Cyrtodactylus pinlaungensis, Grismer & Wood Jr & Quah & Thura & Oaks & Lin, 2019

Grismer, L. Lee, Wood Jr, Perry L., Quah, Evan S. H., Thura, Myint Kyaw, Oaks, Jamie R. & Lin, Aung, 2019, A new species of Bent-toed Gecko (Squamata, Gekkonidae, Cyrtodactylus) from the Shan Plateau in eastern Myanmar (Burma), Zootaxa 4624 (3), pp. 301-321 : 310-318

Cyrtodactylus pinlaungensis sp. nov. Suggested common name: Pinlaung Bent-toed Gecko

Figs. 4 , 5 , 7

Holotype. Adult male LSUHC 14280 was collected on 12 November 2018 at 2000 hrs by Evan S. H. Quah, Myint Kyaw Thura, Jamie R. Oaks, Perry L. Wood Jr., Aung Lin and L. Lee Grismer from the karstic hills immediately behind the Pinlaung Hotel, Pinlaung Township , Pa-O District, Shan State, Myanmar (20.13042°N, 96.78620°E; 1534 m in elevation).

Paratypes. Adult females LSUHC 14278–79 bear the same collection data as the holotype. Adult male LSUHC 14307 , adult female LSUHC 14306 , and subadult female 14308 were collected on 13 November 2018 between 21:00–23:30 hrs by Myint Kyaw Thura, Jamie R. Oaks, Evan S. H. Quah, Perry L. Wood Jr., Aung Lin and L. Lee Grismer at Wingabar Cave , Pinlaung Township, Pa-O District, Shan State, Myanmar (20.06936°N, 96.76998°E; 1464 m in elevation) .

Diagnosis. Cyrtodactylus pinlaungensis sp. nov. differs from all species in the C. linnwayensis group by having the combination of seven or eight supralabials; 8–10 infralabials; 36–42 paravertebral tubercles; 24–29 longitudinal rows of dorsal tubercles; 35–43 ventral scales; 5–7 pore-bearing precloacal scales in males; 9–14 pore-bearing femoral scales in males; 6–8 enlarged precloacal scales; 4–6 enlarged post-precloacal scales; 24–31 enlarged femoral scales; eight or nine transversely expanded subdigital lamellae on the fourth toe; 12–15 unexpanded subdigital lamellae on the fourth toe; 20–23 total subdigital lamellae on the fourth toe; raised and strongly keeled dorsal tubercles that extend beyond the postcloacal swelling; four or five regularly shaped dorsal bands bearing lightened centers; and a mature regenerated tail with a faint to prominent spotted pattern ( Table 4 ).

Description of holotype. Adult male SVL 94.5 mm; head moderate in length (HL/SVL 0.28), wide (HW/HL 0.71), flat (HD/HL 0.42), distinct from neck, triangular in dorsal profile; lores inflated, prefrontal region concave, canthus rostralis rounded; snout elongate (ES/HL 0.43), rounded in dorsal profile, broad in lateral profile; eye large (ED/HL 0.21); ear opening oval, small (EL/HL 0.07); eye to ear distance greater than diameter of eye; rostral rectangular, partially divided dorsally, bordered posteriorly by supranasals and azygous postnasal, laterally by first supralabials; external nares bordered anteriorly by rostral, dorsally by supranasals, posteriorly by two relatively large postnasals, and ventrally by first supralabials; 7(R,L) rectangular supralabials extending to below midpoint of eye; 9(R,L) infralabials tapering posteriorly to commissure of jaw; 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 tubercles; dorsal superciliaries weakly pointed and directed posteriorly; mental triangular, bordered laterally by first infralabials and posteriorly by large left and right trapezoidal postmentals which contact medially for 60% of their length posterior to mental; one row of variably enlarged chinshields bordering first six infralabials; gular and throat scales granular, grading posteriorly into larger, subimbricate pectoral and ventral scales.

