Cyrtodactylus tripartitus , Kraus, Fred, 2008

Kraus, Fred, 2008, Taxonomic partitioning of Cyrtodactylus louisiadensis (Lacertilia: Gekkonidae) from Papua New Guinea, Zootaxa 1883, pp. 1-27: 12-15

publication ID

http://doi.org/ 10.5281/zenodo.184270

persistent identifier

http://treatment.plazi.org/id/586B87D0-FFC9-B82D-FF43-F9E351A85A81

treatment provided by

Plazi

scientific name

Cyrtodactylus tripartitus
status

sp. nov.

Cyrtodactylus tripartitus  sp. nov.

Fig. 1View FIGURE 1 B

Holotype. BPBM 16864 (field tag FK 7122), mature male, collected by F. Kraus on E slope Oya Tau, 10.6548913 ºS, 152.6382783 ºE, 320 m, Misima Island, Milne Bay Province, Papua New Guinea, 16 January 2003.

Paratypes. Papua New Guinea: Milne Bay Province: Misima Island: Nulia River, Liak, 10.6607789 ºS, 152.6854395 ºE, 10–40 m ( BPBM 16860 – 61); Bwaga Bwaga Ridge, 10.67395 ºS, 152.68285 ºE, 440 m ( BPBM 16862 – 63); E slope Oya Tau, 10.6548913 ºS, 152.6382783 ºE, 320 m ( BPBM 16865); N slope Mt. Sisa, 350 m ( AMNH 76812 – 13); near Bwagaoia ( AMS 124955); unspecified locality ( AMS 125263).

Diagnosis. A large (127–148 mm) species of Cyrtodactylus  having a single row of enlarged subcaudal scales; enlarged dorsal tubercles raised, keeled, ~ 4–5 times size of adjacent granules ( Fig. 2View FIGURE 2 F), in 25–28 rows; lateral tubercles distinct, ~ 4 times size of adjacent granules and larger than scales of lateral skin fold, which lack tubercles; 47–55 midbelly scale rows; precloacal/femoral pores 64–78, in three discrete patches; lamellae under fourth toe 26–31; head moderately wide (HW/HL = 0.68–0.75, mean 0.71); five dark dorsal bands between head and hindlimb insertion, of more-or-less even width, margined in black, with 6–7 tubercles sagitally through 3 rd dark band; dark spots absent from light dorsal ground color; mouth and cloacal linings pink; and posterior supralabials dirty white.

Comparisons with other species. Cyrtodactylus tripartitus  sp. nov. is distinguished from all other Papuan members of the genus except C. aaroni  , C. mimikanus  , C. murua  , C. tuberculatus  , C. salomonensis  , C. louisiadensis  , and C. klugei  sp. nov. by its single row of enlarged subcaudals. From C. aaroni  and C. mimikanus  it is distinguished by its much larger size (SV = 127–148 mm vs. 70–86.5 mm in C. aaroni  and 67–103 in C. mimikanus  ), greater number of precloacal/femoral pores (64–78 vs. 17–27 in C. aaroni  and <40 in C. mimikanus  ), and fewer dark dorsal bands between the head and hindlimbs (5 vs. 8–11 in C. aaroni  and C. mimikanus  ). From C. murua  it is distinguished by having lateral tubercles larger than scales of lateral skin fold (vs. of equal size in C. murua  ), a greater number of dorsal tubercles (25–28 rows vs. 20–22 in C. murua  ), a greater number of lamellae under the fourth toe (26–31 vs. 24–25 in C. murua  ), and dorsal bands of approximately equal width to intervening ground color (vs. wider in C. murua  ), and of even width across dorsum (vs. broadening medially in C. murua  ). From C. tuberculatus  it is distinguished by its larger size (SV = 127–148 mm vs. 80–89 mm in C. tuberculatus  ), greater number of mid-belly scale rows (47–55 vs. 27–36 in C. tuberculatus  ), greater number of precloacal/femoral pores (64–78 vs. 36–46 in C. tuberculatus  ) in three separate patches (vs. a continuous series in C. tuberculatus  ), and by having fewer dark dorsal bands (5 vs. 6–7 in C. tuberculatus  ). From C. salomonensis  it is distinguished by absence (vs. presence in C. salomonensis  ) of tubercles along the lateral skin fold, greater number of mid-belly scale rows (47–55 vs. 34–39 in C. salomonensis  ), precloacal/ femoral pores arrayed in three patches (vs. a single row in C. salomonensis  ), and fewer dark dorsal bands (5 vs. 6–7 in C. salomonensis  ). From C. louisiadensis  it differs in having conical, keeled dorsal tubercles (vs. flat and unkeeled in C. louisiadensis  ) of larger size (~ 4–5 times size of adjacent granules vs. ~ 2–3 times in C. louisiadensis  ); lateral tubercles large (~ 4 times size of adjacent granules vs. ~ 2–3 times in C. louisiadensis  ), larger than (vs. approximately equal size in C. louisiadensis  ) scales of lateral skin fold; a greater number of lamellae under the fourth toe (26–31 vs. 24–26 in C. louisiadensis  ); and posterior supralabials dirty white (vs. brown in C. louisiadensis  ). From C. klugei  sp. nov. it differs in having more rows of dorsal tubercles (25–28 rows vs. 20–23 in C. klugei  ), more midbelly scale rows (47–55, mean 51.8 rows vs. 43–49, mean 46.3 rows in C. klugei  ), and somewhat longer snout (EN/SV = 0.089–0.106, mean 0.098 vs. 0.084–0.092, mean 0.089 in C. klugei  ). Cyrtodactylus tripartitus  differs from all other members of the C. louisiadensis  group in having the precloacal/femoral pores arrayed in three distinct series instead of present in a single, continuous series. [Note: Rösler et al. (2007) claimed C. tuberculatus  to have the precloacal/femoral pores in three discrete patches, but P. Couper (Queensland Museum) and G. Shea (University of Sydney) both inform me that their extensive surveys of this species show it to have these pores consistently arranged in a single, continuous series. Their surveys include specimens from the general vicinity of the type locality of C. tuberculatus  (e.g., QM J 17512View Materials, J 27083View Materials, J 52850View Materials, J 53634View Materials), and their findings will be summarized in a forthcoming publication. I have utilized their character-state reassessment for all comparisons herein.]

