Calotes maehongsonensis sp. nov.

Figs 5, 7, 9, 10, Tables 4–6

Calotes versicolor Smith, 1935: 189 (partim); Taylor 1963: 891 (partim); Chan-ard et al. 2015: 97 (partim); Prakobkarn et al. 2016: 482 (partim); Gowande et al. 2021: 680 (partim); Tantrawatpan et al. 2021: 53 (partim).

Calotes versicolor versicolor Auffenberg & Rehman, 1993: 24 (partim); 1995: 1 (partim).

Type material.

Holotype. • Adult male (CUMZ-R -2825) (Fig. 9) from Khun Yuam District, Mae Hong Son Province, Thailand (18.801636°N, 97.898188°E, 499 m a. s. l.), collected by AP on 09 May 2009. Paratypes. • Five adult males (CUMZ-R -2820, CUMZ-R -2823, CUMZ-R -2827 –2828, and CUMZ-R -2832 and five adult females (CUMZ-R -2833, 2835–2837, and 2839) (Fig. 7, Tables 4–6) were collected on 9 May 2009, which is the same collection date as the holotype. All samples were also collected at the same locality as the holotype.

Diagnosis.

Calotes maehongsonensis sp. nov. shares the obliquely posterior or vertical scale-row orientation on the neck and adjacent supra-axillary area with C. irawadi and C. thailandensis sp. nov .. It differs from other congeneric species by the combination of the following characters: 1) having smaller head size (HeadH, JawW, SnN, and SnForeL); 2) more Midbody (mean 44.5, range 43–46) and Dorsal (mean 48.8, range 47–51); 3) moderate middorsal crest spine length (mean 1.44 × tympanum diameter, range 1.20–1.62 × tympanum diameter); 4) short supratympanic spine (<0.5 × tympanum diameter) (Table 6); 5) longer hindlimb adpressed forward (HAF) crossing eye.

Comparisons.

Calotes maehongsonensis sp. nov. can be distinguished from true C. irawadi by adult males having a smaller head size (smaller HeadH, JawW, SnW and SnForel) (Fig. 4); a wider PelvW (mean 11.38 mm, 10.46–12.95 mm vs mean 8.59 mm, 6.90–10.90 mm); a longer middorsal crest spine (> 1 vs ~ 1 × tympanum diameter); HAF crossing eye vs HAF reaching tympanum in C. irawadi. It also differs from C. irawadi by the usual presence of dark patch in jaw muscle and presence of colored patch on throat.

Calotes maehongsonensis sp. nov. differs from C. thailandensis sp. nov. by adult males having a smaller head size (smaller headH, JawW, SnW and SnForel) (Suppl. material 5: fig. S 1); a smaller PelvW (mean 11.38 mm, 10.46–12.95 mm vs mean 13.16 mm, 11.62–15.07 mm) (Table 4); more Midbody (mean 44.5, 43–46 vs mean 42.5, 37–46) and more Dorsal (mean 48.8, 47–51 vs mean 46, 40–49) (Table 5, Suppl. material 5: fig. S 2); a shorter supratympanic spine ((<0.5 vs> 0.5 × tympanum diameter) and the posterior supratympanic spine slightly equal to anterior supratympanic spine (Table 6); hindlimb adpressed forward (HAF) crossing eye (HAF reaching between tympanum and eye in C. thailandensis sp. nov.). In osteological characters, C. maehongsonensis sp. nov. is distinguished from C. thailandensis sp. nov. by having 1) Blunt premaxillary bone; 2) Less concave on posterior portion of the supraoccipital bone; 3) Absence of lateral and posteromedian processes on interclavicle bone (Fig. 5). In coloration, C. maehongsonensis sp. nov. lacks a dark collar-like stripe on ventral neck of males, but dark collar-like stripe occurs ventrally on neck of male C. thailandensis sp. nov. (Fig. 7).

Calotes maehongsonensis sp. nov. can be distinguished from C. wangi by adult males having a smaller body size (SVL, 76.16–83.38 mm vs 88.34–96.4 mm), a smaller head size (EyeEar, InterOrb, HeadH, JawW, SnW, HeadL, SnForeL), and shorter finger and toe (4 FingLng: mean 9.48 mm, 8.80–10.46 mm vs 13.41–14.10 mm; 4 ToeLng: mean 14.34 mm, 13.33–15.89 mm vs 19.04–21.57 mm) (Table 4); a greater HeadH / SVL (mean 0.16, 0.14–0.19 vs mean 0.15, 0.11–0.18) (Suppl. material 3); HAF crossing the eye vs HAF reaching between tympanum and eye in C. wangi.

Calotes maehongsonensis sp. nov. differs from C. versicolor (Zug et al. 2006) by adult males having a smaller body size (mean 78 mm vs mean 119 mm); more Midbody (mean 44.5, 43–46 vs mean 42.8); more Dorsal (mean 48.8, 47–51 vs mean 40.8); a shorter middorsal crest spine (1.2–1.8 vs 2.5–3.0 × tympanum diameter) (Table 6).

