Cyrtodactylus orlovi, Do & Phung & Ngo & Le & Ziegler & Pham & Nguyen, 2021

Do, Quyen Hanh, Phung, Trung My, Ngo, Hanh Thi, Le, Minh Duc, Ziegler, Thomas, Pham, Cuong The & Nguyen, Truong Quang, 2021, A new species of Cyrtodactylus (Squamata: Gekkonidae) from Ninh Thuan Province, southern Vietnam, Zootaxa 4999 (1), pp. 58-76 : 61-74

publication ID	https://doi.org/ 10.11646/zootaxa.4999.1.4
publication LSID	lsid:zoobank.org:pub:500EC80A-AF31-4470-B1BB-1C7A0A3874DC
persistent identifier	https://treatment.plazi.org/id/755F87B9-A516-D704-A38C-F89DFF22FCDD
treatment provided by	Plazi
scientific name	Cyrtodactylus orlovi
status	sp. nov.

Treatment

Cyrtodactylus orlovi sp. nov.

( Figs. 3–5 View FIGURE 3 View FIGURE 4 View FIGURE 5 )

Holotype. IEBR 3812 (Field number PMT. 3.12.2015), adult male, collected on 20 December 2015 by T. M. Phung from the Ca Na forest (11°22’50.5”N 108°47’49.0”E, at an elevation of 800 m asl.), Ca Na Commune, Thuan Nam District, Ninh Thuan Province, southern Vietnam. GoogleMaps

Paratypes. IEBR 3811 (Field number PMT. 2.12.2015), adult male ; IEBR 3814 (Field number PMT. 4.12.2015), adult female ; IEBR 3815 (Field number PMT. 5.12.2015), adult female ; IEBR 3813 (Field number PMT. 6.12.2015), subadult male, the same data as the holotype GoogleMaps .

Diagnosis. The new species can be distinguished from other members of the genus Cyrtodactylus by a combination of the following characters: size medium (SVL 61.0– 77.7 mm); dorsal tubercles in 16–20 irregular rows; 36–39 ventral scale rows; precloacal pores absent in females, 5 or 6 in males, in a continuous row; femoral pores absent; 3–8 enlarged femoral scales; postcloacal spurs 1 or 2; lamellae under toe IV 16–19; neckband continuous; dorsal pattern with irregular transverse bands; subcaudals not transversely enlarged.

Description of holotype. Adult male, snout-vent length (SVL) 61.0 mm; body elongate (TrunkL/SVL 0.46); head distinct from neck, elongate (HL/SVL 0.30), relatively wide (HW/HL 0.69), depressed (HH/HL 0.40); two enlarged supranasals, separated from each other anteriorly by one internasal; nares oval, surrounded by supranasal, rostral, first supralabial, and three postnasals; loreal region concave; snout long (SE/HL 0.42), round anteriorly, longer than diameter of orbit (OD/SE 0.53); snout scales small, round, granular, larger than those in frontal and parietal regions; orbit of moderate size (OD/HL 0.22), pupils vertical, supraciliaries short, forming conical spines, larger anteriorly; ear opening oval, obliquely directed, small in size (ED/HL 0.07), eye to ear distance longer than orbit diameter (Eye Ear/OD 1.36); rostral wider than high with a medial suture, bordered by first supralabial on each side, nostrils, two supranasals and one internasal; mental triangular, slightly wider than rostral; postmentals two, enlarged, in contact posteriorly, bordered by mental anteriorly, first infralabial laterally, and an enlarged chin scale posteriorly; supralabials 10/9; infralabials 8/8.

Dorsal scales granular; dorsal tubercles round, conical, present on occipital region and back, each surrounded by 9 or 10 granular scales, in 17 irregular longitudinal rows at midbody; ventral scales larger than dorsals, smooth, oval, subimbricate, largest posteriorly, in 36 longitudinal rows at midbody; lateral skin folds without tubercles; gular region with homogeneous smooth scales; ventral scales between mental and cloacal slit 165; precloacal groove absent; right thigh with a series of 6 enlarged femoral scales, left thigh with a series of 8 enlarged femoral scales, femoral pores absent; precloacal scales arranged in a diamond shape, precloacal pores 6, in a continuous row, porebearing scales enlarged; postcloacal spur each bearing one much enlarged conical scale.

