Cyrtodactylus phamiensis, Grismer & Aowphol & Grismer & Aksornneam & Quah & Murdoch & Gregory & Nguyen & Kaatz & Bringsøe & Rujirawan, 2024

Grismer, L. Lee, Aowphol, Anchalee, Grismer, Jesse L., Aksornneam, Akrachai, Quah, Evan S. H., Murdoch, Matthew L., Gregory, Jeren J., Nguyen, Eddie, Kaatz, Amanda, Bringsøe, Henrik & Rujirawan, Attapol, 2024, A new species of the Cyrtodactylus chauquangensis group (Squamata, Gekkonidae) from the borderlands of extreme northern Thailand, ZooKeys 1203, pp. 211-238 : 211-238

Cyrtodactylus phamiensis sp. nov.

Figs 4 , 5 , 6 , 7 , 8

Type material.

Holotype. Adult male ( ZMKU R 01086 ) collected from Pha Mi Village , Wiang Phang Kham Subdistrict, Mae Sai District, Chiang Rai Province, Thailand (20.40134 ° N, 99.85369 ° E; elevation 517 m a. s. l.) on 26 March 2023 by A. Aowphol, A. Rujirawan, A. Aksornneam, L. L. Grismer, J. L. Grismer, E. S. H. Quah, and M. L. Murdoch.

Paratypes. Two adult males ( ZMKU R 01085 , ZMKU R 01087 ) and one adult female ( ZMKU R 01084 ) bear the same collection data as the holotype . Four adult females ( ZMKU R 01073–01075 , ZMKU R 01078 ) and one adult male ( ZMKU R 01081 ) bear the same collection data as the holotype except collected on 25 March 2023 .

Referred specimens.

Six hatchlings. ZMKU R 01076 –01077, ZMKU R 01079 –01080 bear the same collection data as the holotype except were collected on 25 March 2023. ZMKU R 01082 –01083 bear the same collection data as the holotype except collected from 20.39800 ° N, 99.85466 ° E; elevation 505 m a. s. l., on 25 March 2023.

Diagnosis.

Cyrtodactylus phamiensis sp. nov. can be separated from all other species of the chauquangensis group by the combination of having a maximum SVL = 74.4 mm (female); 8–12 supralabials; 9–11 infralabials; 30–43 paravertebral tubercles; 19–25 rows of longitudinally arranged tubercles; 29–37 longitudinal rows of ventrals; 6–9 expanded subdigital lamellae on the fourth toe; 12–14 unmodified subdigital lamellae on the fourth toe; 19–22 total subdigital lamellae on the fourth toe; 19–28 total number of enlarged femoral scales; 9–14 total number of femoral pores in males (n = 4); 6–11 enlarged precloacals; 4–6 precloacal pores in males (n = 4); two or three rows of large post-precloacal scales; enlarged femorals and enlarged precloacals continuous; proximal femorals usually smaller than distal femorals; femoral pores restricted to distal scales; body tubercles weakly keeled; small tubercles on forelimbs; tubercles extend beyond base of tail; medial subcaudals 2–3 times wider than long but not extending onto lateral surface of tail; nuchal loop often divided medially, bearing two posteriorly directed projections, no anterior azygous notch, projecting posterior margin; usually no triangular marking anterior to nuchal loop; dark-colored band on nape variably present; dark-colored dorsal bands lack paravertebral elements, have variably lightened centers, are edged with white tubercles, usually jagged in shape, and the same width or wider than interspaces; dark-colored markings in dorsal interspaces; no whitish ventrolateral fold; top of head in adults diffusely mottled, blotched; no light-colored reticulum on top of head; 4–6 dark-colored transverse body bands; 10–13 light-colored caudal bands on an original tail bearing dark-colored markings and not encircling tail (n = 7); 9–12 dark-colored caudal bands on an original tail and wider than light-colored caudal bands (n = 7); and mature regenerated tail mottled (n = 3) (Table 4).

Description of holotype.

