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

CYRTODACTYLUS SADANENSIS View in CoL SP. NOV.

SADAN CAVE BENT-TOED GECKO

( FIG. 36; TABLE 20)

Holotype: Adult male LSUHC 12839 View Materials collected on 5 October 2016 at 1700 h by L. Lee Grismer, Evan S. H. Quah, Perry L. Wood, Jr., Myint Kyaw Thura, Thaw Zin, Matthew L. Murdoch, Marta S. Grismer and Htet Kyaw from the Sadan Cave 17 km south-east of Hpa-an, Hpa-an District, Kayin State, Myanmar (N16°44.605, E97°29.493; 26 m in elevation). GoogleMaps

except where the vegetation was lacking and where H. brookii was abundant. We found no geckos inside Linno Cave. We believe the abundance of bats, rats, cockroaches and a near-toxic atmosphere made the cave uninhabitable for Cyrtodactylus . Much of the cave surfaces were covered with a dark gelatinous ooze through which geckos would likely be unable to locomote.

Comparisons: Cyrtodactylus linnoensis is part of the yathepyanensis group. The PCA and DAPC analyses indicate that the species of this group are completely separate in morphospace and that the first two principal components account for 54% of the total variation ( Fig. 12; Fig. S5) and load most heavily for numbers of paravertebral tubercles and ventral scales ( Table S4). Cyrtodactylus linnoensis sp. nov. is well-differentiated from C. yathepyanenis sp. nov. and C. sadanensis sp. nov. by having varying combinations Paratypes: Adult males BYU 52218 and LSUHC 12848, adult females BYU 52216–17, 52219, LSUHC 12841–47, 12849 and 12853 bear the same collection data as the holotype.

Diagnosis: Cyrtodactylus sadanensis sp. nov. differs from all congeners by having the unique combination of ten or 11 supralabials; 7–9 infralabials; 13–15 longitudinal rows of body tubercles; 30–33 paravertebral tubercles; 30–35 ventral scales; relatively long digits with 7–9 expanded, subdigital lamellae on fourth toe proximal to digital inflection, 13 or 14 unmodified, distal, subdigital lamellae and 21–23 total subdigital lamellae; raised, moderately to strongly keeled, dorsal body tubercles extending beyond base of tail; enlarged femoral and precloacal scales not continuous; 34–41 enlarged femoral scales; 12 or 13 femoral pores in males; 10–13 enlarged precloacal scales; two or three precloacal pores in males; three rows of enlarged post-precloacal scales; medial subcaudal scales three times as wide as long, extending onto lateral surface of tail; top of head bearing diffuse, dark mottling, lacking yellow reticulum; nuchal loop not divided medially, lacking an anterior azygous notch; five rarely six dark, weakly jagged, dorsal bands generally lacking paravertebral elements, same width or narrower than interspaces, faintly lightened centres, edged with yellowish tubercles; dark markings in dorsal interspaces; ventrolateral folds whitish; anterodorsal margins of thighs generally lack pigment; 16 light caudal bands bearing dark markings, not encircling tail;

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

17 dark caudal bands same width or wider than light caudal bands; and mature, regenerated tail not spotted.

Description of holotype: Adult male SVL 73.8 mm; head moderate in length (HL/SVL 0.29), wide (HW/HL 0.69), flat (HD/HL 0.37), distinct from neck, triangular in dorsal profile; lores inflated, prefrontal region concave, canthus rostralis rounded; snout elongate (ES/HL 0.40), rounded in dorsal profile, not flattened in lateral profile; eye large (ED/HL 0.26); ear opening pare-shaped, moderate in size (EL/HL 0.16); 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 small azygous scale, laterally by first supralabials; supranasal separated by two small, azygous scales; external nares bordered anteriorly by rostral, dorsally by supranasal, posteriorly by two postnasals, ventrally by first supralabial; 11(R,L) square supralabials extending to below midpoint of eye; 9(R)8(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 intermixed with small tubercles; dorsal superciliaries not elongate or keeled; mental triangular, bordered laterally by first infralabials and posteriorly by large, left and right trapezoidal postmentals contacting for 50% 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 0.41) with well-defined ventrolateral folds; dorsal scales small, raised and interspersed with large, conical, semi-regularly arranged, moderately to strongly keeled tubercles; tubercles extend from nape to beyond base of tail; tubercles on nape smaller than those on posterior portion of body, less sharply keeled; approximately 14 longitudinal rows of body tubercles; 32 paravertebral tubercles; 31 flat, subimbricate, ventral scales larger than dorsal scales; ten enlarged precloacal scales; three precloacal pores; three rows of large, post-precloacal scales; and no deep, precloacal groove or depression.

