Parvoscincus arvindiesmosi, Linkem, Charles W. & Brown, Rafe M., 2013

Linkem, Charles W. & Brown, Rafe M., 2013, Systematic revision of the Parvoscincus decipiens (Boulenger, 1894) complex of Philippine forest skinks (Squamata: Scincidae: Lygosominae) with descriptions of seven new species, Zootaxa 3700 (4), pp. 501-533 : 508-514

Parvoscincus arvindiesmosi sp. nov.

Figs. 4 G, H, I; 5E, F

Sphenomorphus decipiens: Brown & Alcala, 1980: 186 (part) Parvoscincus decipiens sp. 2: Linkem, Diesmos, Brown, 2011

Holotype. PNM 9781 (formerly KU 306559: CDS 2171); Male; Philippines, Luzon Island, Camarines del Norte Province, Municipality of Labo, Barangay Tulay na Lupa, Mt. Labo, elevation 211 m above sea level, coordinates N: 14.0394º, E: 122.787º. Collected 7 July, 2006 by C. D. Siler.

Paratypes. Same location as holotype: KU 313866 (RMB 9903), KU 306561 (CWL 486) Males; KU 306560 (CWL 485) Juvenile. Quezon Province, Municipality of Tayabas, Barangay Lalo, Mt. Banahao: PNM 8611 (RMB 3656), TNHC62679 (RMB 3685), TNHC 62890 (RMB 3682) Females.

Genetic Data. GenBank KF425372 –KF4276.

Diagnosis. Parvoscincus arvindiesmosi sp. nov. can be identified by the following combination of characters: (1) A small body size (SVL at maturity 36–43 mm); (2) MBSR = 32–36; (3) PV = 65–74; (4) dorsal scales nonstriated with apical pits; (5) apical pits on forelimbs and hind limbs; (6) four enlarged supraoculars; (7) anterior and posterior loreals undivided laterally; (8) three preoculars; (9) and 16–19 Toe IV SDL; (10) narrow snout ( IND / RostL <0.50).

Parvoscincus arvindiesmosi sp. nov. is the sister species to P. agtorum and closely related to P. jimmymcguirei sp. nov., P. abstrusus sp. nov., and P. decipiens sensu stricto ( Fig. 2 ). Parvoscincus arvindiesmosi sp. nov. can be distinguished from all these species by its narrow snout ( IND /RostL 0.44–0.49 vs.> 0.50) and unique color pattern. In addition to the narrow snout, the new species differs from P. jimmymcguirei by lacking throat mottling (vs. heavy throat mottling); dorsolateral band extending dorsally towards midline and broken up along dorsum (vs. dorsolateral band bordered dorsally by large white checks, restricted to lateral regions); ventral edge of dorsolateral band abruptly transitioning to lateral body color (vs. ventral edge of dorsolateral band flecked with white and becoming a mix of dark brown and white spots ventrally).

Parvoscincus arvindiesmosi sp. nov. can be distinguished from P. abstrusus sp. nov. by having a single anterior loreal (vs. laterally divided anterior loreal) and by the presence of apical pits on the dorsal scales (vs. weak to missing apical pits); by having a white throat in males and light brown streaking in females (vs. throat black in males and white in females); presence of a broad dorsolateral band from the head to the tail (vs. dorsolateral band a thin strip along dorsal margin); dorsal coloration with brown mottling extending from the dorsolateral band (vs. dorsal coloration without mottling other than vertebral spots).

Parvoscincus arvindiesmosi sp. nov. can be distinguished from P. decipiens sensu stricto by having dark brown mottling on the dorsal surface (vs. light brown ground color without mottling); labials spotted with dark brown extending posteriorly to the forelimbs (vs. labials white without spotting).

Parvoscincus arvindiesmosi sp. nov. can be distinguished from P. a g t o r u m sp. nov. by having a smaller SVL (30.89–43.14 vs. 44.91 mm); having fewer midbody scale rows (32–36 vs. 39); having apical pores on the dorsal scales (vs. lacking pores); having three preoculars (vs. two preoculars); by having a white throat (vs. a cream throat with brown speckling and a brown incomplete gular collar); and by the presence of a broad dorsolateral band extending from head to tail (vs. narrow dorsolateral band extending from eye to midbody).

Description of holotype. A small-sized Parvoscincus , SVL 36.5 mm, with clawed, pentadactyl limbs. Snout pointed in lateral profile; rostral wide forming an oval dorsal margin with the nasals and frontonasal scale; frontonasal wider than long, in contact with nasals, rostral, anterior loreals, and prefrontal scales; prefrontals in narrow medial contact, in contact with anterior and posterior loreals, frontal, frontonasal, and 1st supraciliary; frontal slightly longer than wide, in contact with two supraoculars, posterior apex rounded; four enlarged supraoculars, 1st largest, 2nd widest; frontoparietals fused, in contact with three supraoculars; interparietal arrowhead-shaped with parietal eye in posterior third; parietals in narrow overlap, left overlapping right, in contact with fourth supraocular, postsupraocular, primary and secondary temporal; nuchals same size as dorsals, not obliquely enlarged.

