Oligosoma albornense, Melzer & Hitchmough & Bell & Chapple & Patterson, 2019

Melzer, Sabine, Hitchmough, Rod A., Bell, Trent, Chapple, David G. & Patterson, Geoff B., 2019, Lost and Found: Taxonomic revision of the speckled skink (Oligosoma infrapunctatum; Reptilia; Scincidae) species complex from New Zealand reveals a potential cryptic extinction, resurrection of two species, and description of three new species, Zootaxa 4623 (3), pp. 441-484 : 471-473

Oligosoma albornense sp. nov.

Figures 9a, b

Synonyms

Oligosoma infrapunctatum

GREAVES et al. 2008; CHAPPLE et al 2009

Oligosoma aff. infrapunctatum “Chesterfield”

HITCHMOUGH, R., BULL, L. & CROMARTY, P. 2007; HITCHMOUGH et al. 2010; HITCHMOUGH et al. 2013; Oligosoma aff. infrapunctatum “Alborn”

HITCHMOUGH et al. 2016a; HITCHMOUGH et al. 2016b; VAN WINKEL et al. 2018.

Holotype. Alborn Coal Mine (42º 31’S, 171º 52’E), NMNZ RE005339, female (coll. R. van Mierlo, P. van Klink, 14 Oct 1997);

Paratypes (3 specimens). Alborn Coal Mine (42º 31’S, 171º 52’E), 2 specimens: NMNZ RE005341, female; NMNZ RE005350, male (coll. R. van Mierlo, P. van Klink, 14 Oct 1997) ; Alborn Coal Mine (42º 31’S, 171º 52’E), NMNZ RE005366, female (coll. R. van Mierlo, P. van Klink, 06 Jan 1998)

.

Diagnosis. O. albornense can be distinguished from other species in the O. infrapunctatum species complex by a combination of characters ( Figure 4 a–j). Compared with O. newmani nuchal pairs are usually 3 or below versus 3 or above ( O. albornense ); usually 69 or more VS ( O. newmani ) versus 69 or fewer VS ( O. albornense ). HL/HW is always 1.7 or below in O. albornense whereas it is usually 1.7 or above in O. newmani . O. robinsoni differs from O. albornense in having a VS count usually 69 or greater versus 69 or below ( O. albornense ); upper ciliaries 6 or less ( O. albornense ) versus usually 6 or more; ventral speckling much more pronounced in O. robinsoni than O. albornense . In O. robinsoni SVL/HW is usually 11 or below, whereas in O. salmo it is 11 or above. There are statistical differences between O. salmo and O. albornense (upper ciliaries, HL/HW, S-Ear/EF, VS). O. salmo has 5 supraciliaries only, versus 6 or more in O. albornense . There are statistical differences between O. albornense and O. auroraensis sp. nov. (VS). It differs from O. auroraensis i n having subdigital lamellae usually 21 or above ( O. auroraensis sp. nov.) versus 21 or below. It appears to have a shorter tail (1.28 TL/SVL versus mean TL/SVL of 1.38 in O. auroraensis sp. nov.).

Description of Holotype. Habit lacertiform, body elongate, oval in cross-section; limbs well developed, pentadactyl. Lower eyelid with a transparent palpebral disc, bordered on sides and below by small, oblong granules. Snout moderately blunt. Nostril centred in lower middle of nasal, not touching bottom edge of nasal, pointing up and back. Supranasals absent. Rostral broader than deep. Frontonasal broader than long, not separated from frontal by prefrontals meeting in midline. Frontal longer than broad, shorter than frontoparietal and interparietal together, in contact with 2 anteriormost supraoculars. Supraoculars 4, 2 nd largest. Preoculars, 2, upper upper one larger. Frontoparietals distinct, larger than the interparietal. A pair of parietals meeting behind interparietal and bordered posteriorly by a pair of nuchals and temporals, also in contact with interparietal, frontoparietal, 4 th supraocular, and 2 postoculars. Loreals 2, similar size; anterior loreal in contact with 1 st and 2 nd supralabial, posterior loreal, prefrontal, frontonasal, and nasal; posterior loreal in contact with 2 nd and 3 rd supralabial, 1 st subocular, upper and lower preocular, prefrontal, and anterior loreal. Supralabials 7, 6 th largest. Infralabials 6, several equally largest. Fifth supralabial below centre of the eye. Temporals: 1 primary; 2 secondary. Ear opening round, moderately large (2.1% as percentage of SVL), with several small projecting granules on anterior margin. Suboculars 8, 4 th and 5 th separated by 5 th supralabial. Mental broader but shallower than rostral. Postmental larger than mental. Chinshields 3 pairs. Dorsal scales largest, smooth. Ventral scales and subdigital lamellae smooth. Adpressed limbs not meeting. Digits moderately long, subcylindrical. Third front digit shorter than the 4 th.

