Cnemaspis huaseesom
A new rock gecko in the Cnemaspis siamensis group (Reptilia, Gekkonidae) from Kanchanaburi Province, western Thailand
Rujirawan, Attapol
Yodthong, Siriporn
Ampai, Natee
Termprayoon, Korkhwan
Aksornneam, Akrachai
Stuart, Bryan L.
Aowphol, Anchalee
Zoosystematics and Evolution
2022
2022-09-13
98
2
345
363
https://zoobank.org/899EA1FF-67AC-453A-87A0-31E55C4A242D
Rujirawan & Yodthong & Ampai & Termprayoon & Aksornneam & Stuart & Aowphol, 2022
Rujirawan & Yodthong & Ampai & Termprayoon & Aksornneam & Stuart & Aowphol
2022
Gekkonidae
Cnemaspis
treatment-meta
Animalia
Cnemaspis auriventralis
Squamata
0
345
species
auriventralis
sp. nov.
Figs 3 , 4 , 5 , 6 , 7 , 8
Cnemaspis huaseesomYodthong, Rujirawan, Stuart, Grismer, Aksornneam, Termprayoon, Ampai & Aowphol, 2022: 160.
Holotype. (Figs 3- 6).ZMKU R 01001, adult male from Thailand, Kanchanaburi Province, Si Sawat District, Tha Kradan Subdistrict, Erawan National Park, Tham Phra That Protection Unit ( 14.39730N, 99.0818E; 747 m elevation), collected 18 November 2021 by Attapol Rujirawan, Siriporn Yodthong, Natee Ampai and Akrachai Aksornneam. Figure 3.Adult male holotype of Cnemaspis auriventralissp. nov. (ZMKU R 01001) in life. Figure 4.Adult male holotype of Cnemaspis auriventralissp. nov. (ZMKU R 01001) immediately after euthanasia. A.Dorsal and ventral views; B.Subcaudal region and C.Precloacal region with precloacal pores (outlined in black). Figure 5.Adult male holotype of Cnemaspis auriventralissp. nov. (ZMKU R 01001) immediately after euthanasia. A.Lateral view of head; B.Dorsal and ventral views of head (supranasal and internasal scales in dorsal view and mental, postmental and first infralabial scales in ventral view; outlined in black); C.Palmar view of the right manus; D.Plantar view of the right pes. Figure 6.Dorsal and ventral views of adult male holotype of Cnemaspis auriventralissp. nov. (ZMKU R 01001) in preservative.
Paratypes. (Figs 7, 8).Two adult males and two adult females. ZMKU R 01002 (adult female), same collection data as the holotype. ZMKU R 01003 (adult female), same collection data as the holotype, except collected 20 November 2021. ZMKU R 00999-01000 (two adult males) same collection data as the holotype, except collected 26 November 2019 by Attapol Rujirawan, Siriporn Yodthong, Korkhwan Termprayoon and Akrachai Aksornneam. Figure 7.Adult female paratype of Cnemaspis auriventralissp. nov. (ZMKU R 01002). A.Dorsolateral view in life; B.Dorsal and ventral views immediately after euthanasia; C.Dorsal and ventral views in preservative. Figure 8. Cnemaspis auriventralissp. nov. paratypes in life. A.Adult male ZMKU R 00999; B.Adult male ZMKU R 01000; C.Adult female ZMKU R 01003.
Diagnosis. Cnemaspis auriventralissp. nov. can be distinguished from all other species in the C. siamensisgroup by having the following combination of morphological and colour pattern characters: SVL 36.7-38.6 mm in adult males ( N= 3), 32.9-36.9 mm in adult females ( N= 2); eight to ten supralabials; seven to nine infralabials; ventral scales smooth; six or seven precloacal pores in males; 16-17 paravertebral tubercles linearly arranged; tubercles on the lower flanks present; lateral caudal furrows present; no caudal tubercles in the lateral furrows; ventrolateral caudal tubercles present anteriorly; caudal tubercles not encircling tail; subcaudals smooth bearing a single median row of enlarged smooth scales; two postcloacal tubercles on each side; no shield-like subtibial scales; subtibial scales smooth; no enlarged submetatarsal scales; 23-27 subdigital lamellae on the fourth toe; sexually dimorphic in dorsal and ventral colour pattern; prescapular marking absent; gular marking absent; and yellow colouration in life on all ventral surfaces of head, body and tail in adult males.
