Adult male ZMKU R 00959 from Tham Than Lot Noi-Tham Than Lot Yai Nature Trail, Chaloem Rattanakosin National Park, Khao Chot Subdistrict, Si Sawat District, Kanchanaburi Province, Thailand (14.66930°N, 99.29060°E, 526 m a.s.l.), collected by Korkhwan Termprayoon, Akrachai Aksornneam, Natee Ampai, and Siriporn Yodthong on 20 April 2019.

Adult males ZMKU R 00958 and ZMKU R 00960 and adult females ZMKU R 00961–64 bear the same collection site as the holotype.

Cyrtodactylus fluvicavus sp. nov. can be separated from all other species of the brevipalmatus group by the combination of having 11–13 supralabials, 9 or 10 infralabials, 26–30 paravertebral tubercles, 14–18 rows of longitudinally arranged tubercles, 30–39 transverse rows of ventrals, 154–175 longitudinal rows of ventrals, 9–11 expanded subdigital lamellae on the fourth toe, 10–13 unexpanded subdigital lamellae on the fourth toe, 19–22 total subdigital lamellae on the fourth toe; 7–9 expanded subdigital lamellae on the fourth finger, 9–11 unexpanded subdigital lamellae on the fourth finger, 17–19 total subdigital lamellae on the fourth finger; 9–12 total enlarged femoral scales, 8–11 total femoral pores in males; 14 or 15 precloacal pores in males; 14 or 15 enlarged precloacals; enlarged femorals and enlarged precloacals not continuous; proximal femorals less than one-half the size of the distal femorals; small tubercles on forelimbs and flanks; small dorsolateral caudal tubercles and narrow ventrolateral caudal fringe; ventrolateral caudal fringe composed scales of different size; tail circular in cross-section; slightly enlarged unpaired medial subcaudals not posteromedially furrowed; maximum SVL 78.2 mm; three dark transverse body bands (Tables 4–6).

(Fig. 4). Adult male SVL 72.5 mm; head moderate in length (HL/SVL 0.28), width (HW/HL 0.70), depth (HD/HL 0.42), distinct from neck, triangular in dorsal profile; lores concave slightly anteriorly, weakly inflated posteriorly; prefrontal region concave; canthus rostralis rounded; snout elongate (ES/HL 0.42), rounded in dorsal profile; eye large (ED/HL 0.25); ear opening obliquely elongate, small; eye to ear distance greater than diameter of eye; rostral rectangular, divided by a deep furrow, bordered posteriorly by large left and right supranasals and one small azygous internasal, bordered laterally by first supralabials; external nares bordered anteriorly by rostral, dorsally by large supranasal, posteriorly by two smaller postnasals, bordered ventrally by first supralabial; 12R/12L rectangular supralabials, second through seventh supralabials nearly same size as first, then tapering abruptly below eye; 10R/10L infralabials tapering smoothly to just below and slightly past posterior margin of eye; scales of rostrum and lores flat to domed, larger than granular scales on top of head and occiput; scales of occiput intermixed with distinct, small tubercles; superciliaries subrectangular, largest dorsally; mental triangular, bordered laterally by first infralabials and posteriorly by large left and right trapezoidal postmentals contacting medially for 50% of their length posterior to mental; one row of slightly enlarged, elongate sublabials extending posteriorly to sixth(L) and fifth(R) infralabial; gular and throat scales small, granular, grading posteriorly into slightly larger, flatter, smooth, imbricate, pectoral and ventral scales.

Figure 4. 

Holotype of Cyrtodactylus fluvicavus sp. nov. ZMKU R 00959 (field no. AA 07001) from Thailand, Kanchanaburi Province, Si Sawat District, Khao Chot Subdistrict, Chaloem Rattanakosin National Park A dorsal view B ventral view C dorsal view of head D ventral view of femoral and precloacal regions E dorsal view of tail F ventral view of tail.

Body relatively short (AG/SVL 0.46) with well-defined ventrolateral folds; dorsal scales small, granular interspersed with larger, conical, semi-regularly arranged, weakly keeled tubercles; tubercles extend from occipital region onto base of tail and slightly beyond as paravertebral rows; smaller tubercles extend anteriorly onto nape and occiput, diminishing in size anteriorly; approximately 17 longitudinal rows of tubercles at midbody; approximately 30 paravertebral tubercles; small tubercles on flanks; 34 longitudinal rows of flat, imbricate, ventral scales much larger than dorsal scales; 155 transverse rows of ventral scales; 15 large, pore-bearing, precloacal scales; no deep precloacal groove or depression; and two rows of post-precloacal scales on midline.

