Cyrtodactylus adorus, Shea & Couper & Wilmer & Amey, 2011

Shea, Glenn, Couper, Patrick, Wilmer, Jessica Worthington & Amey, Andrew, 2011, Revision of the genus Cyrtodactylus Gray, 1827 (Squamata: Gekkonidae) in Australia 3146, Zootaxa 3146 (1), pp. 1-63 : 48-51

Cyrtodactylus adorus sp. nov.

( Figs. 24–25 )

Holotype. QM J86979 , male, Pascoe River mouth, 8 m asl (12º 29' 09" S 143º 16' 28" E) (P. Couper, A. Amey & L. Roberts, 17.ix.2008).

Paratypes. QM J31806 , Pascoe River (12º 30' S 143º 16' E) ; J86978 , J86980 –83, Pascoe River mouth (12º 29' 09" S 143º 16' 28" E) ; J86958 –62 , J86969 , Wattle Hills (12º 32' 57" S 143º 11' 12" E) ; J88831 –32, 2 km S Stanley Hill (12º 27' 50" S 143º 16' 14" E) .

Diagnosis. A large Cyrtodactylus (SVL to 123 mm) with small tubercles on antebrachium, moderately developed dorsal tubercles (those over temporal region small and only slightly projecting); in 21–24 longitudinal rows at the midpoint of the trunk (axilla-groin interval); 34–40 ventral scale rows at the same level; a continuous series of 56–65 enlarged femoroprecloacal scales extending from one knee to the other, each scale bearing a pore in males; mental with a posterior extension extending between postmentals; lips cream to brown; dark dorsal bands on trunk usually three, with a narrow dark edge posteriorly, and often a narrow pale edge anteriorly, dark nape band with a narrow vertebral extension anteriorly, but other dark bands straight-edged; little or no indication of any dark marks in the pale interspaces; basal tail bands broad and evenly dark, about twice the width of pale interspaces.

Description. Size large (males 91.5–119 mm, mean = 109.1 mm, sd = 9.50, n = 7; females 91–123 mm, mean = 111.8 mm, sd = 10.67, n = 8).

Head relatively long (HL/SVL 25.7–30.3%, mean = 28.2%; sd = 1.32, n = 15) and wide (HW/HL 66.0–76.4%, mean = 70.5%; sd = 2.97, n = 15), slightly depressed (HD/HL 34.9–54.6%, mean = 39.6%, sd = 4.82, n = 15, only one individual greater than 43.3%), distinct from neck. Loreal region moderately inflated, canthus rostralis poorly defined. Interorbital region and top of snout concave, deepest and widest just anterior to level of rostral canthus of eye. Snout moderately long (SL/HL 37.4–43.1%, mean = 39.5%, sd = 1.56, n = 115; EN/HL 28.2–32.7%, mean = 29.5%, sd = 1.40, n = 15), much longer than eye diameter (SL/EYE 148.6–192.3%, mean = 174.1%, sd = 10.07, n = 15), and a little longer than eye-ear interval (EE/HL 25.2–30.0%, mean = 27.6%, sd = 1.10, n = 15). Eye large (EYE/HL 20.9–26.2%, mean = 22.7%, sd = 1.51, n = 15), pupil vertical with crenated margin, forming about 3-4 low lobes along each edge of pupil. Supraciliaries in a double row, large, frill-like, well-differentiated from adjacent more medial granules of the brow ridge, and largest anteriorly. Ear opening small (EAR/HL 5.1–9.5%, mean = 7.3%, sd = 1.38, n = 15), usually a little taller than long and slightly angled posterodorsally, but sometimes rounder. Rostral wider than high, height at centre less than that more laterally (except in QM J86982 ), dorsal part divided by a median groove that extends about ¼–½ the midline height of the scale, and fails to reach the oral margin; the groove terminates in roughly a 'J'-shape (38% of specimens), 'T'-shape (31%), 'W'-shape (23%) or some permuta- tion thereof, or takes the form of a widely zigzagging line (8%). Two enlarged supranasals separated by usually a single, less enlarged internasal (77% of specimens), two internasals (15%) or in direct contact (8%). External nares circular, bordered by first supralabial, rostral, supranasal, nasal (extending into posterior part of nostril) and 2–3 smaller granular scales between nasal and first supralabial. Nares moderately separated (IN/HL 11.6–14.2%, mean = 13.0%, sd = 0.66, n = 15). Supralabials anteriorly large, distinct from adjacent loreal granules, 9–11 (mode = 10 (60.0%), mean = 9.7, sd = 0.59, n = 15) to level of mid-orbit, then inflecting dorsally and posteriorly, and becoming smaller, to gradually blend along rictal margin with adjacent small granules; supralabials separated from orbital margin by at least four rows of small granular scales at narrowest point. Mental wider than deep, with a strong median extension ( Fig. 10D ), a little narrower to slightly wider than rostral, and bordered posteriorly by a single elongate pair of large postmentals (except in QM J 86960 in which the postmentals are separated anteriorly by a small elongate scale that contacts the posterior edge of the mental and is probably a fragment of the median extension of the mental). Infralabials anteriorly much larger than adjacent gular scales, becoming smaller posteriorly, 10–12 (mean = 10.6, sd = 0.63, n = 15). First infralabial with ¾ or more of ventral margin contacting postmental (fully contacting postmental on left side of QM J86980 ). Subinfralabial scales anteriorly large, flattened, and polygonal, becoming smaller, more rounded and granular posteriorly and medially (towards gular area).