Nasal pierced in center by large naris, surrounded anteriorly by rostral, dorsally by frontonasal, posteriorly by anterior loreal, and ventrally by 1st supralabial; single anterior loreal, posterior loreal wider than anterior; preoculars two; seven supralabials, 5th widest and under center of eye; supraciliaries 13, anterior three and posterior two larger than rest of series; 14 ciliaries; lower eyelid scaly and transparent, lacking non-scaled “window;” suboculars eight, largest anteriorly; primary temporals three, secondary temporals two, lower overlapping upper; ear large (EarD [1.22]/EyeD [2.00] = 0.61), round, and moderately sunk.

Infralabials seven, decreasing in size posteriorly in series; mental large, forming a straight suture with a single large postmental and first infralabials; postmental contacts anterior two infralabials; chin scales increasing in number posteriorly (one, two, five) and then blending into size and shape of gular scales; gular scales slightly smaller than ventrals.

Body non-elongate (AGD [16.55]/SVL [36.5] = 0.45), cylindrical, with 36 equal-sized midbody scales, limbs overlapping when adpressed; lateral body scales with two or three rows of apical pits; paravertebral scales 65, imbricate, with one row of apical pits. Tail elongate, slightly longer than body (TL [50.0]/SVL [36.5] = 1.37) triangular at base, thicker dorsally than ventrally, becoming dorsoventrally compressed; subcaudal scales nondifferentiated.

Forelimbs smaller than hind limbs (FLL [3.44]/HLL [4.51] = 0.76), pentadactyl; dorsal forelimb scales smaller than body scale, ventral forelimb scales much smaller than ventral scales, dorsal and ventral forelimb scales imbricate with multiple rows of apical pits; multiple rows of dorsal scales on digits. Relative digit length with lamellae (L/R) in parentheses IV(12/12)> III(10/10)> II(9/9)> V(7/7)> I(5/5). Palmar scales irregular, raised, forming ventral protrusions from palmar surface; large set of five scales on distolateral edge of Digit V to the wrist, largest scale at wrist.

Hind limbs small (HLL [4.51]/SVL [36.5] = 0.12), pentadactyl; dorsal and ventral hind limb scales smaller than body scales; dorsal scales bearing apical pits, ventral scales with single row of apical pits; multiple scale rows on dorsal side of digits. Lamellae slightly keeled. Relative digit length with lamellae (L/R) in parentheses: IV(17/ 18)> III(14/15)> V(--/11)> II(10/11)> I(6/6). Plantar scales irregular, slightly raised; four large, ventrally pointed scales along ankle/plantar margin; ventrally raised scales along distolateral edge of Digit V to ankle, increasing in size toward ankle.

Precloacal region with series of enlarged scales between pelvic region and cloaca, more elongate than ventral scales; medial precloacal scales larger, overlapping lateral scales.

Coloration of holotype ( Figs. 4 G, H, I; 5E, F). Dorsal ground color light tan medially, covered by dark brown laterally and a series of vertebral dark brown checks. Lateral brown extends along length of body from post ocular to base of tail and ventrally to the dorsal margin of limbs. Ventral margin of dorsolateral stripe checked with white. Ventrum white with spot on the distal half of tail and a few flecks on gular region, otherwise spotless. Dorsum of limbs dark brown with white spots that extend onto the dorsal surface of the manus and pes. Ventral limb coloration white. Coloration of holotype in life unrecorded.

Variation. Gravid females (TNHC 62679, PNM 8611) have brown streaking on the throat instead of white without pattern, non-gravid females have light brown spotting on the throat. Males have no spots on the throat, as does the holotype. Dorsal and lateral coloration same as holotype. Variation in meristic and mensural characters in the type series and referred specimens presented in Table 2.

Distribution ( Fig. 1 ). The new species is known from two localities on southern Luzon: Mt. Banahao at 600 m above sea level (Municipality of Tayabas, Barangay Lalo) and Mt. Labo at 212 m above sea level (Municipality of Labo, Barangay Tulay Na Lupa).

Natural History. This species is found under logs on stream banks, inside rotten logs and under logs and in leaf litter.

Etymology. The specific epithet is a patronym in the genitive singular, honoring the contributions of Arvin C. Diesmos to the ecology, conservation, and systematics of Philippine herpetofauna.

Figures

FIGURE 1. Map of Luzon Island showing the collection localities for the new species and P. decipiens.

FIGURE 2. Partitioned Bayesian majority rule consensus estimate of molecular phylogeny from the ND 2 data of Parvoscincus. Populations within the P. decipiens complex are genetically unique and are diagnosed as new species based on morphological differences. Black circles label nodes with posterior probabilities above 0.95.

FIGURE 4. Photographs of heads from ventral, lateral, and dorsal perspective to show color pattern variation among species. Images A, B, C Parvoscincus decipiens; D, E, F Parvoscincus jimmymcguirei sp. nov. holotype; G, H, I, Parvoscincus arvindiesmosi sp. nov. holotype; J, K, L Parvoscincus agtorum sp. nov. holotype; M, N, O, Parvoscincus abstrusus sp. nov. holotype (Male); P, Q, R, Parvoscincus abstrusus sp. nov. paratype (Female); S, T, U, Parvoscincus banahaoensis sp. nov. holotype; V, W, X, Parvoscincus palaliensis sp. nov. holotype; Y, Z, AA, Parvoscincus aurorus sp. nov. holotype.