Description of holotype. Adult male; SVL 38.0 mm; head oblong in dorsal profile, moderate in size (HL/SVL 0.28), somewhat narrow (HW/SVL 0.19), flat (HD/HL 0.40), distinct from neck; snout moderate (ES/HL 0.42), snout slightly concave in lateral profile; postnasal region concave medially; scales of rostrum round, weakly keeled, raised, larger than similarly-shaped scales on occiput; weak supraorbital ridges; weak frontorostral sulcus; canthus rostralis smoothly rounded; eye large (ED/HL 0.24); extra-brillar fringe scales small in general, but slightly larger anteriorly; pupil round; ear opening oval, taller than wide; rostral concave dorsally, dorsal 80% divided by longitudinal groove; rostral bordered posteriorly by supranasals, one small azygous internasal and nostrils; bordered laterally by first supralabials; 8R/9L (right/left) raised supralabials of similar size, but smallest posteriorly; 8R/8L infralabials, decreasing gradually in size posteriorly; nostrils small, elliptical, orientated dorsolaterally; bordered posteriorly by single, flat, enlarged postnasal scales; mental large, triangular, flat, extending to level of second infralabials, bordered posteriorly by three postmentals, medial postmental smaller than laterals; gular scales smooth, flat, round or oval, juxtaposed; throat scales smooth, raised, round, juxtaposed to subimbricate. Body slender, elongate (AG/SVL 0.42); small, raised, weakly keeled, dorsal scales generally equal in size throughout body, intermixed with numerous, large, multi-keeled, linearly arranged tubercles; enlarged, multi-keeled, conical tubercles on flanks; tubercles extend from the occiput to base of the tail and continue on tail in whorls; body tubercles slightly smaller anteriorly; 17 paravertebral tubercles; pectoral and abdominal scales smooth, flat, imbricate; abdominal scales larger than pectoral and dorsal scales; seven contiguous, pore-bearing, precloacal scales; precloacal pores round to elongate. Fore-limbs moderately long, slender; dorsal scales raised, weakly keeled, juxtaposed; ventral scales of brachia smooth, raised, juxtaposed; scales beneath forearm smooth, slightly raised, subimbricate; digits long with an inflected joint; claws recurved; subdigital lamellae unnotched; subdigital lamellae wide throughout length of digits, bearing a larger scale at digital inflections; interdigital webbing absent; fingers increase in length from first to fifth, with fourth and fifth nearly equal in length; relative length of fingers I <II <III <V ≤ IV; total subdigital lamellae on fingers I-V: 12-18-21-25-22 (right), 12-18-22-broken-broken (left). Hind-limbs slightly longer and thicker than fore-limbs; dorsal scales keeled, raised, juxtaposed; ventral scales of thigh and subtibial scales smooth, flat, imbricate; plantar scales smooth, raised, subimbricate; enlarged submetatarsal scales beneath first toes absent; digits elongate with an inflected joint; claws recurved; subdigital lamellae unnotched; lamellae wide throughout length of digits; enlarged scales at digital inflections; interdigital webbing absent; toes increase in length from first to fourth and fifth nearly equal in length; relative length of toes I <II <III <V ≤ IV; total subdigital lamellae on toes I-V: 11-18-22-23-22 (right), 11-17-21-24-21 (left). Tail original (broken at tip), long, slender, TL = 45.9 mm (TL/SVL 1.21); dorsal, caudal scales arranged in segmented whorls; caudal scales keeled, raised, juxtaposed; mid-dorsal and lateral, caudal furrows present; subcaudals smooth; median row of enlarged subcaudal scales present; paravertebral, dorsolateral and lateral rows of large, keeled, caudal tubercles extend length of tail; ventrolateral rows of tubercles present only anteriorly; caudal tubercle rows do not encircle tail; tubercles absent from lateral caudal furrow; enlarged postcloacal tubercles 2R/2L on lateral surface of hemipenial swellings at base of tail.