(Figs 4 A , 5 , Suppl. material 3) Adult male SVL 68.5 mm; head moderate in length (HL / SVL 0.28), width ( HW / HL 0.72), flattened ( HD / HL 0.40), distinct from neck, triangular in dorsal profile; lores weakly concave anteriorly, weakly inflated posteriorly; prefrontal region concave; canthus rostralis rounded; snout elongate ( ES / HL 0.40), flat, rounded in dorsal profile; eye large ( ED / HL 0.31); ear opening elliptical, obliquely oriented, moderate in size; eye to ear distance slightly greater than diameter of eye; rostral rectangular, partially divided dorsally by inverted Y-shaped furrow, bordered posteriorly by large left and right supranasals, bordered laterally by first supralabials; external nares bordered anteriorly by rostral, dorsally by large supranasal, posteriorly by two moderately sized postnasals, bordered ventrally by first supralabial; nine (R, L) rectangular supralabials tapering abruptly to below midpoint of eye, first – fifth supralabials largest; 11 (R, L) infralabials tapering smoothly to slightly past the termination of enlarged supralabials to corner of mouth; scales of rostrum and lores flat, larger than granular scales on top of head and occiput; scales of occiput intermixed with small, rounded, tubercles; superciliaries elongate, largest dorsally; mental triangular, bordered laterally by first infralabials and posteriorly by large left and right trapezoidal postmentals contacting medially for ~ 65 % of their length posterior to mental; one row of enlarged, sublabials extending posteriorly to fifth infralabials (R, L); gular and throat scales small, granular, grading posteriorly into slightly larger, flatter, smooth, imbricate, pectoral and ventral scales.

Body relatively long ( AG / SVL 0.46) with well-defined ventrolateral folds; dorsal scales small, granular, interspersed with moderately sized, smooth, rounded, semi-regularly arranged tubercles extending from occiput to slightly beyond base of tail; ~ 25 longitudinal rows of tubercles at midbody; ~ 33 paravertebral tubercles; 33 flat, imbricate, ventral scales much larger than dorsal scales; eight enlarged precloacal scales, six bearing pores; no deep precloacal groove or depression; and two rows of large post-precloacal scales on midline.

Forelimbs moderate in length and stature ( FL / SVL 0.16); granular scales of forelimbs slightly larger than those on body, small rounded tubercles on dorsal surface of forearms; palmar scales flat, juxtaposed; digits well-developed, inflected at basal interphalangeal joints, slightly narrower distal to inflections; subdigital lamellae transversely expanded, those proximal to joint inflections much wider than nearly unmodified lamellae distal to inflections; claws well-developed, sheathed by a dorsal and ventral scale; hind limbs robust, wider and longer than forelimbs ( TBL / SVL 0.20), covered dorsally by granular scales interspersed with moderately sized tubercles, larger and flat scales anteriorly; ventral scales of thighs flat, imbricate, slightly larger than dorsals; subtibial scales small, flat, imbricate; one row of 10 (R) 11 (L) enlarged femoral scales terminating distally before knee, continuous with enlarged precloacal scales; proximal femorals nearly same size as distal femorals, all femorals forming an abrupt union with smaller, granular, ventral scales of posteroventral scales of thigh; femoral pores 4 (R) 5 (L) restricted to distalmost femorals; plantar scales flat, juxtaposed; digits well-developed, inflected at basal interphalangeal joints; claws well-developed, sheathed by a dorsal and ventral scale at base; seven (R, L) wide subdigital lamellae on fourth toe proximal to joint inflection, 12 (R, L) narrower lamellae distal to joint inflection, 19 total subdigital lamellae.

Tail regenerated, long (TL / SVL 1.14), thin, 78.1 mm in length, 6.9 mm wide at base, tapering to a point; dorsal caudal scales small, generally square, juxtaposed; median row of subcaudals significantly larger than dorsal caudals, transversely expanded, not extending dorsally onto lateral side of tail; body tubercles extending slightly beyond base of tail; faint hemipenal swellings at base of tail, two large postcloacal tubercles on both sides; and postcloacal scales flat, imbricate.

Coloration prior to preservation.

