Hemiphyllodactylus ziegleri sp. nov.

Figs 3, 5

Type material.

Holotype. HUS 2025.06 (Field number PAT 188) (Fig. 4), adult male, collected on 15 July 2013 by A. V. Pham, on a limestone cliff in the corn field (20°43.480'N, 104°54.344'E, at an elevation of 1020 m a. s. l.), Nong Vai Village, Co Ma Commune in Copia NR, Son La Province, northern Vietnam. Paratypes. HUS.2025.07 (Field number PAT 95), IB R.6431 (Field PAT. 186), HUS.2025.08 (Field PAT. 187), HUS.2025.09 (Field number PAT. 92), HUS.2025.10 (Field number PAT. 93), IB R.6432 (Field number PAT. 94) (Fig. 5 A), and HUS.2025.11 (Field PAT. 220) (Fig. 5 B), adult female, the same data as the holotype; IB R.6433 (Field SL.2014.33), adult male, collected on 16 September 2014 by T. Q. Nguyen and A. V. Pham on a limestone cliff, Nong Vai Village, Co Ma Commune in Copia NR (20°43.481'N, 104°54.349'E, at an elevation of 1020 m a. s. l.).

Diagnosis.

A bisexual taxon; SVL of adult males 38.7–41.9 mm, adult females 47.0– 49.3 mm; dorsal scale rows 21–27; ventral scale rows 12–16; chin scales bordering mental and first infralabial distinctly enlarged; digital lamellae formula 3444 (forefoot) and 4555 / 4 (hindfoot); femoral and precloacal pores 21–23 in males, absent in females; cloacal spur single, present in both sexes; dorsal trunk pattern yellowish grey; body with a discontinuous light dorsolateral stripe.

Description of holotype.

Body dorsolaterally flattened, size small SVL 41.9 mm, tail regenerated (TaL 16.2 mm +), trunk length (TrunkL 20.08 mm), head longer than wide (HeadL 9.62 mm, HeadW 7.24 mm), eye moderate (EyeD 2.68 mm), ear opening oblique (EarD 0.91 mm), nar-eye length (NarEye 3.24 mm), snout-eye length (SnEye 4.51 mm), internarial distance (SnW 1.59 mm). Proportions: TrunkL / SVL 0.48, HeadL / SVL 0.23, HeadW / SVL 0.17, HeadW / HeadL 0.75, SnEye / HeadL 0.47, NarEye / HeadL 0.34, EyeD / HeadL 0.28, SnW / HeadL 0.17, EyeD / NarEye 0.83, SnW / HeadW 0.22; pupil vertical; ear opening oblique, oval, approximately 37 % of the eye diameter, without bordering enlarged scales.

Scalation. Rostral very large, wider than high (RW 1.62 mm, RH 0.95 mm), with a shallow suture; supralabials 10 / 10, enlarged from rostral to below eye, smaller in subocular rictus; naris in contact with rostral, first supralabial, supranasal, and three nasals posteriorly on each side; supranasals separated from each other by two small granular internasals; snout flat, covered by granular scales; infralabials 9 / 9; mental triangular, wider than long, bordered laterally by first infralabials and posteriorly by two large postmentals; bordered laterally by first infralabials and posteriorly by two large postmentals; two large postmentals in contact with mental and first infralabials anteriorly; seven chin scales; gular scales small, subimbricate; throat and pectoral scales which grade into slightly larger, subimbricate. Dorsal scales small, granular, 25–27 scale rows at midbody contained within one eye diameter, enlarged tubercles absent; ventrolateral folds absent; ventral scales, flat, larger than dorsal scales; enlarged, femoral and precloacal scales; 21 pore-bearing femoral and precloacal scales, in a continuous row; cloacal spur one; dorsal surface of fore and hindlimbs covered with granular scales; terminal two phalanges free, claws absent on first finger and on first toe, present on second to fifth digit of fore and hindfoot; pads of digits II – V each with large triangular lamellae, digital formula 3443 (forefoot) and 4544 (hindfoot); lamellae five on first fingers, five on first toes; dorsal caudal scales granular; subcaudals flat, slightly larger than dorsal caudal scales.

Coloration in preservative.

Dorsal surface of head and body yellowish grey; a light brown streak originating from posterior corner of eye to the neck; neck and dorsum with a row of light spots on each side; dorsal surface of limbs grey with dark bars; upper lips with dark bars; lower lips white; throat white; venter and precloacal region cream with small dark brown dots; testes white, unpigmented. For color and pattern in life see Fig. 3.

Sexual dimorphism and variation.