Colouration in life. (Figs 3- 5).Dorsal ground colour of head, nape and fore-limbs grey; dorsal ground colour of trunk and hind-limbs yellowish-grey; dorsal ground colour of tail yellow; top of head bearing small, diffuse, faint, dark and light markings; dark postorbital stripes faint extending to occiput; pair of dark, diffuse, blotches on nape; large, light, irregularly-shaped, vertebral blotches extend from nape to base of tail, continuing on to tail as light yellow caudal bands; small, light, irregularly-shaped blotches in shoulder regions and flanks; limbs mottled with small, diffuse light and dark blotches; digits light grey bearing thin, dark bands; all ventral surfaces of head, body and tail yellow; ventral surfaces of limbs light grey with yellow speckling.
Colouration in preservative. (Fig. 6).Dorsal and lateral surfaces of head, body, limbs and tail darker grey than in life, with some fading of markings. Ventral surfaces of head, body, limbs and tail creamy-white, with minute dark speckling on gular region, limbs and tail regions.
Variation. Cnemaspis auriventralissp. nov. shows significant sexual dimorphism in colour pattern. All female paratypes lack yellow colouration on the tail and ventral surfaces. Female paratype ZMKU R 01003 was darker coloured in life than other members of the type series. Two male paratypes ZMKU R 00999-01000 were lighter coloured than the holotype in life. Dark markings on the dorsum of all paratypes are more prominent than the holotype. The female paratypes (ZMKU R 01002-01003) lack precloacal pores and have postcloacal tubercles that are relatively smaller than those in males. One male paratype (ZMKU R 01000) has six (2R/4L) pore-bearing precloacal scales separated by a single scale lacking pore. Variation in morphometric and meristic data amongst specimens in the type series are presented in Table 4. Table 4.Descriptive measurements (millimetres) and meristics (right/left) of the type series of Cnemaspis auriventralissp. nov. Key: M = adult male; F = adult female; Cont. = continuous; Sep. = separated; NA = data unavailable or not applicable. Morphological abbreviations are defined in Table 1. Museum number ZMKU R 01001 ZMKU R 00999 ZMKU R 01000 ZMKU R 01002 ZMKU R 01003 All males All females Type holotype paratype paratype paratype paratype N= 3 N= 2 Sex M M M F F Mean +/-SD (min-max) Mean +/-SD (min-max) SVL 38.0 38.6 36.7 32.9 36.9 37.8 +/-0.97 (36.7-38.6) 34.9 +/-2.83 (32.9-36.9) TW 3.3 3.1 3.4 3.3 3.0 3.3 +/-0.15 (3.1-3.4) 