Forelimbs moderate in stature, relatively short (ForL/SVL 0.14); granular scales of forearm slightly larger than those on body, interspersed with large tubercles; palmar scales rounded, slightly raised; digits well-developed, relatively short, inflected at basal interphalangeal joints; digits narrower distal to inflections; subdigital lamellae wide, transversely expanded proximal to joint inflections, narrower transverse lamellae distal to joint inflections; claws well-developed, claw base sheathed by a dorsal and ventral scale; 8R/8L expanded and 10R/10L unexpanded lamellae beneath the fourth finger; hind limbs larger and thicker than forelimbs, moderate in length (TibL/SVL 0.16), covered dorsally by granular scales interspersed with moderately sized, conical tubercles dorsally and posteriorly and anteriorly by flat, slightly larger, subimbricate scales; ventral scales of thigh flat, subimbricate, larger than dorsals; subtibial scales flat, imbricate; one row of 5R/6L enlarged pore-bearing femoral scales not continuous with enlarged pore-bearing precloacal scales, terminating distally at knee; proximal femoral scales smaller than distal femorals, the former forming an abrupt union with much smaller, rounded, ventral scales of posteroventral margin of thigh; plantar scales flat; digits relatively long, well-developed, inflected at basal interphalangeal joints; 9R/9L wide, transversely expanded subdigital lamellae on fourth toe proximal to joint inflection extending onto sole, and 11R/11L unexpanded lamellae beneath the fourth toe; and claws well-developed, claw base sheathed by a dorsal and ventral scale.

Tail original, 97.6 mm long (TL/SVL 1.34), 5.2 mm in width at base, tapering to a point; sub-circular or nearly round in cross-section; dorsal scales flat, square bearing tubercles forming paravertebral rows and small tubercles forming a dorsolateral longitudinal row; slightly larger, posteriorly directed, semi-spinose tubercles forming narrow but distinct ventrolateral caudal fringe; larger scales of ventrolateral fringe occur at regular intervals; medial subcaudals slightly enlarged but not paired, distinctly enlarged single medial subcaudals absent; subcaudals, larger than dorsal caudals; base of tail bearing hemipenial swellings; 3R/2L conical postcloacal tubercles at base of hemipenial swellings; and postcloacal scales flat, imbricate.

(Fig. 5). Ground color of the head, body, limbs, and tail brown; faint, diffuse mottling on the top of the head; thin, dark brown postorbital stripe; ventral portion of lores and suborbital region dark brown; nuchal band faint, bearing two dark-colored posterior projections; paired dark brown paravertebral blotches on nape; three wide faint irregularly shaped body bands edged in dark brown between limb insertions; band interspaces bearing irregularly shaped dark-colored markings; dark-colored speckling on limbs and digits; digits bearing pale-colored bands; eight wide dark-colored caudal bands separated by seven pale-colored bands; first six dark-colored and seven pale-colored caudal bands encircle tail; all ventral surfaces beige, generally immaculate; iris orange-gold in color.

Figure 5. 

Type series of Cyrtodactylus fluvicavus sp. nov. from Thailand, Kanchanaburi Province, Si Sawat District, Khao Chot Subdistrict, Chaloem Rattanakosin National Park.

(Fig. 5). Individuals of the type series are very similar in overall coloration and pattern. TL and TW of complete original tails (ZMKU R 00959–00960, ZMKU R 00963–00964) are 79.7–97.6 mm (mean 91.4 ± 8.2 mm; N = 4) and 4.0–5.2 mm (mean 4.5 ± 0.5; N = 4), respectively. The posterior one-third of the tail of ZMKU R 00958 is regenerated (TL 72.0 mm, TW 4.9 mm); that of ZMKU R 00962 is missing (TL 83.8 mm, TW 4.4 mm); and that of ZMKU R 00961 is broken one-third of the way passed the base and nearly all of the broken section is regenerated (TL 73.6 mm, TW 4.07 mm). Regenerated tail sections lack a color pattern. ZMKU R 00963–64 have seven dark-colored and six pale-colored caudal bands as opposed to eight and seven bands, respectively, in the holotype. ZMKU R 00958, ZMKU R 00960, ZMKU R 00962, ZMKU R 00964 are slight less boldly marked than the holotype. Meristic and morphometric differences are listed in Table 5.

Cyrtodactylus fluvicavus sp. nov. is currently known from the type locality at Tham Than Lot Noi-Tham Than Lot Yai Nature Trail in Chaloem Rattanakosin National Park, Si Sawat District, Kanchanaburi Province, western Thailand (Fig. 1).

The specific epithet fluvicavus comes from the Latin fluvius, meaning stream, river, or flow and the Latin cavus, meaning hollow or hole and refers to a landmark cave in the Chaloem Rattanakosin National Park which has a stream that flows through it.

