Cyrtodactylus pyadalinensis, Grismer & Wood & Thura & Win & Quah, 2019

Grismer, L. Lee, Wood, Perry L., Thura, Myint Kyaw, Win, Nay Myo & Quah, Evan S. H., 2019, Two more new species of the Cyrtodactylus peguensis group (Squamata: Gekkonidae) from the fringes of the Ayeyarwady Basin, Myanmar, Zootaxa 4577 (2), pp. 274-294 : 284-291

Cyrtodactylus pyadalinensis sp. nov.

Panluang-Pyadalin Cave Bent-toed Gecko

( Figs. 5 , 6 )

Holotype. Subadult male CAS 226143 collected during the evening on 16 July 2002 by G.O.U. Wogan, R. S. Lucas, J. V. Vindum , Thin Thin , and A. K. Shein from Panluang-Pyadalin Cave Wildlife Sanctuary , Ywangan Township, Shan State, Myanmar (21.107000°N, 96.352111°E; 220 m in elevation).

Paratypes. Subadult male CAS 226142 collected during the evening on 16 July 2002 by Htun Win from Panluang-Pyadalin Cave Wildlife Sanctuary , Ywangan Township , Shan State, Myanmar (21.115801°N, 96.360694°E; 346 m in elevation). Adult female LSUHC 13932 collected at 2100 hrs on 26 March 2018 by Perry L. Wood Jr., Nyo Min Htwe, and L. Lee Grismer from immediately outside the Pyadalin Cave , Panluang-Pyadalin Cave Wildlife Sanctuary, Ywangan Township, Taunggyi District, Shan State, Myanmar (21.13275°N, 96.34026°E; 306m in elevation.)

Additional material examined. Hatchling LSUHC 13933 bearing the same locality and collection data as LSUHC 13932 except that it was collected by Nyo Min Htwe, Perry L. Wood Jr., and L. Lee Grismer.

Diagnosis. Cyrtodactylus pyadalinensis sp. nov. differs from all other species in the peguensis group by having the unique combination of eight supralabials and 6–8 infralabials; 31–33 paravertebral tubercles; 19–21 longitudinal rows of body tubercles; 38–40 ventral scales; 16–18 subdigital lamellae on the fourth toe; 14 or 15 femoral pores in males; nine or 10 precloacal pores in males; two or three rows of enlarged, post-precloacal scales; top of head bearing dark blotches; 4–6 dark body bands; dark body bands lacking paravertebral elements; and maximum SVL of 72.1 mm ( Table 4).

Description of holotype. Subadult male, SVL 51.1 mm; head moderate in length (HL/SVL 0.28), wide (HW/ HL 0.61), somewhat flattened (HD/HL 0.37), distinct from neck, triangular in dorsal profile; lores inflated, prefrontal region concave, canthus rostralis rounded; snout elongate (ES/HL 0.39), rounded in dorsal profile; eye large (ED/HL 0.21); ear opening elliptical, moderate in size (EL/HL 0.09); eye to ear distance greater than diameter of eye; rostral rectangular, partially divided dorsally, bordered posteriorly by large left and right supranasals separated small internasal, laterally by first supralabials; external nares bordered anteriorly by rostral, dorsally by large supranasal, posteriorly by three postnasals (upper largest), ventrally by first supralabial; eight (R,L) rectangular supralabials extending to below midpoint of eye; seven (R,L) infralabials tapering smoothly to below posterior margin of eye; scales of rostrum and lores flat, larger than granular scales on top of head and occiput; scales on top of head and occiput intermixed with slightly enlarged tubercles; dorsal supraciliaries not elongate or keeled; mental triangular, bordered laterally by first infralabials and posteriorly by large, left and right trapezoidal postmentals that contact medially for 70% of their length posterior to mental; one row of slightly large chinshields tapering posteriorly to fourth infralabial; and gular and throat scales small, granular, grading posteriorly into larger, flatter, smooth, subimbricate to imbricate, pectoral and ventral scales.

