Oligosoma ornatum (Gray, 1843)

Patterson, Geoff B., Hitchmough, Rod A. & Chapple, David G., 2013, Taxonomic revision of the ornate skink (Oligosoma ornatum; Reptilia: Scincidae) species complex from northern New Zealand, Zootaxa 3736 (1) : -

Oligosoma ornatum (Gray, 1843)

Figure 2

Sphenomorphus pseudornatum: McCann 1955 (part): 79. (?) Cyclodina ornata: Hardy 1977: 261 -64.

Cyclodina pseudornata: Robb 1986: 92 , 108, 110, 112. Cyclodina sp. 4: Jewell 2008: 114.

Oligosoma ornatum: Chapple et al. 2009: 472 , 485.

Neotype: Manakau, 12 km south of Levin (40º 42’S, 175º 29’E), NMNZ RE002457 (S912) (adult male) (coll. A.H. Whitaker, September 1971). ( Figure 2 ).

Specimens examined (48 specimens). Castaway Valley, Great Island, Three Kings Islands (34º 9’S, 172º 9’E), NMNZ RE004440 (S798) (adult female) (coll. F.M. Climo, November 1971); South West Island, Three Kings Islands (34º 10’S, 172º 5’E), NMNZ RE004881 (S1244) (male) (coll. J.A. Bartle, January 1976); Track to summit, Great Island, Three Kings Islands (34º 9’S, 172º 9’E), NMNZ RE004439 (S797) (female) (coll. F.M. Climo, November 1970); Castaway Valley, Great Island, Three Kings Islands (34º 9’S, 172º 9’E), NMNZ RE004441 (S799) (male) (coll. F.M. Climo, November 1970); Tasman Valley, Great Island, Three Kings Islands (34º 9’S, 172º 9’E), NMNZ RE004946 (S1309) (male) (coll. G. Kuschel, November 1970); North East Island, Three Kings Islands (34º 8’S, 172º 10’E), NMNZ RE001598#1 (female), NMNZ RE001598#2 (male), NMNZ RE001598#3 (male), NMNZ RE001598#4 (female), NMNZ RE001598#5 (female), (coll. R. Dell and F.M. Climo, February 1974); Mt Camel, Houhora, Northland (34º 49’S, 173º 9’E), NMNZ RE004579 (S939) (male), NMNZ RE004581 (S941) (male) (coll. A.H.Whitaker, May 1972); Matapia Island, Northland (34º 36’S, 172º 47’E), NMNZ RE006121 (FT3113) (male) (coll. P. Anderson, May 1993); West Bay, Hen Island, Hen and Chickens Group (35º 53’S, 174º 42’E), NMNZ RE003863 (S221) (female), (coll. A.H. Whitaker, January 1968); Marotiri (Lady Alice) Islands, Hen and Chickens Group. (35º 53’S, 174º 42’E), NMNZ RE004492 (S851) (male), (coll. A.H. Whitaker, March 1971); Hen Island, Hen and Chickens Group (35º 53’S, 174º 42’E), NMNZ RE006124 (FT583) (male) (coll. I. McFadden, February1989); Lady Alice Island, Hen and Chickens Group (35º 53’S, 174º 42’E), NMNZ RE006125 (FT594) (female) (coll. A. Cree, February 1989); Hen Island, Hen and Chickens Group (35º 53’S, 174º 42’E), NMNZ RE000321 (male) (coll. H. Hamilton, December 1924); Old Woman Cove, Hen Island, Hen and Chickens Group (35º 53’S, 174º 42’E), NMNZ RE003864 (S222) (male) (coll. A.H. Whitaker, January 1968); Summit Track, Little Barrier Island. (36º 13’S, 175º 03’E), NMNZ RE004834 (S1196) (male) (coll. J. Watt, March 1974); Mangere, Auckland (36º 58’S, 174º 47’E), NMNZ RE001631 (male), NMNZ RE001625#21 (female), NMNZ RE001625#22 (female), NMNZ RE001625#23 (female), NMNZ RE001625#24 (male), NMNZ RE001625#25 (female), NMNZ RE001625#26 (female), NMNZ RE001625#27 (male) (coll. G.S. Hardy, January 1970); Devonport, Auckland. (36º 49’S, 174º 