Females differ from males in the absence of hemipenial swellings at the tail base. The scale counts vary among the type series: scales between supranasals 1–3; supralabials 10–12; infralabials 9 or 10; chin scales 4–7; dorsal scale rows 21–27; ventral scale rows 12–16; precloacal pores absent in females (see Table 2).

Distribution.

Hemiphyllodactylus ziegleri sp. nov. is currently only known from the type locality in Nong Vai Village, Co Ma Commune, Son La Province, Vietnam.

Etymology.

We name the new species in honor of Prof. Dr. Thomas Ziegler from Cologne Zoo / Institute of Zoology, University of Cologne, Germany for his outstanding contribution to biodiversity research and conservation in Vietnam. For the common names we suggest Ziegler’s Slender Gecko (English) and Th ạch sùng d ẹp ziegler (Vietnamese).

Natural history.

Specimens were found between 19: 30 and 22: 00, on limestone cliffs and an electric pole in the corn field, ~ 1.0– 2.5 m above the ground, at an elevation of 1020 m a. s. l. The surrounding habitat was disturbed evergreen karst forest of medium hardwood and shrub. The humidity was ~ 80–90 % and the air temperature ranged from 22 to 29 ° C.

Comparisons.

Morphologically, the new species is similar to Hemiphyllodactylus bonkowskii, H. houaphanensis, H. kiziriani, H. ngocsonensis, and H. yunnanensis. However, Hemiphyllodactylus ziegleri is distinguished from H. bonkowskii by having a smaller ratio of HeadW / HeadL (0.73–0.79 vs 0.81–0.88 in H. bonkowskii), more precloacal and femoral pores in males (21–23 vs 19 in H. bonkowskii), and the absence of a cream-colored venter (vs present in H. bonkowskii); from H. houaphanensis by having a greater ratio of EarD / EyeD (0.34–0.37 vs 0.30–0.33 in H. houaphanensis), smaller ratio of HeadL / SVL (0.22–0.24 vs 0.25–0.28 in H. houaphanensis), greater ratio of SnEye / HeadL (0.46–0.48 vs 0.37–0.39 in H. houaphanensis), smaller ratio of EyeD / NarEye (0.79–0.83 vs 0.89–0.96 in H. houaphanensis), fewer precloacal and femoral pores in adult males (21–23 vs 25 in H. houaphanensis), fewer chin scales (4–7 vs 8–9 in H. houaphanensis), and more circumnasal scales (3 vs 2 in H. houaphanensis); from H. kiziriani by having a greater ratio of HeadL / SVL (0.22–0.24 vs 0.17–0.18 in H. kiziriani), smaller ratio of HeadW / HeadL (0.73–0.79 vs 0.93–1.10 in H. kiziriani), fewer circumnasal scales (3 vs 4 in H. kiziriani), more precloacal and femoral pores in males (21–23 vs 10–13 in H. kiziriani); from H. ngocsonensis by having a smaller ratio of HeadW / HeadL (0.73–0.79 vs 0.80–0.87 in H. ngocsonensis), more precloacal and femoral pores in males (21–23 vs 20 in H. ngocsonensis), and more dorsal scale rows (22–27 vs 19–21 in H. ngocsonensis); and from H. yunnanensis Boulenger by having more dorsal scale rows (21–27 vs 8–14 in H. yunnanensis), more ventral scale rows (12–16 vs 5–7 in H. yunnanensis), more precloacal and femoral pores in adult males (21–23 vs 0–20 in H. yunnanensis), and greater ratios of SnW / HeadW, EyeD / NarEye, SnW / HeadL, and EyeD / HeadL (0.21–0.25 vs 0.15–0.19, 0.79–0.83 vs 0.64–0.72, 0.16–0.19 vs 0.13–0.15, and 0.27–0.28 vs 0.20–0.24, respectively in H. yunnanensis).

