Cyrtodactylus boreoclivus, Oliver, Paul, Krey, Keliopas & Richards, Stephen, 2011

Oliver, Paul, Krey, Keliopas & Richards, Stephen, 2011, A new species of bent-toed gecko (Cyrtodactylus, Gekkonidae) from the North Papuan Mountains, Zootaxa 2930, pp. 22-32 : 23-30

Cyrtodactylus boreoclivus sp. nov.

Figures 1–4

Holotype. AMS R135519, adult male, from the Kukumbau area of Mount Sapau, (3° 23' S, 142° 31' E), between 1000–1200 metres altitude, Torricelli Mountains, West Sepik Province, Papua New Guinea, collected by Pavel German on 10 Mar 1990.

Paratypes. MZB lace7474 (field-number SJR 13593), 7475 (SJR 13594), SJR13593, all adult females; SJR 13613, adult male; Foja Mountains (2° 35' 27.8"S, 138° 43' 11.9"E), Papua Province, Indonesia, at approximately 1250 metres altitude, collected by Paul Oliver between 19–21 Nov 2008.

Diagnosis. Cyrtodactylus boreoclivus sp. nov. can be distinguished from all other Melanesian and Wallacean Cyrtodactylus by the following unique combination of characters: moderately large size (SVL to 109 mm); relatively slender body with robust head (HW/SVL 0.193–0.213); enlarged femoral-scale series extending beyond the knees; males with precloacal (12) and femoral (17–25) pores arranged in three independent series; femoral-pore series extending beyond the knee; medial subcaudal scales in mostly single row and transversely enlarged to approximately one third width of tail; tail without prominent dentate tubercles; and dorsal colouration consisting of 5 to 7 very irregular and indistinct dark-brown transverse bands.

Comparisons. A single row of transversely enlarged subcaudal scales distinguishes Cyrtodactylus boreoclivus sp. nov. from the majority of recognised Melanesian Cyrtodactylus . Of those species which share this character; Cyrtodactylus aaroni and C. mimikanus (which also occurs in the Foja Mountains) have a much lower total number of femoral/precloacal pores (<35 v>47) and a distinctive dorsal pattern consisting of six or seven wide chocolate brown bands separated by very thin, strongly defined light bands ( Günther and Rösler 2003); members of the Cyrtodactylus lousiadensis group (restricted to far-eastern New Guinea) also have transversely enlarged subcaudals, however in this group they are much wider (approaching the width of the tail), they are also generally much larger geckos (109mm to 160 mm adult SVL) and most ( Cyrtodactylus epiroticus , C. klugei , C. louisiadensis , C. robustus and C. tripartitus ) can be further distinguished by possessing wide brown dorsal bands of even width with even edges (vs indistinct, ragged-edged dark brown bands); of the remaining two species, Cyrtodactylus murua differs in its lower number (three) and much broader dark dorsal bands, and Cyrtodactylus salamonensis has a much higher number of dorsal tubercle rows (28–29 v 18 –20) ( Rösler et al. 2007; Kraus 2009).

All other recognised species of Melanesian Cyrtodactylus lack a single series of transversely expanded subcaudals; C. sermowaiensis (recorded up to around 700m on Mount Sapua, the type locality of Cyrtodactylus boreoclivus sp. nov. (F. Kraus pers com.)), can be further distinguished by lacking a continuous series of enlarged femoral scales, lacking precloacal and femoral pores in the males, and a dorsal pattern consisting of transverse series of very dark brown and generally highly contrasting blotches or broken bands on a pale background (vs dorsal colouration consisting of less contrasting dark brown transverse bands on a dark background); C. loriae (also known from across northern and eastern New Guinea), can be further distinguished by having a continuous femoral and precloacal pore series; C. serratus , (known only from the Central Cordillera) differs in this same feature and the presence of spinose lateral and dorsal tubercles (v low, rounded and dorsal only) extending to the tip of the tail, ( Kraus 2007); C. novaeguineae (also widespread and overlapping over much of northern New Guinea), C. irianjayaensis and C. zugi , are readily distinguished by their larger size (adult SVL up to 172 mm v <109 mm), absence of ventral-lateral tubercles extending to at least the angle of the lower jaw and sometimes across the throat, and presence of enlarged tubercles below the lateral fold.