(Figs 4 , 5 ) Ground color of top of head, limbs, and dorsum straw to pale brown; top of head bearing poorly defined, irregularly shaped, dark brown markings; dark brown, nuchal loop bearing two posterior projections extend between postorbital regions; well-defined, rectangular dark brown band on nape; six dark brown, immaculate, weakly jagged, dorsal body bands terminating above the ventrolateral folds extending from shoulders to groin, same width as straw-colored interspaces, not edged with white or bright-colored tubercles; one darkly colored sacral band; dorsal interspaces faintly mottled, each bearing a brown “ fuzzy-edged ” longitudinal vertebral marking; forelimbs faintly mottled; hind limbs more darkly mottled, accentuating light-colored tubercles; one post-sacral and five wide, dark brown caudal bands slightly wider whitish caudal bands markings; whitish caudal bands do not encircle tail, bear subcircular dark brown markings; iris reddish gold with thin black reticulations; venter beige with faint, dark shadowing on lateral edges of belly and limbs; and subcaudal region dark-brown, weakly mottled with pale-colored markings.

Etymology.

The species name phamiensis is in reference to the type locality at Pha Mi Village, Wiang Phang Kham Subdistrict, Mae Sai District, Chiang Rai Province, Thailand (Fig. 1 ).

Distribution.

The type series of Cyrtodactylus phamiensis sp. nov. is known only from the type locality at Pha Mi Village, Wiang Phang Kham Subdistrict, Mae Sai District, Chiang Rai Province, Thailand (Fig. 1 ). On 30 March 2023, a bat researcher from the University of Hong Kong, Ada Chornelia, informed us of this species’ potential presence in a two adjacent karst caves at monastery 5 km north of the type locality in Tham Pha Chom along the same line of large karst formations. Examination of a photograph (Fig. 6 ) from this locality, tentatively confirms this observation. Furthermore, on 17 December 2022 three Cyrtodactylus phamiensis sp. nov. were observed, one of which was photographed, only 50 meters west-southwest of the type locality immediately east of Pha Mi Village by H. Bringsøe (Fig. 7 ) from the same karstic formations. It is likely that Cyrtodactylus phamiensis sp. nov. ranges throughout the karstic landscapes of this region.

Variation.

(Table 4) The paratypes closely approach the holotype in general coloration and pattern (Fig. 8 ). The most notable variation pertains to the shape of the nuchal loop, nape band, the caudal pattern and morphology. In ZMKU R 01073 –74, ZMKU R 01081 , ZMKU R 01083 –84 and ZMKU R 01087 , the nuchal loop is medially bifurcated. That of ZMKU R 01075 is irregular and ill-defined. The holotype, ZMKU R 01086 , is the only specimen with a complete rectangular nape band. Nape bands of the paratypes are either tripartite or nearly so. ZMKU R 01074 , ZMKU R 01084 and ZMKU R 01087 have complete tails. Tails of ZMKU R 01075 and ZMKU R 01078 are three-quarters to one-half regenerated, respectively. ZMKU R 01081 and ZMKU R 01085 lack the majority of their tails. The body bands of ZMKU R 01074 –75, ZMKU R 01085 and ZMKU R 01087 have lightened centers. Morphometric, meristic, and categorical data of the type series and referred specimens are listed in Suppl. material 3.

Comparisons.

Cyrtodactylus phamiensis sp. nov. is embedded in clade 2 and is the sister species to a clade composed of three lineages, C. doisuthep , C. erythrops and C. sp. 6. Cyrtodactylus phamiensis sp. nov. differs from those three lineages by mean uncorrected pairwise sequence divergence of 13.5–14.5 % and the remaining species in the chauquangensis group by 13.7–17.3 % (Suppl. material 2). It differs from C. doisuthep by having maximum SVL 74.4 mm (vs 90.5 mm); 9–14 total number of femoral pores in males (vs absent); and lacking light-colored reticulum on the top of the head (vs present; Kunya et al. 2014: fig. 1). Cyrtodactylus phamiensis sp. nov. differs from C. erythrops by having 29–37 longitudinal rows of ventrals (vs 28 rows); 9–14 total number of femoral pores in males (vs 19 pores); 4–6 precloacal pores in males (vs 9 pores); and hatchlings with yellow-colored heads (vs tan colored; Bauer et al. 2009: fig. 5). Additional comparisons (meristics, morphometrics, and subcaudal scale morphology) between Cyrtodactylus phamiensis sp. nov. and the remaining species in the chauquangensis group are presented in Table 4.

Natural history.

