Cyrtodactylus pharbaungensis, Grismer & Wood & Jr. & Thura & Zin & Quah & Murdoch & Grismer & Lin & Kyaw & Lwin, 2018

Grismer, L. Lee, Wood, Perry L., Jr., Thura, Myint Kyaw, Zin, Thaw, Quah, Evan S. H., Murdoch, Matthew L., Grismer, Marta S., Lin, Aung, Kyaw, Htet & Lwin, Ngwe, 2018, Twelve new species of Cyrtodactylus Gray (Squamata: Gekkonidae) from isolated limestone habitats in east-central and southern Myanmar demonstrate high localized diversity and unprecedented microendemism, Zoological Journal of the Linnean Society 182, pp. 862-959 : 913-919

CYRTODACTYLUS PHARBAUNGENSIS SP. NOV.

PHARBAUNG CAVE BENT-TOED GECKO

( FIG. 22; TABLE 13)

Holotype: Adult male LSUHC 12871 collected on 7 October 2016 between 1600 and 1500 h by L. Lee Grismer, Marta S. Grismer, Myint Kyaw Thura, Evan S. H. Quah, Perry L. Wood, Jr., Matthew L. Murdoch, Thaw Zin and Htet Kyaw from Pharbaung Cave 38.4 km south-east of Mawlamyine, Mawlamyine District, Mon State, Myanmar (N16°17.118, E97°54.056; 47 m in elevation).

Paratypes: Adult males BYU 52215 , LSUHC 12870 and 12873 bear the same collection data as the holotype .

Diagnosis: Cyrtodactylus pharbaungensis sp. nov. differs from all congeners by having the unique combination of nine supralabials; seven infralabials; 12–14 longitudinal rows of body tubercles; 28–30 paravertebral tubercles; 34–38 ventral scales; relatively long digits with 7–9 expanded subdigital lamellae on the fourth toe proximal to the digital inflection, 12–14 unmodified distal subdigital lamellae, 21 total subdigital lamellae; body tuberculation variable; body tubercles not extending beyond base of tail; enlarged femoral and precloacal scales continuous; 28–34 enlarged femoral scales; enlarged femoral scales generally equal in size; 14–20 femoral pores in males; 9–11 enlarged precloacal scales; 5–8 precloacal pores in males; two rows of enlarged post-precloacal scales; subcaudal scales three times as wide as long, extending onto lateral surface of tail; top of head bearing a dark mottled pattern, no yellow reticulum; nuchal loop divided medially, lacking an anterior, azygous notch, posterior border straight; five or six dark, regularly shaped, dorsal bands narrower than interspaces with lightened centres, not edged with white tubercles; first dorsal band lacking azygous notch; dark markings in dorsal interspaces; ventrolateral folds whitish; anterodorsal margin of thighs and brachia lacking pigment; 6–8 light caudal bands bearing dark markings and not encircling tail; and 7–9 dark caudal bands of varying width relative to light caudal bands.

Description of holotype: Adult male SVL 70.4 mm; head moderate in length (HL/SVL 0.31), wide (HW/HL 0.67), flat (HD/HL 0.38), distinct from neck, triangular in dorsal profile; lores inflated, prefrontal region moderately concave, canthus rostralis flattened; snout elongate (ES/HL 0.41), rounded in dorsal profile, flat in lateral profile; eye large (ED/HL 0.23); ear opening round, moderate in size (EL/HL 0.08); eye to ear distance greater than diameter of eye; rostral rectangular, partially divided dorsally by inverted Y-shaped furrow, bordered posteriorly by left and right supranasals and one azygous internasal, laterally by first supralabials; external nares bordered anteriorly by rostral, dorsally by supranasal, posteriorly by two postnasals, ventrally by first supralabial; 9(R,L) square supralabials extending to below midpoint of eye; 7(R,L) infralabials tapering posteriorly to below orbit; scales of rostrum and lores slightly raised, larger than granular scales on top of head and occiput; scales on top of head and occiput not intermixed with tubercles; dorsal superciliaries not elongate or keeled; mental triangular, bordered laterally by first infralabials and posteriorly by large left and right, trapezoidal postmentals contacting medially for 55% of their length posterior to mental; one row of slightly enlarged chinshields bordering all infralabials; and gular and throat scales small, flat, grading posteriorly into larger subimbricate pectoral and ventral scales.

Body relatively short (AG/SVL 0.38) with well-defined ventrolateral folds; dorsal scales small, raised, interspersed with moderately sized, low, subconical, semi-regularly arranged, weekly keeled tubercles; tubercles extend from nape onto base of tail but no farther; tubercles on nape very small, those on posterior portion of body larger, more heavily keeled; approximately 14 longitudinal rows of dorsal body tubercles; 29 paravertebral tubercles; 34 flat, subimbricate, ventral scales larger than dorsal scales; ten enlarged precloacal scales; eight precloacal pores; two rows of large post-precloacal scales; and no deep, precloacal groove or depression.

