Eutropis rugifera ( Stoliczka, 1870 )

Thasun Amarasinghe, A. A., Poyarkov Jr, Nikolay A., Campbell, Patrick D., Leo, Sandy, Supriatna, Jatna & Hallermann, Jakob, 2017, Systematics of Eutropis rugifera (Stoliczka, 1870) (Squamata: Scincidae) including the redescription of the holotype, Zootaxa 4272 (1), pp. 103-118 : 107-113

Eutropis rugifera ( Stoliczka, 1870)

( Figs. 1–4 ; Tables 1 –3)

Tiliqua rugifera Stoliczka, 1870 (type locality: Camorta , Nicobar ) Euprepes percarinatus Peters, 1871 (type locality: Malang , East Java) Mabuia rubricollis Bartlett, 1895 (type locality: Kuching , Borneo ) Mabuia quinquecarinata Werner, 1896 (type locality: Sumatra) Holotype. Adult male (ZSI 2350), collected from Camorta, Nicobar Island (8.1299 N, 93.4902 E) by Ferdinand Stoliczka, in 1870 (exact date not given). The type specimen was registered in the Indian Museums on 24 July 1878.

Redescription of holotype. Male, SVL 52.9 mm. Head moderately large (HL 24.9% SVL, HL 50.2% of axilla–groin distance), narrow (HW 56.1% HL, HW 14.0% SVL), indistinct from neck; snout short (snout length 34.1% of head length, snout length 60.8% of head width), slightly convex in lateral profile; rostral shield large, hemispherical, distinctly visible from above, posterior margin of midpoint curved; frontonasal broadly in contact with rostral; frontonasal wide, lateral border touching first loreal; prefrontals separated from each other, largest distance along the longitudinal axis of frontonasal equal to prefrontals in length, lower border touching both loreal scales, the posterior border touching the first supraocular, and frontal; frontal large, elongate, subtriangular, bluntly pointed posteriorly, equal in length to the frontoparietals and interparietal combined; frontoparietals two, in contact, distinct, larger than interparietal; parietals damaged (examined materials have parietals strongly keeled, large, and broadly in contact and overlapping behind the interparietal, touching pretemporal scales laterally); nuchals damaged (examined materials have a single pair of nuchals, overlapping middorsally behind interparietal). Nostril large and situated in the middle of the nasal; single supranasal; two loreals, anterior loreal touching nasal, supranasal, frontonasal, prefrontal, posterior loreal, and 2nd supralabial; posterior loreal longer than the anterior loreal in the antero-posterior axis, touching prefrontal and first supracilliary; two presuboculars; eye large (orbit diameter 27.3% head length), orbit diameter equal in length to tympanum–eye length, pupil rounded; interorbital distance broad; three small postoculars; four wide supraoculars, the second is the longest in the antero-posterior axis and the widest in the sagital axis and fully contacts the frontal; first supraocular in contact with prefrontal and frontal, 2nd in contact with frontal and frontoparietal, 3rd in contact with frontoparietals, and 4th in contact with both frontoparietal and parietal; supracilliaries six; eyelid moveable with a scaly window composed of seven scales. Six supralabials, fifth largest and at the mid orbit position (5th touching eye); three pretemporals; two primary temporals, three secondary temporals; infralabials six; ear opening deep, small, near spherical and approximately one quarter of eye diameter. Mental large; a single large postmental followed by two chin shield pairs, the first pair meeting in midline, the first chinshield in contact with first and second infralabial scales, the second pair in contact with second and third infralabials.

Body scales have five keels with three median prominent and two secondary keels per scale; all scales imbricate and lack apical pits; scales on the dorsal surface of thigh keeled; body slender, elongate (axilla–groin distance 49.7% SVL); midbody scale rows 25+ (damaged); paravertebral scales 30+ (damaged); six enlarged preanal scales.

Forelimbs short; hind limbs relatively long (FEL 15.3% SVL, TBL 14.2% SVL); shank slightly shorter, 92.6% FEL; dorsal surfaces of fore and hind limbs keeled; subdigital lamellae on Toe IV 25; relative length of fingers: IV> III> II> V> I; relative length of toes: IV> III> V> II> I. Tail complete, distal part regenerated; median subcaudal scale row of original tail subequal, median subcaudal scale row of regenerated tail enlarged, wider than long.

Colouration in preservative. Colouration and markings almost faded; dorsal head, body and limbs uniform brown; Venter uniform cream coloured.

Colouration in life. ( Fig. 2 ) for live colouration of Eutropis rugifera based on UIMZ 0 0 51 in life in the Bali Barat National Park , Bali, Indonesia. Dorsal head, body and limbs chestnut brown; dorsal and ventral head with several black spots; a dark vertebral stripe on the back separated by a median pale stripe, commencing from posterior occipital area; two additional dark stripes situated laterally, commencing from snout; the vertebral stripe descends down to posterior end of body then fades away; the lateral stripes extend to the hind limbs. Lateral body creamy brown, and belly creamy white while ventral head sky blue.

Habitat and Natural History. A fast-moving, litter dwelling skink, usually observed in dry mixed habitats with a thin layer of leaf litter on the forest floor, with semi-open canopy (canopy cover 50%; Fig. 3 ), and mostly observed in the morning (06:00–08:00 hr) and evening (16:00–18:00 hr). Almost all the colour variations (with multi-stripes, two stripes, without stripes etc.) found sympatrically, usually found in the same pitfall trap network (25 m 2 area). Larger specimens tried to bite during handling and moved rapidly to escape. While handling their body scales loosened (and some scales fell off the body), this may be an escape strategy used by this species to escape from the predator. Insects should be the main food; because ants, dipterans, and orthopterans were the usual gut contents.

Figures

FIGURE 1. The ML tree resulting from analysis of the studied samples of Eutropis. For the major cladogenetic events ML BS / BI PP values are given.

FIGURE 2. Photographs in life of adult Eutropis rugifera (UIMZ 0 0 51, SVL 56.7 mm) from the Bali Barat National Park, Bali, Indonesia showing (A) dorsal, (B) ventral, and (C) lateral views of the head (Photo: RCCC-UI).

FIGURE 3. Photograph of the habitat of Eutropis rugifera in the Bali Barat National Park, Bali, Indonesia (Photo: A. A. Thasun Amarasinghe).

FIGURE 4. Current distribution of typical Eutropis rugifera (grey shading); type locality of E. rugifera (red), and synonyms of E. rugifera (blue): 1. Euprepes percarinatus, 2. Mabuia rubricollis, 3. Mabuia quinquecarinata; other sampling localities of this study show in green: Bawean and Bali Islands.