Body moderately robust (AGL/SVL 40.2–46.7%, mean = 42.5%, sd = 1.79, n = 15), with low, but distinct, ventrolateral skin folds approximately marking the transition between the enlarged, flattened ventral scalation and the smaller, more rounded, granular lateral scalation. Scales on dorsum of head, body and limbs small, juxtaposed, rounded granules, with interspersed much larger tubercles. Granular scales finest over parietal region of head, becoming coarser over body, then larger, flatter and more polygonal on tail. On head dorsum ( Fig. 11D ), tubercles small and only slightly projecting, anteriorly commencing on crown, becoming larger, more projecting and with a more conical, slightly posteriorly-tilted apex over nape. Tubercles on body dorsum larger again ( Fig. 12D ), but with a more longitudinally ovoid base, sometimes with a weak median keel, and relatively low on anterior body, but becoming slightly larger posteriorly on tail base, where they are more conical. Tubercles persist along tail, one to two whorls per segment, becoming lower and less differentiated until eventually losing their distinction by about the fourth dark band. Large tubercles on body dorsum separated by 2–6 smaller granular scales, as are those on the head, although tiny, and nape. Tubercles on body arranged in about 21–24 (mean = 22.6, sd = 1.18, n = 15) roughly longitudinal rows. Dorsum of brachium with slightly imbricate scalation, larger tubercles sparse to entirely absent; antebrachium with more imbricate larger scales distally and over manus, and with numerous small tubercles ( Fig. 13D ). Dorsum of thigh and crus with small juxtaposed granules and densely packed larger tubercles ( Fig. 13I ), only dorsum of pes with imbricate scales.

Laterally, tubercles commence over temporal region (a few may be present in the postinfralabial area) where they are small and conical and only slightly larger ( Fig. 11I ) than those of the head dorsum, then along nape and body, where they are smaller and noticeably less protuberant than those dorsally, and along tail, commencing on tail base as prominent, protuberant, conical scales, then rapidly losing differentiation by second dark tail band ( Fig. 14D ).