3.2 +/-0.21 (3.0-3.3) TL 45.9 45.6 48.1 36.3 50.0 46.5 +/-0.21 (45.6-48.1)a 50.0b Tail condition broken original original broken original NA NA FL 6.4 6.4 6.2 5.8 6.3 6.3 +/-0.12 (6.2-6.4) 6.1 +/-0.35 (5.8-6.3) TBL 8.3 8.2 8.0 7.3 8.7 8.2 +/-0.15 (8.0-8.3) 8.0 +/-0.99 (7.3-8.7) HL 10.5 10.9 10.4 10.2 11.2 10.6 +/-0.26 (10.4-10.9) 10.7 +/-0.71 (10.2-11.2) HW 7.2 7.3 7.2 6.3 7.3 7.2 +/-0.06 (7.2-7.3) 6.8 +/-0.71 (6.3-7.3) HD 4.2 4.1 3.9 4.0 4.1 4.1 +/-0.15 (3.9-4.2) 4.1 +/-0.07 (4.0-4.1) AG 16.1 16.0 16.2 15.7 16.4 16.1 +/-0.10 (16.0-16.2) 16.1 +/-0.49 (15.7-16.4) ED 2.5 2.5 2.2 2.0 2.2 2.4 +/-0.17 (2.2-2.5) 2.1 +/-0.14 (2.0-2.2) EE 2.8 3.0 2.8 2.7 3.1 2.9 +/-0.12 (2.8-3.0) 2.9 +/-0.28 (2.7-3.1) EL 1.3 0.9 1.1 1.2 1.1 1.1 +/-0.20 (0.9-1.3) 1.2 +/-0.07 (1.1-1.2) EN 3.7 3.7 3.6 3.3 3.4 3.7 +/-0.06 (3.6-3.7) 3.4 +/-0.07 (3.3-3.4) ES 4.4 4.8 4.6 4.6 4.5 4.6 +/-0.20 (4.4-4.8) 4.6 +/-0.07 (4.5-4.6) IO 2.3 2.4 2.5 2.2 2.2 2.4 +/-0.10 (2.3-2.5) 2.2 +/-0.00 (2.2-2.2) IN 1.1 1.1 1.0 0.9 1.0 1.1 +/-0.06 (1.0-1.1) 1.0 +/-0.07 (0.9-1.0) HL/SVL 0.28 0.28 0.28 0.31 0.30 0.28 +/-0.00 (0.28-0.28) 0.31 +/-0.00 (0.30-0.31) HW/SVL 0.19 0.19 0.20 0.19 0.20 0.19 +/-0.00 (0.19-0.20) 0.19 +/-0.00 (0.19-0.20) HD/HL 0.40 0.38 0.38 0.39 0.37 0.38 +/-0.01 (0.38-0.40) 0.38 +/-0.02 (0.37-0.39) ES/HL 0.42 0.44 0.44 0.45 0.40 0.43 +/-0.01 (0.42-0.44) 0.43 +/-0.03 (0.40-0.45) ED/HL 0.24 0.23 0.21 0.20 0.20 0.23 +/-0.01 (0.21-0.24) 0.20 +/-0.00 (0.20-0.20) AG/SVL 0.42 0.41 0.44 0.48 0.44 0.43 +/-0.01 (0.41-0.44) 0.46 +/-0.02 (0.44-0.48) TL/SVL 1.21 1.18 1.31 1.10 1.36 1.23 +/-0.07 (1.18-1.31) 1.23 +/-0.18 (1.10-1.36) Scalation Min-max SL 8R/9L 9R/9L 9R/9L 10R/9L 8R/8L 8-10 IL 8R/8L 9R/7L 8R/8L 9R/8L 7R/7L 7-9 PVT 17 17 16 16 16 16-17 4TL 23R/24L 25R/26L 26R/27L 26R/27L 27R/27L 23-27 PP 7 7 6 (2R/4L) absent absent 6-7 Pore arrangement Cont. Cont. Sep. NA NA NA PPS 2R/2L 2R/2L 2R/2L 2R/2L 2R/2L 2 a Data of original tails from two males. b Data of original tail from one female.
Distribution. This species is known only from the type locality. The type series was collected from a karst formation that is part of the Tenasserim Mountain Range in Erawan National Park, Tha Kradan Subdistrict, Si Sawat District, Kanchanaburi Province, Thailand (Figs 1, 9). Figure 9.Habitat of Cnemaspis auriventralissp. nov. at the type locality at Erawan National Park, Si Sawat District, Kanchanaburi Province, Thailand. A.Microhabitat in karst boulder crevice (white arrow); B.Microhabitat on undersides of karst boulder (white arrow).