Forelimbs moderate in stature, relatively short (FL/ SVL 0.17); flat scales of forearm larger than those on body, not interspersed with tubercles; palmar scales flat; digits well-developed, relatively long, inflected at basal, interphalangeal joints; digits much more narrow distal to inflections; claws well-developed, base sheathed by a dorsal and ventral scale; hindlimbs more robust than forelimbs, moderate in length (TBL/SVL 0.19), covered dorsally by granular scales intermixed with larger tubercles and bearing flat, slightly larger scales anteriorly; ventral scales of thigh flat, imbricate, larger than dorsal scales, one row of 17(R,L) enlarged femoral scales in contact with enlarged precloacal scales; 9(R,L) femoral pores; subtibial scales flat, imbricate; small postfemoral scales form an abrupt union with larger, flat ventral scales of posteroventral margin of thigh; plantar scales low, slightly raised; digits relatively long, well-developed, inflected at basal, interphalangeal joints; 9(R,L) transversely expanded subdigital lamellae on fourth toe proximal to joint inflection, 12(R,L) unmodified subdigital lamellae distal to inflection, 21 total subdigital lamellae; and claws well-developed, base sheathed by a dorsal and ventral scale.

Tail original, moderate in proportions, 104.0 mm in length, 7.1 mm in width at base, tapering to a point; dorsal scales of base of tail flat, rapidly becoming larger posteriorly; median row of wide, transversely expanded subcaudal scales three times as wide as long extending onto lateral surface of tail; two enlarged postcloacal tubercles at base of tail on hemipenal swellings; and postcloacal scales flat.

Coloration in life ( Fig. 22): Dorsal ground colour of head body, and limbs tan, that of anterior portion of tail dull-yellow; top of head and rostrum bearing dark, diffuse, oval and lineate somewhat mottled pattern, no yellow reticulum; superciliary scales yellow; dark-brown nuchal band distinct, unnotched anteromedially, posterior margin smooth; short band on nape bordered laterally and anterolaterally by large, dark markings; six generally regularly shaped body bands (including nape band) with lightened centres, narrower than interspaces, not edged with light-coloured tubercles; one sacral band; interspaces bearing distinct, dark markings; limbs faintly and irregularly banded; brachia weakly pigmented; dorsal margin of thighs unpigmented; and ventrolateral body folds whitish; nine dark caudal bands bearing lightened centres, of varying width relative to eight light caudal bands; white caudal bands not encircling tail, bearing dark markings; ventral surfaces of head body and limbs beige with stippled lateral edges; and anterior subcaudal region beige, posterior region brown.

Variation ( Fig. S6): The paratypes differ most notably from the holotype in the distinction of the dorsal markings. BYU 52215 and LSUHC 12873 are generally darker overall and the yellowish tubercles in the interspaces are more visible. The posterior one-half of the tail of LSUHC 12870 is regenerated. Meristic and mensural differences are presented in Table 13 .

Distribution: Cyrtodactylus pharbaungensis sp. nov. is known only from Pharbaung Cave 38.4 km southeast of Mawlamyine, Mawlamyine District, Mon State, Myanmar ( Fig. 20).

Etymology: The specific epithet, pharbaungensis (pronounced far-bong-ensis), is a noun in apposition in reference to the type locality of Pharbaung Cave.

Natural history: Pharbaung Cave is situated on the north-east side of a small karst hill approximately 70 m wide, 480 m long and 271 m high and is surrounded by paddy fields. The opening of the cave is wide (~ 50 m)

Abbreviations are listed in the Material and Methods. R, right; L, left; /, data unobtainable or not applicable; r, regenerated; b, broken.

and high (~ 20 m) and approximately 60 m above the base of the hill. The interior of the cave is also wide and high with small outcroppings in the centre and alcoves, deep cracks and stalagmites along the walls ( Fig. 23). Lizards were observed only along the edges of the walls and not in the middle structures. Some were observed in narrow cracks 1–5 m above the cave floor and others were found crawling across the ground near cracks and small outcroppings into which they could retreat. One specimen was collected on the wall at the cave entrance 1 m above the cave floor. A juvenile was observed in a crack 4–5 m above the cave floor but could not be caught. It is likely that at night, when the cave is darker, lizards utilize all the microhabitat structures. Hemidactylus garnotii was observed on the hillside outside the cave.

Comparisons: Cyrtodactylus pharbaungensis sp. nov. is part of the sadansinensis group. The PCA and DAPC analyses indicate that the species of this group are completely separate in morphospace where the first two principal components account for 59% of the total variation ( Fig. 12) and load most heavily for longitudinal rows of dorsal body tubercles, enlarged precloacal scales, and number of unmodified and total number of fourth toe lamellae ( Table S2). Cyrtodactylus pharbaungensis sp. nov. is well-differentiated from C. sadansinensis sp. nov. by having statistically significant differences in its mean number of paravertebral tubercles, longitudinal rows of dorsal body tubercles, enlarged femoral scales, enlarged precloacal scales, unmodified subdigital lamellae on the fourth toe, post-precloacal scales rows and precloacal pores and by having continuous, femoral and precloacal scales ( Table 8). It less well-separated from its sister species C. sanpelensis sp. nov. by only showing statistically significant differences in its mean number of enlarged femoral scales and femoral pores. However, the enlarged femoral and precloacal scales in C. pharbaungesis sp. nov. are continuous and are discontinuous in C. sanpelensis sp. nov.; and in C. pharbaungesis sp. nov. the dorsal bands are not wider than the interspaces, whereas they are in C. sanpelensis sp. nov. ( Table 8). Varying combinations of other differences between C. sadansisnensis sp. nov. and C. sanpelensis sp. nov. as well as the other newly described species are presented in Table 7. Genetic distances among the species of this group range from 8.7 to 13.1% ( Table 10).