Ventrally, gular scales small, rounded and juxtaposed, becoming larger, flat and more imbricate over body venter, from clavicular region. Ventral scales at midbody, between ventrolateral skin folds 34–40 (mean = 37.0, sd = 1.71, n = 14). Ventral scales on brachium and antebrachium like gular scales. On ventral surface of thighs, but not on crus or in precloacal region, an abrupt junction between enlarged imbricate scales and much smaller scales posteriorly, enlarged scales 56–65 between distal extent on each thigh (mean = 60.7, sd = 2.99, n = 15). Ventral scales of tail base like those of body, most of tail venter with a single median series of very broad scales about four times the width of adjacent ventrolateral scales.

Precloacal and femoral pores present in males, in a single continuous row, arching shallowly anteriorly in precloacal region. Pores 57–64 (mean = 60.9, sd = 3.02, n = 7), best developed in precloacal region where they are deep and transversely oriented, becoming much shallower, smaller and rounder distally under thigh. No pubic groove. About three large, blunt-tipped postcloacal spurs on ventrolateral surface of tail base, more projecting in adult males than females or juveniles.

Forelimbs and hindlimbs well-developed (FLL/SVL 13.4–15.7%, mean = 15.0%, sd = 0.60, n = 15; HLL/SVL 17.0–20.9%, mean = 18.4%, sd = 0.92, n = 15). Digits well-developed, reflected dorsally at proximal interphalangeal joint, and all bearing robust, strongly curved claws sheathed at the base by two scales. Subdigital lamellae expanded basally, beginning on pes over distal part of metatarsals and ending at point of reflection of toes, lamellae distal to this point not expanded. Lamellae under first toe 7–9 expanded (mean = 8.3, sd = 0.59, mode = 8 (60.0%)) + 8–12 narrow (mean = 9.9, sd = 0.96, mode = 10 (53.3%)), total 16–19 (mean = 18.2, sd = 0.77, mode = 18 (60.0%), n = 15). Lamellae under second toe 9–12 expanded (mean = 10.5, sd = 0.92, mode = 11 (40.0%)) + 10–14 narrow (mean = 11.5, sd = 0.99, modes = 11, 12 (40.0%)), total 21–23 (mean = 22.0, sd = 0.76, mode = 22 (46.7%), n = 15). Lamellae under third toe 9–13 expanded (mean = 10.8, sd = 1.15, mode = 11 (33.3%)) + 12–14 narrow (mean = 12.7, sd = 0.70, mode = 13 (46.7%)), total 22–25 (mean = 23.5, sd = 0.92, mode = 24 (40.0%), n = 15). Lamellae under fourth toe 10–14 expanded (mean = 12.1, sd = 1.10, mode = 12 (46.7%)) + 13–15 narrow (mean = 13.3, sd = 0.61, mode = 13 (73.3%)), total 23–27 (mean = 25.4, sd = 1.06, mode = 25 (40.0%), n = 15). Lamellae under fifth toe 9–11 expanded (mean = 9.5, sd = 0.74, mode = 9 (60.0%)) + 11–14 narrow (mean = 12.2, sd = 0.86, mode = 12 (66.7%)), total 21–23 (mean = 21.7, sd = 0.80, mode = 21 (46.7%), n = 15). Relative lengths of digits on manus I<II<V<III<IV; on pes I<II<III=V<IV. Very slight traces of webbing between bases of fingers; weak webbing between bases of toes 2–3, 3–4 and 4–5.

Tail a little longer than body (TL/SVL 125.7–135.4%, mean = 131.9%, sd = 4.50, n = 4), narrow at base (TW/ SVL 5.5–8.8%, mean = 7.8%, sd = 0.91, n = 15) and tapering evenly to a conical tip. Tail segments externally identifiable by straight scale junctions, segments about 7–9 scales long when counted to include tubercles. Cloacal sacs present in both sexes, larger in males, external orifices just posterior to vent, laterally.

