Holotype. Adult male, UNP070 (Fig. 2), collected from Sarasah Gasang waterfall (0°18'24.25"S, 100°13'45.15"E), Maninjau village, sub-district Tanjung Raya, regency of Agam by Y. Amardi, F. Lestari, and M. Kentino on 31 October 2020 at c. 08.30 pm. Paratypes (N = 17). Four individuals: three females (UNP103, 142, 143) and one male (UNP104), were collected from Lembah Anai Nature Reserve (0°29'24"S, 100°20'24"E), Singgalang village, Sepuluh Koto sub-district, Regency of Tanah Datar, province of Sumatra Barat by M. Rafi, K. Agusdi, F. Rozi, K. Agusdi, and F. A. D. Nugraha on 15 February 2022. Nine individuals: 5 females (UNP069, 075, 073, 067, 072) and 3 males (UNP066, 065, 071) collected from the same locality as holotype. Five individuals: 1 female (UNP153) and 4 males (UNP161, UNP162, UNP163, UNP164) collected from Sungai Sirah village (0°24'8.8128"S, 100°8'37.6728"E), sub-district Sungai Geringging, district Padang Pariaman on 7 May 2022 by M. Rafi and Y. Amardi.

Figure 2. 

The holotype specimen (UNP070), adult male, of Cyrtodactylus awalriyantoi sp. nov. in preservation color. Scale bars: 10 mm.

Cyrtodactylus awalriyantoi sp. nov. is assigned to the sworderi group based on its phylogenetic position (Fig. 1) and the genetic distances to other congenerics (Table 2). This new species can be differentiated from all other Cyrtodactylus by having the following combination of characters: a small size, SVL 37.5–53.78 mm; axilla to groin distance 16.65–24.31 mm; head width 6.21–8.45 mm; longitudinal rows of dorsal tubercles 16–19; paravertebral tubercles 31–41; ventral scales 32–43; 24–49 enlarged precloacal and femoral scales; precloacal pores rarely present, maximum only two pores in one individual (only two individuals possessed pores); no precloacal groove or depression; postcloacal tubercles two on each side; 14–19 subdigital lamellae on fourth toe; 9–15 supralabial scales; 9–12 infralabial scales; 3–4 internasal scales; and 3–6 gular scales that bordered first pair of postmental scales.

This species is the smallest Cyrtodactylus species inhabiting Sumatra with the maximum SVL of adult individual of 53.78 mm. It can be distinguished from other Cyrtodactylus as follows:

1. C. quadrivirgatus by having following combination of characters: shorter maximum SVL (53.78 vs. 67 mm); shorter maximum length of axilla to groin (24.31 vs. 34 mm); shorter maximum length of tail (54.77 vs. 77 mm); shorter maximum length of arm (19.47 vs. 21 mm); shorter maximum length of leg (22.75 vs. 26 mm); shorter maximum length of head (15.42 vs. 18 mm); shorter maximum width of head (8.45 vs. 13 mm); shorter maximum length of snout to arm (21.43 vs. 32 mm); fewer DTR (16–19 vs. 24); maximum number of PVT is 41 (vs. 39); 2 precloacal pores (only in two specimens), mostly lack of pores in femoral and precloacal (vs. up to 12); fewer subdigital lamellae on 4 ^th toe (14–19 vs. 18–23); maximum number of supralabial (15 vs. 11); maximum number of IN scales is 4 (vs. 3); and lack of black stripe between eyes and naris (vs. present).
2. C. psarops by lower number of DTR (16–19 vs. 28–38); greater number of PVT (31–41 vs. 23–26); minimum number of VS of 32 (vs. 38); number of PCT (2 on each side vs. 1 on each side); fewer subdigital lamellae on 4 ^th toe (14–19 vs. 18–22); lacking precloacal groove/depression (vs. present); pores rarely present and maximum of 2 pores (vs. 28–32); lacking U-shaped band on occiput/nuchal; and having extended lateral stripe (vs. lacking).
3. C. semicinctus by lower number of DTR (16–19 vs. 29–35); maximum number of PVT of 41 (vs. 35); maximum number of VS of 40 (vs. 44); maximum number of PCT of 2 on each side (vs. 3 on each side); fewer subdigital lamellae on 4 ^th toe (14–19 vs. 19–22); lacking precloacal depression (vs. present); pores rarely present and maximum of 2 pores (vs. 36–38); brachium tuberculated (vs. not tuberculated); and having extended lateral stripe (vs. lacking).
4. C. lateralis by having more PVT (31–41 vs. 21–28); fewer VS (32–43 vs. 51–66); 0–2 precloacal pores and rarely present (vs. 9–15); fewer subdigital lamellae on 4 ^th toe (14–19 vs. 18–24); lacking spinose tubercles in caudal region, conical tubercles in the ventrolateral fold; and lacking a prehensile tail.
5. C. consobrinus by having fewer VS (32–43 vs. 58–65); fewer precloacal pores (0–2 vs. 9–10); fewer subdigital lamellae on 4 ^th toe (14–19 vs. 23–28); lacking narrow light line like network on the head; having extended lateral stripe (vs. lacking); and lacking white crossbands on the dorsum.
6. C. agamensis by lower number of DTR (16–19 vs. 50–67); greater maximum number of PVT (41 vs. 37); pores rarely present and maximum of two pores (vs. 9–10); lower number of subdigital lamellae under the 4 ^th toe (14–19 vs. 21–26); 15 supralabial scales (vs. 13); and having four dorsal stripes (vs. absence).