Natural history. The type locality of Cnemaspis auriventralissp. nov. is a karst forest at 747 m elevation. The type series was collected in November 2019 at 14:00-14:30 h with temperature 25.4 °C and relative humidity 62.1% and in November 2021 at 16:00-20:00 h with temperature 25.3-26.8 °C and relative humidity 79.9-88.0%. All specimens were found on karst boulders along the nature trail to the Tham (= cave) Phra That. Most were observed clinging upside down to the undersides of large boulders (around 1-3 m2) or in narrow crevices of the boulders. Four individuals (ZMKU R 00999-01002) were found during the daytime (14:00-16:30 h) and one individual (ZMKU R 01003) was found at night (20:30 h). Most observed individuals were found during the daytime and they were active and rapidly escaped from disturbances. The one individual found at night was relatively inactive (slow-moving). At night, the new species was found to co-occur with five other species of gekkonid lizards, Cyrtodactylus monilatusYodthong, Rujirawan, Stuart, Grismer, Aksornneam, Termprayoon, Ampai & Aowphol, 2022, Cyrtodactylus tigroidesBauer, Sumontha & Pauwels, 2003, Gehyra mutilata(Wiegmann, 1834), Dixonius hangseesomBauer, Sumontha, Grossmann, Pauwels & Vogel, 2004 and Dixonius siamensis(Boulenger, 1899).
Etymology. The species epithet auriventralis is derived from aurum(L.) for gold and ventralis(L.) for venter in reference to the new species having distinct yellow colouration on all ventral surfaces of the head, body and tail in adult males. We propose "Erawan Rock Gecko" for the common English name and "จิ้งจกนิ้วยาวเอราวัณ"(Jing Jok Niew Yao Erawan) for the common Thai name of the new species.
Comparisons. Cnemaspis auriventralissp. nov. is distinguishable from all other members of the C. siamensisgroup by a combination of morphological and colour pattern characteristics (see Table 5for additional comparisons). Table 5.Diagnostic morphological and colour pattern characteristics distinguishing Cnemaspis auriventralissp. nov. from other species of the C. siamensisgroup. Grey highlight indicates differences with the new species. Key: Cont. = continuous; Sep. = separated; NA = data unavailable or not applicable. Characters C. auriventralissp. nov. C. adangrawi C. chanardi C. huaseesom C. kamolnorranathi C. lineatubercularis C. omari C. phangngaensis C. punctatonuchalis C. roticanai C. selenolagus C. siamensis C. thachanaensis C. vandeventeri Morphology Max SVL 38.6 44.9 40.1 43.5 37.8 41.8 41.3 42.0 49.6 47.0 36.2 39.7 39.0 44.7 Supralabial 8-10 10 7-10 7-10 8-9 8-9 8-9 10 8 8-9 10-11 8-9 10-11 8-9 Infralabial 7-9 9 6-8 6-9 7-8 8-9 7-8 10 7-8 7-8 10 6-8 9-11 7-9 Ventral scales smooth keeled keeled smooth weakly keeled or smooth keeled keeled keeled smooth keeled smooth keeled keeled keeled No. of precoacal pores 6-7 6-8 6-8 5-8 7 4-7 4 4 0 3-6 6-7 0 0 4 Precloacal pores arrangement Cont. or Sep. Sep. Sep. Cont. Cont. Sep. Sep. Cont. NA Sep. Cont. NA NA Sep. No. of paravertebral tubercles 16-17 23-25 20-30 18-24 19-24 19-21 22-29 22 24-27 25-27 16-18 19-25 15-19 25-29 Tubercles arranged linearly randomly randomly weakly linear or randomly semi-linearly linearly semi-linearly or randomly linearly semi-linearly randomly randomly randomly linearly randomly Tubercles on lower flanks present absent present present present present generally present absent present present absent present generally present absent Lateral caudal furrows present present present present present present present present present present absent present present present Caudal tubercles in lateral furrow absent present absent present present absent absent absent absent absent NA absent absent absent Ventrolateral caudal tubercles anteriorly present present absent absent absent present absent present present absent absent absent present