Cyrtodactylus fluvicavus sp. nov. is the sister species to a clade composed of ten lineages in a phylogenetic sequence of C. sp.9, C. sp.10, Cyrtodactylus uthaiensis sp. nov., C. sp.11, C. interdigitalis, C. cf. ngati1, C. cf. ngati2, C. ngati3, and the sister lineages C. ngati4 and C. ngati (Fig. 2). Cyrtodactylus fluvicavus sp. nov. differs from those lineages by an uncorrected pairwise sequence divergence of 9.55–12.13% and from all members of the brevipalmatus group by 11.61–20.26% (Table 2). It differs categorically from C. elok by having as opposed to lacking paravertebral tubercles and femoral pores, and by having 14–18 as opposed to 4–7 longitudinal rows of tubercles. It differs from C. brevipalmatus, C. interdigitalis, C. ngati, C. ngati3, C. rukhadeva, and C. sp.9 in having statistically significant different mean values of the morphometric characters of AG, HumL, ForL, FemL, TibL, HL, HW, HD, EE, ES, EN, EL and IN (Table 6). It differs further from C. brevipalmatus, C. interdigitalis, C. ngati, C. ngati3, C. rukhadeva, and C. sp.9 in having statistically significant different mean values of the meristic characters of SL, PVT, LRT, VS, VSM, TL4E, TL4T, FL4E, FL4U, FL4T, FS, PCS, and BB. Statistically significant and discrete differences between Cyrtodactylus fluvicavus sp. nov. and all other species and populations are presented in Tables 4–6.

All individuals were found in karst forests bearing mixed deciduous and dry evergreen trees amidst rocky streams and a nearby waterfall (Fig. 6). This area is surrounded by agricultural fields and residential areas. Specimens (N = 7) were collected at night (1900–2100 h) during the dry season (April) on the tree trunks or palm tree leaves (57.1%; N = 4), twigs of shrubs (14.3%; N = 1), karst walls (14.3%; N = 1), and a wooden bridge (14.3%; N = 1) at 526 m elevation with a temperature of 31.9 °C and relative humidity of 56.9%. The holotype (ZMKU R 00959) and two specimens (ZMKU R 00960, ZMKU R 00962) were found on tree trunks ≤ 100 cm above ground level. One specimen (ZMKU R 00964) was found on a palm tree branch approximately 50 cm above the ground. Another specimen (ZMKU R 00963) was found on the twig of a shrub. Another specimen (ZMKU R 00961) was found on a karst wall approximately 3 m above the ground, and another (ZMKU R 00958) on a wooden bridge over a stream. Given these observations, this species appears to be an arboreal habitat generalist. The new species was found to co-occur with two other species of gekkonid lizards, Cyrtodactylus monilatus Yodthong, Rujirawan, Stuart, Grismer, Aksornneam, Termprayoon, Ampai & Aowphol, 2022 and Dixonius siamensis (Boulenger, 1899).

Figure 6. 

Habitat of Cyrtodactylus fluvicavus sp. nov. at Thailand, Kanchanaburi Province, Si Sawat District, Khao Chot Subdistrict, Chaloem Rattanakosin National Park.

Adult female ZMKU R 00947 from Pa La-U Waterfall, Kaeng Krachan National Park, Huai Sat Yai Subdistrict, Hua Hin District, Prachuap Khiri Khan Province, Thailand (12.53685°N, 99.45972°E, 368 m a.s.l.), collected by Attapol Rujirawan, Siriporn Yodthong, Korkhwan Termprayoon, Natee Ampai, and Piyawan Puanprapai on 15 September 2017.

Adult female ZMKU R 00946 bearing the same data as the holotype.

Cyrtodactylus rivularis sp. nov. can be separated from all other species of the brevipalmatus group by the combination of having 12 or 13 supralabials, 9–11 infralabials, 33 or 34 paravertebral tubercles, 18–20 rows of longitudinally arranged tubercles, 34–37 transverse rows of ventrals, 160–166 longitudinal rows of ventrals, nine expanded subdigital lamellae on the fourth toe, 12 or 13 unexpanded subdigital lamellae on the fourth toe, 21 or 22 total subdigital lamellae on the fourth toe; eight expanded subdigital lamellae on the fourth finger, 10–12 unexpanded subdigital lamellae on the fourth finger, 18–20 total subdigital lamellae on the fourth finger; 14–16 total enlarged femoral scales; 15 enlarged precloacals; enlarged femorals and enlarged precloacals not continuous, and lacking pores; proximal femorals less than one-half the size of the distal femorals; small tubercles on forelimbs and flanks; large dorsolateral caudal tubercles and wide ventrolateral caudal fringe; ventrolateral caudal fringe composed generally homogeneous scales; tail square in cross-section; single enlarged unpaired medial subcaudals not posteromedially furrowed; maximum SVL 73.9 mm; three or four dark transverse body bands (Tables 4, 5).