Hemiphyllodactylus ziegleri sp. nov. differs from H. banaensis Ngo, Grismer, Pham & Wood by having fewer scales between supranasals (2–3 vs 4–11 in H. banaensis) and more dorsal scale rows (21–27 vs 17–20 in H. banaensis); from H. changningensis Guo, Zhou, Yan & Li by having more dorsal scale rows (21–27 vs 11–15 in H. changningensis), and more ventral scale rows (12–16 vs 6–8 in H. changningensis); from H. dushanensis Zhou & Liu by having fewer chin scales (4–7 vs 8–10 in H. dushanensis), more dorsal scale rows (21–27 vs 14–15 in H. dushanensis), more ventral scale rows (12–16 vs 8–9 in H. dushanensis), and fewer precloacal and femoral pores in males (21–23 vs 24–26 in H. dushanensis); from H. dupanglingensis by having more dorsal scale rows (21–27 vs 14–15 in H. dupanglingensis), more ventral scale rows (12–16 vs 10–11 in H. dupanglingensis), and fewer chin scales (4–7 vs 11 in H. dupanglingensis); from H. hongkongensis Sung, Lee, Ng, Zhang & Yang by having more dorsal scale rows (21–27 vs 12–15 in H. hongkongensis), more ventral scale rows (12–16 vs 9–10 in H. hongkongensis), and fewer precloacal and femoral pores in males (21–23 vs 24–25 in H. hongkongensis); from H. huishuiensis Yan, Lin, Guo, Li & Zhou by having fewer chin scales (4–7 vs 8–10 in H. huishuiensis), more dorsal scale rows (21–27 vs 13–15 in H. huishuiensis), and more ventral scale rows (12–16 vs 7–9 in H. huishuiensis); from H. indosobrinus Eliades, Phimmachak, Sivongxay, Siler & Stuart by having fewer supralabials (10–12 vs 15 in H. indosobrinus), fewer dorsal scale rows (21–27 vs 30 in H. indosobrinus), and digital lamellae formula 3444 (forefoot) (vs 4554 in H. indosobrinus); from H. jinpingensis Zhou & Liu by having more dorsal scale rows (21–27 vs 11–12 in H. jinpingensis) and more ventral scale rows (12–16 vs 5–7 in H. jinpingensis); from H. khpoh Grismer, Sinovas, Quah, Thi, Chourn, Chhin, Hun, Cobos, Geissler, Ching & Murdoch by having fewer chin scales (4–7 vs 16 in H. khpoh), and more dorsal scale rows (21–27 vs 15 in H. khpoh); from H. laowozhenensis Zhou, Wang, Cui, Zhang, Shen, Li, Liu & Rao by having fewer chin scales (4–7 vs 10–11 in H. laowozhenensis), fewer circumnasal scales (2–3 vs 6 in H. laowozhenensis), more dorsal scale rows (21–27 vs 15–16 in H. laowozhenensis), and more ventral scale rows (12–16 vs 9 in laowozhenensis); from H. longlingensis Zhou & Liu by having fewer circumnasal scales (2–3 vs 4–5 in H. longlingensis), more dorsal scale rows (21–27 vs 10–14 in H. longlingensis), more ventral scale rows (12–16 vs 6–7), and the presence of anteriorly projecting arms on postsacral (vs absent in H. longlingensis); from H. lungcuensis by having fewer chin scales (4–7 vs 8–10 in H. lungcuensis), more dorsal scale rows (21–27 vs 12–17 in H. lungcuensis), and more ventral scale rows (12–16 vs 6–11 in H. lungcuensis); from H. nahangensis by having fewer chin scales (4–7 vs 8–9 in H. nahangensis), more subdigital lamellae on the first finger (3–5 vs 3 in H. nahangensis), and a higher number of subdigital lamellae on the first toe (4–5 vs 3 in H. nahangensis); from H. serpispecus Eliades, Phimmachak, Sivongxay, Siler & Stuart by having more ventral scale rows (12–16 vs 10 in H. serpispecus), more precloacal and femoral pores in males (21–23 vs 11 in H. serpispecus), and fewer cloacal spurs (1 vs 2 in H. serpispecus); from H. typus Bleeker by having fewer chin scales (4–7 vs 9–14 in H. typus) and more dorsal scale rows (21–27 vs 12–19 in H. typus); from H. vanhoensis by having a greater ratio of HeadW / HeadL (0.73–0.79 vs 0.68–0.72 in H. vanhoensis), more dorsal scale rows (22–27 vs 15–19 in H. vanhoensis), fewer circumnasal scales (3 vs 5–6 in H. vanhoensis), and more precloacal and femoral pores in males (21–23 vs 0 in H. vanhoensis); from H. xiengkhouangensis by having fewer chin scales (4–7 vs 8–9 in H. xiengkhouangensis), more dorsal scale rows (22–27 vs 19–20 in H. xiengkhouangensis), and more ventral scale rows (12–16 vs 9–11 in H. xiengkhouangensis); from H. yenchauensis by having more precloacal and femoral pores in males (21–23 vs 0 in H. yenchauensis) and more dorsal scale rows (22–27 vs 21 in H. yenchauensis); and from H. zugi by having fewer chin scales (4–7 vs 9–12 in H. zugi).