Cyrtodactylus boreoclivus sp. nov. is readily distinguished from all remaining Melanesian Cyrtodactylus ; C. papuensis and C. nuaulu possess a precloacal pit, lack femoral pores extending to the knees, and are much smaller (<90mm), C. nuaulu also has a distinctive series of dentate lateral tubercles extending to the tip of the tail; and Cyrtodactylus capreoloides and Cyrtodactylus derongo have different dorsal patterns, consisting respectively of thin brown bands on a light brown background, or thin bands of light creamish dots on a dark reddish brown background ( Brown and Parker 1973; Rosler et al. 2007).

Description of holotype. A moderately large (109 SVL mm), slender gecko; head long (HL/SVL 0.26), moderately wide (HW/HL 0.75) and distinct from neck; snout sharply rounded in dorsal profile, relatively long, longer than eye diameter; loreal region weakly inflated; interorbital region and top of snout concave; canthus rostralis smoothly rounded ( Fig.1 ). Eyes very large, pupil vertical, superciliaries extending from anterio-ventral to posterior dorsal edge of eye, largest at the anterior-dorsal corner. Ear opening small and obscured by a superior skin fold.

Rostral wider (4.8 mm) than high (2.9 mm), widest at and extending into nostrils, bordered dorsally by two supranasals, distinct medial suture extending from dorsal edge of rostral, less distinct lateral suture extending from ventral tip of medial suture. Nares bordered by first supralabial, rostral, first supranasal and series of 5 postnasals. Supralabials to rictus 11 on right and 12 on left, approximately 9 to midpoint of eye; supralabials anterior to eye much longer than high, bordered dorsally by a single series of enlarged scales. Head scales small and granular, temporal and nuchal scales smaller than those on snout, scattered small conical tubercles on dorsal half of temporal region. Infralabials to rictus 8 on right and left, all longer than high, bordered by several rows of enlarged scales grading into small and granular gular scales. Mental almost rectangular, with triangular posterior extension, wider than long, bordered by first infralabials and two pentagonal postmentals in contact for approximately 70% of their length.

Body elongate (TrL/SVL 0.45), skin moderately tuberculate, distinct ventrolateral fold with 37–40 slightly conical tubercles oriented posteriorly and separated by one or no smaller granules, posterior tubercles largest. Dorsum with approximately 17–18 rows (not including lateral fold) of low rounded tubercles at midpoint of body, surrounding scales small and granular; ventral scales much larger than dorsal scales, increasing in size medially, arranged in approximately 37 rows at midpoint of body. Distinctly enlarged femoral and precloacal scales in nearcontinuous series extending in single row along proximal third of tibia, in one to two rows along femur and in up to five rows in precloacal region. Precloacal pores in slightly angled series of 12 in the third enlarged precloacal scale row. Femoral pores extend along distal half of femur onto proximal third of tibia, 25 in right series, 24 in left series ( Fig. 2 ).

Forelimbs relatively elongate (FA/SVL 0.16), hindlimbs more robust and longer than forelimbs (CS/SVL 0.18). Dorsal surfaces of hindlimbs and lower forelimbs with numerous rounded tubercles. Digits long and well developed, inflected at basal interphalangeal joints, digits narrowing distal to joints; subdigital lamellae smooth, rounded and expanded proximal to joint inflection (9–10–10–10–9 manus; 8–10–10–12–10 pes); narrow lamellae distal to digital inflection (8-9-10-11-9 manus; 9–10–13–12–11 pes) (not including ventral claw sheath); large recurved claws sheathed by a dorsal and ventral scale. Slight basal webbing between digits I–IV on manus and pes.

Tail original, long and slender, tapering to point with a lateral groove extending most of its length. Caudal scales granular, increasing in size ventrally, a distinct series of transversely enlarged subcaudals scales extending almost to tip of tail, few scattered tubercles extending along dorsal surface of tail to approximately 4–5 cm from groin. Cloacal sacs swollen and prominent, left hemipene slightly everted, two enlarged postanal tubercles at anterior lateral edge of each cloacal sac.

