Cyrtodactylus equestris, Oliver, Paul M., Richards, Stephen J., Mumpuni, & Roesler, Herbert, 2016

Oliver, Paul M., Richards, Stephen J., Mumpuni, & Roesler, Herbert, 2016, The Knight and the King: two new species of giant bent-toed gecko (Cyrtodactylus, Gekkonidae, Squamata) from northern New Guinea, with comments on endemism in the North Papuan Mountains, ZooKeys 562, pp. 105-130 : 110-112

Taxon classification Animalia Squamata Gekkonidae

Cyrtodactylus equestris sp. n. Figures 2, 4

Holotype.

AMS R135520 adult male with everted left hemipenis and completely regrown tail, Papua New Guinea, Sandaun Province, Torricelli Mountains, Mt. Sumbau (3°23'S, 142°31'E, between 1000-1200 m a.s.l.), collected by P. German, 10 March 1990, with frozen tissue at the South Australian Museum (ABTC50282).

Paratypes

(n = 6). Papua New Guinea: AMS R119547 Sandaun Province, Torricelli Mtns, Wigote (3°25'S, 142°09'E), collected by T. Flannery, 20 July 1985; BPBM 23314-16 Sandaun Province, Torricelli Mountains, between 2.9-3.2 km east of Mt Sapau summit (3°23'27.0636"S, 142°31'47.028"E, 550-700 m a.s.l.), collected by F. Kraus between 23-25 May 2005. Indonesia: MZB lace 5435-6 Papua Province, Foja Mountains, camp above Marina Valen Village (02°22.230'S, 138°12.753'E; 500 m a.s.l.), collected by S. Richards and B. Tjaturadi between 17-22 July 2004.

Referred material

(n = 5). Papua New Guinea: AMNH 100050-1, Sandaun Province, Lumi (~530 m a.s.l.), collected by M. Lorenz; AMNH 100052 Sandaun Province, Mt Menawa, Bewani Mountains, collected by J. Diamond; AMNH 82360 Madang Province, Adelbert Mountains, Maratambu (~700 m a.s.l.), collected by E.T. Gillard; AMNH 103193 Madang Province, Adelbert Mountains, Wanuma (~700 m a.s.l.), collected by A.C. Zeigler. The last two specimens are listed as referred material because of taxonomic uncertainty (see below), while the remainder are relatively poor specimens.

Diagnosis.

A large Cyrtodactylus (SVL to 139 mm), with a moderately broad head (HW/SVL 0.19-0.22), enlarged tubercles on the infra-angular region and often extending across the posterior throat, mid-dorsal tubercles in 19 to 25 rows at midpoint of body, subcaudal scales not transversely widened, high number of mid-body ventral scale rows (42-59), femoral pores in two separated rows of 9-19, usually with a further medial precloacal row of 6-13 pores (up to 39 pores in total), venter relatively plain brown with at most scattered darker brown maculations, and dorsum with three distinct to indistinct medium-brown transverse bands on relatively plain light brownish-grey background.

Description of holotype.

A moderately large (113 mm SVL) and slender gecko. Head large (HL/SVL 0.28), moderately wide (HW/SVL 0.21) and clearly distinct from neck. Snout rounded in dorsal profile, broadly truncate in lateral profile, eye to naris distance longer than eye diameter (EN/EYE 1.4), loreal region slightly inflated, interorbital region and top of snout concave, canthus rostralis rounded, weakly defined. Eyes large (EYE/HL 0.26), pupil vertical, supraciliaries extending from anteroventral to posterodorsal edge of orbit, longest at the anterodorsal corner. Ear opening rounded, bordered by distinct dorsal skin fold.