(Fig. 7). Adult female SVL 73.9 mm; head moderate in length (HL/SVL 0.27), width (HW/HL 0.73), depth (HD/HL 0.40), distinct from neck, triangular in dorsal profile; lores concave slightly anteriorly, weakly inflated posteriorly; prefrontal region concave; canthus rostralis rounded; snout elongate (ES/HL 0.41), rounded in dorsal profile; eye large (ED/HL 0.29); ear opening horizontally elongate, small; eye to ear distance greater than diameter of eye; rostral rectangular, divided dorsally by a deep furrow, bordered posteriorly by large left and right supranasals and one slightly smaller azygous internasal, bordered laterally by first supralabials; external nares bordered anteriorly by rostral, dorsally by large supranasal, posteriorly by two smaller postnasals, bordered ventrally by first supralabial; 13R/12L rectangular supralabials, first two largest, then tapering abruptly below eye; 11R/10L infralabials tapering smoothly to just below eye and then more rapidly beyond posterior margin of eye; scales of rostrum and lores flat to domed, larger than granular scales on top of head and occiput; scales of occiput intermixed with distinct, small tubercles; superciliaries subrectangular, largest anteriorly; mental triangular, bordered laterally by first infralabials, posteriorly by large left and right elongate postmentals contacting medially for approximately 40% of their length posterior to mental; one row of two (R) and four (L) slightly enlarged sublabials extending posteriorly to third(L) and second(R) infralabial, subsequent sublabials much smaller; gular and throat scales small, granular, grading posteriorly into slightly larger, flatter, smooth, imbricate, pectoral and ventral scales.

Figure 7. 

Holotype of Cyrtodactylus rivularis sp. nov. ZMKU R 00947 (field no. AA 04887) from Thailand, Prachuap Khiri Khan Province, Hua Hin District, Huai Sat Yai Subdistrict, Kaeng Krachan National Park, Pa La-U Waterfall A dorsal view B ventral view C dorsal view of head D ventral view of femoral and precloacal regions E dorsal view of tail F ventral view of tail.

Body relatively short (AG/SVL 0.47) with well-defined ventrolateral folds; dorsal scales small, granular, interspersed with larger conical, semi-regularly arranged, weakly keeled tubercles; tubercles extend from occipital region onto base of tail and slightly beyond as paravertebral rows; tubercles of nape and occiput small; approximately 20 longitudinal rows of tubercles at midbody; approximately 34 paravertebral tubercles; tubercles on flanks nearly same size as those on dorsum; 34 longitudinal rows of flat, imbricate, ventral scales much larger than dorsal scales; 160 transverse rows of ventral scales; no pore-bearing, precloacal scales; 15 enlarged precloacal scales; no deep precloacal groove or depression; and three rows of post-precloacal scales on midline.

Forelimbs moderate in stature, relatively short (ForL/SVL 0.13); granular scales of forearm slightly larger than those on body, interspersed with tubercles; palmar scales rounded, slightly raised; digits well-developed, relatively short, inflected at basal interphalangeal joints; digits narrower distal to inflections; subdigital lamellae wide, transversely expanded proximal to joint inflections, narrower transverse lamellae distal to joint inflections; claws well-developed, claw base sheathed by a dorsal and ventral scale; 8R/8L expanded and 11R/11L unexpanded lamellae beneath the fourth finger; hind limbs larger and thicker than forelimbs, moderate in length (TibL/SVL 0.15), covered dorsally by granular scales interspersed with moderately sized, conical tubercles dorsally and posteriorly and anteriorly by flat, slightly larger, subimbricate scales; ventral scales of thigh flat, subimbricate, larger than dorsals; subtibial scales flat, imbricate; no pore-bearing femoral scales; 8R/8L enlarged femoral scales; enlarged femoral scales not contiguous with enlarged precloacal scales, terminating distally at knee; proximal femoral scales smaller than distal femoral scales, the former forming an abrupt union with much smaller, rounded, ventral scales of posteroventral margin of thigh; plantar scales flat; digits relatively long, well-developed, inflected at basal interphalangeal joints; 9R/9L wide, transversely expanded subdigital lamellae on fourth toe proximal to joint inflection that extend onto sole, and 13R/13L unexpanded lamellae beneath the fourth toe; and claws well-developed, sheathed by a dorsal and ventral scale at base.

