Cyrtodactylus lateralis (Werner)

Harvey, Michael B., O’Connell, Kyle A., Wostl, Elijah, Riyanto, Awal, Kurniawan, Nia, Smith, Eric N. & Grismer, L. Lee, 2016, Redescription Cyrtodactylus lateralis (Werner) (Squamata: Gekkonidae) and Phylogeny of the Prehensile-tailed Cyrtodactylus, Zootaxa 4107 (4), pp. 517-540 : 520-527

Cyrtodactylus lateralis (Werner)

Gymnodactylus lateralis Werner 1896: 11 . Holotype female (ZMB 12029, Fig. 1 , 2 , examined) from “Sumatra.” [herein traced to Binjai, Sumatera Utara, Indonesia].

Gymnodactylus lateralis Werner: Werner 1900 : 499; Barbour 1912: 80; De Rooij 1915: 7.

Cyrtodactylus lateralis (Werner) : Kluge 1993: 8; Manthey and Grossmann 1997: 223; Rösler 2000: 66; Teynié et al. 2010: 33.

Referred specimens examined (19). Seven males ( MZB 13171, MZB 13173; UTA 62916, UTA 62919–62921) and six females ( MZB 13172, MZB 13174–13176, MZB 18330, UTA 62917–62918) from trail up SE slope of Gunung Seulawah Agam, Aceh Besar Regency, Aceh Province, Sumatra, Indonesia, 685–1065 m collected 30 July and 1 August 2015 by M. B. Harvey and E. Wostl and one female ( UTA 62915) from Gunung Batee Meucica, Aceh Besar Regency, Aceh Province, Sumatra, Indonesia, 5.26157° N, 95.54176° E, 498 m collected 1 August 2015 by G. C. Sarker and I. Sidik; two males ( ZMB 65273–65274) and two females ( ZMB 65271–65272) from Gurah, Aceh Province, Sumatra, Indonesia, collected January 1997 by C. Schäfer and W. Grossmann (traced to a village of the same name in Kecamatan Peukan Bada, Kabupaten Aceh Besar). One female ( ZMB 49125) from Ketambe, Aceh Province, Sumatra, Indonesia, collected March 1990 by W. Denzer, C. Steiof and U. Manthey.

Diagnosis. A large species of Cyrtodactylus reaching 100 mm SVL (LSUHC 12579) and distinguished from all congeners by the following combination of characters: (1) body robust; limbs and digits moderate in length; (2) tail prehensile; intact tails 0.97–1.22 times longer than body; (3) tubercles extending from frontal region and supraorbital skin to cover most of tail, 16–20 irregular longitudinal rows of tubercles at midbody, 21–28 irregular transverse rows between limbs; (4) dorsal antebrachium and brachium tuberculate; (5) tubercles on tail extending to 90% of its length; (6) 51–66 ventrals in a transverse row at midbody; (7) conical, spinose tubercles in ventrolateral fold; (8) subcaudals not transversely enlarged; (9) moderate longitudinal sulcus in precloacal region of males; (10) 9–13 precloacal pores in males (0–15) pore primordia in females), femoral pores absent, precloacal pores sunken into precloacal sulcus; pore secretions red; (11) greatly enlarged precloacal pore-bearing scales present; (12) ventral surface of thighs entirely granular or granular except for 2–13 (count combined for both sides) widely spaced enlarged femoral scales; (13) 18–24 lamellae under fourth toe; (14) cloacal tubercles 1–2 on each side, usually in contact with one another; (15) dorsum gray to brown with dark brown markings; venter pale pink, immaculate or with diffuse, darkly pigmented scales forming no obvious pattern; (16) labials pale, contrasting with darker facial band; occiput with few large blotches; postocular stripe brown, edged dorsally by thin black line then by pale pigmented scales; (17) 5–6 transverse, usually broken bands on body; 7–9 bands on tail; caudal bands complete ventrally though faint.