Colouration in preservative. Dorsal ground colour moderately dark greyish-brown with scattered lighter grey flecking, especially on tubercles; a series of five indistinct bands on the body formed by a grade from light greyish brown to progressively darker brown, bordered posteriorly by a thin very dark brown jagged region; bands becoming more indistinct posteriorly. Laterally, torso relatively uniform medium-brown with scattered small light-grey and dark-brown spots and blotches. Nuchal region with a dark-brown indistinct W-shaped marking, further extending across the temporal region to the posterior edge of eye and bordered dorsally by a thin pale-grey line. Dorsum of head greyish brown with extensive fine dark-brown mottling and blotching; supralabials and infralabials light greyish brown. Ventral surfaces light grey with dense brown speckling. Lateral and dorsal surfaces of limbs same ground colour as dorsum; digits slightly lighter, all with scattered dark-brown and light-greyish spots, sometimes forming indistinct thin bands; ventral surfaces of limbs and digits with relatively less pigmentation, but retaining extensive fine brown flecking. Tail with seven broad dark-brown bands and six thinner light-grey bands, thinner light-grey bands with scattered dark spots, ultimate two centimetres light grey heavily mottled with dark brown.

Variation. Variation in mensural and meristic characters among the type series is presented in Table 1 ; variation in colour pattern is illustrated in Figure 3 . All female paratypes lack precloacal and femoral pores but do possess a row of distinctly enlarged femoral scales extending to the knee. Three of the paratypes have partially or fully regrown tails. The regrown tail is always uniformly dark greyish brown with irregular scalation and, in at least two specimens, has distinct longitudinal ridges (MZB lace 7474, SJR13613). The only paratype with a complete and original tail (SJR13592) lost this during capture. The original tail has six broad dark-brown bands and five much narrower light-grey bands.

Although the number (5–7), width, intensity and distinctness of the dark and lighter transverse bands vary ( Fig. 3 ), this basic colour pattern is relatively consistent across the type series. A distinct dark W-shaped mark in the nuchal region is also present in all specimens. Paratype MZB lace 7474 has the most distinct dorsal pattern, in this specimen the dark blotches do not always extend completely across the dorsum and the light-grey blotches are larger, lighter and sometimes join laterally to form an indistinct broken longitudinal ‘ladder’ pattern along the dorsum. In other specimens (e.g., SJR 13592), the light transverse bands are very indistinct, especially posteriorly. The venter is always predominately light grey, but there is slight variation in the degree and intensity of grey-brown spotting and flecking on the venter of the head, throat, body and legs.

Appearance in life. Photographs of paratypes MZB7474 and SJR 13613 in life ( Fig. 4 ) show the same pattern as in preservative, but with a higher level of contrast between light and dark-brown areas that makes the bands more obvious. Some light-brown areas in preservative appear almost yellowish in life, especially on supracilaries. Eye cream with extensive dark-brown vermiculations, pupil vertical; tongue pink.

AMSR135519 MZB lace 7474 MZB lace 7475 SJR13592 SJR13613 Distribution and natural history. Cyrtodactylus boreoclivus sp. nov. is currently known only from two sites in the north coast ranges of mainland New Guinea ( Fig. 5 ). The Foja Mountains and Torricelli Mountains are separated by over 300 km, and further surveys may reveal that it is found in intervening ranges such as the Bewanis and Cyclops. Specimens from the Foja Mountains were located at 1250 metres altitude in undisturbed lower-montane forest (sensu Johns 1976). Although exact altitude data are not available for the holotype from Mt Sapau, discussions with the collector (P. German) indicate that it was found in lower-montane forest at around 1200 metres.

Specimens from the Foja Mountains were collected on the trunks of either small shrubs or large trees, generally less than five metres above the ground. Although additional Cyrtodactylus were detected by their eyeshine 15–20 metres high in large trees, these were impossible to collect and in some cases it was not possible to confirm their identities. Two uncollected individuals of Cyrtodactylus boreoclivus sp. nov. were observed less than a metre apart, one on a large tree trunk and another on a liana approximately 10 metres high in the canopy. Female SJR 13593 contained two well-developed eggs, indicating that at least some individuals are reproducing in November.

