Ornithuroscincus shearmani, Slavenko & Tamar & Tallowin & Kraus & Allison & Carranza & Meiri, 2022
|
publication ID |
https://doi.org/ 10.1093/zoolinnean/zlab052 |
|
DOI |
https://doi.org/10.5281/zenodo.6536344 |
|
persistent identifier |
https://treatment.plazi.org/id/03EF4E77-7C39-CA4A-FF6D-FD57229CFE15 |
|
treatment provided by |
Plazi |
|
scientific name |
Ornithuroscincus shearmani |
| status |
sp. nov. |
ORNITHUROSCINCUS SHEARMANI View in CoL View at ENA SP. NOV.
SHEARMAN’ S SMOOTH- EARED SKINK
( FIGS 16 View Figure 16 , 22 View Figure 22 ; 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: E9C004B6-8694-4984-9FA1-A438E335141D
Holotype: BPBM 47915 (field tag AA 19603), adult female, collected by P. Shearman at 9.7192°S, 148.9846°E (WGS 84), 3456 m a.s.l., Mt Suckling , Milne Bay Province, Papua New Guinea, 5 September 2009. GoogleMaps
Diagnosis: A large species of Ornithuroscincus (adult SVL 69.2 mm), characterized by the unique combination of short limbs (forelimbs 28.4% of SVL, hindlimbs 35.6% of SVL); frontoparietals fused; nuchals single pair; paravertebral scales 83; mid-body scale rows 37; 4 th digit on front foot longer than 3 rd; subdigital lamellae 18 under 4 th toe; single supradigital scales four on 4 th toe; dorsal coloration jet black; medial dorsal golden striations extending posteriorly from occiput to tail, bordered laterally by fragmented golden stripes made up of narrow spots one to two scales long; dorsolateral stripes present as narrow uniform golden stripes, a half scale wide, extending from postorbital region to tail, bordered on both sides by parallel narrow golden striations; flanks jet black, marked with multiple spots one scale wide, pale blue in preservative, pale yellow in life; ventral surfaces pale blue in preservative, with dark brown blotches on chin and dark brown striations on chest, abdomen, thighs, precloacal region and tail, becoming more pronounced posteriorly; palmar and plantar surfaces dark brown.
Comparisons: Ornithuroscincus shearmani is easily distinguished from all other species of Ornithuroscincus by its large size (adult SVL 69.2 vs. 29.4–62.3 mm), high paravertebral scale count (83 vs. 47–70) and unique colour pattern consisting of jet black dorsal coloration with golden mid-dorsal striations. It further differs from O. albodorsalis , O. nototaenia , O. sabini , O. inornatus , O. pterophilus and O. cf. venemai in having fused (vs. unfused) frontoparietals.
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 anterodorsally onto dorsum of snout; nostril circular, centred within nasal; frontonasal large, with seven sides, extending laterally to slightly above the level of nares, not contacting frontal; prefrontals large, in shallow medial 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, suture with frontoparietal shallowly convex; frontoparietal single, partially cleft by a suture on the posterior edge, in contact with frontal; interparietal smaller than fused frontoparietal, diamond shaped, widest anteriorly; parietal eye spot absent; parietals in contact behind interparietal, in contact anteriorly with frontoparietal, posteriormost supraocular and pretemporals; single pair of transversely enlarged nuchals, wider than long, separated from secondary temporal by a single smaller intercalated scale on the left side and two fragmented scales, possibly due to damage, on the right side. Anterior loreal similar in size to posterior loreal, higher than long; posterior loreal roughly as high as long; lower preocular wedge shaped; upper preocular much smaller, longer than high; presubocular single, slightly smaller than lower preocular; postsuboculars two, lower interdigitated between subocular supralabial and penultimate supralabial; lower eyelid scaly, moveable, with an opaque palpebral disc of roughly similar size as ear opening; supraciliaries eight, anteriormost not contacting frontal, posteriormost projecting medially and interdigitated between posteriormost supraocular and upper pretemporal; primary temporal single, interdigitated between penultimate and posteriormost supralabials; secondary temporals two, upper larger and overlapping lower; supralabials seven, fifth in contact with small scales of lower eyelid; postsupralabials two; ear opening moderate sized and oval, without lobules. Mental single; postmental single, contacting two anteriormost infralabials; infralabials six; enlarged chin shields four on left side and three on right side, the first right in medial contact with first and second left, second right narrowly separated by single medial scale from second and third left, third right separated by three medial scales from third and fourth left; posteriormost chin shield in contact with antepenultimate infralabial. Body scales smooth, in 37 rows at midbody; paravertebral scales 83; 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, four single scales; subdigital lamellae under 4th toe 18, smooth. In preservative ( Fig. 22 View Figure 22 ), dorsal colour jet black, extending to tail, with medial dorsal golden striations extending posteriorly from occiput to tail, bordered laterally by fragmented golden stripes made up of thin spots one to two scale long; golden striations become less pronounced posteriorly on tail; dorsolateral stripes present as narrow (0.5 scale wide) unfragmented golden stripes extending from postorbital region to tail, bordered on both sides by parallel narrow golden striations, becoming less pronounced posteriorly on tail; flanks jet black, marked irregularly with multiple pale blue spots one scale wide; head scales dark brown to jet black, lighter brown on snout; anterior margins of head scales light brown to golden; labials dark brown at margins and pale blue or light brown in centre; ventral surfaces pale blue with dark brown blotches on chin and dark brown striations on chest, abdomen, thighs, precloacal region and tail, becoming more pronounced posteriorly; golden spots cover dorsal surfaces of limbs; palmar and plantar surfaces dark brown.