Posterior one-half of tail regenerated, tail long 91.5 mm (TL/SVL 1.24), 4.8 mm in width at base, tapering to a point; nearly square in cross-section; dorsal scales flat, square bearing large tubercles forming a discontinuous dorsolateral longitudinal row; slightly larger, posteriorly directed, semi-spinose tubercles forming large distinct ventrolateral caudal fringe; scales of ventrolateral fringe generally homogeneous; single medial subcaudals enlarged but not paired; subcaudal scales, larger than dorsal caudal scales; base of tail bearing hemipenial swellings; 2R/2L conical postcloacal tubercles at base of hemipenial swellings; and postcloacal scales flat, imbricate.

(Fig. 8). Ground color of the head, body, limbs, and tail pale brown; faint, diffuse mottling on rostrum; lores darkly colored; wide, distinct, pale-colored post-orbital stripe; nuchal band faint, bearing two posterior projections; three very faint, wide irregularly shaped body bands edged in slightly darker brown between limb insertions; band interspaces bearing irregularly shaped, faint, dark-colored markings; dark-colored speckling on limbs and digits; digits bearing pale-colored bands; four wide faint dark-colored caudal bands separated by three pale-colored bands on original portion of tail; all caudal bands encircle tail; all ventral surfaces beige, generally immaculate; iris orangish to coppery in color.

Figure 8. 

Type series of Cyrtodactylus rivularis sp. nov. from Thailand, Prachuap Khiri Khan Province, Hua Hin District, Huai Sat Yai Subdistrict, Kaeng Krachan National Park, Pa La-U Waterfall A holotype ZMKU R 00947 B paratype ZMKU R 00946.

(Fig. 8). The paratype (ZMKU R 00946) closely approximates the holotype in overall coloration and pattern except that it is more boldly marked. It has four dark-colored body bands as opposed to three and a complete original tail (TL 89.0mm, TW 4.1 mm) bearing eight dark-colored and seven pale-colored bands. The pale-colored postorbital stripe is slightly thinner and less distinct. Meristic and morphometric differences are listed in Table 5.

Cyrtodactylus rivularis sp. nov. is currently known from the type locality at Pa La-U Waterfall, Kaeng Krachan National Park, Huai Sat Yai Subdistrict, Hua Hin District Prachuap Khiri Khan Province, Thailand.

The specific epithet rivularis is derived from the Latin rivus, meaning stream, brook, or creek refers to rocky brook or stream habitat of the new species.

Cyrtodactylus rivularis sp. nov. is the sister species to C. rukhadeva (Fig. 2) from which it differs by an uncorrected pairwise sequence divergence of 3.61% (Table 2). It differs from C. rukhadeva and C. cf. rukhadeva by having large versus small dorsolateral caudal tubercles and a wide versus narrow ventrolateral fringe. Although no statistical mean differences were recovered between Cyrtodactylus rivularis sp. nov. and C. rukhadeva which we attribute to the small sample sizes of both species (N = 2), they do respectively differ discretely (at this point) in their ranges of SL (12 or 13 vs. 9–11), PVT (33–34 vs. 27–30), VSM (160–166 vs. 152–154), and TL4T (21–22 vs. 18–20) and the morphometric characters of HumL, ForL, FemL, TibL, HD, ED, and IO (Table 5). Discrete differences among Cyrtodactylus rivularis sp. nov. and all other species and populations are presented in Tables 4, 5.

The holotype and paratype were collected at night (1900–2055 h) on granite boulders by a rocky stream dry evergreen forest at 368 m in elevation (Fig. 9) with a temperature of 25.3 °C and relative humidity of 86.9%. The new species was found to co-occur with two other species of gekkonid lizards, Cyrtodactylus oldhami (Theobald, 1876) and Gehyra mutilata (Wiegmann, 1834).

Figure 9. 

Habitat of Cyrtodactylus rivularis sp. nov. at Thailand, Prachuap Khiri Khan Province, Hua Hin District, Huai Sat Yai Subdistrict, Kaeng Krachan National Park, Pa La-U Waterfall.

Cyrtodactylus rivularis sp. nov. and C. cf. rukhadeva occur on separate branches of the phylogeny, thus neither is embedded within one another’s branch indicating there is no evidence of gene flow between them. Both species are reported to occur within the boundaries of Kaeng Krachan National Park (Grismer et al. 2022). Kaeng Krachan National Park is the largest national park in Thailand, encompassing 2,914.7 km² across five districts through the provinces of Phetchaburi and Prachuap Khiri Khan and extending approximately 300 km in latitude. As such, it harbors a wide range of habitats from lowland forests near sea level to cloud forests at its highest peak of 1,513 m in elevation. The seven specimens of C. cf. rukhadeva (THNHM 01807, 24622, 24838, 03251–54) were obtained by various collectors between 11 March 1991 and 25 October 2015 with no specific collection data other than Phetchaburi Province. The locality reported by Grismer et al. (2021c) was an estimate obtained from Ulber (1993) from the central portion of the park in Phetchaburi Province who referred to a specimen he examined (THNHM 24838) as C. brevipalmatus. Cyrtodactylus rivularis sp. nov. however, is known only from the Park’s southernmost limit in Prachuap Khiri Khan Province. Additional collecting and DNA sequencing will be required to establish the approximate distribution limits of each population.