47’E), NMNZ RE006122 (FT188) (female) (coll. R. A. Hitchmough, November 1987); Great Barrier Island (36º 05’S, 175º 21’E), NMNZ RE001629#45 (female), NMNZ RE001629#46 (male) (coll. G.S. Hardy, December 1974); Tryphena, Great Barrier Island (36º 18’S, 175º 29’E), NMNZ RE002041 (male) (coll. D. Towns January 1985); 2 km N. of Leigh, Northland. (36º 18’S, 174º 18’E), NMNZ RE003865 (S223) (female) (coll. A.H. Whitaker, January 1968); Devonport, Auckland (36º 49’S, 174º 46’E), NMNZ RE003980 (S338) (female) (coll. D. Waddington, January 1969); Moturoa Islands, Northland (34º 47’S, 173º 20’E), NMNZ RE003831 (S189) (male) (coll. R. Falla, January 1968); Mt Mangere Auckland (36º 58’S, 174º 47’E), NMNZ RE004470 (S828) (male) (coll. E. Nichols, May 1970); Pouawa-Tirihau Bridge, 16 km N of Gisborne (38º 37’S, 178º 10’E), NMNZ RE004307 (S665) (male) (coll. T. Jewell, July 1970); Groper Rock, Mokohinau Islands (35º 55’S, 175º 06’E), NMNZ RE004798 (S1160) (male) (coll. A.H. Whitaker, November 1973); Kelburn, Wellington (41º 17’S, 174º 46’E), NMNZ RE003751 (S106) (male) (coll. D. Castle, January 1964); Korokoro, Lower Hutt, (41º 12’S, 174º 51’E), NMNZ RE004087 (S445) (female) (coll. G Woodward, July 1969); Mt Curl, Marton District (39º 57’S, 175º 26’E), NMNZ RE004225 (S583) (female) (coll. M. Meads, February 1969); Mt Curl, Marton District (39º 57’S, 175º 26’E), NMNZ RE004835 (S1197) (female), (coll. M. Meads, June 1972); Rata, Rangitikei (40º 00’S, 175º 31’E), NMNZ RE003647 (S2) (female) (coll. T. Brown, April 1966); Johnsonville (41º 13’S, 174º 48’E), NMNZ RE005160 (S1525) (male) (coll. J. Boyd October 1976); Mt Curl, Marton District (39º 57’S, 175º 26’E), NMNZ RE004171 (male) (coll. M. Meads December 1968); Black Rock Stn, 10 km NE Masterton, Wairarapa (40º 54’S, 175º 43’E), NMNZ RE004844 (S1206) (female) (coll. A.H. Whitaker, March 1972); Reikorangi, Waikanae (40º 52’S, 175º 03’E), NMNZ RE004528 (S887) (female) (coll. A.H. Whitaker, November 1971); Waiopehu Reserve, Levin (40º 38’S, 175º 19’E), NMNZ RE003750 (S105) (female) (coll. A.H. Whitaker, March 1967); Kapiti Island (40º 52’S, 174º 55’E), NMNZ RE004732 (female) (coll. B.D. Bell, Nov. 1972).

Diagnosis. Oligosoma ornatum can be distinguished from other Oligosoma species through a combination of characters. The orange iris clearly visible in living animals separates the species from all other Oligosoma except O. aeneum , O. levidensum (Chapple et al, 2008), O. hardyi (Chapple et al, 2008), O. townsi (Chapple et al, 2008), O. oliveri (McCann, 1955) , O. macgregori (Robb, 1975) , O. whitakeri (Hardy, 1977) , O. striatum (Buller, 1871) , O. homalonotum (Boulenger, 1906) , and O. roimata sp. nov.. The unbroken subocular scale row separates O. ornatum from O. striatum , O. homalonotum and O. hardyi . Oligosoma ornatum has a prominent teardrop marking under the eye, and a moderately large ear opening, which separates it from O. aeneum , O. levidensum and O. hardyi which lack this marking and have small ear openings. Oligosoma townsi midbody scale count of ≥38 does not overlap with O. ornatum .

