Oligosoma inconspicuum (Patterson & Daugherty, 1990)

Chapple, David G., Bell, Trent P., Chapple, Stephanie N. J., Miller, Kimberly A., Daugherty, Charles H. & Patterson, Geoff B., 2011, Phylogeography and taxonomic revision of the New Zealand cryptic skink (Oligosoma inconspicuum; Reptilia: Scincidae) species complex, Zootaxa 2782, pp. 1-33 : 9-16

publication ID	https://doi.org/ 10.5281/zenodo.205462
DOI	https://doi.org/10.5281/zenodo.6182740
persistent identifier	https://treatment.plazi.org/id/03AC4C11-8D2A-A43A-FF4C-FEB7FAC14AC2
treatment provided by	Plazi
scientific name	Oligosoma inconspicuum (Patterson & Daugherty, 1990)
status

Treatment

Figure 3 View FIGURE 3

Oligosoma inconspicuum Chapple et al. 2009: 485

Oligosoma inconspicuum Jewell 2008: 88

Oligosoma sp. ‘mahogany skink’ Bell & Patterson 2008: 65 Oligosoma sp. ‘mahogany skink’ Bell et al. 2008: 12 Oligosoma sp. 7 (Big Bay skink) Jewell 2008: 90

Oligosoma sp. 8 (mahogany skink) Jewell 2008: 91 Oligosoma inconspicuum Gill & Whitaker 2001: 72 Leiolopisma inconspicuum Patterson & Daugherty 1990: 66

Holotype. Tree Island, Lake Wakatipu (44º 55’S, 168º 25’E), RE002079, adult male (coll. C. Daugherty & R. Marquand, November 1988).

Paratypes (5 specimens). Tree Island, Lake Wakatipu (44º 55’S, 168º 25’E), 4 specimens (RE006135 [CD1905], female; RE006402 [CD1906], male; RE006136 [CD1907], male; RE006137 [CD1908], female) (coll. I. Southey, March 1986); Tree Island, Lake Wakatipu (44º 55’S, 168º 25’E), RE006169 [FT2063], female (coll. unknown, December 1988)

Other specimens examined (29 specimens). Gorge Burn, Eyre Mountains (44º 18’S, 168º 15’E), 5 specimens (RE006127 [CD1101], male; RE006128 [CD1102], female; RE006129 [CD1103], female; RE006013 [CD1104], male; RE006131 [CD1124], sex unknown) (coll. G. Patterson, March 1985); Eyre Mountains (grid reference unknown), RE002122, female (coll. I. Southey, April 1986); Macraes Flat (45º 23’S, 170º 26’E), 2 specimens (RE006141 [CD421], male; RE006142 [CD423], subadult) (coll. C. Daugherty, December 1983); McKenzie Creek, Big Bay, South Westland (44º 22’S, 168º 02’E), 4 specimens (RE005382 [FT3788], female; RE005383 [FT3789], female; RE005386 [FT3792], female; RE005387 [FT3793], female) (coll. R. van Mierlo & P. van Klink, January 1998); Barn Bay, Westland (44º 04’S, 168º 18’E), RE005507 [FT3813], male (coll. R. van Mierlo & P. van Klink, January 1998); Awarua Point, Big Bay, Westland (44º 16’S, 168º 03’E), 4 specimens (RE005434 [FT3031], female; RE005435 [FT3032], male; RE005436 [FT3033], male; RE005437 [FT3034], male) (coll. I. Southey, September 1992); Awarua Point, Big Bay, Westland (44º 16’S, 168º 03’E), 6 specimens (RE005377 [FT3783], subadult; RE005378 [FT3784], male; RE005371 [FT3785], subadult; RE005380 [FT3786], male; RE005381 [FT3787], female; RE005385 [FT3791], juvenile) (coll. M. Tocher, January 1998); Te Anau township (45º 26’S, 167º 43’E), RE002393, female (coll. G Patterson, February 1985); Tower Peak, Cameron Mountains (46º 01’S, 167º 02’E), RE005497 [FT2924], subadult (coll. G. Gibbs, January 1991); Dipton, Southland (45º 87’S, 168º 23’E), RE001889, female (coll. M. Smith, November 1977); Catlins, Department of Conservation Red Tussock Reserve (45º 36’S, 167º 14’E), RE006529 [FT3633], male (coll. M. Tocher, January 1997); Sinbad Gully, Llawrenny Peaks, Fiordland (44º 38’S, 167º 48’E), RE006880, male (coll. T. Bell February 2008); Mt Nicholas Road, Eyre Mountains (45º 15’S, 168º 18’E), 4 specimens (RE007284, female; RE007288, female; RE007293, female; RE007298, female) (coll. J. Reardon, January 2010).