Adult female ZMKU R 00945 from Ko Chang Island, Ko Phayam Subdistrict, Mueang Ranong District, Ranong Province, Thailand (9.82411°N, 98.43999°E, 36 m a.s.l.), collected by Siriporn Yodthong, Natee Ampai, Attapol Rujirawan, and Piyawan Puanprapai on 8 July 2017.

Cyrtodactylus cf. kochangensis sp. nov. adult male THNHM 01667 from Khlong Naka Wildlife Sanctuary, Suk Samran District, Ranong Province, Thailand (~N 9.4596, E 98.5044, elevation unknown), collected by Yodchaiy Chuaynkern between 28 December 2000 and 2 January 2001.

(based on the holotype). Cyrtodactylus kochangensis sp. nov. can be separated from all other species of the brevipalmatus group by the combination of having 12 or 13 supralabials, nine infralabials, 34 paravertebral tubercles, 14 rows of longitudinally arranged tubercles, 35 transverse rows of ventrals, 172 longitudinal rows of ventrals, 8 or 9 expanded subdigital lamellae on the fourth toe, 11 or 12 unexpanded subdigital lamellae on the fourth toe, 19–21 total subdigital lamellae on the fourth toe; eight expanded subdigital lamellae on the fourth finger, ten unexpanded subdigital lamellae on the fourth finger, 18 total subdigital lamellae on the fourth finger; 12 total enlarged femoral scales; 12 enlarged precloacal scales; enlarged femoral and enlarged precloacal scales not continuous; proximal femoral scales less than one-half the size of the distal femorals; small tubercles on forelimbs and flanks; large dorsolateral caudal tubercles and a wide ventrolateral caudal fringe not composed homogeneous scales; tail square in cross-section; slightly enlarged paired medial subcaudals not posteromedially furrowed; maximum SVL 60.1 mm; five dark transverse body bands (Tables 4, 5).

(Fig. 10). Adult female SVL 60.1 mm; head moderate in length (HL/SVL 0.29), width (HW/HL 0.67), depth (HD/HL 0.38), distinct from neck, triangular in dorsal profile; lores flat anteriorly, weakly inflated posteriorly; prefrontal region slightly concave; canthus rostralis rounded; snout elongate (ES/HL 0.40), rounded in dorsal profile; eye large (ED/HL 0.24); ear opening subcircular, small; eye to ear distance greater than diameter of eye; rostral rectangular, furrowed dorsally, bordered posteriorly by large left and right supranasals and one slightly smaller azygous internasal, bordered laterally by first supralabials; external nares bordered anteriorly by rostral, dorsally by large supranasal, posteriorly by two slightly smaller postnasals, bordered ventrally by first supralabial; 12R/13L rectangular supralabials tapering smoothly to below eye; 9R/9L infralabials tapering smoothly to below eye; scales of rostrum and lores domed, slightly larger than granular scales on top of head and occiput; scales of occiput intermixed with distinct, small tubercles; superciliaries subrectangular, largest anteriorly; mental triangular, bordered laterally by first infralabials and posteriorly by large left and right trapazoidal postmentals contacting medially for approximately 40% of their length posterior to mental; one row of six (R,L) slightly enlarged sublabials extending posteriorly fifth infralabials, subsequent sublabials much smaller; gular and throat scales small, granular, grading posteriorly into slightly larger, flatter, smooth, imbricate, pectoral and ventral scales.

Figure 10. 

Holotype of Cyrtodactylus kochangensis sp. nov. ZMKU R 00945 (field no. AA 04439) from Thailand, Ranong Province, Mueng Ranong District, Ko Phayam Subdistrict, Ko Chang A dorsal view B ventral view C dorsal view of head D ventral view of femoral and precloacal regions E dorsal view of tail F ventral view of tail G holotype in life.

Body relatively short (AG/SVL 0.48) with well-defined ventrolateral folds; dorsal scales small, granular, interspersed with larger conical, semi-regularly arranged, weakly keeled tubercles; tubercles extend from occipital region onto base of tail and slightly beyond as paravertebral rows; tubercles of nape and occiput smaller than those on body; approximately 14 longitudinal rows of tubercles at midbody; approximately 34 paravertebral tubercles; tubercles on upper flanks smaller than those on dorsum; approximately 35 longitudinal rows of flat, imbricate, ventral scales much larger than dorsal scales; approximately 172 transverse rows of ventral scales; no pore-bearing, precloacal scales; 12 enlarged precloacal scales; no deep precloacal groove or depression; and approximately three rows of post-precloacal scales on midline.