Colour in preservative. Dorsal pale ground colour greyish brown. Head dorsum ( Fig. 11D ) relatively unmarked, bordered posterolaterally by a narrow pale band which sometimes has a dark smudge along its anterior edge. Pale nape zone bordered posteriorly by a U-shaped dark chocolate coloured chevron on nape, widest vertebrally (with a small to moderate, rounded to pointed anterior vertebral extension) and extending anteriorly over temporal region to eye, then visible as a narrowing, increasingly diffuse streak over the lores to the nostril. Second broad dark transverse dorsal band over shoulders. Three dark bands over trunk, extending lateroventrally with even width, but dissipating over flanks. A dark band over hips. Tail with dark bands over most of length, but distal third of tail usually paler, with bands less evident. When they can be counted to the distal end of tail, dark tail bands 9–12 (mean = 11.2, sd = 1.30, n = 5). On nape and body, dark bands wider than pale interspaces, and with abrupt straight edges; pigmentation generally darkest along posterior margin of dark band and often paler along the anterior edge. Bands on tail ( Fig. 14D ) of similar width to body bands but wider than the pale interspaces and darker and more solidly dark than those of body. Pale interspaces of body darkest across centre, but otherwise generally unmarked.

Upper and lower lips ( Fig. 11I ) cream to mid-brown. Dorsum of forelimbs and hindlimbs relatively unmarked, pale to mid greyish brown.

Entire ventral surface immaculate off-white to diffusely marked with greyish brown. Generally with diffuse brown mottling on gular region and abdomen. Ventral surface of tail dark with some pale band edges visible.

Description of holotype. The holotype of C. adorus is a mature-sized male, with the following character states of those variable for the taxon: SVL 104.5 mm, AGL 42.5 mm, TL 141.5 mm, TW 8.7 mm, HL 30.2 mm, HW 22.2 mm, HD 11.6 mm, IN 4.0 mm, SL 12.0 mm, EN 8.9 mm, EYE 7.2 mm, EE 8.4 mm, EAR 2.5 mm, FLL 16.4 mm, HLL 21.8 mm, lamellae below digits I–V 9+10, 11+11, 12+12, 12+13, 9+12 respectively, supralabials 9, infralabials 10, rows of dorsal tubercles 21, transventral rows 38, femoroprecloacal scales 63 and dark tail bands 11.

Etymology. From the Greek άδωρος (adoros; = pure, incorruptible), alluding to the evenly and straight banded coloration, unmarred by dark spotting, curves or irregular margins.

Distribution. Known only from rocky outcrops on or near the lower reaches of the Pascoe River ( Fig. 21 ). Wattle Hills is about 12 km upstream from the type locality near the river mouth, while the Stanley Hill site is about 2.5 km north of the type locality. The known sites are among the few rock outcrops in the area.

Conservation status. This species has a very small known distribution that is unlikely to be much more extensive and is probably also very fragmented. We have no clear understanding of population size but expect it to be small, given the very small area of occupancy and the low genetic diversity of this species on current sampling. The large adult size and colourful pattern of this species, together with its ready collection from accessible rock outcrops, could lead to it being targeted by illegal collection from the wild for the pet trade. These factors fulfil the IUCN criteria for a Vulnerable listing (criteria D1, VU D2).

Comparison with other species ( Table 6). Cyrtodactylus adorus genetically differs from C. tuberculatus , C. mcdonaldi and C. hoskini by average sequence divergences of 14.28–16.43% ( Table 2). Morphologically, it has many more femoroprecloacal pores (57–64 vs 48 or fewer) and enlarged femoroprecloacal scales (56–65 vs 48 or fewer) than C. tuberculatus , C. mcdonaldi and C. hoskini . The hindlimbs are immaculate (vs mottled), and the caudal dark bands are solid black (vs dark-edged with paler centres) and are much wider than the pale interspaces at the tail base (vs more nearly equal width). In comparison to all three species, C. adorus has much less developed tubercles, those that are present being smaller and less projecting than the other species, and the tubercles are much reduced on the tail, not reaching the third pale caudal band. In comparison to C. mcdonaldi , C. adorus has a continuous row of femoroprecloacal pores in males (vs broken into three segments). In comparison to the geographically closest species, C. hoskini , C. adorus also has dark dorsal bands on the body that lack vertebral extensions.