Rostral rectangular, wider than high, with medial suture extending approximately halfway from dorsal edge towards ventral edge, bordered dorsally by two flattened nasals and single tiny internasal. Nares bordered by first supralabial (point contact), rostral, nasal, 2-3 enlarged postnasals and 2-3 tiny granular postnasals. Supralabials generally wider than high, 10 on right, 11 on left, 8 to midpoint of eye. Head, temporal and nuchal scales small and granular, interspersed with numerous enlarged weakly conical tubercles, approximately 3-4 times width of surrounding scales, on temporal and posterior nuchal regions. Enlarged infralabials slightly to much wider than high, 11 on right and 10 on left, bordered by rows of slightly enlarged scales that grade into small granular gular scales. Mental slightly wider than long, broadly triangular, but with distinctly concave edges at contact with postmentals, in contact with first infralabials. Scattered small conical tubercles (approximately twice size of surrounding scales) in the infra-angular regions of the lower jaw only.

Body moderately robust (TrK/SVL 0.44) with distinct ventrolateral folds. Moderately tuberculate, tubercles along lateral fold heterogeneous, up to 3 times larger than surrounding scales. Dorsum with approximately 23 rows (not including lateral fold) of often keeled tubercles up to 4 times width of surrounding granular scales. Ventral scales much larger than dorsal scales, increasing in size medially, arranged in approximately 39 rows at midpoint of body. Several continuous rows of enlarged femoral scales, posterior row extending almost to knee, distinctly larger and contrasting against granular posterior femorals. Precloacal pores in a series of 8, femoral pores in individual series of 15-16, respective series separated by 7 poreless scales.

Limbs moderately robust, forelimbs (FA/SVL 0.14) shorter and less robust than hindlimbs (CS/SVL 0.19). Lateral and dorsal surfaces of antebrachium and crus with numerous conical tubercles. Digits long and well developed, inflected at basal interphalangeal joints; subdigital lamellae smooth, rounded and expanded proximal to digital inflection (8-12-11-13-11 manus; 9-12-15-15-13 pes); narrow distal to digital inflection (9-10-11-11-11 manus; 7-12-12-14-13 pes) (counts not including ventral claw sheath); large recurved claws sheathed by a dorsal and ventral scale.

Tail almost completely regrown, scalation heterogeneous and irregular. Cloacal sacs swollen and prominent, each with 3 rounded cloacal spurs at anterior edge.

Measurements of holotype

(in mm).SVL 113, TL 97, OT 13, TrK 49.5, HW 23.4, HH 13.1, HL 32.2, EN 11.6, IN 4.2, EYE 8.3, EAR 2.0, FA 15.3, CS 21.5.

Color in ethanol.

Dorsal pattern consisting of alternating light brown and medium brown regions. Nuchal band medium brown, posterior edge triangular with thin continuous dark brown margin and extending along dorsum to level of forelimb insertion, anterior edge deeply notched and less clearly margined. Nuchal dark band bordered posteriorly by a deeply notched light brown band with distinct thin dark brown edging on medial anterior and posterior edges, and extending anteriorly onto lower jaw. Subsequent dark bands not deeply notched and less distinctly margined, but generally with at least some dark brown edging at their midpoint. Dorsal surface of head medium brown, darker anteriorly, without pattern, with the exception of a pair of small curved dark brown lines on the nape. Lower lateral region of head whitish brown, strongly demarcated against upper lateral and dorsal brown colouration. Ventral colouration dirty brown with scattered darker brown maculations on the throat and and across the venter. Limbs medium brown dorsally, slightly lighter ventrally, largely unpatterned except for scattered dark maculations and very small blotches on the hindlimbs. Stub of original tail medium brown dorsally with a pair of smeared very dark brown markings. Regrown tail plain light brown on all surfaces.

Variation.

The type series includes 4 adult males (with fully expressed pore series) varying from 113-129 mm SVL, two adult females both of 139 mm, and one juvenile male of 104 mm. Mensural data for the type series are summarized in Table 2. Supralabials to center of eye 8-10, to rictus of jaw 11-15, Infralabials 10-13. Fourth toe wide lamellae 11-13, fourth toe narrow lamellae 11-13, mid-belly scale rows 39-59, and maximum number of dorsal tubercle rows 19-23. Cloacal spurs 3-4, expressed precloacal pores from 6-8, femoral pore series from 8-15, total number of pores 24-35.

