Ornithuroscincus inornatus, Slavenko & Tamar & Tallowin & Kraus & Allison & Carranza & Meiri, 2022

ORNITHUROSCINCUS INORNATUS View in CoL View at ENA SP. NOV.

PLAIN SMOOTH- EARED SKINK

( FIGS 18–19 View Figure 18 View Figure 19 ; TABLE 1 View Table 1 )

Z o o b a n k r e g i s t r a t i o n: u r n:l s i d: z o o b a n k. org:act: 89DE7131-76CC-43C0-95CA-C41541C3563E

Holotype: BPBM 41226 (field tag AA 21402), collected by A. Allison at Kesemani, 7.9372°S, 147.0544°E (WGS 84), 1733 m a.s.l., N slope of Mt Strong , Morobe Province, Papua New Guinea, 23 February 2012 GoogleMaps .

Diagnosis: A moderate-sized species of Ornithuroscincus (adult SVL 47.9 mm), characterized by the unique combination of short limbs (forelimbs 32.7% of SVL, hindlimbs 41.2% of SVL); frontoparietals separate; nuchals two pairs; paravertebral scales 51; mid-body scale rows 35; 4 th digit on front foot no longer than 3 rd; subdigital lamellae 21 under 4 th toe; single supradigital scales three on 4 th toe; dorsal coloration uniform light brown; dorsolateral stripes present as thick, one to two scales wide, unfragmented stripes extending from orbital region to tail, becoming gradually thicker posteriorly, pale brown in preservative, pale green-yellow in life; dark brown lateral field present, lightly speckled with spots, pale blue in preservative, light brown in life; lateral field breaking up to brown spots ventrally; ventral surfaces uniform pale blue in preservative, with dark brown spotting on the thighs, precloacal region and tail; in life, ventral surfaces are green-yellow, becoming lemon yellow on the thighs and base of tail; palmar and plantar surfaces light brown in preservative, dark yellow in life.

Comparisons: Ornithuroscincus inornatus differs from O. bengaun in having unfused (vs. fused) frontoparietals. It differs from O. albodorsalis , O. noctua , O. nototaenia and O. cf. venemai by having a uniform light brown dorsum with thick pale brown dorsolateral stripes (vs. uniform pale yellow dorsum, light brown dorsum with dark brown longitudinal stripes, pale yellow dorsum with single dark vertebral stripe or dark olive grey dorsum powdered with brown with thick white dorsolateral stripes, respectively), by lacking a parietal eye spot (vs. present) and by having a higher count of midbody scale rows (35 vs. 22–26, 23–28, 24–25 and 24–26, respectively; Brongersma, 1953a; Zweifel, 1979; Shea & Greer, 2002). It further differs from O. noctua by lacking a light yellow to white patch on the occiput. It differs from O. sabini in having uniform dorsal coloration (vs. spotted).

Description of the holotype: Rostral broad and shallow, wider than deep, projecting slightly onto top of snout; nasals more or less rectangular, separated by rostral and frontonasal contact, projecting anteriorly towards snout; nostril circular, centred within nasal; frontonasal large, with seven sides, extending laterally to slightly above the level of nares, in narrow contact with frontal; prefrontals large, separated medially by frontonasal and frontal contact, bordered ventrolaterally by two loreals; supraoculars four, anterior two in contact with frontal, posterior three in contact with frontoparietals; frontal kite shaped, widest anteriorly; frontoparietals single pair in medial contact, anteriorly in contact with frontal; interparietal smaller than single frontoparietal, diamond shaped, widest anteriorly; parietal eye spot absent; parietals in contact behind interparietal, in contact anteriorly with frontoparietals, posteriormost supraocular and pretemporals; nuchals two pairs, transversely enlarged, followed by a third enlarged nuchal on the left side, wider than long, anteriormost pair separated from secondary temporal by a single smaller intercalated scale. Anterior loreal higher than posterior loreal, higher than long; posterior loreal roughly as high as long; lower preocular rectangular shaped; upper preocular much smaller, longer than high; presubocular single; postsuboculars two, lower interdigitated between subocular supralabial and penultimate supralabial; lower eyelid scaly, moveable, with a clear palpebral disc smaller than size of ear opening; supraciliaries eight, anteriormost in narrow contact with frontal, posteriormost projecting medially and interdigitated between posteriormost supraocular and upper pretemporal; primary temporal single, interdigitated between penultimate and posteriormost supralabial; secondary temporals two, upper larger and overlapping lower; supralabials seven, fifth in contact with small scales of lower eyelid; postsupralabials two; ear opening large and oval shaped, without lobules. Mental single; postmental single, contacting two anteriormost infralabials; infralabials six; enlarged chin shields three pairs, the first pair in medial contact, second pair narrowly separated by a single medial scale, third pair separated by three medial scales; posteriormost chin shield in contact with penultimate infralabial. Body scales smooth, in 35 rows at midbody; paravertebral scales 51; medial precloacal scales enlarged, overlapping lateral precloacals. Scales on dorsal surface of 4th toe in two rows proximally, single row distally beginning at third interphalangeal joint, three single scales; subdigital lamellae under 4th toe 21, smooth. In preservative ( Fig. 18 View Figure 18 ), dorsum uniform light coppery brown, extending to tail; dorsolateral stripes present as broad (1–2 scales wide) unfragmented pale brown stripes extending from orbital region to tail, gradually becoming thicker posteriorly, bordered medially by extremely light speckling of small dark brown spots; dorsolateral stripes bordered laterally by dark brown field, extending from preorbital region through eye to base of tail, above level of limbs; dark brown lateral field lightly speckled by pale blue spots, becomes gradually lighter ventrally before breaking up into irregularly placed small dark brown spots on pale blue background; head scales light brown with small, infrequent dark brown spots on margins, paler on snout; ventral surfaces uniformly pale blue with dark brown spotting on thighs, precloacal region and tail; palmar and plantar surfaces light brown.

Colour in life: Dorsal surfaces light brown and lateral field dark brown, as in preservative ( Fig. 19 View Figure 19 ). Dorsolateral stripes green-yellow. Ventral surfaces green-yellow, becoming lemon yellow on thighs and base of tail. Palmar and plantar surfaces dark yellow.

Etymology: Combined masculine adjectival form of the Latin in, not, and ornatus , decorated, referring to its bland and simple colour pattern compared to other members of the genus.

Distribution: Known from a single specimen collected at 1733 m a.s.l. on the northern slopes of Mt Strong, where it occurs in sympatry with at least two lineages of Papuascincus (V and VI) and Lo. fortis .

Natural history: The single specimen that we collected was from around the village of Kesemani. The village, which is perched on a steep slope high above a river, included around ten bush material houses surrounded by anthropogenic grassland (see account for Lo. fortis ). The lizard was active in the morning on a steep, c. 2 m high moss and lichen encrusted earthen bank along a walking track at the edge of the village.

Conservation status: Only known from a single specimen. However, Mt Strong was well sampled, the village of Kesemani specifically was visited several times and no other O. inornatus were observed. Therefore, it appears to be rare compared to sympatric lizard taxa such as Lo. fortis or Papuascincus spp. This may suggest a small population size and restricted distribution, but more data are required for a proper assessment. It does not occur near any protected areas. We recommend assigning a status of Data Deficient to O. inornatus .