In comparison to C. robustus , C. adorus is smaller (maximum SVL 123 vs 161 mm), has a much more boldly contrasting and "cleaner" colour pattern, lesser development of tubercles, lacks dark speckling on the venter and orange cloacal mucosa, and has fewer dorsal tubercle rows (21–24 vs 24–30), transventral scales (34–40, mean = 37.0 vs 41–54, mean = 48.6; our counts on the type series of C. robustus ); femoroprecloacal pores (57–64 vs 75–85) and enlarged femoroprecloacal scales (56–65 vs 75–92), and a generally narrower head (HW/HL 66–76%, mean = 71% vs 69–84%, mean = 77%).

In comparison to C. klugei , C. adorus is smaller (maximum SVL 123 vs 143 mm), has more dark body bands over the trunk (three vs usually two), pale lips (vs brown posterior supralabials), a more contrasting dorsal colour pattern, fewer transventral scales (34–40 vs 43–49), and fewer femoroprecloacal pores (57–64 vs 66–76) and enlarged femoroprecloacal scales (56–65 vs 69–77).

For comparisons with C. pronarus , see that species.

Natural history. Cyrtodactylus adorus was collected from a large granitic outcrop near the mouth of the Pascoe River ( Fig. 23B ) where it was most prevalent on rock faces in sheltered, sparsely vegetated crevices. The Wattle Hills sample came from a rocky, seasonal watercourse in monsoon forest. The Stanley Hill sample was collected on rock in deeply piled granite boulder habitat festooned with vegetation (vines, ferns, umbrella trees) (C. Hoskin, pers. comm.).

Figures

FIGURE 10. Chin shields of Australian Cyrtodactylus species. A. C. tuberculatus (QM J87009), B. C. mcdonaldi (QM J87075), C. C. hoskini (QM J86950), D. C. adorus (QM J86979), E. C. pronarus (QM J86900), F. C. pronarus (QM J86909).

FIGURE 11. Dorsal (A-E) and lateral (F-J) aspects of head of Australian Cyrtodactylus species. A,F. C. tuberculatus (QM J87009), B,G. C. mcdonaldi (QM J30062), C,H. C. hoskini (QM J86950), D, I. C. adorus (QM J86979), E,J. C. pronarus (QM J86900).

FIGURE 12. Dorsal aspect of trunk of Australian Cyrtodactylus species. A. C. tuberculatus (QM J87189), B. C. mcdonaldi (QM J87075), C. C. hoskini (QM J86950), D. C. adorus (QM J86979), E. C. pronarus (QM J86909).

FIGURE 13. Tubercles on front (A-E) and hind (F-J) limbs of Australian Cyrtodactylus species. A,F. C. tuberculatus (QM J87189), B,G. C. mcdonaldi (QM J87075), C,H. C. hoskini (QM J86950), D,I. C. adorus (QM J86979), E,J. C. pronarus (QM J86900).

FIGURE 14. Tubercles and colour pattern on tail base dorsum of Australian Cyrtodactylus species. A. C. tuberculatus (QM J87189), B. C. mcdonaldi (QM J30062), C. C. hoskini (QM J86950), D. C. adorus (QM J86979), E. C. pronarus (QM J86900).

FIGURE 21. Distribution of Cyrtodactylus hoskini (diamonds), C. adorus (circles) and C. pronarus (squares). Open symbols indicate photographic record only.

FIGURE 23. Habitats of A. Cyrtodactylus hoskini at Tozer's Gap (Photo: A. Amey) and B. C. adorus at mouth of Pascoe River (Photo: P. Couper).

FIGURE 24. Holotype of Cyrtodactylus adorus (QM J86979).

FIGURE 25. Cyrtodactylus adorus from Wattle Hills in life (Photo: P. Couper).