Comparisons. Cyrtodactylus lateralis is very similar to C. durio . Cyrtodactylus lateralis has rounded to subpyramidal tubercles in the temporal region, on the occiput, and on the neck, whereas tubercles in these areas are noticeably larger and distinctly spinose in C. durio . We scored three new specimens of C. durio for the same characters used in the description of C. lateralis . Ranges of meristic and mensural characters of C. durio overlap those of C. lateralis , however extremes of three characters were slightly higher or lower than those of C. lateralis . The three specimens of C. durio (data for KU 173086 followed by KU 173087 then LSUHC 12579 vs. ranges [mean ± standard deviation, sample size] for C. lateralis ) had slightly fewer tubercles at midbody (17, 15, and 15 vs 16–20 [18 ± 1, n = 13]), slightly fewer lamellae under finger IV (15, 17, and 17 vs. 16–20 [18 ± 1, n = 14]), and a slightly larger orbit (diameter of orbit 27.8%, 28.7%, and 26.5% of head length vs. 20.6–27.6% [25.4 ± 1.6, n = 16]) than the series of C. lateralis . All specimens of C. durio lack enlarged subfemoral scales, whereas 70% of C. lateralis had these scales.

Cyrtodactylus lateralis , C. brevipalmatus , C. durio , C. elok , and C. stresemanni are the only Sunda Shelf species with a spinose, prehensile tail. Unlike C. stresemanni (characters in parentheses), C. lateralis has 16–20 tubercles across midbody (13), a transversely banded dorsum (wide, dark brown chevrons on flanks separated by undulating pale vertebral stripe), and small irregular blotches on the occiput (large, dark triangular occipital mark). Unlike C. brevipalmatus and C. elok , C. lateralis has a precloacal sulcus (absent), spinose tubercles in the ventrolateral fold (tubercles absent from fold), 51–66 ventrals (35–49), and caudal whorls of six tubercles separated by granular scales ventrolaterally (caudal whorls of four tubercles; ventrolateral tubercles separated by lanceolate scales forming ventrolateral fringe).

Description. Characteristics of the holotype placed in brackets follow those of all specimens examined. Large Cyrtodactylus reaching at least 93 mm SVL in females [77 mm], 82 mm in males; smallest specimen subadult female, 62.1 mm SVL; body robust, accounting for 38–49% (45.6 ± 3.7, n = 7) of SVL in males, 43.0–53.9% (48.2 ± 3.8, n = 8) [49.4%] of SVL in females; tail 0.99–1.14 (n = 8) [0.97] times longer than body and accounting for 49.3–55.1% (51.8 ± 2.3, n = 8) [49.3%] of total length; head triangular in dorsal view, much wider than body and distinct from neck; head 28.9–34.0% (30.8 ± 1.7, n = 7) of SVL, 63.9–78.9% (70.2 ± 6.1, n = 7) as wide as long, and 36.2–43.2% (38.8 ± 2.6 n = 7) as deep as wide in males and 28.5–33.4% (31.0 ± 1.7, n = 9) [30.1%] of SVL, 64.3–71.6% (69.4 ± 2.7, n = 9) [64.3%] as wide as long, and 38.0–46.2% (41.6 ± 2.8, n = 9) [41.1%] as deep as wide in females.