C. awalriyantoi sp. nov. has unique morphological combination and can be separated from other congeners within the sworderi group as follows:

1. C. gunungsenyumensis by shorter SVL (37.5–53.78 mm vs 65.1–74.7 mm); fewer subdigitall lamellae on fourth toe (14–19 vs 20–23); and more enlarged precoloaco femoral scales (24–49 vs 31–39).
2. C. tebuensis by shorter SVL (37.5–53.78 mm vs 73.1–84.1 mm); fewer ventral scales (32–43 vs 43–51); fewer subdigital lamellae on fourth toe (14–19 vs 17–21); more infralabial scales (9–12 vs 8–10); and more enlarged precoloaco femoral scales (24–49 vs 31–38).
3. C. sworderi by shorter SVL (37.5–53.78 mm vs 69–80 mm); and fewer ventral scales (32–43 vs 42–49)
4. C. guakanthanensis by shorter SVL (37.5–53.78 mm vs 82.2 mm); more supralabial (9–15 vs 9–10); more infralabials (9–12 vs 7–8); fewer subdigital lamellae on fourth toe (14–19 vs 19–21); and more enlarged precloaco-femoral scales (24–49 vs 36–41).

Small-sized Cyrtodactylus with SVL of 37.5–53.78 mm; the length of the tail is 31.4–54.77 mm including the original or regenerated tip; the axial body length is 16.65–24.31 mm (Fig. 3). The head is triangular in dorsal view with moderate length (HL/SVL= 0.25–0.31), wide (HW/HL 0.52–0.63), and slightly flattened (HH/HL= 0.29–0.45), distinguishable from neck; medium length of snout (SL/HL 0.33–0.45) and rounded; snout longer than eye diameter (SL/OD 1.38–2.03); eyes large (OD/HL 0.18–0.27); ear openings oval and small (EL/HL 0.02–0.1); eye to ear distance greater than diameter of eye (OEL/OD 0.89–1.54); postorbital and around ear region consists of enlarged tubercles; scales on post nasal to preorbital and post-rostral to frontal region slightly larger in size than scales on the parietal part and occiput; region of parietal containing small scales intermixed with weak, scattered, rounded tubercles while occiput region contained slightly enlarged tubercles (Fig. 4).

Figure 3. 

Representative type series of C. awalriyantoi sp. nov. after preservation. UNP070 (male); UNP075 (female); UNP066 (male); UNP065 (male); UNP103 (female). Scale bars: 10 mm; upper for dorsal view and lower for ventral view.

Figure 4. 

The head of holotype specimen (UNP070) of Cyrtodactylus awalriyantoi sp. nov. A dorsal view B ventral view C, D lateral views of right and left, respectively. Images not to scale.

The nares are oval, bordered by rostral anteriorly, by supranasals and internasals dorsally, by 1^st supralabial ventrally. Supranasal scales larger than post-nasal scales. The supranasal scales as large as intersupranasals and separated from each another by three or four intersupranasal scales (Fig. 4F).

The triangular mental is bordered laterally by first infralabial and posteriorly by right and left first postmental. First postmentals medially connected each other for ~ 30% of their length. Second postmentals in contact with 1^st and 2^nd infralabials (N = 2) (Fig. 5A), separated from infralabials by relatively smaller scales (N = 1) (Fig. 5B), by relatively similar-sized scales (N = 5) (Fig. 5C), and by relatively larger scales (N = 1) (Fig. 5D). Right scale contacts with 1^st and 2^nd infralabials but the left only with 2^nd infralabial (N = 2) (Fig. 5E), or the right contacted with 2^nd infralabial and the left with small part of 1^st infralabial and large part of 2^nd infralabial (Fig. 5F). Right and left second postmentals are bordered by 3–6 relatively smaller scales (Fig. 5).

Figure 5. 

Ventral view of head showing second postmental variations in which they attach to the supralabials and variation in number of smaller scales separating them A UNP067 B UNP073 C UNP070 D UNP142 E UNP069 F UNP072. Images not to scale.

Body moderate in length (AX/SVL 0.38–0.53); defined ventrolateral fold with tubercles smaller than dorsal tubercles; dorsum with small scales interspersed with large conical or pyramidal, tubercles most dense on flanks; tubercles extending from occipital region to the base of tail, tubercles on tail largest; 16–19 tubercles between lateral fold in middle of body; 31–41 tubercles of paravertebral from posterior insertion of arm to body to anterior of femur insertion to body; 32–43 ventral scales larger than dorsal scales; ventral scales in middle part slightly larger than those near the ventrolateral folds; from middle of body, scales are smaller anteriorly to the head, ventrum, and posteriorly until groin region (Fig. 6).

Figure 6. 