Diagnosis. Oligosoma inconspicuum can be distinguished from other related Oligosoma species through a combination of characters ( Figure 4 View FIGURE 4 a – b ; Wessa 2011). Compared to O. maccanni , O. inconspicuum has a glossy appearance, with brown predominating whereas O. maccanni has a greyer ground colour. Oligosoma maccanni has a pale grey ventral colour rather than the yellow or bronze ventral colour seen in O. inconspicuum . The ear opening in O. maccanni often has large projecting scales on the interior margin, whereas these are often minimal or lacking altogether in O. inconspicuum . Longitudinal striping is more pronounced in sympatric populations of O. polychroma , which almost always have a pale stripe on the outside of the forelimbs. The ear opening in O. polychroma often has prominent projecting scales on the interior margin. There are statistical differences between O. inconspicuum and O. burganae sp. nov. (AG/SF, HL/HW, SE/EF, SVL/HL, SVL/FLL), O. notosaurus (SVL/HL, ventral scales), and O. toka sp. nov (SVL/FLL, SVL/HLL ventral scales) (see Figure 4 View FIGURE 4 a – b ). Unlike O. repens sp. nov. and O. toka sp. nov. which have three supraoculars all O. inconspicuum have four supraoculars. Most O. burganae sp. nov. have only three supraoculars. Oligosoma repens sp. nov. has a more elongate appearance than O. inconspicuum (e.g. TL/SVL of 1.28 and 1.16, respectively). The number of subdigital lamellae (17–23) is greater in O. inconspicuum compared to O. tekakahu sp. nov. (16).

Description of Holotype: Body elongate, oval in cross-section; limbs moderately well-developed, pentadactyl. Lower eyelid with a transparent palpebral disc, bordered on sides and below by small, oblong granules. Nostril centred just below middle of nasal, pointing up and back, not touching bottom edge of nasal. Supranasals absent. Rostral broader than deep. Frontonasal broader than long, separated from frontal by scale between prefrontals. Frontal longer than broad, shorter than frontoparietal and interparietal together, in contact with 2 anteriormost supraoculars. Supraoculars 4, the second is the largest. Frontoparietals distinct, larger than interparietal. A pair of parietals meeting behind interparietal and bordered posteriorly by a pair each of nuchals and temporals, also in contact with interparietal, frontoparietal, third/fourth supraocular and 2 postoculars. Loreals 2, anterior one the larger; anterior loreal in contact with first supralabial, posterior loreal, prefrontal, frontonasal and nasal; posterior loreal in contact with second supralabial, first subocular, upper and lower preocular, prefrontal and anterior loreal. Supralabials 7, the sixth is the largest. Infralabials 7, several of them equal in size; fifth supralabial below centre of eye. Mental broader but shallower than rostral. Suboculars 3 and 4 separated by fifth supralabial. Postmental larger than mental. Chinshields 3 pairs. One primary temporal. Dorsal scales largest, weakly striate. Ventral scales smooth. Subdigital lamellae smooth. Ear opening round, moderately large, with one projecting granule on anterior margin. Forelimbs shorter than hindlimbs. Adpressed limbs not meeting in adult. Digits moderately long, cylindrical. Third front digit shorter than the fourth.

Measurements (in mm; holotype with the variation shown in the paratypes /specimens examined in parentheses). SVL 61.5 (mean 54.7, range 24.0–74.4), HL 8.5 (mean 7.8, range 5.2–9.7), HW 6.2 (mean 5.4, range 3.2–6.7), AG 32.1 (mean 28.9, range 10.5–44.9), SF 22.2 (mean 20.1, range 11.0–25.4), SE 10.7 (mean 9.4, 5.7–11.8), EF 11.2 (mean 10.6, range 5.1–14.5), HLL 21.5 (mean 19.1, 11.5–23.7), FLL 15.5 (mean 13.5, 8–16.0) and TL unknown (not intact) (mean 64.4, range 41.0–82.0; N = 14).