No other gekkonids were found in sympatry with Cyrtodactylus boreoclivus sp. nov. in the Foja Mountains, but at lower altitudes Cytodactylus mimikanus and Cyrtodactylus novaeguineae were present. In the Torricellis C. sermowaiensis , C . novaeguineae and C. cf. lorie have also been collected in relatively close proximity to the type locality, but whether the distributions of these taxa overlap or abut with Cyrtodactylus boreoclivus sp. nov. is unknown.

Etymology. From the latin boreo meaning northern, and clivus meaning slopes, in reference to the northern Ranges of New Guinea, to which the species is presumably endemic.

Figures

FIGURE 1. Dorsal a) and ventral b) views of holotype (AMS R 135519) of Cyrtodactylus boreoclivus sp. nov. Scale = 20 mm.

FIGURE 2. Details of cloacal region of holotype (AMS R 135519) of Cyrtodactylus boreoclivus sp. nov. Extent and position of precloacal pore series indicated by small arrows, and femoral pore series by large arrows. Scale = 10 mm.

FIGURE 3. Dorsal view of paratypes of Cyrtodactylus boreoclivus sp. nov. showing variation in colour pattern (labels on specimens are all field numbers). From left to right MZB lace 7474 (F-num SJR 13593), MZB lace 7475 (F-num SJR 13594), SJR 13613, SJR 13592. Scale = 20 mm.

FIGURE 4. Photographs in life of paratypes of Cyrtodactylus boreoclivus sp. nov. from the Foja Mountains A) MZB lace 7474, and B) SJR 13613. Photographs courtesy T. Laman and National Geographic.

FIGURE 5. Map of northern New Guinea showing type locality (square) and paratypic locality (star) for Cyrtodactylus boreoclivus sp. nov.

Tables

TABLE 1. Mensural and meristic data for the type series of Cyrtodactylus boreoclivus sp. nov.

holotype	paratype	paratype	paratype	paratype
SEX m	f	f	f	m
SVL 109.0	104.3	107.3	108.5	105.7
TrL 40.1	51.1	51.2	53.1	52.4
TL 137.0	108.0	121.0	127.0	128.0
OT 137.0	39.0	68.0	127.0	21.0
FA 16.9	16.7	16.6	15.6	16.5
CS 19.5	20.5	19.8	20.6	20.0
HW 21.6	21.5	20.9	20.9	22.5
HL 28.8	28.0	28.4	27.3	27.8
HD 12.1	11.7	12.8	11.7	11.8
EN 11.2	9.9	10.4	10.1	10.4
EYE 7.7	7.4	7.5	7.1	7.9
IN 4.0	4.4	4.5	4.7	4.6
EAR 2.5	2.1	2.3	1.5	2.0
SUPR (R) 9/11	7/10	7/9	8/11	8/10
SUPR (L) 9/12	9/11	9/10	7/9	8/11
INFR (R) 8	9	10	8	10
INFR (L) 8 DTR 17/18	9 16/17	10 17/19	9 18/18	9 18/19
LTTUBR 37	43	38	36	40
LTTUBL 40	39	41	37	41
VENT 37	36	44	39	39
LAM MANUS I: 8+9	I: 8+7	I: 8+7	I: 9+7	I: 9+8
II: 9+10	II: 10+12	II: 10+9	II: 8+8	II: 10+12
III: 10+10	III: 12+11	III: 9+10	III: 10+8	III: 11+10
IV: 11+ 10	IV: 12+11	IV: 12+11	IV: 10+9	IV: 13+10
V: 9+9	V: 12+11	V: 12+8	V: 11+8	V: 12+9
LAM PES I: 9+8	I: 9+9	I: 9+7	I: 9+8	I: 10+10
II: 10+10	II: 11+12	II: 11+10	II: 9+10	II: 11+11
III: 13+10	III: 13+12	III: 12+12	III: 11+11	III: 11+11
IV: 12+12	IV: 12+14	IV: 12+12	IV: 11+10	IV: 13+11
V: 11+10	V: 13+11	V: 12+11	V: 12+8	V: 13+11
PREPORES 12	na	na	na	12
FEMPORES 25R, 24L	na	na	na	18R, 17L
PATUB 2/2	2/2	2/2	2/2	1/1