Description of holotype: A mature male, with lateral, posterior, and mid-ventral incisions and digestive tract removed. Animal large (SV = 127 mm, TrL = 53.4 mm); tail folded back on itself and unamenable to accurate measurement, longer than SV. Head relatively long (HL/SV = 0.31) and wide (HW/HL = 0.70), not depressed (HH/HL = 0.42), distinct from neck. Loreal region slightly inflated; canthus rostralis poorly defined. Interorbital region and top of snout concave. Snout relatively long (SN/HL = 0.42), much longer than eye diameter (SN/EY = 1.5). Eye relatively large (EY/HL = 0.28); pupil vertical, with weakly crenellated margins; supraciliaries large, frill-like, well-differentiated from adjacent granules. Ear opening small (Ear/HL = 0.070), somewhat depressed; distance between ear and eye larger than eye diameter. Rostral wider (5.9 mm) than high (3.6 mm), highest just medial to nares, lower between these points; length 1.9 mm; dorsal half divided by weak medial groove. Two enlarged supranasals separated by two internasals. Rostral in contact with first supralabials, two supranasals, and one internasal. External nares elliptical; right bordered by rostral, two supranasals, first supralabial, and nasal. Nasals bordered posteriorly by five small granular scales. Circa six rows of small scales separate orbit from supralabials at narrowest point. Mental shallowly triangular, wider (5.1 mm) than long (3.2 mm). Mental bordered posteriorly by two elongate postmentals. Infralabials bordered by slightly enlarged, elongate scales that gradually decrease in size posteriorly. Supralabials to mid-orbital position ten on each side, to angle of jaw 13 on each side. Infralabials 13 on each side.

Body moderately robust (TrL/SV = 0.42), with lateral skin folds consisting of scales approximately same size as adjacent ventral scales and dorsal granules; no enlarged tubercles in lateral skin fold. Dorsal scales on head, body, and limbs tiny, juxtaposed granules, each with small raised asperities. Conical tubercles present on head, body, and limbs; best developed posteriorly; 4–5 times size of adjacent granules; distinct from granules in profile. Dorsal tubercles keeled; those on head, limbs, and sides of body generally unkeeled. Tubercles arranged in approximately 27 irregular rows between the lateral folds. Ventral scales flat and smooth; those on chin and throat smaller and juxtaposed; those on abdomen larger and subimbricate, arrayed in 55 rows across mid-venter.

Precloacal pores 21; femoral pores 21 (right) and 22 (left), separated from precloacal pores by 14 (right) and 12 (left) smooth scales lacking pores. Scales of precloacal and femoral regions of approximately uniform size and not distinct from those on abdomen; scales on posterior femoral region smaller, one-third to one-half size of precloacal scales. Scales bearing precloacal pores approximately half size of those in row immediately anterior. No precloacal groove. Scales on palms and soles rounded, smooth.