Rostral wider than or about as wide as mental (96.8–126.81%, 106.8 ± 8.5, n = 17, of width of mental) [103.2%], posteriorly forming border of nostril; dorsal margin of rostral notched medially by shallow groove; rostral groove bifurcating slightly ventral to center of nostril; rostral bordered posteriorly by four (50%, n = 16), five (31%), six (6%), or seven (13%) postrostrals [rostral irregular in holotype; rostral partially fragmented into two large plates just anterior to straight row of 5 postrostrals; short, bifurcating groove below these large irregular plates; rostral of ZMB 49125 also irregular, postrostral series fused to rostral, large diamond-shaped plate partially fractured within rostral in front of fused postrostrals]; internarial region narrow, 10.4–18.8% (15.7 ± 2.0, n = 17) [17.6%] as wide as head, 55.6–70.3% (63.8 ± 4.5, n = 17) [60.9%] as wide as narrowest point between orbits; narrowest point between orbits 18.7–28.9% (24.5 ± 2.7, n = 17) [28.9%] as wide as head; deep depression occupying most of prefrontal and frontal areas; prefrontal-frontal depression bordered laterally by raised canthal and circumorbital ridges, bordered posteriorly by slightly arched, transverse ridge located just behind orbits; central parietal region slightly depressed; scales on dorsal snout granular, rounded, smooth, subequal in size, about as large as tubercles in parietal regions and distinctly smaller than granules between eyes; tubercles extending to frontal region and supraorbital skin; tubercles on dorsal surface of head subpyrimidal and smooth, much smaller than those on body, those in occipital region surrounded by seven or eight granular scales; few tubercles around back of head subconical; dorsal body tubercles unicarinate, circular, slightly projecting from dorsum, about ten times as large as dorsal granules, 16–20 (18 ± 1, n = 13) [18] longitudinal rows at midbody including tubercles in ventrolateral folds, 21–28 (23 ± 2, n = 13) [27] irregular transverse rows between limbs; dorsal tubercles on flanks like those middorsally or attenuated into conical tubercles; dorsal granules smooth.

Nostril oval, directed postero-laterally and somewhat dorsally; bordered by rostral, postrostral, supranasal, postnasals, and narrow antero-dorsal process of first supralabial; supranasal rounded to rhomboidal, about four times as large as adjacent postnasals; postnasals granular, 5–7 (6 ± 1, n = 19) [5/5]; snout length 36.7–41.2% (39.3 ± 1.4, n = 16)[39.4%] of head length and distance from orbit to nostril accounting for 71.2–78.4% (74.1 ± 2.0, n = 17) [75.3%] of snout length; loreal region sloping, concave just behind nostril; lips flared; loreals granular, juxtaposed; 19–25 (21.9 ± 2, n = 21) [21/21] loreals between nasal and anterior border of orbit; lorilabials in front of orbit flat, plate-like, enlarged relative to other loreals (1.5–2 times as large as loreals above them, but much smaller than supralabials); eye separated from supralabials by one or two longitudinal rows of tiny granules; diameter of orbit 20.6–27.6% (25.4 ± 1.6, n = 16) [26.3%] of head length; temporal region with granular scales separating rounded to subpyrimidal, smooth or weakly keeled tubercles; distance from posterior border of orbit to anterior border of auditory meatus 23.6–31.3% (29.0 ± 1.9, n = 16) [30.9%] of head length; skin fold overlapping dorsal edge of auditory meatus; auditory meatus elliptical, it’s greatest diameter vertical or directed posterodorsally less than 20° to vertical, positioned at posterior end of head and with its dorsal margin at same level as rictus; greatest diameter of auditory meatus 17.7–39.6% (25.6 ± 5.8, n = 17) [25.5%] of diameter of orbit; smallest diameter of auditory meatus 60–70% smaller than greatest diameter; external ear canal deep; supralabials 8–12 (10 ± 1, n = 21) [9/10] to center of orbit; total enlarged supralabials 10–14 (12 ± 1, n = 21) [11/12], last separated by 2–5 small granular scales from rictus (13–17 total supralabials to rictus) [15/16]; first supralabial with anterodorsal extension reaching nostril and separating lorilabials from rostral; remaining supralabials subrectangular with rounded dorsal edges, reducing in size to anterior border of orbit where one or two supralabials somewhat longer than rest.