Variation (holotype with the variation shown in the paratypes /specimens examined in parentheses). Upper ciliaries 7 (mean 7, range 6-9); lower ciliaries 10 (mean 10, range 9–13); nuchals 2 pair (mean 3 pairs, range 1–4 pairs); midbody scale rows 28 (mean 29, range 27–32); ventral scale rows 74 (mean 74, range 67–86); subdigital lamellae 22 (mean 20, range 17–23); supraciliaries 5[right]/6[left] (mean 5, range 5–6); suboculars 6 (mean 7, range 4–8). Frontonasal not usually separated from frontal by prefrontals meeting in midline. Anterior loreal always in contact with first and second supralabial, posterior loreal usually in contact with second supralabial only. Supralabials 7 (usual) or 8, the sixth or seventh the largest. Infralabials 5, 6 (usual), or 7. Third front digit as long as or shorter than the fourth. Maximum SVL 74.4 mm. Fourteen specimens had intact tails (TL/SVL = 1.16). Ratios for morphological measurements (± SD): AG/SF: 1.42 ± 0.18; SE/EF: 0.91 ± 0.10; HL/HW: 1.45 ± 0.10.

Colouration: Although colouration in the species is extremely variable, brown is the predominant colour. Dorsal surface light brown or tan to dark brown, with irregular flecks. Mid-dorsal stripe where present not usually continuous, and margins not straight. Often a pale dorsolateral stripe extending from near tip of snout to base of tail, becoming indistinct thereafter. Brown lateral stripe two or more scale rows wide, notched on upper and lower edges, running from tip of snout through eye towards tip of tail. May contain flecks of dark and light brown. Soles of feet brown/black. Belly yellow, bronze (in Big Bay animals, Tocher 1999), or deep yellow (in the ‘mahogany’ form), often unmarked. Outer surface of forelimbs brown, speckled with light and dark. Chin and neck may be pale, usually speckled with black, or uniformly black. There do not appear to be sexually dimorphic colour patterns. Juvenile colouration similar to adult.

Etymology. From inconspicuum (Latin, neuter)—not readily visible, referring both to the difficulty in distinguishing this taxon from other similar sympatric species, and the cryptic behaviour of this species in its natural environment. The common name is the cryptic skink.

Habitat and life history. This species is found throughout the lower South Island, as far north as central Otago ( Figure 5 View FIGURE 5 a,b). This species has been recorded throughout the lower South Island and central Otago in the following Ecological Regions and Districts ( McEwen 1987; regions are in capitals, districts in lower case): ASPIRING 51.07 Dart; WAITAKI 64.02 St Mary, 64.04 St Bathans; LAKES 66.03 Richardson, 66.05 Remarkables; CENTRAL OTAGO 67.01 Lindis, 67.03 Dunstan, 67.04 Maniototo, 67.05 Old Man; LAMMERLAW 68.01 Macraes, CAT- LINS 70.01 Waipahi; OLIVINE 71.01 Cascade, 71.02 Pyke; FIORD 72.01 Darran; MAVORA 73.02 Eyre, 73.03 Upukerora; WAIKAIA 74.01 Nokomai; GORE 75.01 Gore; SOUTHLAND HILLS 76.01 Takitimu, 76.02 Taringatura, 76.03 Hokonui; TE WAE WAE 77.03 Longwood; MAKAREWA 78.01 Southland Plains, 78.02 Waituna. Similarly, environmental classifications range from (to Level II only): K3; L1, L3, L4; M1; N3, N4, N5, N6; O1; P5; Q1, Q2, Q3, Q4; R1, R2; and S2 ( Leathwick et al. 2003). Consequently this species tolerates an extremely wide range of environmental conditions from coastal to montane environments in both cold or cool, wet climates and cool but dry climates with low to moderate radiation ( McEwen 1987, Leathwick et al. 2003).

It has a distinct microhabitat preference for herbs and shrubs over tussocks and rocks, and tends to tolerate quite damp environments such as Sinbad Gully in Fiordland and Big Bay on the West Coast. Adults usually give birth in February-March, with number of offspring ranging from one to three. Diet consists of fruit and insects (Patterson and Daugherty 1990; Tocher 1999).

Conservation status. Oligosoma inconspicuum is currently considered Not Threatened (Partial Decline) in the New Zealand Department of Conservation’s national threat classification lists ( Hitchmough et al. 2010).