Cyrtodactylus sakaeratensis Ampai & Rujirawan, 2025

Ampai, Natee, Aowphol, Anchalee, Yodthong, Siriporn, Termprayoon, Korkhwan, Grismer, L. Lee & Rujirawan, Attapol, 2025, Description of a new forest-dwelling bent-toed gecko of the Cyrtodactylus intermedius group (Squamata: Gekkonidae) from the Sakaerat Biosphere Reserve, Nakhon Ratchasima Province, northeastern Thailand, Zootaxa 5666 (3), pp. 361-388 : 374-384

Cyrtodactylus sakaeratensis Ampai & Rujirawan sp. nov.

Figures 3–5

Cyrtodactylus intermedius Murdoch et al. 2019: 5 (part); Grismer et al. 2020: fig. 1 (part).

Cyrtodactylus sp. 2 Grismer et al. 2021a: 274; Grismer et al. 2023: fig. 1; Chhin et al. 2024: fig. 2; Tran et al. 2024: 491. Cyrtodactylus sp. Ampai et al. 2024: 108.

Holotype. ZMKU R 01050 , adult male ( Figs. 3 , 4 ) from Thailand, Nakhon Ratchasima Province, Wang Nam Khiao District, Udom Sap Subdistrict, Sakaerat Biosphere Reserve , 14°30.044’N, 101°55.168’E, 494 m elevation, collected on 1 February 2014 by Natee Ampai (=NA), Anchalee Aowphol (=AA), Attapol Rujirawan (=AR), Korkhwan Termprayoon (=KT) and Siriporn Yodthong (=SY).

Paratypes. Twenty-one paratypes. Thirteen adult males: ZMKU R 01047 same data as holotype except collected on 5 October 2013 by AA, AR and SY; ZMKU R 01051 same data as holotype except collected on 3 February 2014; ZMKU R 01053 same data as holotype except collected on 6 July 2014 by NA, AA, AR and KT; ZMKU R 00726–00727 , ZMKU R 01057–01058 same data as holotype except collected on 11–12 October 2014 by NA, AA, AR, KT, Sengvilay Seateun (=SS) and SY; ZMKU R 01048–01049 same data as holotype except 14°30.091’N, 101°55.285’E, 443 m elevation, collected on 2 February 2014; ZMKU R 01052 same data as holotype except 14°30.091’N, 101°55.285’E, 443 m elevation, collected on 20 June 2014 by NA, AA and KT; ZMKU R 01054–01056 same data as holotype except 14°30.091’N, 101°55.285’E, 443 m elevation, collected on 7 July 2014 by NA, AA, AR and KT .

Eight adult females: ZMKU R 01059 same data as holotype except 14°30.044’N, 101°55.372’E, 455 m elevation, collected on 3 November 2013; ZMKU R 01060–01061 same data as holotype except from 14°30.091’N, 101°55.285’E, 443 m elevation, collected on 7 July 2014 by NA, AA, AR and KT; ZMKU R 01062 same data as holotype except 14°29.434’N, 101°55.094’E, 650 m elevation, collected on 11 October 2014 by NA, AA, AR, KT, SS and SY; ZMKU R 00724–00725 , ZMKU R 01063–01064 same data as holotype except 14°30.091’N, 101°55.285’E, 443 m elevation, collected on 12 October 2014 by NA, AA, AR, KT, SS and SY .

Referred Specimens. ZMKU R 01065 (one juvenile), same data as holotype ; ZMKU R 01066 (one immature male), same data as holotype except collected 7 July 2014 by NA, AA, AR and KT.

Etymology. The specific epithet, sakaeratensis referred to the type locality of Sakaerat Biosphere Reserve, Udom Sap Subdistrict, Wang Nam Khiao District, Nakhon Ratchasima Province, northeastern Thailand.