Colour in life: Dorsal surfaces dark brown to jet black, with medial golden striations extending posteriorly from occiput to tail, bordered laterally by fragmented pale yellow stripes made up of thin spots one to two scales long ( Fig. 16 View Figure 16 ). Dorsolateral stripes pale yellow. Sides dark brown to jet black, marked irregularly with multiple pale yellow to white spots a single scale wide. Pale yellow spots cover dorsal surfaces of limbs.
Etymology: The species is named in honour of Dr Phil Shearman, who collected the sole specimen.
Distribution: Known from a single population near the summit of Mt Suckling in the southern Owen Stanley Mts, at 3456 m a.s.l., of which a single specimen was collected.
Natural history: Our single collection, and all additional sightings of O. shearmani , were from a small area on the south-eastern side of a large (c. 450 ha) grassy plateau above the tree line enclosed by ridges of Goë Denedeniwa, a peak within the main summit complex of Mt Suckling. The grasslands were dominated by two tussock-forming species, Chimaerochloa archboldii (Hitchc.) Pirie & H.P.Linder and Deschampsia klossii Ridl. , and included pockets of a shrub, Eurya albiflora C.T.White & W.D.Francis (Pentaphylacaceae) and scattered populations of the tree fern Alsophila gleichenioides (C.Chr.) R.M.Tryon. The area was drained by a small stream, with numerous adjacent bogs.
The lizards appeared to be confined to a small, dry, rocky area dominated by the woody ground creeper Vaccinium prostratum Sleumer and several small shrubs including Acrothamnus suaveolens , Hypericum papuanum Ridl. and Coprosma papuensis W.R.B.Oliv.
They were active for only a few hours each day, beginning at around 08:00–09:00 h, when the first sun reached the area. The temperature during the night generally dropped below -5°C and ground frosts were common. The ambient temperature when the lizards were initially active was only around 5–7°C, but the ground quickly warmed under direct sun. The lizards occurred mostly on scattered rocky outcrops and boulders and were occasionally seen on the ground. Although there appeared to be a wide expanse of suitable habitat along the margins of the plateau, the lizards were confined to this one area.
We did not find any other species of amphibians and reptiles on the plateau or on the summit of Goë Denedeniwa. However, the monotreme Zaglossus bartoni (Thomas, 1907) was common in bogs along the stream and wallabies were common in the grasslands. We occasionally saw tree kangaroos ( Dendrolagus dorianus Ramsay, 1883 ), bandicoots and we found a skull of a quoll, Dasyurus albopunctatus Schlegel, 1880 .
The lizards were extremely wary and difficult to approach. This was a little surprising because the area is rarely visited by people. Although quolls are voracious predators, they tend to be nocturnal so are unlikely to prey upon the lizards. The bandicoot we observed was diurnal and is a possible but unlikely predator.
Conservation status: We estimate a population of ~50 individuals at the type locality. Another plateaeu with a similar habitat is located ~ 50–100 m lower in elevation than the topotypic site, but we were unable to survey it to determine if O. shearmani occurs there as well. Thus, true population size and trend is unknown. It does not occur near any protected areas. However, the entire area around the collecting locality is wilderness for many kilometres, and human disturbance in this vast area is virtually unknown. The extremely dark pigmentation of O. shearmani is only found in four other species with alpine distributions: A. alpinus , A. subalpinus , N. glacialis and N. stellaris . This would suggest O. shearmani is an alpine specialist, endemic to the summit of Mt Suckling, and is unlikely to occur in lower elevations nearby. Therefore, global warming is likely to cause range contraction. However, this is also a remote location with few anthropogenic disturbances posing additional immediate threats. Further surveys on Mt Suckling are needed to fully assess its lower distributional boundaries, but since it likely only occurs in a single location, and climate change poses a viable future threat to its persistence, with little suitable habitat to escape to, we recommend assigning a status of Vulnerable D2 to O. shearmani .
No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.