Parvoscincus aurorus

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 : 521-523

Parvoscincus aurorus sp nov.

Figs. 2 ; 4Y, Z, AA; 5O, P

Sphenomorphus decipiens: Brown & Alcala, 1980: 186 (part)

Holotype. PNM 9786 (formerly KU 323324, A. C. Diesmos Field No. 4859): Female; Aurora Province, Municipality Maria Aurora, Barangay Villa Aurora, Mt. Dayap, coordinates N: 15.660°, E: 121.327°, elevation 915 m above sea level, Collected by A. C. Diesmos.

Paratypes. Same locality as holotype: KU 323323 Male; KU 323309, KU 323320– 22 Females.

Genetic data. GenBank KF425338 – KF425342 .

Diagnosis. Parvoscincus aurorus sp. nov. can be identified by the following combination of characters: (1) A small body size (SVL at maturity 39.5–46.6 mm); (2) MBSR = 31–35; (3) PV = 65–75; (4) dorsal scales nonstriated without apical pits; (5) apical pits on hind limbs, none on forelimbs; (6) four enlarged supraoculars; (7) anterior loreal single; (8) three preoculars; (9) and 15–17 Toe IV SDL.

Parvoscincus aurorus sp. nov. is most closely related to P. banahaoensis and P. palaliensis ( Fig. 2 ), and these three species are related to other high elevation Parvoscincus species ( P. boyingi , P. laterimaculatus , P. igorotorum , P. beyeri , and P. hadros ). Parvoscincus aurorus sp. nov. can be distinguished from P. boyingi , P. laterimaculatus , P. igorotorum , P. beyeri , and P. hadros by being generally smaller (SVL 39.55–46.64 vs. 42–86.7 mm) and having fewer PV (<88) than all species but only slightly fewer than P. laterimaculatus ( Table 1 ).

Parvoscincus aurorus sp. nov. can be distinguished from P. banahaoensis sp. nov. by having more PV scales (65–75 vs. 62–66); more midbody scale rows (31–35 vs. 28–32); by having flanks brown with white spots (vs. white flanks); dorsolateral band irregular dorsally with half circles of dorsal color interrupting the dark brown band (vs. dorsolateral band bordered dorsally by straight light line).

Parvoscincus aurorus sp. nov. and P. palaliensis sp. nov. are most similar morphologically with overlapping scale counts ( Tables 1 , 2). Parvoscincus aurorus sp. nov. has a slightly higher profile head (3.8–4.5 mm vs. 3.44 mm) and longer head–forelimb length (14.3–16.45 vs. 13.4). Coloration is very similar, though the pattern of the dorsolateral band is different on the dorsal margin. Parvoscincus aurorus sp. nov. has a dark brown dorsolateral band broken up dorsally by half circles of dorsal coloration ( Fig. 5 O, P) whereas Parvoscincus palaliensis sp. nov. has a dark brown dorsolateral band broken dorsally by inverted “hook” or “claw” shaped marks of the dorsal color ( Fig. 5 M, N).

Description of holotype. A small-sized Parvoscincus , SVL 41.61 mm, with clawed, pentadactyl limbs. Snout rounded in lateral profile with lower jaw slightly sunk; 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 broad medial contact, left overlapping right, in contact with anterior and posterior loreals, frontal, frontonasal, 1st supraciliary, and 1st supraocular; frontal slightly longer than wide, in contact with two supraoculars, posterior apex rounded and narrow; four enlarged supraoculars, 2nd largest, 2nd widest; frontoparietals fused, in contact with three supraoculars; interparietal tear-drop shaped with parietal eye in posterior third; parietals in broad overlap, right overlapping left, 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 three; seven supralabials, 5th widest and under center of eye; supraciliaries 10, 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 moderately large (EarD [1.60]/EyeD [2.64] = 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, three) and then blending into size and shape of gular scales; gular scales slightly smaller than ventrals.

Body slightly elongate (AGD [21.48]/SVL [41.61] = 0.52), cylindrical, with 32 equal-sized midbody scales, limbs overlapping when adpressed; lateral body scales with one row of apical pits; paravertebral scales 71, imbricate, without apical pit scales. Tail elongate, slightly longer than body (TL [55.0]/SVL [41.61] = 1.32) rectangular at base, slightly thicker dorsally than ventrally; subcaudal scales nondifferentiated; tail complete, last 1/ 5 regenerated.

Forelimbs smaller than hind limbs (FLL [3.66]/HLL [4.76] = 0.77), pentadactyl; dorsal forelimb scales slightly smaller than body scale, ventral forelimb scales much smaller than ventral scales, dorsal and ventral forelimb scales imbricate without apical pits; multiple rows of dorsal scales on digits. Relative digit length with lamellae (L/ R) in parentheses IV(11/11)> III(9/9)> II(7/7)> V(7/7)> I(5/5). Palmar scales irregular, raised, forming ventral protrusions from palmar surface; large set of four scales on distolateral edge of Digit V to the wrist, largest scale at wrist.

Hind limbs small (HLL [4.76]/SVL [41.61] = 0.11), pentadactyl; dorsal and ventral hind limb scales smaller than body scales; dorsal scales with apical pits, ventral scales without apical pits; multiple scale rows on dorsal side of digits. Lamellae slightly keeled. Relative digit length with lamellae (L/R) in parentheses: IV(15/15)> III(11/11)> V(8/8)> II(8/8)> I(5/5). Plantar scales irregular, slightly raised; three 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. Dorsal ground color brown throughout; a series of small dark brown dorsovertebral spots from the nuchals to the base of the tail. Dorsolateral line broad near head, from posterior midline of ear to nuchal region tapering irregularly on ventral margin to forelimb; bordered anteriorly by a tan line one scale wide that irregularly breaks the dorsolateral band with small half circles of dorsal color; dark brown dorsolateral line blends into flanks becoming lighter and blending in with small white flecks. Anterior to the forelimb and ventral to the dorsolateral line is some brown ticking that continues around the gular region. The ground color of the gular and ventral region is cream. The mental, postmental, infralabials scale margins have a concentration of brown flecks that blend in with the gular streaks. The ventrum from the gular region posteriorly and the ventral side of limbs are all cream without any markings. Distal portion of ventral tail has some brown ticking. Dorsal aspect of limbs dark brown with random tan spots that decrease in size and increase in frequency towards the solar surface of the feet. Coloration in life unrecorded.

Variation. Coloration is invariant across the type series. Variation in meristic and mensural characters in the type series and referred specimens is presented in Table 2.

Distribution ( Fig. 1 ). The new species is known from only two sites in Aurora Province: at 540 m above sea level at Barangay Lipimiental (in the Municipality of San Luis) and at 915 m above sea level on Mt. Dayap (Municipality Maria Aurora, Barangay Villa Aurora).

Natural History. This species is found at mid- to high elevation in Aurora Province, central Sierra Madre Mountain Range. The species was found in leaf litter and under logs in the forested regions.

Etymology. The specific epithet is derived from the Latin formation of the noun Aurora in nominative (subject) case, in reference to Aurora Province (where all known localities of the new species are found) and Maria Aurora Memorial National Park which protects much of the habitat of this distinctive species.

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 5. Dorsal and lateral views of representative specimen flanks, exhibiting diagnostic color pattern variation among species.