Fore and hind limbs moderately slender and long (ForeaL/SVL 0.17, CrusL/SVL 0.2); forelimbs dorsally covered by few slightly developed tubercles; hind limb dorsally covered by distinctly developed tubercles; fingers and toes without distinct webbing; subdigital lamellae: finger IV 15 (with 5 basally broadened lamellae), toe IV 16 (with 6 basally broadened lamellae).

Tail regenerated, approximately 1/3 distal from the tip (TaL 71.2 mm); dorsal tail base with distinct tubercles on original part; subcaudals larger than supracaudal scales, but not forming enlarged transverse plates.

Coloration in life. Ground color yellowish brown; dorsal surface of head light brown with irregular, small, dark brown spots; scales above the eyes yellow; eyelids yellow; nuchal loop dark brown, in V-shape, extending from posterior corner of eye to the neck, edged in indistinct yellow; tubercles on head, limbs, dorsum and tail light to dark brown; flanks with numerous light yellow tubercles; dorsum with three dark brown chevrons-like irregular bands and some small, irregularly distributed, dark brown spots between fore- and hind-limb insertions, edged in indistinct yellow anteriorly and posteriorly; dorsal surface of fore and hind limbs with dark brown blotches; original part of tail with five transverse dark brown bands, regenerated part dark greyish brown, yellow marbling without bands; chin, throat, chest, belly and ventral side of limbs cream.

Coloration in preservative. Color became darker, yellow color disappeared in preservation. Dorsal ground color of head, neck, body, limbs and tail greyish brown; skin above the eyes grayish; labials brown with cream bars; nuchal loop and transverse bands edged in light gray; chin, throat, chest, belly and lower limbs did not change noticeably in preservation.

Sexual dimorphism and variation. The females differ from males in the absence of precloacal pores and hemipenial swellings at the tail base. The dorsal pattern differs between individuals, for instance banded pattern ranges from three to five irregular bands. For other morphological characters see Table 1.

regenerated or broken tail, Min = minimum, Max = maximum, other abbreviations defined in the text).

Distribution. Cyrtodactylus orlovi sp. nov. is currently known only from the type locality in Thuan Nam District, Ninh Thuan Province, southern Vietnam ( Fig. 1 View FIGURE 1 ).

Etymology. We name this new species in honor of our colleague and friend, Dr. Nikolai Orlov, Zoological Institute, St. Petersburg, Russia, in recognition of his great contribution to the herpetofaunal exploration in Vietnam. As common names we suggest Orlov’s Bent-toed Gecko (English) and Thạch sùng ngón orlov (Vietnamese).

Natural history. Type specimens were found between 19:00 and 23:00 on rock boulders along a rocky stream, about 0–1 m above the ground. The surrounding habitat was secondary forest of medium and large hardwoods mixed with shrubs ( Fig. 6 View FIGURE 6 ). Some individuals of the new species were observed at elevations up to 800 m asl.

Comparisons. We compared the new species with its 22 congeners of the Cyrtodactylus irregularis complex based on examination of specimens and data obtained from the literature ( Smith 1921; Heidrich et al. 2007; Orlov et al. 2007; Nazarov et al. 2008; Ngo & Bauer 2008; Rösler et al. 2008; Geissler et al. 2009; Ngo & Chan 2010; Nazarov et al. 2012; Ngo 2013; Nguyen et al. 2013; Ziegler et al. 2013; Schneider et al. 2014; Luu et al. 2017; Pauwels et al. 2018; Ngo et al. 2020; Neang et al. 2020; Ostrowski et al. 2020; Ostrowski et al. 2021) (see Table 2).

