Bronchocela cyanopalpebra Chandramouli & Adhikari & Amarasinghe & Abinawanto 2023, sp. nov.

Bronchocela cyanopalpebra sp. nov.

(Fig. 2)

Pseudocalotes archiducissae (nomen nudum)—Fitzinger in Steindachner (1867)

Calotes cristatellus (non Kuhl, 1820)— Biswas & Sanyal (1977), (1980); Biswas (1984) part

Bronchocela cristatella (non Kuhl, 1820)— Das (1999); Das & Gemel (2000) part

Bronchocela sp. — Vijayakumar (2005)

Bronchocela cf. cristatella (non Kuhl, 1820)—Harikrishnan et al. (2009) part; Chandramouli (2020) part

Holotype: DOSMB 05054, an adult male collected from Chukchuka (9.21358ºN, 92.79647ºE, 33 m asl.) Car Nicobar, Nicobar Islands, India by S.R. Chandramouli in June 2017.

Paratype: DOSMB 05089, an adult male collected along with the holotype from the same locality.

Referred material: BNHS 1610 (adult male), BNHS 1662 (adult female) collected from Air-force station, Car Nicobar by S. Krishnan in 2004; BNHS 961 (adult male) collected from Car Nicobar by Humayun Abdulali & party in 1966.

Etymology: The specific epithet cyanopalpebra is a noun in apposition referring to the bright blue (=cyan) coloured eyelid (=palpebra), a diagnostic character of this species.

Nomenclatural note: As the name Pseudocalotes archidussicae, attributed to the Car Nicobar population by Fitzinger in: Steindachner (1867) has been shown to be a nomen nudum (Das & Gemel, 2000), it cannot be applied to this species as it is not an available nomen (ICZN Art. 11.6).

Differential diagnosis and comparisons: A species of Bronchocela endemic to the northern group of Nicobar Islands characterized by: moderate to large body size (81.23–103.6 mm SVL); relative tail length (336 % SVL versus 330-390 % SVL in B. cristatella sensu stricto); 56–78 scale rows around mid-body (versus 61–79 in B. cristatella), of which, the first 3–4 rows on the dorsum oriented posterodorsally, the next 1–3 rows oriented posteriorly, followed by 17–22 rows oriented posteroventrally; 7–12 enlarged and elongated scales forming the nuchal crest; dorsal crest merely a serrated ridge; three postmentals; 9–10 supralabials; 8–10 infralabials; 5–6 canthals; 6–8 supraciliaries; 32–43 subdigital lamellae under toe IV (versus 31–34 in B. cristatella); 76–85 ventrals (versus 60–86 in B. cristatella); bright grass green dorsal colouration with a distinctly cyan coloured ring around the eyes (versus absent in B. cristatella) in both sexes (Table 2).

Description of the Holotype: An adult male, measuring 81.23 mm SVL; with a very long tail (TaL:SVL 3.39) with a short and robust body (AG:SVL 0.45). Head large (HL:SVL 0.28); longer than broad (HL:HW 1.75) and about as broad as deep (HW:HD 1.04). Snout long (ES:HL 0.45) with a rounded tip. Canthus rostralis sharply defined, with five canthal scales. Eyes relatively small, about 1/5 th the length of the head (ED:HL 0.21); tympanum circular, relatively small, about half as large as the orbit (TYH:ED 0.51) and black in colour. Scales between the eye and tympanum slightly enlarged and keeled. Nasal relatively large, with a pointed anterior and rounded posterior ends. Scales on the check below the tympanum slightly enlarged and keeled. Mental semicircular, bounded by three small postmentals and nine infralabials on either sides. Rostral relatively small, bounded by nine supralabials on each side. Nostrils separated from each other by nine small internasals. Nuchal crest composed of nine slightly enlarged, triangular scales projecting posterodorsally. Dorsal body scales relatively small, feebly keeled and homogeneous, in 68 rows around the mid-body. Of the dorsal scales, the first two rows on the dorsum on either sides oriented posteriorly; the next three rows of scales below oriented posterodorsally, with the rest of the scales on the lateral body oriented posteroventrally. Ventrals 80 in a longitudinal series; much larger (about twice) than the dorsal scales, bearing a strong median keel, projecting posteriorly towards the lower vertex. Limbs relatively robust and elongate; upper arm short and slender (UAL:SVL 0.19); lower arm nearly as long as the upper arm (UAL:LAL 1.05); palm about as long as the lower arm (LAL:PAL 1.06). Fingers long and slender, relative length of fingers IV>III>V>II>I. Thigh long and slender (FEL:SVL 0.25); tibia slightly longer than thighs (FEL:TBL 0.95); foot elongated, slightly longer than thigh (FEL:FOL 0.87). Hindlimbs much longer than half the body length (HLL:SVL 0.82). Relative lengths of toes IV>III>V>II>I; 35 subdigital lamellae under toe IV.

Dorsal coloration verdant green throughout the body; tip of the tail reddish. Ventral side of the head and body of a lighter shade of green than the dorsum. Sides of the lips, cheeks and eyelids bright aqua blue in color. Lips with an orange-red streak; tympanum black. Upper portion of the head slightly more bluish. In preservation, overall body colouration bright green with trunk and posterior edge of the neck being dark grey; tail brownish. Venter greenish brown without any specific pattern on the throat.

Variation: Measurements and scale-counts of the male paratype and the referred specimens are presented in Table 3. Females slightly smaller than males, with a weekly developed nuchal crest and less legible blue shade around the eyes on the face.

Distribution and Natural history: This species is endemic to Car Nicobar and possibly, the smaller southern island of Batti Malv. It is arboreal and diurnal in habit and is a fairly common species found in an array of habitats ranging from evergreen forests, secondary forests and plantations to home gardens (Fig. 8).