Body relatively short (AG/SVL 0.43) with well-defined ventrolateral folds; dorsal scales small, raised and interspersed with large, raised, semi-regularly arranged, strongly keeled tubercles; tubercles extend from nape onto base of tail beyond the postcloacal swelling; tubercles on nape smaller than those on posterior portion of body; 36 paravertebral tubercles; approximately 24 longitudinal rows of dorsal tubercles; 39 flat, subimbricate, ventral scales larger than dorsal scales; seven enlarged precloacal scales; six 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, juxtaposed scales of forearm larger than those on body, intermixed with large tubercles; palmar scales slightly raised; 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; no webbing at base of digit; claws well-developed, sheathed by a dorsal and ventral scale at base; hind limbs more robust than forelimbs, moderate in length (TBL/SVL 0.19), covered dorsally by small, raised, juxtaposed scales intermixed with large pointed tubercles and bearing flat, slightly larger imbricate scales anteriorly; ventral femoral scales imbricate, larger than dorsals; one row of 12 (R,L) enlarged femoral and enlarged precloacal scales not continuous; enlarged femoral scales nearly equal in size; small, postfemoral scales form an abrupt union with larger, flat ventral scales of posteroventral margin of thigh; four (R) and five (L) femoral pores; subtibial scales flat, imbricate; plantar scales raised; digits relatively long, well-developed, inflected at basal, interphalangeal joints; eight (R,L) transversely expanded subdigital lamellae on fourth toe proximal to joint inflection that do not extend onto sole, 15 (R,L) unmodified subdigital lamellae distal to inflection; and claws well-developed, base of claw sheathed by a dorsal and ventral scale.

Tail complete, original, robust in proportions, 110.1 mm in length, 9.9 mm in width at base, tapering to a point, TL/SVL (1.17); dorsal scales of tail flat, not forming distinct whorls; median row of transversely expanded subcaudal scales twice as wide as long, not extending onto lateral subcaudal region; two enlarged postcloacal tubercles at base of tail on hemipenal swellings; and postcloacal scales flat.

Coloration in life during dark phase ( Fig. 4 ). Dorsal ground color of head, body, limbs, and tail dark-brown; top of head and rostrum bearing dark blotches outlined by a yellow reticulum; wide dark-brown nuchal loop extends across the occiput between opposing postorbital regions; four regularly shaped body bands bearing lightened centers and edged with yellow tubercles extend from the shoulder to the presacral region; nuchal loop and lacks an anterior azygous notch; darkened interspaces between bands; yellow tubercles scattered on flanks; sacral and postsacral bands continue onto the tail to form nine black caudal bands that are wider than nine white caudal bands; white caudal bands bear dark markings and encircle tail posteriorly; limbs bear semi-transversely arranged yellow spots; and ventral surfaces of head body, and limbs beige, generally immaculate.

Variation ( Fig. 5 ). The paratypes closely resemble the holotype in all aspects of coloration and pattern. Paratype LSUHC 14306 is in its light phase, has a distinctly spotted fully mature regenerated tail, and an anterior azygous notch on its nuchal loop. Paratypes 14279 and 14307 have faintly spotted regenerated tails. Paratype 14287 is missing its tail. Paratype 14279 has five body bands as opposed to four. Additional variation in meristic and mensural characters are presented in Tables 4 and 5 .

Distribution. Cyrtodactylus pinlaungensis sp. nov. is known only from the vicinity of Pinlaung Town, Pinlaung Township, Pa-O District, Shan State, Myanmar from directly behind the Pinlaung Hotel and the Wingabar Cave ( Fig. 1 ).

Natural history. All individuals of the type series were found in karstic microhabitats ( Fig. 6 ). The hills framing the eastern edge of the Pinlaung Valley are punctuated with karst outcroppings along the ridgeline. That portion directly behind the Pinlaung Hotel was centered around large closely spaced outcroppings wherein three specimens were collected. All were found during a rainy evening between 1800–2100 hrs on boulders and vertical faces 1–3.5 m above the ground. LSUHC 14287 was coerced out of a shallow outpocketing in a small crack 3.5 m above the ground. LSUHC 14279 was found on a vertical surface near a crack at the base of a cliff and was somewhat concealed by vegetation. LSUHC 14280 was found sitting near a crack on a large boulder covered with roots.

Wingabar Cave is one of several isolated karst tower formations west of Pinalaung Town on the western edge of Pinlaung Valley and serves as a monastery and well-known tourist destination. The tower formation is composed of several jagged spires that have a series of interconnecting tunnels and caves at their bases that were initially carved out by subterranean streams. All individuals from Wingabar Cave were found outside of the caves on vertical surfaces 0.5–1 m above the ground from 1800–2150 hrs.