Mental triangular; infralabials 7–9 to center of orbit (8 ± 1, n = 22) [7/7], 9–13 (10 ± 1, n = 22) [10/10] total enlarged infralabials to rictus; first pair of postmentals in contact medially, length of their contact about half as long as mental; second pair of postmentals as long as first pair but extending medially only one-half to two-thirds as far, separated from one another medially by 2–7 (6 ± 1, n = 17) [5] small granular scales bordering first pair of postmentals; sublabial row decreasing in size posteriorly, not differentiated from adjacent gulars at level of eye; gulars small, smooth, granular, nonimbricate, much smaller than ventrals; in front of pectoral girdle, gulars grading into progressively larger, imbricate scales; scale of chest like ventrals; ventrals smooth, imbricate, flat, circular, about three-fourths as wide as tubercles on dorsum at midbody; ventrals in transverse row at midbody 51–66 (55 ± 3) [59]; ventrolateral skin fold distinct, containing long spinose tubercles separated by granular scales intermixed with smaller spinose tubercles, subpyrimidal tubercles, and smooth rounded tubercles ( Fig. 2 ); tubercles of ventrolateral fold lacking keels.

Tail cylindrical, though somewhat flattened dorsally and ventrally, with distinct lateral sulcus proximally for about two-thirds its length; caudal tubercles 2–3 times as large as those on body, heavily keeled, and projecting, separated from one another by granular scales; caudal tubercles on about 90% of intact tails, disposed in six longitudinal rows and in regular whorls, one tubercle of each whorl below lateral sulcus on each side; 2–3 tubercles in irregular transverse row between successive whorls on proximal one-third to one-half of tail; tubercles between whorls same shape but only one-half to one-third as large as tubercles forming whorls; size and distribution of tubercles at base of tail like posterior body; subcaudals smooth, flat, homogenous, imbricate, 2–3 times as large as granules on sides of tail; each subcaudal about as long as wide; transversely enlarged subcaudal plates absent; cloacal tubercles rounded, smooth, one (7%, n = 27) or two (93%) on each side, contacting one another (80%, n = 25 paired tubercles) or separated from one another by a single granular scale (20%) [2/2 cloacal tubercles contacting one another on each side of holotype].

Tubercles of limbs keeled, subpyramidal, largest same size as those on dorsum; tuberculation of brachium variable, almost entirely granular to as tuberculate as antebrachium [brachium of holotype tuberculate, but not as heavily tuberculate as antebrachium]; antebrachium tuberculate; antebrachial tubercles about six times as large as granular scales between them; granules and tubercles grading to dorsal patch of about seven rows of large juxtaposed scales covering distal antebrachium and proximal hand; ventral surfaces of brachium covered in smooth, slightly imbricate, homogenous granules; tubercles extending across postaxial and ventral surfaces of antebrachium to approximate position of radius, then transitioning to granular scales on preaxial side of antebrachium; scales on palm juxtaposed to slightly imbricate; lamellae under finger I 8–9 [8], under finger II 12–16 [13], under finger III 15–19 [16], under finger IV 16–20 [17], under finger V 13–16 [14]; one or two scales widened and similar to lamellae extending onto palm at base of digits.

Thigh, shank, and postaxial half of dorsal foot (at base of toes IV–V) tuberculate; tubercles of leg subpyrimidal, unicarinate, largest about same size as those on dorsum, about six times as large as small granular scales between them; tubercles on thigh decreasing in size postaxially, grading to tiny granular scales on postaxial edge of thigh (no sharp transition along postaxial edge of thigh); ventral thigh entirely granular (30%, n = 23) or granular except for row of 1–7 (3–13 total count including both sides; 70% of the time; Fig. 3 ) flat enlarged subfemoral scales [ventral thigh entirely granular in holotype, lacking enlarged subfemoral scales]; enlarged subfemoral scales separated from one another by gaps occupied by granular scales; gaps between subfemorals increasing in width distally; sole covered in flat, juxtaposed to weakly imbricate, rounded scales; lamellae under toe I 8–10 [10], under toe II 11–16 [13], under toe III 16–19 [16]; under toe IV 18–24 [19], under toe V 17–20 [18]; one or two scales widened and similar to lamellae extending onto sole at base of toes II–V, three or four extending onto sole at base of toe I.