Body relatively short (AG/SVL 0.44) with weak ventrolateral folds; dorsal scales small, interspersed with larger, semi-regularly arranged, moderately keeled tubercles; tubercles extend from occiput onto base of tail but no farther; tubercles on occiput and nape smaller than those on posterior portion of body; approximately 21 longitudinal rows of dorsal tubercles; 31 paravertebral tubercles; approximately 40 flat, imbricate, ventral scales larger than dorsal scales; nine pore-bearing precloacal scales; two rows of large post-precloacal scales; and no deep precloacal groove or depression.

Forelimbs moderate in stature, relatively short (FL/SVL 0.15); flat scales of anterior margin of forearm larger than those on body, not interspersed with tubercles; palmar scales raised; digits relatively short, well-developed, inflected at basal, interphalangeal joints, slightly narrower distal to inflections; claws well-developed, sheathed by a dorsal and ventral scale; hind limbs more robust than forelimbs, moderate in length (TBL/SVL 0.16), covered dorsally by granular scales interspersed with slightly larger, weakly keeled tubercles and anteriorly by large, flat, imbricate scales; ventral scales of femora flat, imbricate, larger than dorsals, lacking a distinct row of enlarged femoral scales; small postfemoral scales form an abrupt union with large, flat ventral scales of posteroventral margin of thigh; subtibial scales flat, imbricate; plantar scales slightly raised; digits relatively short, well- developed, inflected at basal, interphalangeal joints, slightly narrower distal to inflections; 18 subdigital lamellae (R,L) on fourth toe; claws well-developed, base of claw sheathed by a dorsal and ventral scale; two enlarged postcloacal tubercles at base of tail; and postcloacal scales flat.

Tail original, 56.9 mm in length, 4.9 mm in width at base, tapering to a point; dorsal scales square and flat; transversely enlarged, median, subcaudal scales twice as wide as long, not extending onto lateral margin of tail in original section.

Coloration in life ( Fig. 6 ). Dorsal ground color of head body, limbs, and tail yellow; top of head bearing large, dark-brown, irregularly shaped, conjoined blotches edged in yellow; dark-brown, wide, nuchal loop extending from posterior margin of one eye, across occiput, to posterior margin of other eye; nape bearing a wide, dark-brown band edged in yellow; five wide, dark-brown body bands between limb insertions edged in yellow lacking paravertebral components, posterior three obliquely oriented; large, round, dark-brown markings between body bands; 6–8 smaller, diffuse brown blotches along lower margins of flanks; one dark-brown post-sacral band edged in yellow not bearing paravertebral elements; 12 dark-brown caudal bands wider than the 12 yellow caudal bands; dorsal portion of forelimbs darkly mottled to banded; dorsal portion of hind limbs bearing irregularly shaped, darkbrown blotches edged in yellow; and all ventral surfaces generally beige, immaculate.

Variation. The paratypes generally approach the holotype in most aspects of coloration and pattern. The most notable difference is in the dorsal banding pattern where the paratypes have more transversely oriented dark, dorsal bands as opposed to the holotype whose bands are more obliquely oriented. In the paratype CAS 226142 , the central band between the limb insertions is somewhat oval-shaped and bears a central light spot. The dark dorsal bands in the paratype LSUHC 13933 are considerably narrower than those of all the other specimens in the type series and the distal one-half of the tail is missing. The paratype LSUHC 13932 has a regenerated tail bearing a dark-beige ground color overlain with small, dark, irregularly shaped markings. Meristic differences among specimens of the type series are resented in Table 5 .

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22 TABLE 5. Meristic, mensural, and color pattern data for Cyrtodactylus pyadalinensis sp. nov. and C. nyinyikyawi sp. nov. / = data unobtainable.