Comparisons ( Figs. 3 , 7 , Table 4 ). Cyrtodactylus pinlaungensis sp. nov. differs from all other species in the C. linnwayensis group in having a significantly higher mean number of paravertebral tubercles (38.8 versus 28.6–33.6, collectively) and dorsal tubercles that extend beyond the postcloacal swelling as opposed to terminating anterior to it. Cyrtodactylus pinlaungensis sp. nov. differs from C. linnwayensis and C. shwetaungorum in having a higher mean number of longitudinal rows of tubercles (26.2 versus 17.8 and 19.0, respectively), a significantly lower mean number of enlarged precloacal scales (7.2 versus 10.1 and 9.8, respectively), and raised and strongly keeled versus low and weekly keeled dorsal tubercles. It differs further from C. ywanganensis in having a significantly higher mean number of post-precloacal scales (5.0 versus 3.0) and ventral scales (39.3 versus 35.0), and regularly shaped dorsal bands bearing lightened centers as opposed to jagged dorsal bands lacking lightened centers. Cyrtodactylus pinlaungensis sp. nov. differs further from C. shwetaungorum in having a significantly lower mean number of postprecloacal scales (5.0 versus 3.2 and 3.0, respectively) and a mature regenerated tail bearing as opposed to lacking dark spots. Cyrtodactylus pinlaungensis sp. nov. is completely separated from all species in the C. linnwayensis group in the PCA and DAPC. Given the small sample size for C. pinlaungensis sp. nov. (N=6) and C. ywanganensis (N=5), the statistical significance of some of these characters may increase or decrease with the acquisition of additional specimens.

Figures

FIGURE 1. Distribution of the species of the Cyrtodactylus linnwayensis group on the Shan Plateau. 1 = Wingabar Cave, Shan State. 2 = Pinlaung Town, Shan State. 3 = Pyinyaung Village, Mandalay Division. 4 = Apache Cement Co., Mandalay Division. 5 = Magyidar Forest Camp, Shan State. 6 = 2.7 km west of Ywangan, Shan State. 7 = Hmyarkalay Village, Shan State. 8 = Lin- nway Village vicinity, Shan State. 9 = Wun Twin Cave, Shan State.

FIGURE 3. A. Plot of the principal component analysis (PCA) ordinated along the first two principal components. B. Plot of the discriminant analysis of principal components (DAPC). C. Boxplots of characters bearing significantly different mean values determined by TukeyHSD tests. Species pairs above individual plots are those that bear significant mean differences. Boxes represent the 50% quartiles, the horizontal black bars the medians, and the blue circles the means. Character abbreviations are in the Materials and Methods.

FIGURE 4. Adult male holotype of Cyrtodactylus pinlaungensis sp. nov. LSUHC 14280 from immediately behind the Pinlaung Hotel, Pinlaung Township, Pa-O District, Shan State, Myanmar (20.13042°N, 96.78620°E; 1534 m in elevation).

FIGURE 5. Paratypes of Cyrtodactylus pinlaungensis sp. nov. A. Subadult female LSUHC 14308 from Wingabar Cave, Pinlaung Township, Pa-O District, Shan State, Myanmar (20.06936°N, 96.76998°E; 1464 m in elevation). B. Adult female LSUHC 14306 from Wingabar Cave. C. Adult male LSUHC 14307 from Wingabar Cave. D. Adult female LSUHC 14279 from immediately behind the Pinlaung Hotel, Pinlaung Township, Pa-O District, Shan State, Myanmar (20.13042°N, 96.78620°E; 1534 m in elevation). E. Adult female LSUHC 14287 from behind the Pinlaung Hotel.

FIGURE 6. A. Karst tower of Wingabar Cave, approximately 6 km southwest of Pinlaung Town, Shan State. B. Karstic mountain ridge east of Pinlaung Town.

FIGURE 7. Comparison of overall color pattern characteristics among the species of the Cyrtodactylus linnwayensis group. A. Adult male Cyrtodactylus linnwayensis LSUHC 12971 from Yae Htwat Cave, Shan State. B. Adult male C. pinlaungensis sp. nov. LSUHC 14280 from immediately behind the Pinlaung Hotel, Shan State. C. Adult female C. ywanganensis LSUHC 13758 from 2.7 km west of Ywnagan, Shan State. D. Adult female C. shwetaungorum LSUHC 13118 from Pyinyaung Village, Mandalay Division.