Measurements (holotype with the variation shown in the paratypes /specimens examined in parentheses). SVL 86.6 (mean 63.3, range 33.6–86.6), HL 12.0 (mean 9.5, range 6.4–12.0), HW 7.3 (mean 5.9, range 3.8–7.3), AG 47.3 (mean 33.7, range 17.9–47.3), SF 31.3 (mean 23.9, range 14.3–31.3), S-Ear 14.7 (mean 11.7, range 7.8– 14.7), EF 16.3 (mean 12.7, range 7.8–16.3), HLL 27.1 (mean 20.4, range 10.0–27.1), D-Ear 1.8 (mean 1.5, range 0.8–1.8).

Variation (holotype with the variation shown in the paratypes /specimens examined in parentheses). Upper ciliaries 6 (mean 6, range 5–6); lower ciliaries 8 (mean 9.5, range 8–11); nuchals 4 pairs (mean 4 pairs, range 3–4 pairs); midbody scale rows 30 (mean 32, range 30–33); ventral scale rows 68 (mean 67, range 65–69); subdigital lamellae 18 (mean 19.5, range 18–21); supraciliaries 6 (mean 6, range 6–7); suboculars 6 (mean 6, range 6–6). Frontonasal sometimes not separated from frontal by prefrontals meeting in midline. Anterior loreal usually in contact with first and second supralabial, posterior loreal usually in contact with second and third supralabial. Supralabials 7 (usual) or 8, the sixth or seventh the largest. Infralabials 6. Projecting scales present in ear opening. Maximum SVL 86.6 mm.

None of the specimens had an intact tail at the time of examination but an intact tail length of 113 mm of one specimen was listed in the records prior to tail removal. TL+/ SVL = 1.28. Ratios for morphological measurements (+ SD): AG/SF 1.39 + 0.11; S-Ear/EF 0.93 + 0.05; HL/HW 1.62 + 0.064 (N=4).

Colouration. Mid-dorsal stripe, intact or broken. Dorsal surface mid brown, with light and dark flecking, 6 scale rows wide, grading into pale dorsolateral stripe extending from behind head to base of tail, often becoming indistinct along body. This pale stripe is notched above and below, and is bordered below by a ½ scale row wide dark brown band, below that a 1–2 scale wide lighter brown row, notched on upper and lower edges, running from behind nostril through eye towards base of tail and continuing thereafter (unfortunately no specimens have intact tails so not able to say if it continues to tip). This band may have lighter speckling. Then a darker brown band 1 half-scales wide. This lower dark brown band is bordered below by a pale stripe, 1 to 2 half-scale rows wide running from below the eye, through the ear, above the limbs to become indistinct after the hindlimbs. This band is notched above and below. Soles of feet grey/brown. Belly colour unknown as colour has probably faded in preserved specimens. Usually speckling on belly. Throat pale, occasionally speckled. Outer surface of forelimbs brown speckled with light and dark. Colour of juveniles similar to adult.

Etymology. The scientific name is derived from the type locality, the Alborn Coal Mine of the South Island. The suggested vernacular name is “Alborn skink”.

Distribution. The species is recorded from the West Coast of the South Island, in one location only within the 48.07 Totara Flat Ecological District. This is a cool, mid-altitude, steep region that experiences high rainfall over the greywacke/argillite mountains, where much of the original forest remains. It was originally discovered among discarded mine machinery in an area where native vegetation was regenerating after mining stopped and has now been found in nearby wetland areas. It appears to be a species of forest gaps, wetland edges and high points (to c. 600 m ASL). It is currently known from artificial clearings in beech forest, pākihi, wetlands and regenerating shrubland ( van Winkel et al. 2018). May occur in forest, or small wetlands within a forest matrix. When pākihi habitats flood after heavy rains, the species uses high points and logs to escape the water ( van Winkel et al. 2018).

Natural History. Diurnal, heliothermic, terrestrial. A medium-sized skink, up to at least 87 mm SVL, 11.5 g in weight ( van Winkel et al. 2018). Natural history is very poorly known. No studies have been undertaken on this species, apart from the surveys by Whitaker & Meads (1993) and Avis & Lyall (1995). Recent searches in the known 2 hectare range only resulted in 1 animal being found (J. Reardon, pers. comm.).

Figures

FIGURE 4. a–j. Notched boxplots comparing the morphological characteristics of the species in the Oligosoma infrapunctatum species group (O. albornense, n=4; O. auroraensis, n=6; O. newmani, n=50; O. robinsoni, n=14; O. salmo, n=5). a) snout-ear (SE)/ear-axilla (EF), b) midbody scales, c) ventral scales, d) upper ciliaries, e) supraciliaries, f) supralabials, g) snout-vent length (SVL)/ hindlimb length (HLL), h) subdigital lamellae, i) axilla-groin (AG)/snout-forelimb (SF), j) head-length (HL)/ head-width (HW). If there is no overlap between two medians, then the medians are significantly different at a 95% confidence interval.

FIGURE 9. a) O. albornense holotype, Alborn Mine, West Coast of South Island (photo: Jean-Claude Stahl). b) Live specimen of albornense, Alborn Mine, West Coast of South Island (photo: James Reardon).