Diagnosis. Cyrtodactylus sakaeratensis sp. nov. differs from all members of the C. intermedius group by having the following combination of characters: (1) SVL of 64.6–80.0 mm (mean 72.5 ± 5.0 mm, n = 14) in adult males and 65.0– 83.1 mm (mean 71.3 ± 7.2 mm, n = 8) in adult females; (2) nine to 11 supralabial and nine or 10 infralabial scales; (3) 27 or 28 paravertebral tubercles; (4) 17–19 longitudinal rows of dorsal tubercles; (5) 46–48 ventral scales; (6) seven or eight expanded subdigital lamellae on 4 th toe; (7) 12 or 13 unmodified subdigital lamellae on 4 th toe; (8) 20 total subdigital lamellae on the fourth toes; (9) 22–28 total number of enlarged femoral scales; (10) enlarged femoral and precloacal scales continuous; (11) seven or eight pore-bearing precloacal scales in males; (12) three rows of enlarged post-precloacal scales; (13) two or three postcloacal tubercles; (14) proximal femoral scales from greater than 1/2 the size of distal femoral scales; (15) absence of interdigital pocketing between digits of forefeet and hindfeet; (16) posterior border of the nuchal loop pointed.

Description of holotype. Adult male in good state of preservation with 71.9 mm SVL; head relatively moderate in length (HL/SVL 0.29), moderately wide (HW/HL 0.67), slightly depressed (HD/HL 0.36), distinct from neck, and subtriangular in dorsal profile; lores concave anteriorly, inflated posteriorly; frontal region flattened, prefrontal region slightly concave; canthus rostralis rounded; snout rather elongate (ES/HL 0.41), rounded in the rostral region, eye to snout distance slightly greater than head depth; eye large (ED/HL 0.24), 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 (3.10 mm) than high (1.77 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 supralabials; external nares anteriorly bordered by rostral, dorsally by large supranasal, posteriorly by two small postnasals, ventrally bordered by 1 st supralabials; 7L/7R subrectangular supralabials extending to below the center of the eye, 9L/9R to the posterior margin of the eyeball, subrectangular anteriorly, elliptical shape posteriorly; 2 nd to 6 th supralabials slightly larger than 1 st suprabials; 7L/7R 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 flat to domed, relatively raise, slightly larger than granular scales on top of head and occiput; scales of occiput and top of head intermixed with distinct, enlarged tubercles, more prominent tubercles between occiput and ear opening; dorsal supraciliaries smooth, not elongate; mental large, triangular, 2.9 mm in width, 2.0 mm in length, laterally bordered by 1 st infralabials 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 extending posteriorly to 7 th infralabials for both side; and gular and throat scales small, granular, grading posteriorly into larger, flatter, smooth, imbricate, pectoral and ventral scales.

Body slightly slender, relatively short (AG/SVL 0.46), with poorly defined narrow ventrolateral folds posteriorly; dorsal scales small, mostly homogenous, granular, interspersed with relatively large, conical, irregularly arranged, slightly prominent trihedral keeled tubercles; tubercles extending from occipital region onto anterior portion of original 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 18 longitudinal rows of dorsal tubercles between ventrolateral body folds at midbody; 27 paravertebral tubercles; 47 longitudinal rows of flat, imbricate smooth ventral scales between ventrolateral body fold much larger than dorsal scales; one row of 12L/12R enlarged femoral scales continuous with enlarged precloacal scales, enlarged femoral scales extending along 2/3 of the femora; proximal femoral scales greater than 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; 3L/3R postcloacal tubercles.

Forelimbs moderately 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; 16L/16R total subdigital lamellae on 4 th finger; 10L/10R proximal subdigital lamellae rectangular with rounded, wide, transversely expanded proximal to joint inflection on 4 th finger, 12L/12R 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, thicker than forelimbs, moderate in length (TBL/SVL 0.17); dorsal scales slightly rounded, granular, conical, interspersed with enlarged, conical, 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, 83.7 mm in length, longer than SVL (TL/SVL 1.16), moderate in proportions, segmented, cylindrical, wide anteriorly, 6.6 mm in width at base, tapering to a point; becoming slender toward the tip; dorsal scales of original portion of tail small, flat, squared; dorsal scales of tail base granular, slightly 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, 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.