absent Enlarged median subcaudal scale row present absent present absent weak absent absent absent present present absent present absent present Subcaudals smooth keeled keeled smooth keeled keeled keeled or smooth keeled smooth keeled smooth keeled keeled keeled Single median row of subcaudals smooth keeled smooth smooth keeled keeled smooth keeled smooth keeled NA keeled keeled weakly keeled Caudal tubercles encircle tail no no no no no no yes no no no yes no no no No. of postcloacal tubercles in males 2 1 1 1 or 2 1 or 2 1 1 2 1-3 1 or 2 2 1 or 2 0 1-3 Subtibial scales smooth keeled keeled smooth keeled or smooth keeled keeled keeled smooth keeled smooth keeled keeled keeled Shield-like subtibial scales absent absent absent absent absent absent absent absent absent absent absent absent absent absent Enlarged submetatarsal scales on 1st toe absent absent absent absent absent absent absent absent absent absent present absent present absent No. of 4th toe lamellae 23-27 26-28 25-30 21-31 24-28 27-29 25-28 29 29-31 26-29 22 24-26 23-25 24-28 Colouration and pattern Dorsal colour pattern sexually dimorphic yes no no yes no no no yes yes yes NA no yes no Ventral pattern sexually dimorphic yes yes yes yes NA yes yes yes yes yes NA yes yes yes Anterior 1/2 of body orange-yellow, posterior 1/2 grey no no no no no no no no no no yes no no no Ocelli on brachium and side of neck no no no no no no no no yes no yes no no no Light or yellowish, prescapular crescent no yes yes no variable yes yes yes no yes yes no no yes Fore-limbs yellow in males no no no yes no no no no no no yes no no no Original tail yellow in males yes no no yes no no no no no no no no no no Regenerated tail yellow no no no no no no no no NA yes no no no no Lineate gular markings no no no no no no no no no no no yes yes no All ventral surfaces of head, body and tail yellow in males yes no no no no no no no no yes no no no no Cnemaspis auriventralissp. nov. differs from C. adangrawiby having a smaller maximum SVL of 38.6 mm (vs. 44.9 mm); ventral scales smooth (vs. keeled); 16-17 paravertebral tubercles (vs. 23-25); paravertebral tubercles linearly arranged (vs. randomly); tubercles on lower flanks present (vs. absent); caudal tubercles in lateral furrow absent (vs. present); enlarged median subcaudal scales row present (vs. absent); subcaudal scales smooth (vs. keeled); single median row of subcaudals smooth (vs. keeled); two postcloacal tubercles on each side in males (vs. one); subtibial scales smooth (vs. keeled); sexual dimorphism of dorsal colour pattern present (vs. absent); light or yellowish prescapular crescent absent (vs. present); yellow colouration on original tail in males present (vs. absent); and yellow colouration on all ventral surfaces of head, body and tail in males (vs. yellowish colouration only on gular region, abdominal region and caudal region). Cnemaspis auriventralissp. nov. differs from C. chanardiby having ventral scales smooth (vs. keeled); 16-17 paravertebral tubercles (vs. 20-30); paravertebral tubercles linearly arranged (vs. randomly); ventrolateral caudal tubercles anteriorly present (vs. absent); subcaudal scales smooth (vs. keeled); two postcloacal tubercles on each side in males (vs. one); subtibial scales smooth (vs. keeled); sexual dimorphism of dorsal colour pattern present (vs. absent); light or yellowish prescapular crescent absent (vs. present); yellow colouration on original tail in males present (vs. absent); and yellow colouration on all ventral surfaces of head, body and tail in males (vs. yellow colouration only on gular region, belly, underside of hind-limbs and subcaudal region). Cnemaspis auriventralissp. nov. is most closely related in mitochondrial DNA to C. huaseesom(Fig. 2), but differs in morphology from C. huaseesomby having a smaller maximum SVL of 38.6 mm (vs. 43.5 mm); 16-17 paravertebral tubercles (vs. 18-24); caudal tubercles in lateral furrow absent (vs. present); ventrolateral caudal tubercles anteriorly present (vs. absent); enlarged median subcaudal scales row present (vs. absent); yellow dorsal colouration on fore-limbs in males absent (vs. present); and yellow colouration on all ventral surfaces of head, body and tail in males (vs. yellow colouration only on gular region, throat, pectoral region, underside of fore-limbs and subcaudal region). Cnemaspis auriventralissp. nov. differs from C. kamolnorranathiby having 16-17 paravertebral tubercles (vs. 19-24); caudal tubercles in lateral furrow absent (vs. present); ventrolateral caudal tubercles anteriorly present (vs. absent); subcaudal scales smooth (vs. keeled); single median row of subcaudals smooth (vs. keeled); sexual dimorphism of dorsal colour pattern present (vs. absent); yellow colouration on original tail in males present (vs. absent); and yellow colouration on all ventral surfaces of head, body and tail in males (vs. lacking yellow colouration on ventral surfaces). Cnemaspis auriventralissp. nov. differs from C. lineatubercularisby having ventral scales smooth (vs. keeled); 16-17 paravertebral tubercles (vs. 19-21); enlarged median subcaudal scales row present (vs. absent); subcaudal scales smooth (vs. keeled); single median row of subcaudals smooth (vs. keeled); two postcloacal tubercles on each side in males (vs. one); subtibial scales smooth (vs. keeled); sexual dimorphism of dorsal colour pattern present (vs. absent); light or yellowish prescapular crescent absent (vs. present); yellow colouration on original tail in males present (vs. absent); and yellow colouration on all ventral surfaces of head, body and tail in males (vs. yellowish colouration only on anterior gular, abdominal and subcaudal regions). Cnemaspis auriventralissp. nov. differs from C. omariby having ventral scales smooth (vs. keeled); 6-7 precloacal pores in males (vs. 4); 16-17 paravertebral tubercles (vs. 22-29); ventrolateral caudal tubercles anteriorly present (vs. absent); enlarged median subcaudal scales row present (vs. absent); caudal tubercles not encircling the tail (vs. encircling); two postcloacal tubercles on each side in males (vs. one); subtibial scales smooth (vs. keeled); sexual dimorphism of dorsal colour pattern present (vs. absent); light or yellowish prescapular crescent absent (vs. present); and yellow colouration on all ventral surfaces of head, body and tail in males (vs. yellow colouration only on gular region, belly, underside of hind-limbs, and subcaudal region). Cnemaspis auriventralissp. nov. differs from C. phangngaensisby having 7-9 infralabials (vs. 10); ventral scales smooth (vs. keeled); 6-7 precloacal pores in males (vs. 4); 16-17 paravertebral tubercles (vs. 22); tubercles on lower flanks present (vs. absent); enlarged median subcaudal scales row present (vs. absent); subcaudal scales smooth (vs. keeled); single median row of subcaudals smooth (vs. keeled); subtibial scales smooth (vs. keeled); 23-27 subdigital lamellae on the fourth toe (vs. 29); light or yellowish prescapular crescent absent (vs. present); and yellow colouration on all ventral surfaces of head, body and tail in males (vs. yellow colouration only on anterior gular region, abdomen and subcaudal region). Cnemaspis auriventralissp. nov. differs from C. punctatonuchalisby having a smaller maximum SVL of 38.6 mm (vs. 49.6 mm); 6-7 precloacal pores in males (vs. 0); 16-17 paravertebral tubercles (vs. 24-27); 23-27 subdigital lamellae on the fourth toe (vs. 29-31); ocelli on brachium and side of neck in males absent (vs. present); yellow colouration on original tail in males present (vs. absent); and yellow colouration on all ventral surfaces of body and tail in males (vs. orange colouration