Forelimbs moderate in stature, relatively short (ForL/SVL 0.13); granular scales of forearm slightly larger than those on body, interspersed with tubercles; palmar scales rounded, slightly raised; digits well-developed, relatively short, inflected at basal interphalangeal joints; digits narrower distal to inflections; subdigital lamellae wide, transversely expanded proximal to joint inflections, narrower transverse lamellae distal to joint inflections; claws well-developed, claw base sheathed by a dorsal and ventral scale; 8R/8L expanded and 10R/10L unexpanded lamellae beneath the fourth finger; hind limbs larger and thicker than forelimbs, moderate in length (TibL/SVL 0.14), covered dorsally by granular scales interspersed with moderately sized, conical tubercles dorsally and posteriorly and anteriorly by flat, slightly larger, subimbricate scales; ventral scales of thigh flat, subimbricate, larger than dorsals; subtibial scales flat, imbricate; no pore-bearing femoral scales; 6R/6L enlarged femoral scales; enlarged femoral scales not contiguous with enlarged precloacal scales, terminating distally at knee; proximal femoral scales smaller than distal femorals, the former forming an abrupt union with much smaller, rounded, ventral scales of posteroventral margin of thigh; plantar scales flat; digits relatively long, well-developed, inflected at basal interphalangeal joints; 9R/8L wide, transversely expanded subdigital lamellae on the fourth toe proximal to joint inflection that extend onto sole, and 12R/11L unexpanded lamellae beneath the fourth toe; and claws well-developed, sheathed by a dorsal and ventral scale at base.

Tail original (but in two pieces), long 80.3 mm (TL/SVL 1.34), 4.0 mm in width at base, tapering to a point; nearly square in cross-section; dorsal scales flat, square bearing tubercles forming paravertebral rows and large tubercles forming a dorsolateral longitudinal row; slightly larger, posteriorly directed, semi-spinose tubercles forming wide distinct ventrolateral caudal fringe; scales of ventrolateral fringe generally interspersed at regular intervals with larger spinose scales; medial subcaudal scales paired, slightly enlarged; subcaudals, larger than dorsal caudal scales; base of tail bearing hemipenial swellings; one conical postcloacal tubercle at base of hemipenial swellings; and postcloacal scales flat, imbricate.

(Fig. 10). Ground color of the head, body, limbs, and tail pale brown; faint, diffuse mottling on rostrum; lores darkly colored; wide, distinct, pale-colored postorbital stripe; nuchal band faint, bearing two posterior projections; three very faint, wide, irregularly shaped body bands between limb insertions edged in slightly darker brown; band interspaces bearing irregularly shaped, faint, dark-colored markings; dark-colored speckling on limbs and digits; digits bearing pale-colored bands; four wide, faint, dark-colored caudal bands separated by three pale-colored bands on original portion of tail; all caudal bands encircle tail; all ventral surfaces beige, generally immaculate; and iris orangish to coppery in color.

The additional specimen (THNHM 01667) closely approximates the holotype in overall coloration and pattern except that it is more boldly marked. It has four dark-colored body bands as opposed to three and a complete original tail bearing eight dark-colored and seven pale-colored bands. The pale-colored postorbital stripe is slightly thinner and less distinct. Meristic and morphometric differences are listed in Table 5. Given its overall morphological and color pattern similarities and close geographic proximity to the holotype (~ 40 km), we consider this individual as C. cf. kochangensis sp. nov. pending genetic data.

Cyrtodactylus kochangensis sp. nov. is currently known only from the type locality at Ko Chang Island, Ko Phayam Subdistrict, Mueang Ranong District, Ranong Province, Thailand. The additional population of pending species status occurs in the Khlong Naka Wildlife Sanctuary, Suk Samran District Ranong Province.

