Hemiphyllodactylus pinlaungensis, Grismer & Wood & Quah & Thura & Oaks & Lin, 2020

Grismer, L. Lee, Wood, Perry L., Quah, Evan S. H., Thura, Myint Kyaw, Oaks, Jamie R. & Lin, Aung, 2020, Four new Burmese species of Hemiphyllodactylus Bleeker (Squamata: Gekkonidae) from distantly related parapatric clades from the Shan Plateau and Salween Basin, Zootaxa 4758 (1), pp. 45-82 : 71-79

Hemiphyllodactylus pinlaungensis sp. nov.

Pinlaung Slender Gecko

( Figs. 11 , 12 )

Holotype. Adult male ( LSUHC 14274 ) collected on 12 November 2018 at 1900 hrs by Jamie R. Oaks, L. Lee Grismer, Perry L. Wood Jr., Myint Kyaw Thura, Evan S. H. Quah, and Aung Lin from Pinlaung City, Shan State, Myanmar (20.12869°N 96.78464°E WGS; 1498 m in elevation).

Paratypes. Paratypes ( LSUHC 14257 , 14259–73 , 14275–77 ) bear the same collection data as the holotype .

Additional specimens. Additional specimens ( LSUHC 14301–05) were collected from Wingabar Cave approximately 7 km southwest of Pinlaung City, Shan State, Myanamar (20.06936°N 96.76988°E WGS; 1464 m in elevation) by Jamie R. Oaks, L. Lee Grismer, Perry L. Wood Jr., Myint Kyaw Thura, Evan S. H. Quah, and Aung Lin on 13 November 2018.

Diagnosis. Hemiphyllodactylus pinlaungensis sp. nov. can be separated from all other species of Hemiphyllodactylus by possessing the unique combination of having a maximum SVL of 43.0 mm; 9–14 chin scales; enlarged postmentals; five or six circumnasal scales; 2–5 intersupranasals (=postrostrals); 7–10 supralabials; 8–11 infralabi- als; 12–19 longitudinally arranged dorsal scales at midbody contained within one eye diameter and 7–12 ventral scales; 17–24 pore-bearing femoroprecloacal scales in males; three or four subdigital lamellae on first finger and first toe; no plate-like subcaudal scales; adult females not yellow; a dark postorbital stripe extending to at least base of neck; dorsolateral light-colored spots on trunk variable; no dark, dorsolateral stripe on trunk; dark ventrolateral stripe on trunk; dark paravertebral markings on trunk; light-colored postsacral marking bearing anteriorly projecting arms; and caecum and gonads unpigmented. These characters are scored across all Burmese species in Tables 3 and 6 and from all other species of Hemiphyllodactylus from southern China and western Thailand (clades 3 and 4 in Grismer et al. (2017: Table 3)).

Description of holotype Adult male SVL 38.9 mm; head triangular in dorsal profile, depressed, distinct from neck; lores flat; rostrum moderate in length (SN/SVL 0.10); prefrontal region weakly concave; canthus rostralis smoothly rounded, barely discernable; snout moderate, rounded in dorsal profile; eye large; ear opening circular, small; eye to ear distance greater than diameter of eye; rostral wider than high, bordered posteriorly by large supranasals; five equally sized intersupranasals (=postnasals); external nares bordered anteriorly by rostral, dorsally by supranasal, posteriorly by two postnasals, ventrally by first supralabial (=circumnasals); 10 (R, L) rectangular supralabials tapering to below posterior margin of eye; 8 (R, L) rectangular infralabials tapering to below posterior margin of eye; scales of rostrum, lores, top of head, and occiput small, granular, raised, those of rostrum largest; dorsal superciliaries flat, mostly square, subimbricate, largest anteriorly; mental triangular, bordered laterally by first infralabials, posteriorly by two trapizoidal postmentals; each postmental in contact with first infralabial, bordered laterally by slightly smaller sublabial; 10 chin scales; gular scales small, subimbricate to slightly raised, grading posteriorly into slightly larger, subimbricate throat and larger pectoral scales which grade into slightly larger, subimbricate ventrals.

Body somewhat elongate (AG/SVL 0.48), dorsoventrally compressed; ventrolateral folds absent; dorsal scales small, granular, 14 dorsal scales at midbody contained within one eye diameter; ventral scales flat, subimbricate much larger than dorsal scales, eight ventral scales contained within one eye diameter; precloacal scales larger than abdominal scales; 19 pore-bearing femoroprecloacal scales; single enlarged tubercle on lateral margin of tail base; forelimbs short, robust in stature, covered with flat, subimbricate scales dorsally and 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, U-shaped, lamellae proximal to these transversely expanded; distal lamellar formula of digits II–V 3-4-4-3 (R, L); three 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 raised, juxtaposed scales dorsally and by larger, flat, subimbricate scales anteriorly and ventrally; plantar scales slightly raised, subimbricate; all digits except digit I well-developed; digit I vestigial, clawless; distal subdigital lamellae of digits II–V undivided, angular, and Ushaped, lamellae proximal to these transversely expanded; distal lamellar formula of digits II–V 3-4-4-4 (R, L); three 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; caudal scales not occurring in distinct whorls; dorsal caudal scales of original tail larger than dorsal body scales, flat, subcycloid, subimbricate; ventrolateral caudals enlarged, weakly flared giving a weak fringe-like appearance punctated every 4–6 scales by slightly larger, raised scales; subcaudals flat, slightly larger than dorsal caudals, not plate-like. Morphometric data are presented in Table 11.

