Hemiphyllodactylus chiangmaiensis, Grismer, L. Lee, Wood, Perry L. & Cota, Michael, 2014

Grismer, L. Lee, Wood, Perry L. & Cota, Michael, 2014, A new species of Hemiphyllodactylus Bleeker, 1860 (Squamata: Gekkonidae) from northwestern Thailand, Zootaxa 3760 (1), pp. 67-78 : 70-77

Hemiphyllodactylus chiangmaiensis sp. nov.

Chiang Mai Dwarf Gecko

Ching-chok-khaosung-chiang-mai Figs. 3 , 4

Holotype. Adult male ( THNHM 15194) collected in the vicinity of Chiang Mai, Chiang Mai Province, Thailand. Precise locality, collector, and date of collection unknown.

Paratypes. THNHM 15192–93, 15195–200 bear the same data as the holotype.

Diagnosis. Hemiphyllodactylus chiangmaiensis sp. nov. can be separated from all other species of Hemiphyllodactylus by having the unique combination of a maximum SVL of 41.2 mm; 8–12 chin scales extending transversely from unions of second and third infralabials and posterior margin of mental; enlarged postmental scales; three or four circumnasal scales; 1–3 scales between supranasals (=postrostrals); 9–11 supralabials; 9–11 infralabials; 11–21 longitudinally arranged dorsal scales at midbody contained within one eye diameter; 6–10 longitudinally arranged ventral scales at midbody contained within one eye diameter; lamellar formula on hand 3–3–3–3 or 3–4–3–3; lamellar formula on foot 3–3–3–3 or 3–4–4–4; continuous precloacal and femoral pores; dorsal body pattern consisting of dark, irregularly shaped, paravertebral blotches; postsacral mark cream-colored, bearing anteriorly projecting arms; and caecum and oviducts pigmented. These characters and potentially diagnostic morphometric characters are scored across all species in Table 1. The taxonomy of H. yunnanensis follows Zug (2010).

Description of holotype. Adult male; head triangular in dorsal profile depressed, distinct from neck; lores and interorbital regions flat; rostrum relatively long (NarEye/ HeadL = 0.32); prefrontal region flat to weakly concave; canthus rostralis smoothly rounded, barely discernable; snout moderate, rounded in dorsal profile; eye large; ear opening oval, small; eye to ear distance greater than diameter of eye; rostral wider than high, partially divided dorsally, bordered posteriorly by large supranasals; three internasals (=postnasals); external nares bordered anteriorly by rostral, dorsally by supranasal, posteriorly by two postnasals, ventrally by first supralabial (=circumnasals 3R,L); 9 (R,L) square supralabials tapering to below posterior margin of orbit; 10 (R,L) square infralabials tapering to below posterior margin of orbit; scales of rostrum, lores, top of head, and occiput small, granular, those of rostrum largest; dorsal superciliaries flat, rectangular, imbricate; mental triangular, bordered laterally by first infralabials and posteriorly by two large postmentals; each postmental bordered laterally by a single sublabial; row of smaller scales extending transversely from juncture of second and third infralabials and contacting mental; gular scales triangular small, granular, grading posteriorly into slightly larger, subimbricate, throat and pectoral scales which grade into slightly larger, subimbricate ventrals.

Body somewhat elongate, dorsoventrally compressed; ventrolateral folds absent; dorsal scales small, granular, 11 scales contained within one eye diameter; ventral scales, flat, subimbricate much larger than dorsal scales, seven scales contained within one eye diameter; no enlarged, precloacal scales; 25 pore-bearing scales extending from midway between the knee and hind limb insertion of one leg to the other; forelimbs short, robust in stature, covered with granular scales dorsally and with slightly larger, flat, subimbricate scales ventrally; palmar scales flat, subimbricate; all digits except digit I well developed; digit I vestigial, clawless; distal, subdigital lamellae of digits II–V undivided, angular and U-shaped; lamellae proximal to these transversely expanded; lamellar formula of digits II–V 3–4 –3–3 (R,L); four transversely expanded lamellae on digit I; claws on digits II–V well developed, unsheathed; distal portions of digits strongly curved, terminal joint free, arising from central portion of lamellar pad; hind limbs short, more robust than forelimbs, covered with slightly pointed, juxtaposed scales dorsally and by larger, flat subimbricate scales ventrally; plantar scales low, flat, subimbricate; all digits except digit I well developed; digit I vestigial, clawless; distal, subdigital lamellae of digits II–V undivided, angular and U-shaped; lamellae proximal to these transversely expanded; lamellar formula of digits II–V 3–3 –3–3 (R,L); four transversely expanded lamellae on digit I; claws on digits II–V well developed, unsheathed; distal portions of digits strongly curved, terminal joint free, arising from central portion of lamellar pad; posterior section of tail broken, round in cross-section; all caudal scales flat, imbricate, not forming distinct caudal segments. Morphometric data are presented in Table 2.