Color of holotype in life ( Figs. 3 , 4 ). Dorsal ground color of head, body, and limbs light brown; superciliary scales yellow; iris brown with dark-brown vermiculations; rostral and loreal regions lighter brown with scattered yellowish scales; supralabial, infralabial and mental scales off-white with yellowish markings; dark-brown nuchal loop with pointed posterior border extends from posterior margin of orbit to posterior margin of the other orbit; nuchal loop edged with yellowish margins and tubercles; four similar dark-brown body bands, bordered by yellowish margins and tubercles with slightly lightened centers occur between limb insertion; first body band terminates at shoulders near anterior margin of forelimb insertion; second and third body bands terminate near to mid-flank region, not reaching to ventrolateral folds; fourth body band terminates at anterior margin of hindlimb insertion; limbs lighter brown with yellowish on enlarged tubercles; dorsal portion of forelimbs bearing scattered dark-brown marking with dull yellow spots; dorsal portion of hindlimbs bearing mottled with yellow spots; five wide dark-brown caudal bands slightly wider than five light-colored caudal bands on original portion of tail; dark caudal bands encircling ventral scales, bordered by yellowish margins and tubercles; regenerated portion of tail, uniformly brown with small, scattered creamy white markings dorsally; regenerated tail extending from posterior margin of 5 th light caudal bands. All ventral surfaces of head, body, and limb dull white to beige, generally 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 dark mottling anteriorly.

Color in preservative ( Fig. 5 ). The overall color pattern similar to that in life with some fading. Dorsal ground color of head, body, limbs, flanks, and tail became pale brown; regenerated tail turned pale brown. All yellow coloration on dorsal and ventral surfaces faded to greyish white; dark body and dark caudal bands lighter marking; entire ventral surfaces changed to greyish white with small, dark mottling.

Variation ( Fig. 6 ). All paratypes closely approach the holotype in coloration. Morphometric, meristic, and color pattern characters of the type series of Cyrtodactylus sakaeratensis sp. nov. are presented in Tables 6 and 7 . Most paratypes have four body bands except two adult males ( ZMKU R 01048 and ZMKU R 01052 ) who five body bands. One immature male ( ZMKU R 01066 ; referred specimen) has three body bands. The fourth body band of ZMKU R 01052 is incomplete. The third body band of ZMKU R 01057 is incomplete. The third body band of ZMKU R 01061 bifurcates on the midline to the left ventrolateral fold. The third and fourth body bands of ZMKU R 00725 , 01054 , 01057 , 01059 , 01062–01063 are irregular pattern. All adult females paratypes have precloacal scales with pits rather than pores. Posterior portion of tail in juveniles white ( Fig. 6C–D ).

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Distribution and natural history. Cyrtodactylus sakaeratensis sp. nov. is known only from the type locality at Sakaerat Biosphere Reserve, Udom Sap Subdistrict, Wang Nam Khiao District, Nakhon Ratchasima Province, Thailand ( Fig. 1A ). The type locality is dominated by dry evergreen forest mixed with deciduous vegetation and rocky terrain in various microhabitats ( Figs. 6 , 7 ). All type series and referred specimens were found at night (1900–2200 h). The holotype (ZMKU R 01050) was found on tree trunk, up to 2 m above the ground level. All other paratypes and referred specimens were found in various microhabitats, including perched on tree trunk, branch, twig, log, ground and leaf litter. Most geckos used tree trunks 1.0–25.0 cm. in diameter. Cyrtodactylus sakaeratensis sp. nov. appears to be a nocturnal species, as animal observed during daytime were inactive, slow-moving or asleep on tree holes, soil holes or termite mounds. During observations, when disturbed, the geckos retreated into preexisting holes in the ground, suggesting that Cyrtodactylus sakaeratensis sp. nov. may use these holes as daytime refuges and that soil characteristics might be associated with their habitat selection.