Dorsum generally with alternating transverse regions of light and medium brown, however the width and distinctiveness of these region varies. Some variation in the intensity of colouration may be ontogenetic. On the largest specimens the medium brown regions are relatively narrow, and not or only weakly defined by dark brown edging, giving the overall impression of a somewhat faded pattern. On smaller specimens the transverse bands are more distinct and strongly defined. An indistinct trace of medium brown mottling or barring is also sometimes apparent on the dorsal and lateral surfaces of the hindlimbs. Venter medium to light brown, sometimes with very scattered darker brown maculations. Original tails with alternating medium-brown dorsal blotches and light-brown to creamish regions, border between colours often sharply defined by dark- brown edging. Regrown tails creamish or light brown with at most a few very indistinct light brownish streaks and patches. Iris in life deep chestnut brown with dark brown vermiculations (Figure 4).

Comparisons.

Cyrtodactylus equestris sp. n. can be distinguished from most other Cyrtodactylus by its large size (males to 129 mm, females to 139 mm), including all species from west of Lydekker’s Line (maximum size <130 mm). It can be differentiated from the other large Papuan taxa as follows. Cyrtodactylus equestris sp. n. differs from Cyrtodactylus loriae and Cyrtodactylus serratus in having enlarged tubercles on the infra-angular region and often extending across the throat (vs. absent), a lower number of pores (up to 39 vs. up to 81) in a discontinuous series (vs. continuous), and in lacking enlarged tubercles extending the length of the tail (vs. Cyrtodactylus serratus only). Cyrtodactylus equestris sp. n. differs from members of the Cyrtodactylus lousiadensis group ( Cyrtodactylus epiroticus , Cyrtodactylus klugei , Cyrtodactylus lousiadensis , Cyrtodactylus murua , Cyrtodactylus robustus , Cyrtodactylus salomonensis and Cyrtodactylus tripartitus ) in its smaller subcaudal scales, in having tubercles on the infra-angular region and throat, and in its more poorly defined light-brown bands or blotches on the dorsum (vs. strongly defined and unbroken transverse brown banding). Cyrtodactylus equestris sp. n. differs from Cyrtodactylus zugi in its smaller size (139 vs. 159 mm SVL), more extensive tuberculation that usually extends across the throat (vs. on infra-angular region only), and dorsal colour pattern on torso consisting of light-brown transverse bands on a plain greyish-brown background (vs. alternating dark brown blotches on a mottled dark-grey and off-white background). Cyrtodactylus equestris sp. n. differs from Cyrtodactylus irianjayaensis by its smaller size (139 vs. 163 mm SVL), the presence of enlarged tubercules usually extending across the throat (vs. infra-angular region only) and its higher number of femoral and precloacal pores (24-39 vs. 7-16). Cyrtodactylus equestris sp. n. differs from other populations of Cyrtodactylus here referred to Cyrtodactylus novaeguineae (both syntypes and genotyped material) in its wider head (HW/SVL 0.19-0.23 vs. 0.18-0.19), larger size (SVL 139.0 vs. 129.0) and tripartite femoral and precloacal pore arrangement (vs. continuous or at most one poreless intervening scales).

Distribution and natural history.

Known from scattered localities in the Foja, Torricelli and possibly the Adelbert Ranges (see below) of northern New Guinea (Figure 7). Specimens for which detailed information is available were collected in relatively undisturbed hill or lower montane forest between 500-1200 m a.s.l.

Etymology.

Equestris latin for knight, in reference to the relative size of this species - large for the genus, but still subordinate to some of its near relatives.

Comments.

The referred material include two specimens in the American Museum of Natural History (AMNH 82360, AMNH 103193) from separate localities in the Adelbert Ranges, Morobe Province. These specimens have plain venters and two-toned brown and light brown dorsal colouration. On this basis they do not conform with 'north 2' (the only other member of the Cyrtodactylus novaeguineae complex from northern New Guinea) and are tentatively assigned to Cyrtodactylus equestris sp. n. However these localities are separated from the other localities in the North Papuan Mountains by the low swampy country around the Sepik River, and the single male from this region has a bipartite pore arrangement (vs. clearly tripartite). Fresh material and genetic samples are required to confirm the taxonomic status of these easternmost populations.