Trunk in A dorsal B ventral C ventrolateral views of holotype specimen (UNP070).

Forelimbs medium length (AL/SVL 0.33–0.4); granular scales on upper arm larger than those on dorsum of body (~ 2–3 ×larger); without tubercles; lower arm with smaller scales than upper arm scales, intermixed with weak tubercles slightly larger than weak tubercles on parietal parts; hindlimbs also moderate in size (LL/SVL 0.40–0.52); more robust than forelimbs; covered dorsally by granular scales intermixed with large, rounded tubercles; ventral scales of thigh larger than dorsals; 14–19 subdigital lamellae on 4^th toe. Continuous enlarged precloacal and femoral scales present (N = 24–49); no specimen has precloacal groove/ depression; enlarged post-precloacal scales present; two post-cloaca tubercles on left and right base of tail, mostly connected to each another (Fig. 7).

Figure 7. 

Tail in dorsal A and ventral B views, precloacal and femoral view (C) and ventral of 4^th toe (D). All images from holotype specimen (UNP070). Images not to scale.

Tail length ~ 1.1 × of SVL, circular in cross-section but tapering at the end portion; tubercles on base of tail dorsally similar in size to those on body dorsum; 4–11 black dorsoventral stripes separated by white stripes; black stripes on venter more faded than on dorsal; part; no median, transversely enlarged, series of scales on the subcaudal; subcaudal cycloidal scales relatively larger than dorsal (Fig. 7).

Ground color of body dorsum dark grey to brown; top of head blackish with irregular broken spots scattered on parietal region to nostril; on occipital regions three short black lines extending longitudinally: one in the middle, two begin behind each side of eyes almost parallel to the supraorbital regions; those three short black bands stop at approximately parallel to ears, after which there is a transverse white line extending from each pre-ear region; after the white line, there are two black lines at the nape of the neck that extend backwards, then some meet at an angle and some remain separate, as if these two lines continue the black line originating from the back of the eye parallel to the supraorbital area; after the meeting, there are two lines that separate to the back of the tail, and some are still united to the tail so that it tends to look like a black transverse band; in individuals with the two midlines converging, the confluence of the two lines begins just before the anterior part of the upper arm; there are eight or nine rows of black transverse bands that are counted from the beginning of the union of the two lines to the base of the tail; on the dorsolateral, there are two black lines that extend from behind the eyes to the base of the tail; unpatterned black blotches or obscure irregular black banding on limbs; black and white bands on tails; the width of the black line increases towards the posterior; and the white is opposite; in some individuals, the above-mentioned black stripes are not clear and not strong along the dorsal and dorsolateral body. Ventral surface of head, trunk, and limbs are white, pale grey to cream; ventral surface of tail cream in the first third at the anterior, then the rest to the posterior tends to black with narrow white rings (Fig. 8).

Figure 8. 

Coloration in life of C. awalriyantoi sp. nov. A, B UNP142 C, D UNP143 E, F UNP153 G, H 162 I, J unvouchered specimen. Images not to scale.

Ground color of dorsal trunk, limbs, and tail brown to dark; parietal part to the tip of snout paler than any other parts of dorsum; the individuals with unclear or weak black lines on middle dorsum and dorsolateral tend to be dark from the nape to the base of the tails; black lines on nape and trunk still visible; tail with black and white bands; ventral head, trunk, limbs whitish to dark brown. Fresh specimens darker than the others both in ventral or dorsal parts of the body (Fig. 3).

We collected the type series in the primary forest of LANR, SG, and SS with elevation ~ 380–767 m a.s.l. and we encountered non-vouchered individuals from ~ 7 m a.s.l. At SG, this species was found on leaves measuring ~ 7–10 cm width and on twigs, ~ 1 m above the ground, 1–3 m from the edge of the rocky stream. The stream that empties into the waterfall has a breadth of ~ 2 m with a heavy flow. Fewer specimens were found closer to the waterfall. At LANR and SS, this species occupied the same microhabitat as the SG population, but the stream at this location is wider (~ 5–7 m width; Fig. 9). We also encountered this species (an unvouchered individual) at a lower elevation of 7 m a.s.l. in Bungus Selatan village. At this location, the gecko was perching on a bush leaf just beside the paddy field at ~ 70 cm above the ground. Another unvouchered individual was in the Sarasah Uwak waterfall area but far from the waterfall, perching on bushes at ~ 60 cm above the ground (Fig. 10).

Figure 9. 

Habitat type of Cyrtodactylus awalriyantoi sp. nov. in Sarasah Gasang Waterfall (A) and Lembah Anai Nature Reserve (B).

Figure 10. 

Type locality and distribution of C. awalriyantoi sp. nov. in Sumatra Barat Province.

Currently, this new species is found only in Sumatra.

The specific epithet awalriyantoi is in reference to the Indonesian herpetologist, Awal Riyanto. He has dedicated much of his time researching Indonesian Cyrtodactylus from Indonesia, as well as patiently and continuously supervising many younger amphibian and reptile taxonomists from both academic institutions and independent positions. Moreover, his contribution to the study of amphibians and other reptiles is significant for Indonesian herpetological knowledge and conservation.