Comparisons. Cyrtodactylus sakaeratensis sp. nov. is differentiated from 15 recognized species of the C. intermedius group ( Table 8 ; Fig. 8 ) by having a unique combination of diagnostic characteristics and phylogenetic placement, and uncorrected pairwise sequence divergences of mtDNA (ND2) of 6.02–29.10%.

Cyrtodactylus sakaeratensis sp. nov. is distinguished from C. auralensis by having 27 or 28 paravertebral tubercles between limb insertions (vs. 29–32 tubercles); 46–48 ventral scales (vs. 37–44 scales); proximal femoral scales <1/2 size of distal femoral scales absent (vs. present); dark pigmented blotches on top of the head absent (vs. present); and posterior border of the nuchal loop pointed (vs. rounded).

Cyrtodactylus sakaeratensis sp. nov. differs from C. bokorensis by having a smaller maximum SVL of 83.1 mm (vs. 93.0 mm); nine to 11 supralabial scales (vs. eight scales); 27 or 28 paravertebral tubercles between limb insertions (vs. 31–33 tubercles); and proximal femoral scales <1/2 size of distal femoral scales absent (vs. present).

Cyrtodactylus sakaeratensis sp. nov. differs from C. borgattaorum by having a larger maximum SVL of 83.1 mm (vs. 65.8 mm); nine to 11 supralabial scales (vs. 12 scales); 27 or 28 paravertebral tubercles between limb insertions (vs. 22 or 23 tubercles); 17–19 longitudinal rows of body tubercles (vs. 12 rows); 46–48 ventral scales (vs. 35 or 39 scales); enlarged femoral and precloacal scales continuous (vs. discontinuous); and dark pigmented blotches on top of the head absent (vs. present).

Cyrtodactylus sakaeratensis sp. nov. differs from C. cardamomensis by having 27 or 28 paravertebral tubercles between limb insertions (vs. 29–34 tubercles); 46–48 ventral scales (vs. 36–43 scales); seven or eight expanded subdigital lamellae on 4 th toe (vs. five or six lamellae); 20 total subdigital lamellae on 4 th toe (vs. 17–19 lamellae); seven or eight precloacal pores in males (vs. nine to 10 pores); and posterior border of the nuchal loop pointed (vs. rounded).

Cyrtodactylus sakaeratensis sp. nov. differs from C. disjunctus by having a larger maximum SVL of 83.1 mm (vs. 66.7 mm); nine to 11 supralabial scales (vs. 12 scales); nine or 10 infralabial scales (vs. 11 scales); 27–28 paravertebral tubercles between limb insertions (vs. 41 tubercles); 17–19 longitudinal rows of body tubercles (vs. 11 rows); 46–48 ventral scales (vs. 36 scales); 12 or 13 unmodified subdigital lamellae on 4 th toe (vs. nine lamellae); 20 total subdigital lamellae on 4 th toe (vs. 17 lamellae); 22–28 total number of enlarged femoral scales (vs. 21 scales); three post-precloacal scales rows (vs. one row); two or three postcloacal tubercles (vs. one tubercle); enlarged femoral and precloacal scales continuous (vs. discontinuous); and proximal femoral scales <1/2 size of distal femoral scales absent (vs. present).

Cyrtodactylus sakaeratensis sp. nov. differs from C. hontreensis by having a smaller maximum SVL of 83.1 mm (vs. 88.9 mm); 27 or 28 paravertebral tubercles between limb insertions (vs. 20–24 tubercles); 17–19 longitudinal rows of body tubercles (vs. 14 rows); 46–48 ventral scales (vs. 40–42 scales); 22–28 total number of enlarged femoral scales (vs. 4–9 scales); enlarged femoral and precloacal scales continuous (vs. discontinuous); and dark pigmented blotches on top of the head absent (vs. present).