Scales of precloacal region forming patch ( Fig. 2 , 3 ) of enlarged, smooth, imbricate scales grading to smaller ventrals anteriorly and small imbricate scales edging vent posteriorly; males with parallel series of 9–13 total precloacal pores; pore-bearing series of males sunken into shallow longitudinal sulcus; same scales of females with 0–15 pore primordia lacking secretions [no detectable pore or pore primordia in holotype]; females lacking longitudinal sulcus; scales flanking pore-bearing scales smaller than pore-bearing scales anteriorly, subequal to them posteriorly; both sexes with pair of post-cloacal slits; males with post-cloacal ossicle in wall of each slit.

Coloration. In life (based on field notes of M.B. Harvey and photos of all specimens collected by the summer 2015 expedition to Aceh), Cyrtodactylus lateralis resembles tree bark. This species has a gray, light brown, or reddish brown ground coloration overlain by diffuse, fine darker speckling in addition to bold, dark brown blotches and pale areas largely devoid of speckling ( Fig. 4 ). Dorsal tubercles are the same color as adjacent scales.

Dorsally, a few, small, dark brown blotches mark the parietal and occipital regions; however, the rest of the dorsal head is usually devoid of solid dark brown blotches [holotype faded to cream with light brown markings]. The supraciliaries are suffused with orange; they may be almost entirely orange in young specimens, whereas brown pigment obscures the orange supraciliary pigment in older individuals. A wide band extends from the rostral to the eye and continues as a postocular stripe to the arm. The facial band is always weakly defined and may be quite diffuse in some specimens [loreal region of holotype brownish]. Behind the eye, weak, thin, and often broken black pinstripes edge the postocular band dorsally and ventrally [postocular band with black pinstripes extending above and slightly behind arm]. Several rows of temporals above the black pinstripe are cream, pale gray, or pale yellow. These pale temporals form a band behind the eye that breaks up into subcircular spots at the back of the head and on the neck. The labials are also pale, almost immaculate to heavily mottled but always contrasting with the facial band and gular skin [bands of melanophores covering supralabials 5–6, anterior portion of 7, and 8–9 on left/ 1–2 and 9–10 on right; chin diffusely speckled with melanophores]. In specimens with mottled labials, subcircular cream, pale gray, or pale yellow spots, each about as large as a supralabial, mark the labial series.

The iris is grayish tan or tan, heavily reticulated with black lines. The ciliary body is only slightly lighter than the iris and indistinct. The tongue is white and lacks the black ventral patch described for some congeners ( Harvey et al. 2015); the buccal epithelium is pink.

Cyrtodactylus lateralis has a broken V-shaped mark on the nape, one narrow band on the neck, 5–6 [5] bands on the body, and 7–9 (8 ± 1) [7] bands on the tail. Bands on the neck and body usually break up into oval blotches, and pale areas separate the bands middorsally and on the upper flanks. Bands on the body usually have a “butterflylike” shape [ Fig. 1 , 4 , see also plate 1, figure 4 of Werner, 1896]. The lower flanks are darkly pigmented and frequently sharply contrast with a pale ventrolateral fold or a fold of the same color with pale yellow or cream spinose tubercles [fold of holotype like flanks, covered in melanophores but with large spinose tubercles of fold white and lacking melanophores]. Caudal bands are square to rectangular, narrower than the pale interspaces at the base of the tail, but longer than the interspaces distally. The third caudal band is 0.60–1.17 (0.89 ± 2.3, n = 4) [0.86] times as long as the interspace behind it; it extends for 15–27 (21 ± 4, n = 7) [25] vertebral granules and the interspace extends for 18–29 (24 ± 4, n = 6) [29] granules. Distally, the caudal interspaces become increasingly more pale. Ventrally, the caudal bands are continuous (i.e., the tail is ringed), however the ventral surface of the tail is paler than the lateral and dorsal sides. Regenerated tails lack bands and are tan to brown with irregular or broken, sinuous lines extending longitudinally to the tip. The brachium, antebrachium, thigh, and shank each bears two to three diffuse (i.e., dark speckling rather than solid bands like those on the body and tail) bands and banding extends to the hands and feet.