Among the species of the Cyrtodactylus irregularis group, Cyrtodactylus orlovi sp. nov. differs from C. bidoupimontis by having fewer enlarged femoral scales on each side (3–8 versus 8–10 in C. bidoupimontis ), different dorsal banding (irregular bands with indistinct yellow edges versus dorsal bands with distinct light edges in C. bidoupimontis ), and dark brown transverse bands of the tail narrower than light brown interspaces (versus wider transverse bands than light interspaces in C. bidoupimontis ); from C. bugiamapensis by having fewer precloacal pores in males (5–6 versus 7–11 in C. bugiamapensis ), different dorsal color pattern (banded versus blotched in C. bugiamapensis ), a continuous neckband (versus medially divided in C. bugiamapensis ), and dark brown transverse bands of the tail narrower than light brown interspaces (versus wider transverse bands than light interspaces in C. bugiamapensis ); from C. caovansungi by having a smaller size (SVL 61.0– 77.7 mm versus 90.4–94 mm in C. caovansungi ), the absence of femoral pores (versus 6 in C. caovansungi ), fewer precloacal pores in males (5–6 versus 9 in C. caovansungi ), fewer lamellae under finger IV (15–17 versus 22 in C. caovansungi ), fewer lamellae under toe IV (16–19 versus 23–25 in C. caovansungi ), and the absence of transversely enlarged subcaudal plates (versus present in C. caovansungi ); from C. chungi by having fewer supralabials (8–10 versus 11–12 in C. chungi ), more ventral scale rows (36–39 versus 30–31 in C. chungi ), fewer precloacal pores in males (5–6 versus 7 in C. chungi ), and the absence of precloacal pitted scales in females (versus 6 pitted scales in C. chungi ); from C. cryptus by having fewer ventral scale rows (36–39 versus 47–50 in C. cryptus ), the presence of enlarged femoral scales on each side (3–8 versus absent in C. cryptus ), fewer precloacal pitted scales in males (5–6 versus 9–11 in C. cryptus ), fewer number of lamellae under finger IV (15–17 versus 18–19 in C. cryptus ), fewer lamellae under toe IV (16–19 versus 20–23 in C. cryptus ), and dark brown transverse bands of the tail narrower than light brown interspaces (versus dark transverse bands wider than light interspaces in C. cryptus ); from C. cucdongensis by having fewer ventral scale rows (36–39 versus 41–44 in C. cucdongensis ), the absence of precloacal pitted scales in females (versus 4–6 pitted scales in C. cucdongensis ), and the transverse dark brown bands on dorsum more distinct than those in C. cucdongensis ; from C. culaochamensis by having fewer ventral scale rows (36–39 versus 45–50 in C. culaochamensis ), the presence of enlarged femoral scales on each side (3–8 versus absent in C. culaochamensis ), fewer precloacal pores in males (5–6 versus 7–8 in C. culaochamensis ), fewer lamellae under finger IV (15–17 versus 18–19 in C. culaochamensis ), fewer lamellae under toe IV (16–19 versus 20–23 in C. culaochamensis ), and dark brown transverse bands of the tail narrower than the light brown interspaces (versus dark transverse bands wider than the light interspaces in C. culaochamensis ); from C. dati by having the absence of femoral pores (versus 3–4 on each thigh in C. dati ), a continuous neckband (versus discontinuous in C. dati ), and different dorsal color pattern (banded versus blotched in C. dati ); from C. gialaiensis by the presence of enlarged femoral scales on each side (3–8 versus absent in C. gialaiensis ), having fewer precloacal pores in males (5–6 versus 9–10 in C. gialaiensis ), and the absence of precloacal pitted scales in females (versus 8 pitted scales in C. gialaiensis ); from C. huynhi by having fewer ventral scale rows (36–39 versus 43–46 in C. huynhi ), the absence of femoral pores (versus 3–8 in C. huynhi ), fewer precloacal pores in males (5–6 versus 7–9 in C. huynhi ), and dark brown transverse bands of the tail narrower than light brown interspaces (versus dark transverse bands wider than the interspaces in C. huynhi ); from C. irregularis by having smooth enlarged femoral scales (versus pitted enlarged femoral scales in C. irregularis ), different dorsal color pattern (banded versus blotched in C. irregularis ), and dark brown transverse bands of the tail narrower than light brown interspaces (versus dark transverse bands wider than the interspaces in C. irregularis ); from C. kingsadai by having a smaller size (SVL 61.0– 77.7 mm versus 83.0–94.0 mm in C. kingsadai ), fewer enlarged femoral scales on each side (3–8 versus 9–12 in C. kingsadai ), fewer precloacal pores in males (5–6 versus 7–9 in C. kingsadai ), the absence of precloacal