Fore- and hindlimbs relatively well-developed (FA/SV = 0.15, CS/SV = 0.18). Digits well-developed, reflected at basal interphalangeal joints; all with robust, recurved claws surrounded by two scales. Subdigital lamellae narrow and smooth, expanded proximally. Lamellae of manus 18–23 – 25 – 24–27 on right, 17–21 – 25– 26 – 23 on left; of pes 20–25 – 29 – 28 – 27 on right, 21–25 – 29–30 – 26 on left. Relative lengths of digits on manus I <V <II <III <IV; on pes I <II <V <III <IV. Slight interdigital webbing on manus and pes.

Tail complete, with rather narrow base (TW/SV = 0.061), tapering to a blunt point, with single row of enlarged subcaudals until distal 2.4 cm. Cloacal sacs swollen, with small external orifices situated near lateral margins of vent; midventral scales of sac not distinctly larger than those ventrolaterally. Scales of tail small, flat, smooth, subimbricate; with approximately eight rows of enlarged dorsal tubercles just behind cloacal sacs but then disappearing distally; four enlarged postcloacal spurs on each side of tailbase.

Color in preservative: Dorsal ground color medium sienna brown; slightly darker sienna brown chevron on nape whose anterior arms enter posterior border of eye; four more dark sienna brown bands to region between hindlimbs; eight more on tail before dark markings become indistinct. Dark dorsal bands of approximately even width across dorsum, each marked by dark brown margins, these in turn bordered externally by light margins. Tubercles same color as surrounding granules. Labials light brown, contrasting with face. Venter with dirty white ground color heavily suffused with same medium brown color as dorsal ground. Palms and soles light brown.

Measurements (in mm). SV = 127, TrL = 53.4, TW = 7.8, FA = 19.4, CS = 23.1, HL = 38.8, HW = 27.0, HH = 16.2, Ear = 2.7, EE = 10.4, EY = 10.7, SN = 16.4, EN = 12.9, IN = 5.1, IO = 10.4.

Color in life. A color photo of BPBM 16861 ( Fig. 1View FIGURE 1 B) indicates the dorsum to be medium sienna brown with dark sienna brown dorsal bands, these margined in dark brown, which are further narrowly margined in light tan. The supralabials are distinctly white and contrast with the brown face. Tail with three broad dark gray bands interrupted by narrow white bands. Iris dark reddish brown.

Variation. The type series consists of two adult males varying from 127–136 mm SV, four adult females varying from 131–148 mm, and four juveniles varying from 81–108 mm. Mensural data for the ten specimens of the type series are given in Table 2. Supralabials to center of eye vary from 9–12, to angle of jaw 12–16. Infralabials vary from 9–13, fourth toe lamellae 26–31, mid-belly scale rows 47–55, and number of rows of dorsal tubercles 25–28. Numbers of precloacal/femoral pores vary from 64–78; the sole male paratype has 22 precloacal pores, 27 femoral pores on the right, and 29 on the left.

Ground color varies from dark tan to dark brown and is usually on the darker end of that spectrum. Color pattern usually includes five dark dorsal bands (including the nuchal chevron), but one female has four broken bands of indeterminate outline. All dark bands have black edges that are further margined in light tan. These dark bands contrast moderately well with the somewhat lighter ground color except in the female with the indeterminate dark bands, which superficially appears almost unicolor. Ventral color can be bright dirty white (one specimen) but usually appears brown because of heavy suffusing of brown pigment in a dirty white ground. Posterior supralabials are generally white, but in one specimen ( BPBM 16864) they are brown instead.

Etymology. The trivial epithet is a Latin masculine adjective meaning “divided in three parts” and refers to the characteristic arrangement of the precloacal/femoral pores, which is an unusual trait in this species complex.

Range. Known only from Misima Island, Milne Bay Province, Papua New Guinea ( Fig. 3View FIGURE 3, square).

Ecology. I found this species at night on tree trunks, frequently adjacent to streams. Animals occurred in secondary rainforest and ranged from sea level to 440 m elevation. It seems likely that the species can span the entire elevational range of Misima (1050 m). I found it syntopic with the geckos Gehyra oceanica  , Gekko vittatus  , Lepidodactylus lugubris  , and at least one species of Nactus  .

Remarks. Comparisons made to “ Cyrtodactylus louisiadensis  ” in Rösler et al. (2007) refer to this species.

TABLE 2. Mensural characters for type series of Cyrtodactylus tripartitus sp. nov. F = female, M = male, imm. = immature.

Character BPBM 16860 Sex F BPBM 16861 imm. F BPBM 16862 M BPBM 16863 F   BPBM 16865 F AMS 124955 imm. AMS 125263 imm. AMNH 76812 F AMNH 76813 imm.
BPBM

Bishop Museum

AMNH

American Museum of Natural History