Holotype. IEBR A.2013.23, adult male, collected on 14 May 2013 by T.M. Phung in a rocky cave from Ba Den Mountain, Thanh Tan Ward, Tay Ninh Town, Tay Ninh Province (11 ° 21 ' 52 "N 106 ° 10 ' 27 "E), southern Vietnam, at an elevation of 600 m a.s.l.
Paratypes. IEBR A.2013.24, adult female, IEBR A.2013.25, adult female, VNMN A.2013.12, adult female, were collected on 16 December 2012; VNMN A.2013.13, adult male, ZFMK 94994–94997, adult females, and ZFMK 94998–94999, subadults, were collected on 14 May 2013 by T.M. Phung, the same collection data as the holotype.
Diagnosis. A medium-sized Cyrtodactylus with a maximum SVL of 77.6 mm, distinguished from all congeners by a combination of the following characters: 1) dorsal pattern consisting of irregular blotches on dorsum and occiput; nuchal loop sometimes interrupted medially; 2) precloacal pore absent or one in males; 3) femoral pore series separated from precloacal pore series, 0–3 on each thigh in males; 4) ventrals in 29–44 longitudinal rows at midbody; 5) lateral skin folds present, without interspersed tubercles; 6) dorsal tubercles in 16–18 irregular rows; 7) enlarged femoral scales and precloacal scales present; 8) postcloacal spurs two or three; 9) subcaudal scales slightly enlarged; and 10) precloacal groove absent.
Description of holotype. Size small (SVL 67.6 mm), tail regenerated (TaL 41.55 mm); supralabials 8 / 9; infralabials 7 / 8; nares bordered by rostral anteriorly, first supralabial laterally and four or five nasals posteriorly; supranasals separated from each other by a pentagonal internasal and two postnasals; upper anterior ciliaries three times larger than posterior ciliaries; dorsal scales of head granular; mental square, as wide as rostral; one pair of enlarged postmentals, longer than wide, in contact with each other posteriorly about a half of their length, bordering mental anteriorly, first two labials laterally, and six gular scales posteriorly; outer pair of gular scales is as large as postmentals; dorsal scales somewhat granular to flattened; dorsal tubercles round, conical, surrounded by 10 granular scales, in 17 irregular longitudinal rows at midbody; ventral scales smooth, in 36 longitudinal rows at midbody; lateral folds present, poorly developed, without interspersed tubercles; upper and lower surface of fore limb without distinct tubercles; dorsal surface of hind limb covered by distinctly developed, round, conical tubercles; fingers and toes lacking distinct webbing; lamellae under fourth finger 15 / 14 and under fourth toe 16 / 17; claws surrounded by a small scale on upper and a large scale on lower sides; series of distinctly enlarged femoral scales separated from enlarged precloacal scales by 15 or 16 small, poreless femoral scales; femoral pores absent; precloacal pore one; enlarged precloacal scales nine, including one pore-bearing scale; precloacal region covered by a patch of approximately 23 enlarged scales behind precloacal pore-bearing scale; precloacal groove absent; postcloacal tubercles 1 / 2, enlarged, on lateral surface of slight hemipenial swelling; hemipenes everted; tail regenerated, dorsum of original tail bearing distinct round tubercles; subcaudals not distinctly enlarged.
Coloration in ethanol. Ground coloration light grey, with dark brown dorsal pattern; dorsum with dark blotches, lighter on the sides; legs, including digits and toes and dorsal surface of tail lighter with dark brown blotches and irregular faint brownish markings between blotches; dorsal surface of head grey with dark irregular blotches on the occiput, snout slightly spotted; venter light cream; ventral surface of tail grey; tubercles on edges of blotches lighter in color; nuchal loop distinct, interrupted and tapering medially. For coloration in life see Fig. 1View FIGURE 1 A.
Variation of paratypes. Two subadults ( ZFMK 94998–94999) are uniformly light grey in ground colouration and have distinct brown blotches on dorsum and occiput; limbs and snout are uniformly light grey and their nuchal loops are distinct, complete and tapering medially. The male paratype VNMN A.2013.13 lacks precloacal and femoral pores. Internasal scales vary from two (in the paratype VNMN A.2013.13) to three (in the paratypes ZFMK 94994, 94995 and 94997). For further variation in scalation see Table 1, and for colour pattern variation see Figure 3View FIGURE 3.
Comparisons. Comparisons are based on the original descriptions or descriptions provided in broader faunal and taxonomic publications (e.g., Grismer et al. 2008; Rösler & Glaw 2008; Bauer et al. 2009, 2010; Ngo & Grismer 2010; Ngo & Pauwels 2010; Sumontha et al. 2010; Ziegler et al. 2010; David et al. 2011; Iskandar et al. 2011; Luu et al. 2011; Ngo 2011; Ngo & Chan 2011; Schneider et al. 2011; Nazarov et al. 2012; Ngo & Grismer 2012, Ziegler et al. 2013).
Cyrtodactylus thuongae sp. nov. differs from C. eisenmanae Ngo, 2008 by having more dorsal tubercle rows (16–18 vs. 14), fewer ventral scale rows (29–44 vs. 44 or 45), the lack of transversely enlarged subcaudals, and the presence of femoral and precloacal pores in males.
Etymology. The species name is dedicated to the wife of the first author, Dr. Thuong Thi Lien Nguyen from University of Food Industry, Ho Chi Minh City, Vietnam, for support of his field research in Vietnam.