Except for the tail, the venter is pale pink and immaculate to diffusely mottled with dark brown [diffuse melanophones in holotype]. Palms and soles are charcoal or pale charcoal [light brown]. Adult males have a distinctive pale orange patch surrounding the precloacal sulcus ( Fig. 4 ) and extending posteriorly for about five rows behind the sulcus. The pale orange pore-bearing scales contrast with red secretions exuding from the pores. Extending distally from the precloacal area, widely spaced, enlarged subfemoral scales are also pale orange in males and contrast with the pinkish skin of the ventral thigh. Females lack orange pigment in the precloacal region. In females, enlarged scales homologous with the pore-bearing series of males are pinkish and immaculate, whereas small granules adjacent to them are a slightly darker shade of pink and may be diffusely mottled [granular scale of thighs and precloacal region diffusely covered in melanophores but enlarged precloacal scales of holotype nearly immaculate]. In both sexes, cloacal tubercles are pale yellow or cream and contrast with surrounding skin; they are the same color as the largest spinose tubercles of the ventrolateral fold.

Measurements of Holotype (mm). Snout–vent length 77, tail length 75, tail with tubercles 70, body length 38, head length, 23.2, head width 14.9, head depth 9.5, snout length 9.1, eye–nostril distance 7.2, interorbital distance 4.3, internarial distance 2.6, maximum diameter of tympanum 1.6, width of rostral 2.9, width of mental 2.8.

Standard English Name. Werner’s Prehensile-tailed Bent-toed Gecko.

Distribution, Natural History, and Remarks Regarding the Type Locality. Cyrtodactylus lateralis occurs in Aceh and Sumatera Utara Provinces, Sumatra, Indonesia ( Manthey & Grossmann 1997; this study). In their checklist of Sumatran reptiles and amphibians, Teynié et al. (2010, their Table 1 ) added “Mentawai Archipelago and other islands of the West coast of Sumatra (Simeulue, Nias, and so on)” to the range of C. lateralis . We have been unable to locate any specimen from these islands or any other reference to its occurrence there.

To our knowledge, the holotype is the only specimen known from Sumatera Utara. Werner (1896) only reported “Sumatra” as the type locality and in his 1900 checklist failed to add any additional information. Perhaps after conducting her own investigation into the origin of the holotype, De Rooij (1915) reported C. lateralis from “Deli!,” an old name for the area around modern Medan. Ludwig Martin collected the holotype of C. lateralis .

Letters accompanying the specimens kindly provided to M. B. Harvey by the Historischen Bild- und Schriftgutsammlungen (Historical pictures and documents collections) of the Museum für Naturkunde Berlin were sent from “Bindji, Deli, Sumatra.” A staff member (Malschie) of the ZMB tallied the contents of this shipment on 19 March 1891. The list included 75 specimens of reptiles and amphibians in addition to various mammals. The museum did not purchase some of the reptiles and amphibians, and ultimately paid 45 Marks for the remainder. Other authors have published on specimens collected by L. Martin such as Cameron (1906) who described Phaedraspis, a new genus of ichneumonid wasp from “Bindji, Deli, Sumatra.” Bindji likely refers to the modern city of Binjai (sometimes spelled “Bindjai”), Sumatera Utara, 3.6001° N, 98.4854°E, 28 m elevation (coordinates based on Falling Rain Genomics Inc. 2015), bordered by Deli Serdang Regency to the east and Langkat Regency to the west. About 8 air km (22 road km) separate Binjai from Medan ( Fig. 5 ).