Forelimbs moderate in stature, relatively short (FL/SVL 0.18); slightly raised, subimbricate scales of forearm larger than those on body, lacking tubercles; palmar scales low, rounded; digits well-developed, relatively long, inflected at basal, interphalangeal joints; digits much more narrow distal to inflections; widened, proximal, subdigital lamellae do not extend onto palm; claws well-developed, sheathed by a dorsal and ventral scale at base; hindlimbs more robust than forelimbs, moderate in length (TBL/SVL 0.22), covered dorsally by raised 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 19(R,L) enlarged femoral scales in contact with enlarged precloacal scales, proximal femoral scales one-half to one-third distal femoral scales; 6(R)7(L) femoral pores; small postfemoral scales form abrupt union with larger, flat ventral scales of posteroventral margin of thigh; subtibial scales flat, imbricate; plantar scales raised; digits relatively long, well-developed, inflected at basal, interphalangeal joints; 7(R,L) transversely expanded subdigital lamellae on fourth toe proximal to joint inflection not extending onto sole, 14(R,L) unmodified subdigital lamellae distal to inflection, 21 total subdigital lamellae; distal one-half of digit 1 of left hand missing; and claws well-developed, base of claw sheathed by a dorsal and ventral scale.

Tail moderate in proportions, 112.0 mm in length, last 40.0 mm regenerated, 8.7 mm in width at base, tapering to a point; dorsal scales of tail flat; medial subcaudal scales three times as wide as long, extending onto lateral surface of tail; 2(R,L) enlarged postcloacal tubercles at base of tail on hemipenal swellings; and postcloacal scales flat.

Coloration in life: Dorsal ground colour of head body, limbs and yellowish tan; top of head bearing, diffuse, irregularly shaped, dark mottling, yellow reticulum absent; rostrum bearing diffuse, dark, speckling; superciliary scales yellowish; dark, nuchal loop bearing a sinuous posterior margin; five weakly jagged, body bands narrower than interspaces, bearing faintly lightened centres, lacking paravertebral elements, partly edged with light tubercles, posterior two bands broken and irregularly shaped; one sacral band; interspaces bearing large, dark, diffuse, medial spots; dark markings on flanks; dark banding on limbs indistinct, mottled with yellowish markings; anterodorsal margins of thighs and brachia not pigmented; ventrolateral folds faintly whitish; dark caudal bands bearing slightly lightened centres, wider than light caudal bands; light caudal bands bearing dark markings, not encircling tail; venter beige, generally unpigmented; and subcaudal region darker.

Variation ( Fig. 36; Fig. S13): The paratypes closely approximate the holotype in aspects of colour pattern. LSUHC 12851 View Materials has six instead of five body bands. BYU 52217 View Materials , LSUHC 12844 View Materials and 12948 have broken tails and LSUHC 12846 View Materials is missing its right arm. The nape band on BYU 52218 View Materials , LSUHC 12845 View Materials and 12847 is divided medially. Meristic and mensural differences are presented in Table 20 .

Distribution: Cyrtodactylus sadanensis sp. nov. is known only from the Sadan Cave 17 km south-east of Hpa-an, Hpa-an District, Kayin State, Myanmar ( Fig. 20).

950 L. L. GRISMER ET AL .

Etymology: The specific epithet, sadanensis , is a noun in apposition in reference to the type locality of Sadan Cave.

Natural history: Sadan Cave is located immediately south-east of Hpa-an and situated on the south end of a large, isolated, karst hill approximately 3.6 km wide, 16.4 km long and 338 m high that is surrounded by paddy fields. Sadan Cave is connected to Sin Yine Cave as they occur along the same, semicircular, karst ridge. The mouth of Sadan Cave is approximately 700 m from the opening of Sin Yine Cave across an ephemerally flooded paddy field. The interior of Sadan Cave is wide, airy and high-roofed and approximately 0.25 km in length from the southern entrance to the northern exit. Most of the interior of the cave is smooth-walled and there is not an abundance of the appropriate microhabitat structure necessary for Cyrtodactylus similar to what we had observed in other caves. Outside the cave along the base of the karst hill, has an abundance of cracks, holes, and broken boulders and associated rubble that had been shed from the hillside ( Fig. 37). Cyrtodactylus were common and ubiquitous in this habitat after dark and absent only from the nearby vegetation. Only one lizard was seen in the cave.

Comparisons: Cyrtodactylus sadanensis sp. nov. is part of the yathepyanensis group. The PCA and DAPC analyses indicate that the species of this group are completely separate in morphospace and that the first two principal components account for 55% of the total variation ( Fig. 12; Fig. S5) and load most heavily for numbers of paravertebral tubercles and ventral scales ( Table 8). See Comparisons for C. yathepyanensis sp. nov. and C. linnoensis sp. nov. for additional differences among them. Morphological differences from other species in the Indo-Chinese clade are listed in Table 8.

Remarks: The fact that Cyrtodactylus sadanensis sp. nov. is sympatric but not syntopic with C. sinyineensis from Sin Yine Cave is an indication of the degree of niche partitioning that may occur in many of the karst habitats we explored. The hillside walls outside Sadan Cave are continuous with those of Sin Yine Cave and would enable these two species to share the same microhabitat. Yet the larger C. sinyineensis sp. nov. (maximum SVL = 91.6 mm) was only found inside the cave at least 100 m from the opening and the smaller C. sadanensis sp. nov. (maximum SVL = 73.8 mm) was abundant on the karst walls outside the cave. Additionally, these two species do not occur in the same species group, indicating that this karst system has been invaded multiple times.