Cyrtodactylus sakaeratensis sp. nov. differs from C. intermedius by having a smaller maximum SVL of 83.1 mm (vs. 88.9 mm); 27 or 28 paravertebral tubercles between limb insertions (vs. 31–33 tubercles); 46–48 ventral scales (vs. 42–45 scales); proximal femoral scales <1/2 size of distal femoral scales absent (vs. present); and posterior border of the nuchal loop pointed (vs. rounded).

Cyrtodactylus sakaeratensis sp. nov. differs from C. kampingpoiensis by having a larger maximum SVL of 83.1 mm (vs. 79.6 mm); 27 or 28 paravertebral tubercles between limb insertions (vs. 30–37 tubercles); enlarged femoral and precloacal scales continuous (vs. discontinuous); and posterior border of the nuchal loop pointed (vs. rounded).

Cyrtodactylus sakaeratensis sp. nov. differs from C. khlonghatensis by having a smaller maximum SVL of 83.1 mm (vs. 88.5 mm); nine to 11 supralabial scales (vs. eight scales); 27 or 28 paravertebral tubercles between limb insertions (vs. 30–32 tubercles); 17–19 longitudinal rows of body tubercles (vs. 20 or 21 rows); 46–48 ventral scales (vs. 43 or 44 scales); 22–28 total number of enlarged femoral scales (vs. 31 or 32 scales); proximal femoral scales <1/2 size of distal femoral scales absent (vs. present); and posterior border of the nuchal loop pointed (vs. rounded).

Cyrtodactylus sakaeratensis sp. nov. differs from C. kohrongensis by having a larger maximum SVL of 83.1 mm (vs. 76.1 mm); 46–48 ventral scales (vs. 38–42 scales); enlarged femoral and precloacal scales continuous (vs. discontinuous); proximal femoral scales <1/2 size of distal femoral scales absent (vs. present); and posterior border of the nuchal loop pointed (vs. rounded).

Cyrtodactylus sakaeratensis sp. nov. differs from C. kulenensis by having a smaller maximum SVL of 83.1 mm (vs. 89.6 mm); 27 or 28 paravertebral tubercles between limb insertions (vs. 33–38 tubercles); 46–48 ventral scales (vs. 38–44 scales); 22–28 total number of enlarged femoral scales (vs. 12–21 scales); proximal femoral scales <1/2 size of distal femoral scales absent (vs. present); seven or eight precloacal pores in males (vs. nine to 10 pores); and posterior border of the nuchal loop pointed (vs. rounded).

Cyrtodactylus sakaeratensis sp. nov. differs from C. laangensis by having 27 or 28 paravertebral tubercles between limb insertions (vs. 29–32 tubercles); 46–48 ventral scales (vs. 37–40 scales); 22–28 total number of enlarged femoral scales (vs. 0–16 scales); proximal femoral scales <1/2 size of distal femoral scales absent (vs. present); and posterior border of the nuchal loop pointed (vs. rounded).

Cyrtodactylus sakaeratensis sp. nov. differs from C. phuquocensis by having 46–48 ventral scales (vs. 38–43 scales); 20 total number of subdigital lamellae beneath the 4 th toe (vs. 17–19 lamellae); proximal femoral scales <1/2 size of distal femoral scales absent (vs. present); and posterior border of the nuchal loop pointed (vs. rounded).

Cyrtodactylus sakaeratensis sp. nov. differs from C. regicavernicolus by having a larger maximum SVL of 83.1 mm (vs. 80.7 mm); 46–48 ventral scales (vs. 37–44 scales); enlarged femoral and precloacal scales continuous (vs. discontinuous); and dark pigmented blotches on top of the head absent (vs. present).

Cyrtodactylus sakaeratensis sp. nov. differs from C. septimontium by having a smaller maximum SVL of 83.1 mm (vs. 90.4 mm); 46–48 ventral scales (vs. 38–42 scales); proximal femoral scales <1/2 size of distal femoral scales absent (vs. present); and posterior border of the nuchal loop pointed (vs. rounded).