Cyrtodactylus lateralis lives singly or in pairs on the trunks of large trees with buttressed roots. We found these geckos at night (20:00–23:44 hrs), 1.0–5.0 m aboveground, between 685–1065 m elevation on Gunung Seulawah Agam and at 498 m on the nearby Gunung Batee Meucica. Although we visited these sites during the dry season, rain fell during our trips (July 30 and August 1, 2015) to Seulawah Agam. In contrast, Batee Meucica was very dry on August 1 and appeared to have received little rain. Although we visited many other forested sites in the interior of Aceh Province, we found no additional specimens of C. lateralis despite considerable effort.

When individual Cyrtodactylus lateralis detected us, they usually remained immobile even when closely approached. One specimen ran around to the other side of a small tree just as the beam of our flashlight illuminated it. These geckos closely resemble tree bark and the long spinose tubercles of the ventrolateral fold appear to help them blend into the substrate. Like other Cyrtodactylus with prehensile tails ( Grismer 2008, 2011; Grismer et al. 2010; Linkem et al. 2008), specimens of C. lateralis coiled their tails while resting in collecting bags and during some photo sessions ( Fig. 4 ). However, in all instances, their tails were fully extended when we first encountered them on tree trunks at night. The release call of C. lateralis is a single “raak” and is surprisingly faint for such a large species. The senior author heard this call several times while taking color notes from this species. Cyrtodactylus lateralis occurs in sympatry with C. quadrivirgatus Taylor. On Gunung Seulawah Agam we found C. quadrivirgatus to be relatively common on 30 July and 1 August, however all specimens were on the ground or in low vegetation. Cyrtodactylus quadrivirgatus likely enters the microhabitat of C. lateralis rarely, if ever.

The largest female in our sample (UTA R-62917, 93 mm SVL) weighed 14.66 g and the largest male (MZB 13171, 82.38 mm SVL) weighed 10.00 g, however only the male had a complete, unregenerated tail.

Remarks. For its age, the holotype remains in good condition ( Fig. 1 ). The specimen does not bear a tag; it is stored by itself in a jar containing a small white tag with the ZMB # “12029” written on it. The jar contains a second old, very faded tag with “ Gymnodactylus lateralis ” written at the top and some mostly illegible script at the bottom. The tail has been broken off, but is intact and not regenerated. The abdominal cavity has not been opened. Only relatively small patches of skin are missing from the right and left sides of the neck, the dorsal surface of the left leg, and posterior left flank. Although faded, diagnostic elements of the color pattern remain visible.

Figures

FIGURE 1. Adult female holotype of Cyrtodactylus lateralis (Werner) (ZMB 12029) from Binjai, Sumatera Utara, Indonesia.

FIGURE 2. Morphology of (A) dorsal tubercles and ventrolateral fold and (B) cloacal region of female holotype of Cyrtodactylus lateralis (ZMB 12029).

FIGURE 3. Precloacal patch and ventral thigh of male Cyrtodactylus lateralis (UTA 62921, SVL 79 mm).

FIGURE 4. Coloration of living Cyrtodactylus lateralis from Gunung Seulawah Agam, Aceh, Sumatra. (A – B) head morphology of two males (A, MZB 13172, head length 18.3 mm, and B, MZB 13173, head length 21.9). (C) Largest known specimen, an adult female (MZB 13175, SVL 96 mm). (D) Pale pigmented male with regenerated tail (UTA 62921, SVL 79 mm). (E) Precloacal coloration and cloacal tubercles of an adult male (UTA 62921, SVL 79 mm). (F) Detail of tail and cloacal tubercles of male (MZB 13172). Photos by E. N. Smith.

FIGURE 5. Distribution of bent-toed geckos with spinose, prehensile tails in northern Sumatra and Peninsular Malaysia.