrtodactyluskhlonghatensis sp. nov. is distinguished from C.intermedius by having 31 or 32 total number of enlarged femoral scales (vs 23–26 scales); and dark pigmented blotches on top of the head varies (vs absent).

Cyrtodactyluskhlonghatensis sp. nov. is distinguished from C.kohrongensis by having a larger maximum SVL of 88.5 mm (vs 76.1 mm); 43 or 44 longitudinal rows of ventral scales (vs 38–42 rows); 31 or 32 total number of enlarged femoral scales (vs 14–26 scales); enlarged femoral and precloacal scales continuous (vs discontinuous); and dark pigmented blotches on top of the head varies (vs absent).

Cyrtodactyluskhlonghatensis sp. nov. is distinguished from C.kulenensis by having 30–32 paravertebral tubercles between limb insertions (vs 33–38 tubercles); 20 or 21 longitudinal rows of body tubercles (vs 17–19 rows); 31 or 32 total number of enlarged femoral scales (vs 10–21 scales); 6–8 precloacal scales (vs 9 or 10 scales); and dark pigmented blotches on top of the head varies (vs absent).

Cyrtodactyluskhlonghatensis sp. nov. is distinguished from C.laangensis by having a larger maximum SVL of 88.5 mm (vs 82.2 mm); 9 infralabial scales (vs 10–11 scales); 20 or 21 longitudinal rows of body tubercles (vs 17 or 18 rows); 43 or 44 longitudinal rows of ventral scales (vs 37–40 rows); and 31 or 32 total number of enlarged femoral scales (vs 0–16 scales).

Cyrtodactyluskhlonghatensis sp. nov. is distinguished from C.phuquocensis by having a larger maximum SVL of 88.5 mm (vs 85.8 mm); 8 supralabial scales (vs 9–13 scales); 20 or 21 longitudinal rows of body tubercles (vs 16–18 rows); 7 or 8 expanded subdigital lamellae proximal to the digital inflection on the 4^th toe (vs 5 or 6 lamellae); 31 or 32 total number of enlarged femoral scales (vs 21–28 scales); and dark pigmented blotches on top of the head varies (vs absent).

Cyrtodactyluskhlonghatensis sp. nov. is distinguished from C.regicavernicolus by having a larger maximum SVL of 88.5 mm (vs 80.7 mm); 20 or 21 longitudinal rows of body tubercles (vs 15–18 rows); 31 or 32 total number of enlarged femoral scales (vs 8–23 scales); and enlarged femoral and precloacal scales continuous (vs discontinuous).

Cyrtodactyluskhlonghatensis sp. nov. is distinguished from C.septimontium by having a smaller maximum SVL of 88.5 mm (vs 90.4 mm); 20 or 21 longitudinal rows of body tubercles (vs 16–19 rows); 43 or 44 longitudinal rows of ventral scales (vs 38–42 rows); and 31 or 32 total number of enlarged femoral scales (vs 24–28 scales)

Cyrtodactyluskhlonghatensis sp. nov. is distinguished from C.thylacodactylus by having a larger maximum SVL of 88.5 mm (vs 74.6 mm); 8 supralabial scales (vs 7 scales); 43 or 44 longitudinal rows of ventral scales (vs 36–42 rows); 7 or 8 expanded subdigital lamellae proximal to the digital inflection on the 4^th toe (vs 5 or 6 lamellae); 19 or 20 total number of subdigital lamellae beneath the 4^th toe (vs 15–18 lamellae); 31 or 32 total number of enlarged femoral scales (vs 17–22 scales); proximal femoral scales < 1/2 size of distal femoral scales present (vs absent); interdigital pocketing between digits of forefeet and hindfeet absent (vs present); and dark pigmented blotches on top of the head varies (vs absent).

The specific epithet khlonghatensis is named after the type locality of Khlong Hat Subdistrict, Khlong Hat District, Sa Kaeo Province, Thailand.