Calotes maehongsonensis sp. nov. differs from C. calotes (Pal et al. 2018) by adult males having more Midbody (43–46 vs 30–35); a shorter supratympanic spine and a shorter middorsal crest spine.

Calotes maehongsonensis sp. nov. can be separated from C. goetzi by the absence of both prominent dark brown dorsolateral blotches and a path of small dark granular scales in front of forelimb insertion in adult males.

Calotes maehongsonensis sp. nov. differs from C. emma by adult males lacking large postorbital spine and patch of small dark granular scales in front of forelimb insertion.

Description of holotype.

(Fig. 9): An adult male of 76.16 mm SVL, 23.72 mm SnForeL, 34.54 mm TrunkL, 10.72 mm TailH, 9.37 mm TailW, 210 mm TailL, 13.38 mm PectW, 13.47 mm UpArmL, 12.03 mm LoArmL, 13.15 mm ForefL, 8.80 mm 4 FingLng, 19.20 mm UpLegL, 16.72 mm CrusL, 21.02 mm HindfL, and 13.08 mm 4 ToeLng. Head pentagonal (dorsal outline) covered largely with small, mostly smooth scales slightly overlapping; 23.00 mm HeadL, 18.68 mm HeadW, 12.24 mm JawW, 11.66 mm HeadH, 7.55 mm SnEye, 4.34 mm NarEye, 4.80 mm EyeEar, 4.12 mm SnW, and 7.42 mm InterOrb.

Head distinct from neck; triangle head with blunt snout-tip; sides of head flat, sharp canthus rostralis and supraciliary edge to lips with slightly rotund eye; slightly protruding eye; generally flat chin and throat. Dorsally head scales are smooth and vary in size and scales of some individuals are equal to trunk scales. Rostral scale size is equal to supralabials in height; 5 SnS; 7 / 8 (left / right) elongate and sharply folded CanthR, enlarged scales on supraocular area, 14 HeadSLn and 13 HeadSTr; irregularly shaped interparietal scales. Laterally head with single large nasal scale; small scales at loreal and preocular area with two parallel longitudinal rows above supralabials; 11 / 11 SL; double row of eyelid scales with outer row pyramidal-like scales, inner row smooth and flat 13 / 14 Eyelid; modest to small and smooth postocular and temporal scales; large and naked tympanum; pair of tympanic spines in supratympanic area are separated by seven scale rows; posterior supratympanic spine is a single narrow, spine-like scale (length slightly <0.5 × tympanum maximum diameter) projecting upward; 10 / 10 IL along mouth margin; first supralabials are barely larger than other supralabials.

Keeled trunk scales dorsally and laterally; elongated middorsal crest scale (3 × length of adjacent parasagittal scales) separated from interparietal by four rows; 51 Dorsal, 44 Midbody.

Modest to large and keeled scales on limbs; strongly bicarinate lamellae ventrally of fingers (19 / 19 4 FingLng) and toes (23 / 23 4 ToeLng); long and thin claws and sharply pointed on all digits.

Coloration of holotype.

In preservation (Fig. 9). Dorsally the head is brown and ventrally whitish. There are six pale brown stripes around the eyes. No transverse stripe occurs on the anterior dorsal head, but diagonal stripes appear on ventral posterior head. There is pale dark patch on jowl muscles, but absence of dark patch on ventral neck; trunk transverse bands and middorsal stripe on above body are also absence. Distinct stripes occur on the ventral sides of the body, but absence of forearm stripe and pairs of nuchal spots.

Variation.

Variation in morphometry and meristic characters, spine characters, and stripe pattern of paratype specimens are shown in Fig. 7 and Tables 4–6. Those characters are congruent with the holotype, excluded in coloration pattern. Coloration of paratypes in preservation, in adult male paratypes, transverse bands are rarely found, although broad transverse bands are usually present and straight in males and straight or zig-zag in females. Coloration in life (Fig. 10). Pale brown transverse bands on dorsal surface of body are usually absent in male and usually present in female.

Distribution.

Calotes maehongsonensis sp. nov. has the restricted occurrence in western and northern Thailand (Kanchanaburi and Mae Hong Son Provinces) along Thailand-Myanmar border and southeastern Myanmar including Mon, Bago, and Yangon (Fig. 1).

Habitat and natural history notes.

Its name is represented by type locality from Mae Hong Son Province, Northern Thailand (at approx. more than 500 m elevation). This species inhabits forest edges, primarily occurring on high hills but also adapting to anthropogenic habitats including disturbed secondary forests, agricultural areas, and rural settlements (Fig. 10). Specimens were typically observed on tree trunks and branches 1–4 meters above ground, often basking in sunlight during morning hours. The species appears to be insectivorous, with observed prey including ants and small millipede.

Etymology.

The specific epithet maehongsonensis is referred from its type locality in Mae Hong Son Province (Fig. 10), and they were also found in Kanchanaburi Province, Thailand and Southern Myanmar.