Cyrtodactylus sakaeratensis sp. nov. differs from C. thylacodactylus by having a larger maximum SVL of 83.1 mm (vs. 74.6 mm); nine to 11 supralabial scales (vs. seven scales); 27 or 28 paravertebral tubercles between limb insertions (vs. 29–31 tubercles); 46–48 ventral scales (vs. 36–42 scales); seven or eight expanded subdigital lamellae proximal to the digital inflection on the 4 th toe (vs. five or six lamellae); 20 total number of subdigital lamellae beneath the 4 th toe (vs. 15–18 lamellae); interdigital pocketing between digits of forefeet and hindfeet absent (vs. present); and posterior border of the nuchal loop pointed (vs. rounded).

Figures

FIGURE 1.A. Map illustrating the type locality (star) of Cyrtodactylus sakaeratensis sp.nov. and the Cyrtodactylus intermedius group samples used in the molecular analyses. B.A best maximum likelihood topology illustrating the phylogenetic relationships of the Cyrtodactylus intermedius group. The topology is based on 1,198 bp of the ND2 gene and flanking tRNA sequences. Nodal support values are presented as posterior probabilities (BPP) from Bayesian analysis followed by ultrafast bootstrap values (UFB) from Maximum Likelihood analysis.

FIGURE 3.Adult male holotype of Cyrtodactylus sakaeratensis sp. nov. (ZMKU R 01050), photographed prior to preservation. A. Palmar view of the right hand. B. Plantar view of the right foot. C. Lateral view of the left side of the head. D. Dorsal view. E. Ventral view. F. Precloacal region showing the arrangement of enlarged femoroprecloacal scales. Scale bar: 10 mm.

FIGURE 4. Adult male holotype (ZMKU R 01050) of Cyrtodactylus sakaeratensis sp. nov. in life from Sakaerat Biosphere Reserve, Udom Sap Subdistrict, Wang Nam Khiao District, Nakhon Ratchasima Province, Thailand.

FIGURE 5. Adult male holotype of Cyrtodactylus sakaeratensis sp. nov. (ZMKU R 01050; field number AA 01865) in preservation from Sakaerat Biosphere Reserve, Udom Sap Subdistrict, Wang Nam Khiao District, Nakhon Ratchasima Province, Thailand.A. Dorsal view. B. Ventral view. Scale bars in both views: 10 mm.

FIGURE 6. Variation in color pattern in Cyrtodactylus sakaeratensis sp. nov. from Sakaerat Biosphere Reserve, Udom Sap Subdistrict, Wang Nam Khiao District, Nakhon Ratchasima Province, Thailand. A. Adult male (not collected). B. Adult female (not collected). C. and D. Juveniles (not collected).

FIGURE 7. Habitat of Cyrtodactylus sakaeratensis sp. nov. at the type locality, Sakaerat Biosphere Reserve, Udom Sap Subdistrict, Wang Nam Khiao District, Nakhon Ratchasima Province, Thailand.

FIGURE 8. The comparison of the posterior border of the nuchal loop among Cyrtodactylus sakaeratensis sp. nov. and closely related Thai species reveals distinct morphological differences. A. C. sakaeratensis sp. nov. (ZMKU R 01050) is characterized by a pointed posterior border of the nuchal loop. B. C. khlonghatensis (ZMKU R 01068) and C. C. intermedius (ZMKU R 01041), both exhibit a rounded posterior border of the nuchal loop.

Tables

TABLE 8. Comparative characters of the Cyrtodactylus sakaeratensis sp. nov. and the C. intermedius group. Abbreviations are defined in Materials and methods. Grey highlight indicates differences with a new species. Key: NA = no data or not applicable.