Coloration in life. All Hemiphyllodactylus are capable of considerable change in the intensity and boldness of their coloration and pattern. The description below is of that when the holotype was photographed the morning after capture, approximately 12 hours after the time of collection when in its light-phase. Ground color of top of head, body, limbs, and tail straw-colored but heavily mottled with dark-brown markings; top of head overlain with a lightcolored mottling and small, dark-brown reticulations on occiput; broad, faint, diffuse pre- and postorbital stripe extends from external nares, through eye to forelimb, preorbital portion very faint; dorsolateral row of faint, diffuse, dark, paravertebral markings extend from nape to base of tail, countershaded posteriorly by diffuse light-colored spots composing a dorsolateral row; faint, wide dark, ventrolateral stripe on trunk; beige, postsacral marking bears light-colored, anteriorly projecting arms; flanks faintly mottled with diffuse, brown speckling; limbs bearing faint, dark, irregularly shaped markings; base of toes bearing a single faint, orange spot; gular region mottled with brown, dense stippling in most scales; stippling density increases posteriorly with the abdomen being generally darker, especially laterally; original tail bearing 10 faint, irregularly shaped, brown bands and heavily mottled interspaces; enlarged scales of ventrolateral fringe highlighted in white; subcaudal region densely stippled.

Variation ( Figs. 11 , 12 ). Given the large sample size (25) across all ages classes and both sexes coupled with the ability of this species to change the intensity and boldness of is color pattern, dorsal color pattern characteristics vary considerably ranging from nearly unicolor gray-brown ( Fig. 11A ) to boldly contrasted patterns being offset by lightly colored areas ( Figs. 11B, D ). Other specimens have dorsal patterns that are more lightly colored overall and overlain with relatively faint, diffuse darker markings ( Figs. 11C, E ). The single hatchling had a nearly uniform gray dorsal coloration and pattern ( Fig. 11F ). Caudal pattern of original tails is especially variable, ranging from lightyellow to dull-white with bold, dark-colored bands ( Figs. 11B, D ) to having wide, faint, diffuse bands ( Fig.11C ) or thin, dark, dorsal, transverse markings ( Fig. 11E ). There are no consistent differences in color pattern variation between individuals from the Pinlaung City (n=20) population and those from the Wingabar Cave population (n=5). Variation in scales counts, mensural data, and additional minor aspects in coloration are presented in Table 11.

Distribution. Hemiphyllodactylus pinlaungensis sp. nov. is known from the type locality of Pinlaung City and from Wingabar Cave approximately 7 km to the southwest, Shan State and is expected to occur in other nearby areas ( Fig. 1 ).

Natural History. During the evening from 1800–2400 hrs, we observed dozens of individuals on the cement and brick walls of nearly every building on the outskirts of the city but none in the surrounding upland forest ( Fig. 12 ). Many of the females were gravid with two eggs and we also found hatchlings (SVL <22 mm). This indicates that November is within the reproductive season of this species. Given the small area of urban habitat through which we walked on our route to forested areas (~ 0.5 km), we suspect individuals of this species in Pinlaung City number well into the thousands if not more. We also observed several individuals on the following evening during the same hours on the walls of buildings and karst tower formations at Wingabar Cave (Fig. 13). Here too, we found gravid females but no hatchlings.

Etymology. The specific epithet is a toponym referring to the type locality of Pinlaung City, Shan State, Myanmar.

Comparisons. The molecular analyses indicate that Hemiphyllodactylus pinlaungensis sp. nov. is a genetically distinct member of the south lineage and is the sister species to H. kyaiktiyoensis sp. nov. ( Fig. 1 ) from which it bears an uncorrected pairwise sequence divergence of 9.5% ( Table 10). Its differences from H. kyaiktiyoensis sp. nov. and H. zwegabinensis sp. nov. are listed in the comparisons sections for those species.

Figures

FIGURE 1. Maximum likelihood consensus tree of Hemiphyllodactylus clades with UFB and BI support value coding at the nodes. Topographical map showing the distribution of the species in the north and south lineages on the Shan Plateau and in the Salween Basin. Localities of H. ngwelwini sp. nov. from north to south are Pwe Hla Village, Thayeumin Cave, and Myintmahati Cave, Shan State.

FIGURE 11. Color pattern variation among holotype, selected paratypes and a hatchling of Hemiphyllodactylus pinlaungensis sp. nov. from Pinlaung City, Shan State, Myanmar. A. Adult male holotype (LSUHC 14274). B. Adult female (LSUHC 14266). C. Adult female (LSUHC 14273). D. Adult female (LSUHC 14265). E. Adult female (LSUHC 14277). F. Hatchling (LSUHC 14258). Photographs by L. Lee Grismer.

FIGURE 12. Natural and man-made microhabitat habitat of Hemiphyllodactylus pinlaungensis sp. nov. A. Pinlaung City, Shan State, Myanmar. B. Wingabar Cave, Shan State, Myanmar.