(Fig. 9 ) All specimens were collected during the evening between 19: 30 and 20: 50 hours on karst formations, at the entrance of a karst cave, within the cave, or on karst vegetation outside the cave at varying distances from the cave entrance. One specimen was observed during the day in a crack ~ 5 m above the cave floor ~ 20 m in from the entrance. Juveniles ( SVL <40 mm) were found outside the cave less than 1 m above ground level on karst boulders or on the base of small trees. Most were found farther away (~ 20–40 m) from the cave entrance than adults. On 26 March, four or five juveniles (not collected) were also observed far from the cave entrance on karst boulders and on the base of trees. That same night, other juveniles were observed near ground level on small karst outcroppings along a shallow ravine ~ 0.3 m southeast of the type locality. We have noted similar behavior in juveniles of Cyrtodactylus aunglini Grismer, Wood, Thura, Win, Grismer, Trueblood & Quah, 2018 , C. bayinnyiensis Grismer, Wood, Thura, Quah, Murdoch, Grismer, Herr, Lin & Kyaw, 2018 , C. chrysopylos Bauer, 2003 , and C. shwetaungorum Grismer, Wood, Thura, Zin, Quah, Murdoch, Grismer, Lin, Kyaw & Lwin, 2017 , of unrelated species groups in Myanmar ( Grismer et al. 2018 a, 2018 b, 2018 c). All hatchlings of these were found on the ground far from the adults on karst formations. We suspect this may be a way to avoid predation by adults as well as a means to disperse to other karst habitats. The fact that several juveniles of Cyrtodactylus phamiensis sp. nov. and no gravid females were observed indicates the reproductive season must have terminated prior to March. The three individuals of Cyrtodactylus phamiensis sp. nov. which were found 50 meters from the type locality on 17 December 2022 were adults and were observed on the karst walls outside caves at night between 21: 30 and 22: 30 hours (Fig. 7 ).

Other species of herpetofauna observed in the vicinity during this period were two species of frogs, Sylvirana nigrovittata (Blyth, 1856) and Polypedates megacephalus Hallowel, 1861 ; four other gecko species, Gehyra mutilata (Wiegmann, 1834) , Gekko gecko (Linnaeua, 1758) , Hemidactylus garnotii Duméril & Bibron, 1836 , and Hemidactylus platyurus (Schneider, 1797) ; and a pitviper Trimeresurus macrops Kramer, 1977 . We postulate that the high number of adult Cyrtodactylus phamiensis sp. nov. that had missing or regenerated tails as well as their skittish nature and that they did not stray far from their shelters could have been due to predation pressures from the large G. gecko that were also found on the karst walls and the pitvipers that were observed coiled in ambush position on vegetation beside the karst.

Figures

Figure 1. Distribution of nominal species and unnamed populations of the Cyrtodactylus chauquangensis group. The star denotes the type locality of Cyrtodactylus phamiensis sp. nov.

Figure 4. Selected individuals of the type series and referred specimen of Cyrtodactylus phamiensis sp. nov. from Pha Mi Village, Wiang Phang Kham Subdistrict, Mae Sai District, Chiang Rai Province, Thailand.

Figure 5. Adult male holotype of Cyrtodactylus phamiensis sp. nov. A dorsal view B ventral view C dorsal view of head D gular region E thighs and precloacal region F ventral view of right manus G ventral view of left pes H subcaudal region I lateral view of left side of head. Photographs by Attapol Rujirawan.

Figure 6. Cyrtodactylus cf. phamiensis sp. nov. from 5 km north of the type locality in Tham Pha Chom. Photograph by Ada Chornelia.

Figure 7. Cyrtodactylus phamiensis sp. nov. from 50 meters west-southwest of the type locality, immediately east of Pha Mi Village. 17 December 2022. Photograph by Henrik Bringsøe.

Figure 8. Paratypes of Cyrtodactylus phamiensis sp. nov. from Pha Mi Village, Wiang Phang Kham Subdistrict, Mae Sai District, Chiang Rai Province, Thailand. Photographs by Attapol Rujirawan.

Figure 9. Karst habitat of the type locality from Pha Mi Village, Wiang Phang Kham Subdistrict, Mae Sai District, Chiang Rai Province, Thailand. Photograph by Evan S. H. Quah.