The specific epithet kochangensis is in reference to the type locality, Ko Chang, Ranong Province, Thailand

(based on the holotype). Cyrtodactylus kochangensis sp. nov. forms a clade with the sister species Cyrtodactylus rivularis sp. nov. and C. rukhadeva (Fig. 2) from which it differs by an uncorrected pairwise sequence divergence of 12.00–12.52% and 12.52–13.68%, respectively (Table 2) and it and C. cf. kochangensis sp. nov. are separated from C. rukhadeva and Cyrtodactylus rivularis sp. nov. by geographic distance of no less than ~280–470 km (Fig. 1). The small sample size (N = 1) precludes it from statistical analyses, however at this point, it differs from C. rukhadeva and C. cf. rukhadeva in having 34 PVT versus 26–30; 14 LRT versus 18–20; 172 VSM versus 152–165; 12 FS versus 13–18; 12 PCS versus 13–17 and 1 PCT versus 2 or 3, collectively. From C. rukhadeva by having 12 FS versus 16 or 17; and five BB versus three. From Cyrtodactylus rivularis sp. nov. it differs in having 14 LRT versus 18–20; 172 VSM versus 160–166; 12 FS versus 14–16; and five BB versus three or four. Discrete differences between Cyrtodactylus kochangensis sp. nov. and C. cf. kochangensis sp. nov. and all other species and populations are presented in Tables 4, 5.

The holotype (ZMKU R 00945) was collected at night (2107 h) among branches of a small tree approximately 100 cm above the ground at 36 m elevation with a temperature of 28.6 °C and relative humidity of 83.9%. The surrounding habitat was dry evergreen forest with a rocky stream nearby (Fig. 11). The new species was found to co-occur with two other species of gekkonid lizards, Cyrtodactylus oldhami (Theobald, 1876) and Gekko tokehos (Grismer, Wood, Grismer, Quah, Thy, Phimmachak, Sivongxay, Seateun, Stuart, Siler, Mulcahy, Anamza & Brown, 2019).

Figure 11. 

Habitat of Cyrtodactylus kochangensis sp. nov. at Thailand, Ranong Province, Mueng Ranong District, Ko Phayam Subdistrict, Ko Chang.

Adult male ZMKU R 00949 from Thung Na Ngam Subdistrict, Lan Sak District, Uthai Thani Province, Thailand (15.37649°N, 99.63426°E, 106 m a.s.l.), collected by Attapol Rujirawan, Siriporn Yodthong, Korkhwan Termprayoon, and Natee Ampai on 18 June 2018.

Cyrtodactylus uthaiensis sp. nov. can be separated from all other species of the brevipalmatus group by the combination of having 13–15 supralabials, 10–11 infralabials, 33 paravertebral tubercles, 17 rows of longitudinally arranged tubercles, 36 transverse rows of ventrals, 159 longitudinal rows of ventrals, eight expanded subdigital lamellae on the fourth toe, 12 unexpanded subdigital lamellae on the fourth toe, 20 total subdigital lamellae on the fourth toe; seven expanded subdigital lamellae on the fourth finger, 11 unexpanded subdigital lamellae on the fourth finger, 18 total subdigital lamellae on the fourth finger; 16 total enlarged femoral scales, 12 total femoral pores; 14 enlarged pore-bearing precloacals; enlarged femorals and enlarged precloacals not continuous; proximal femorals less than one-half the size of the distal femorals; small tubercles on forelimbs and flanks; large dorsolateral caudal tubercles and wide ventrolateral caudal fringe; ventrolateral caudal fringe composed scales of different size; tail circular in cross-section; slightly enlarged medial subcaudals intermittent, medially furrowed, posteriorly emarginated; maximum SVL 58.1 mm; and six dark transverse body bands (Tables 5, 6).

(Fig. 12). Adult male SVL 58.1 mm; head moderate in length (HL/SVL 0.28), width (HW/HL 0.68), depth (HD/HL 0.39), distinct from neck, triangular in dorsal profile; lores concave slightly anteriorly, weakly inflated posteriorly; prefrontal region slightly concave; canthus rostralis rounded; snout elongate (ES/HL 0.40), rounded in dorsal profile; eye large (ED/HL 0.29); ear opening elliptical, small; eye to ear distance greater than diameter of eye; rostral rectangular, dorsally furrowed, bordered posteriorly by large left and right supranasals, bordered laterally by first supralabials; external nares bordered anteriorly by rostral, dorsally by large supranasal, posteriorly by two smaller postnasals, ventrally by first supralabial; 13R/15L rectangular supralabials tapering smoothly to posterior margin of eye; 10R/11L infralabials tapering smoothly to posterior margin of eye; scales of rostrum and lores flat to domed, slightly larger than granular scales on top of head and occiput; scales of occiput intermixed with distinct, small tubercles; superciliaries subrectangular, largest dorsally and anteriorly; mental triangular, bordered laterally by first infralabials and posteriorly by large left and right trapezoidal postmentals contacting medially for approximately 40% of their length posterior to mental; one row of slightly enlarged, elongate sublabials extending posteriorly to fifth(L) and seventh(R) infralabial; gular and throat scales small, granular, grading posteriorly into slightly larger, flatter, smooth, imbricate, pectoral and ventral scales.