Coloration in alcohol ( Fig. 3 ). Top of head and body nearly unicolor dull brown with weak, darker mottling; faint, dark, diffuse preorbital stripe; slightly more prominent postorbital stripe extends to occipital region, becoming more faint and diffuse and wider as it continues posteriorly onto body; faint, dark, dorsal, paravertebral markings weakly counter-shaded with lighter coloration; light postsacral marking bearing anteriorly projecting arms and dark medial chevron; dorsal surface of limbs same color as body, nearly unicolor; original portion of tail bearing irregular shaped, alternating, diffuse light and dark bands.

Variation. The paratypes closely match the holotype in coloration and pattern ( Fig. 3 ). THNHM 15198 has a faint, wide, lateral stripe extending from the posterior margin of the eye to the groin. Coloration of this species in life is much more rich ( Fig. 4 ). Variation in scale counts and morphometric data are presented in Table 2.

Distribution. Hemiphyllodactylus chiangmaiensis sp. nov. is known only from the type locality near the city of Chiang Mai in Chiang Mai Province ( Fig. 1 ) but is expected to range more widely throughout the northwestern portion of Thailand and perhaps into Myanmar.

Natural History. Hemiphyllodactylus chiangmaiensis sp. nov. occurs in rocky areas in the vicinity of 600 m in elevation, where it takes refuge between rocks when threatened at night and during the day. This species is also found on the vertical surfaces of man-made structures, which they occupy when the human commensals Hemidactylus and Gehyra are absent.

Etymology. This species is named after the Thai Province of Chiang Mai where the type locality is located.

Comparisons. The taxonomy of Zug (2010) is used in the comparisons below for H. titiwangsaensis Zug , H. typus Bleeker and H. yunannensis (Boulenger) except for H. zugi Nguyen, Lehmann, Le, Duong, Bonkowski & Ziegler which has been removed from the latter species (Nguyen et al. 2013). Hemiphyllodactylus chiangmaiensis sp. nov. differs from H. ganoklonis Zug in having a maximum known SVL of 41.2 mm versus 34.2 mm and from H. margarethae Brongersma , H. titiwangsaensis , H. typus , and H. yunnanensis by having a maximum SVL less than 46.1 mm – 49.3 mm. It differs from H. aurantiacus Beddome , H. ganoklonis , and H. insularis Taylor in having enlarged as opposed to small postmentals. Hemiphyllodactylus chiangmaiensis sp. nov. has three or four circumnasal scales that separates it from H. tehtarik which has five and is further separated by having 6–10 as opposed to 12 ventral scales. Hemiphyllodactylus chiangmaiensis sp. nov. has a lamellar hand formula of 3–3–3–3 or 3–4–3–3 which separates it from H. aurantiacus (2–2–2–2), H. ganoklonis (3–4–4–3), H. margarethae (4–4–4– 4), H. titiwangsaensis and H. typus (3–4–4–4). From H. titiwangsaensis and H. typus , H. chiangmaiensis sp. nov. differs in having three or four transversely expanded subdigital lamellae beneath digit 1 on the hand as opposed to 5–8. It can be separated further from H. harterti (Werner) in having 17–25 continuous femoral and precloacal pores as opposed to 42–45. The caecum and gonadal tracts of H. chiangmaiensis sp. nov. are pigmented, further differentiating it from H. harterti , H. insularis , some H. margarethae , H. tehtarik , H. titiwangsaensis , and H. yunnanensis . Hemiphyllodactylus chiangmaiensis sp. nov. differs from H. zugi in having a smaller maximum SVL (41.2 versus 46.6 mm); 6–10 versus 15 or 16 ventral scales; having a 3–3–3–3 or 3–3–4–3 versus a 3–4–4–4 lamellar formula on the hand; having as opposed to lacking dark dorsal transverse blotches on the body; and a pigmented caecum and gonads. From H. larutensis Boulenger , H. chiangmaiensis is separated on the basis of having a maximin SVL of 41.2 versus 52.2 mm; 17–25 continuous femoral and precloacal pores as op[p[osed to 27– 36; one as opposed to two or three cloacal spurs on each side; having a banded to blotched dorsal pattern as opposed to a unicolor dorsal pattern; and a pigmented caecum and gonads as opposed to these structures being unpigmented. Four morphometric ratios, HeadL/SVL, HeadW/SVL, HeadW/HeadL, and EyeD/HeadL of other species of Hemiphyllodactylus differ discretely from the corresponding ratios in H. chiangmaiensis sp. nov. (Table 1).

Figures

FIGURE 1. Map showing the type locality of Hemiphyllodactylus chiangmaiensis sp. nov. at Chiang Mai, Chiang Mai Province, Thailand.

FIGURE 3. Holotype (upper) and type series (lower) of Hemiphyllodactylus chiangmaiensis sp. nov.

FIGURE 4. Hemiphyllodactylus chiangmaiensis sp. nov. (LSUDPC 6668) from the type locality of Chiang Mai, Chiang Mai Province, Thailand.