on throat and subcaudal region). Cnemaspis auriventralissp. nov. differs from C. roticanaiby having a smaller maximum SVL of 38.6 mm (vs. 47.0 mm); ventral scales smooth (vs. keeled); 16-17 paravertebral tubercles (vs. 25-27); paravertebral tubercles linearly arranged (vs. randomly); ventrolateral caudal tubercles anteriorly present (vs. absent); subcaudal scales smooth (vs. keeled); single median row of subcaudals smooth (vs. keeled); subtibial scales smooth (vs. keeled); light or yellowish prescapular crescent absent (vs. present); yellow colouration on original tail in males present (vs. absent); and yellow colouration on regenerated tail absent (vs. present). Cnemaspis auriventralissp. nov. differs from C. selenolagusby having 7-9 infralabials (vs. 10); paravertebral tubercles linearly arranged (vs. randomly); tubercles on lower flanks present (vs. absent); lateral caudal furrow present (vs. absent); ventrolateral caudal tubercles anteriorly present (vs. absent); enlarged median subcaudal scales row present (vs. absent); caudal tubercles not encircling the tail (vs. encircling); enlarged submetatarsal scales on the first toe absent (vs. present); 23-27 subdigital lamellae on the fourth toe (vs. 22); orange-yellow colouration on anterior 1/2 of body in males absent (vs. present); ocelli on brachium and side of neck in males absent (vs. present); light or yellowish prescapular crescent absent (vs. present); yellow dorsal colouration on fore-limbs in male absent (vs. present); yellow colouration on original tail in males present (vs. absent); and having yellow colouration on all ventral surfaces of head, body and tail in males (vs. yellow colouration only on anterior part of body). Cnemaspis auriventralissp. nov. differs from C. siamensisby having ventral scales smooth (vs. keeled); 6-7 precloacal pores in males (vs. 0); 16-17 paravertebral tubercles (vs. 19-25); paravertebral tubercles linearly arranged (vs. randomly); ventrolateral caudal tubercles anteriorly present (vs. absent); subcaudal scales smooth (vs. keeled); single median row of subcaudals smooth (vs. keeled); subtibial scales smooth (vs. keeled); sexual dimorphism of dorsal colour pattern present (vs. absent); lineate gular marking absent (vs. present); and yellow colouration on all ventral surfaces of head, body and tail in males (vs. yellow colouration only on gular region, throat and pectoral region). Cnemaspis auriventralissp. nov. differs from C. thachanaensisby having ventral scales smooth (vs. keeled); 6-7 precloacal pores in males (vs. 0); enlarged median subcaudal scales row present (vs. absent); subcaudal scales smooth (vs. keeled); single median row of subcaudals smooth (vs. keeled); two poscloacal tubercles on each side in males (vs. 0); subtibial scales smooth (vs. keeled); lineate gular marking absent (vs. present); and yellow colouration on all ventral surfaces of head, body and tail in males (vs. yellowish-orange colouration only on gular region). Cnemaspis auriventralissp. nov. differs from C. vandeventeriby having a smaller maximum SVL of 38.6 (vs. 44.7 mm); ventral scales smooth (vs. keeled); 6-7 precloacal pores in males (vs. 4); 16-17 paravertebral tubercles (vs. 25-29); paravertebral tubercles linearly arranged (vs. randomly); tubercles on lower flanks present (vs. absent); ventrolateral caudal tubercles anteriorly present (vs. absent); subcaudal scales smooth (vs. keeled); single median row of subcaudals smooth (vs. weakly keeled); subtibial scales smooth (vs. keeled); sexual dimorphism of dorsal colour pattern present (vs. absent); light or yellowish prescapular crescent absent (vs. present); and yellow colouration on all ventral surfaces of head, body and tail in males (vs. orange colouration on gular region, throat, pectoral region, underside of limbs, belly and subcaudal region).