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Distribution. Cyrtodactylus pyadalinensis sp. nov. is known only from the vicinity of the Panluang-Pyadalin Cave in the Panluang-Pyadalin Cave Wildlife Sanctuary, Ywangan Township, Taunggyi District, Shan State, Myanmar ( Fig. 1 ).

Etymology. The specific epithet, pyadalinensis , is a toponym referring to the type locality in the vicinity of the Pyadalin Cave.

Natural history. The type series of Cyrtodactylus pyadalinensis sp. nov. were all collected in the vicinity of the Kinda Reservoir between the Panulaung River and the Pyadalin Cave. This area is within the foothills and rocky plain of the Nwalabo Mountain range on the western fringe of the Shan Plateau ( Fig. 1 ) between 213 and 306 m in elevation. The habitat is composed of low-lying, highly eroded terrain and scree of the Nwalabo Mountains. It bears scattered karstic rocks and boulders surrounded by disturbed, drought-adapted, scrub Indiang Forest vegetation that is seasonally burned ( Fig. 7 ). All specimens were found at night between 1900 and 2300 hrs among small rocks and leaf-leaf litter.

Comparisons. Cyrtodactylus pyadalinensis sp. nov. descends from one of the deeper divergences of the peguensis group and the sister species to the clade ( C. niyniykyawi sp. nov. ( C. peguensis ( C. pyinyaungensis and C. myintkyawthurai ))) from which it differs by an uncorrected pairwise sequence divergence of 9.0–10.3%. From C. meersi and C. annandalei which occur outside this clade, it differs by 10.7–11.0% and 14.0–14.3%, respectively. It differs from all other species except C. nyinyikyawi sp. nov. in the dark-brown dorsal bands lacking as opposed to having paravertebral elements. It differs further from C. annandalei in that the top of the head is blotched as opposed to being unicolor. Differences from C. nyinyikyawi sp. nov. are presented in the Comparisons section above. Statistically significant mean differences in meristic characters among C. pyadalinensis sp. nov., C. myintkyawthurai , and C. pyinyaungensis are presented in Tables 3 and 4.

Figures

FIGURE 1. Distribution of the species of the Cyrtodactylus peguensis group.

FIGURE 5. A. Cyrtodactylus peguensis (LSUHC 13454) from the Myin Mo Shwe Taung Pagoda, 9.5 km east of Hpa Lon, Bago Region Myanmar. B. Cyrtodactylus meersi (LSUHC 13455) from the Myin Mo Shwe Taung Pagoda, 9.5 km east of Hpa Lon, Bago Region Myanmar. C. Cyrtodactylus pyadalinensis sp. nov. (LSUHC 13932) from immediately outside the Pyadalin Cave, Panluang-Pyadalin Cave Wildlife Sanctuary, Ywangan Township, Taunggyi District, Shan State, Myanmar. D. Cyrtodactylus myintkyawthurai (LSUHC 13949) from from 5.7 km north of Pyinyaung Village at the Apache Cement factory mining site, Mandalay Region, Myanmar. E. Cyrtodactylus pyinyaungensis (LSUHC 13807) from Taung Twin Chaung camp, Mt. Popa, Kyauk-pa-taung Township, Mandalay Region, Myanmar. Photos by L. Grismer.

FIGURE 6. Cyrtodactylus pyadalinensis sp. nov. from the vicinity of the Pyadalin Cave, Panluang-Pyadalin Cave Wildlife Sanctuary, Ywangan Township, Shan State, Myanmar. Upper to lower; paratype adult female LSUHC 13932, juvenile LSUHC 13933 (photos by L. Grismer), and adult male holotype CAS 226143 (photo provided by the California Academy of Sciences).

FIGURE 7. Habitat at the type locality of Cyrtodactylus pyadalinensis sp. nov. in the Panluang-Pyadalin Cave Wildlife Sanctuary, Ywangan Township, Taunggyi District, Shan State, Myanmar. Photo by P. Wood, Jr.