pitted scales in females (versus 4–8 in C. kingsadai ), fewer lamellae under finger IV (15–17 versus 19–21 in C. kingsadai ), fewer lamellae under toe IV (16–19 versus 21–25 in C. kingsadai ), the absence of transversely enlarged subcaudal plates (versus present in C. kingsadai ), and dark brown transverse bands of the tail narrower than light brown interspaces (versus wider transverse bands than the light interspaces in C. kingsadai ); from C. phnomchiensis by having fewer ventral scale rows (36–39 versus 45–54 in C. phnomchiensis ), the absence of precloacal pitted scales in females (versus 1–7 in C. phnomchiensis ), fewer lamellae under finger IV (15–17 versus 18–20 in C. phnomchiensis ), fewer lamellae under toe IV (16–19 versus 20–23 in C. phnomchiensis ), and dark brown transverse bands of the tail narrower than light brown interspaces (versus wider transverse bands than light interspaces in C. phnomchiensis ); from C. phumyensis by having a single internasal (versus 2 in C. phumyensis ), the absence of precloacal pitted scales in females (versus 6 pitted scales in C. phumyensis ), fewer lamellae under finger IV (15–17 versus 18–19 in C. phumyensis ), and the absence of two irregular dark longitudinal stripes on shoulder (versus present in C. phumyensis ); from C. phuocbinhensis by having a larger size (SVL 61.0– 77.7 mm versus 46.0– 60.4 mm in C. phuocbinhensis ), fewer ventral scale rows (36–39 versus 43–47 in C. phuocbinhensis ), fewer precloacal pores in males (5–6 versus 7 in C. phuocbinhensis ), different dorsal color pattern (banded versus striped or blotched in C. phuocbinhensis ), and a continuous neckband (versus interrupted in C. phuocbinhensis ); from C. pseudoquadrivirgatus by having fewer ventral scale rows (36–39 versus 41–57 in C. pseudoquadrivirgatus ), the presence of enlarged femoral scales (3–8 versus absent in C. pseudoquadrivirgatus ), the absence of precloacal pores in females (versus 5–10 in C. pseudoquadrivirgatus ), and a continuous neckband (versus medially interrupted in C. pseudoquadrivirgatus ); from C. sangi by having a larger size (SVL 61.0– 77.7 mm versus 49.9–56.3 mm in C. sangi ), fewer precloacal pores in males (5–6 versus 7 in C. sangi ), the absence of precloacal pitted scales in females (versus 4 in C. sangi ), and a continuous neckband (versus medially interrupted, irregular in C. sangi ); from C. takouensis by having more precloacal pores in males (5–6 versus 3–4 in C. takouensis ), the absence of transversely enlarged subcaudal plates (versus present in C. takouensis ), and dark brown transverse bands of the tail narrower than light brown interspaces (versus dark transverse bands wider than light interspaces in C. takouensis ); from C. taynguyenensis by having fewer ventral scale rows (36–39 versus 42–49 in C. taynguyenensis ), 3–8 enlarged femoral scales (versus absent in C. taynguyenensis ), and different dorsal color pattern (banded versus blotched in C. taynguyenensis ); from C. yangbayensis by having a smaller size (SVL 61.0– 77.7 mm versus 78.5–92.3 mm in C. yangbayensis ), the absence of transversely enlarged plates in the subcaudal scales (versus present in C. yangbayensis ), and a continuous neckband (versus broken in C. yangbayensis ); from C. ziegleri by having a smaller size (SVL 61.0– 77.7 mm versus 84.6–93.0 mm in C. ziegleri ), the absence of femoral pores (versus 0–6 in C. ziegleri ), the absence of precloacal pores in females (versus 0–8 in C. ziegleri ), and dark brown transverse bands of the tail narrower than the light brown interspaces (versus dark transverse bands wider than the light interspaces in C. ziegleri ).

Morphologically, Cyrtodactylus orlovi sp. nov. is most similar to C. cattienensis . We re-examined the type series of C. cattienensis (the holotype and 5 paratypes deposited in the collection of IEBR) and two recently collected specimens from Vinh Cuu Nature Reserve, Dong Nai Province: IEBR 4854 (Field number ĐN 2021. 54), adult female and IEBR 4855 (Field number ĐN 2020.2), adult female. The new species differs from C. cattienensis by having a larger size in females (71.9–77.7 mm versus 47.7–67.1 mm in C. cattienensis ), a single internasal (versus 1–4 in C. cattienensis ), more scales along the midbody from mental shield to anterior edge of cloaca (SLB 165–172 versus 151–156 in C. cattienensis ), the absence of precloacal pitted scales in females (versus 0–8 pitted scales in C. cattienensis ), and more keeled tubercles on the original tail (on about 2/3 of the anterior part versus 1/3–1/2 anterior part in C. cattienensis ) ( Table 1, Fig. 7 View FIGURE 7 ).