Characters / species	C. sakaeratensis sp. nov.	C. auralensis	C. bokorensis	C. borgattaorum	C. cardamomensis	C. disjunctus	C. hontreensis	C. intermedius	C. kampingpoiensis	C. khlonghatensis	C. kohrongensis	C. kulenensis	C. laangensis	C. phuquocensis	C. regicavernicolus	C. septimontium	C. thylacodactylus
References	This study	Murdoch et al. 2019		Tran et al. 2024	Murdoch et al. 2019	Grismer et al. 2023	Ngo et al. 2008	Ampai et al. 2024	Quah et al. 2025	Ampai et al. 2024	Grismer et al. 2020	Grismer et al. 2021	Murdoch et al. 2019	Ngo et al. 2010	Chhin et al. 2024	Murdoch et al. 2019
Maximum SVL	83.1	84.3	93.0	65.8	84.1	66.7	88.9	88.9	79.6	88.5	76.1	89.6	82.2	85.8	80.7	90.4	74.6
SL	9–11	8–9	8	12	7–9	12	11–13	8–10	9–11	8	8–10	8–11	7–9	9–13	7–10	8–9	7
IL	9–10	9–11	8–10	10 or 11	9–10	11	9–12	9–11	9–10	9	7–10	8–11	10–11	9–11	6–9	9–11	8–10
PVT	27–28	29–32	31–33	22 or 23	29–34	41	20–24	31–33	30–37	30–32	25–33	33–38	29–32	NA	25–31	27–30	29–31
LRT	17–19	17 or 18	18–20	12	17–21	11	14	19 or 20	19–21	20 or 21	16–20	17–19	17 or 18	16–18	15–18	16–19	18–20
VS	46–48	37–44	42–48	35 or 39	36–43	36	40–42	42–45	38–46	43 or 44	38–42	38–44	37–40	38–43	37–44	38–42	36–42
4SLE	7 or8	6 or 7	6 or 7	8 or 10	5 or 6	8	NA	7 or 8	5–7	7 or 8	7–9	7 or 8	7	5 or 6	7–10	6 or 7	5 or 6
4SLU	12 or13	12–15	12–14	12 or 13	12 or 13	9	NA	13	11–13	12	12–15	10–14	11–13	12 or 13	12–14	11–13	10–12
4SLT	20	19–21	18–20	21 or 22	17–19	17	NA	19–21	18–20	19 or 20	20–24	18–21	18–20	17–19	19–23	17–20	15–18
FS	22–28	23–28	26–30	21 or 22	23–28	21	4–9	23–26	26–34	31 or 32	14–26	12–21	0–16	21–28	7–23	24–28	17–22
PS	6–9	7–9	7–10	8 or 9	8–10	10	7–8	8–11	5–9	6–8	7–9	9–10	7–9	6–9	6–9	7 or 8	7–9
PP	7 or 8	7–9	7–9	8 or 9	9–10	NA	NA	8–11	7–9	6–8	7	9–10	8–9	6–7	6–9	7 or 8	7–9
PPS	3	2 or 3	2 or 3	2 or 3	2 or 3	1	NA	3	3 or 4	3 or 4	2 or 3	2 or 3	2 or 3	2 or 3	3	2 or 3	3
PCT	2 or3	3	2 or 3	3	2 or 3	1	NA	1–3	0–3	1–3	2	2 or 3	2–4	2 or 3	2–5	2	3
FS–PS	yes	yes	yes	no	yes	no	no	yes	no	yes	no	yes	yes	yes	no	yes	yes
FS<1/2	no	yes	yes	no	no	yes	no	yes	no	yes	yes	yes	yes	yes	NA	yes	no
PDH	no	no	no	no	no	no	no	no	no	no	no	no	no	no	no	no	yes
PDF	no	no	no	no	no	no	no	no	no	no	no	no	no	no	no	no	yes
HeadMrk	no	yes	variable	yes	no	no	yes	no	no	variable	no	no	variable	no	yes	no	no
PBNL	pointed	rounded	pointed	NA	rounded	NA	NA	rounded	rounded	rounded	rounded	rounded	rounded	rounded	rounded or pointed	rounded	rounded