The maximum SVL is much less than that of O. oliveri (105.6 mm) and the AG/SF ratios are quite different (Chapple et al. 2008a). There is minimal overlap between O. ornatum and O. whitakeri in midbody and ventral scale counts with O. whitakeri having a higher range for both indices (Hardy 1977). O. ornatum lacks the yellow and orange colouration of many O. whitakeri specimens (Hardy 1977). O. whitakeri generally has dark blotches on the ventral surface, whereas it is often lightly speckled in O. ornatum . Oligosoma whitakeri has a longer tail (TL/ SVL: 1.32; Hardy 1977) compared to O. ornatum (TL/SVL: 1.14). Colour pattern distinguishes O. ornatum from O. macgregori and there is no overlap in midbody counts between these two species. The ventral colouration of O. ornatum which is usually flushed with orange, red, pink or yellow is different from the white venter of O. roimata sp. nov..

Description of Neotype. Body elongate, squarish in cross-section; limbs moderately well-developed, pentadactyl. Lower eyelid with a large, opaque central scale, bordered anteriorly and posteriorly by relatively large scales. Snout blunt. Nostril centred just below middle of nasal, not touching bottom edge of nasal. Supranasals absent. Rostral broader than deep. Frontonasal broader than long, not separated from frontal by prefrontals meeting in midline. Frontal longer than broad, similar in length to frontoparietal and interparietal together, in contact with 2 anteriormost supraoculars. Supraoculars 4, the second largest. Preoculars 2, the upper one larger. 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, fourth supraocular and 2 postoculars. Loreals 2, posterior one the larger; anterior loreal in contact with first and second supralabial, posterior loreal, prefrontal, frontonasal and nasal; posterior loreal in contact with second and third supralabial, first subocular, upper and lower preocular, prefrontal and anterior loreal. Supralabials 7, the sixth largest. Infralabials 6, several of them equal in size; fifth supralabial below centre of eye. Mental broader but shallower than rostral. Suboculars series continuous. Postmental larger than mental. Chinshields 3 pairs. Two primary temporals. Dorsal scales largest, weakly striate. Ventral scales smooth. Subdigital lamellae smooth. Ear opening round, moderately large, with no projecting granules. Forelimbs shorter than hindlimbs. Adpressed limbs not meeting in adult. Digits short, sub-cylindrical. Third front digit shorter than the fourth.

Measurements (in Millimeters; Neotype with the Variation Shown in the Specimens Examined in Parentheses): SVL 65.2 (mean 62.3, range 40.0–80.5), HL 10.5 (mean 9.0, range 6.6–10.8), HW 6.8 (mean 6.4, range 4.7–7.6), AG 32.0 (mean 31.9, range 19.4–47.8), SF 26.0 (mean 23.9, range 16.4–28.8), S-E 12.3 (mean 11.5, range 8.1–13.6), EF 14.7 (mean 12.7, range 7.7–16.5), and TL unknown (not intact) (mean 65.1; N = 6).

Scalation (Neotype with the Variation Shown in the Specimens Examined in Parentheses): Upper ciliaries 8 (mean 7, range 5-10); lower ciliaries 11 (mean 10, range 8–13); nuchals 1 pair (mean 1 pair, range 0–2 pairs); midbody scale rows 32 (mean 32, range 28–36); ventral scale rows 74 (mean 74, range 60–88); subdigital lamellae 18 (mean 19, range 15–26); supraciliaries 7 (mean 7, range 7-8); suboculars 8 (mean 8, range 7–11). Frontonasal seldom separated from frontal by prefrontals meeting in midline. Anterior loreal in contact with first and second supralabial, occasionally in contact with second only. Posterior loreal usually in contact with second supralabial only, occasionally in contact with second and third supralabial. Supralabials 7 (usual) or 8, the sixth or seventh largest. Infralabials 5 or 6 (usual). One, occasionally two primary temporals. Third front digit usually as long as the fourth. Maximum SVL 80.5 mm. Six specimens had intact tails (TL/SVL = 1.14). Ratios for morphological measurements (± SD): AG/SF 1.33 ± 0.16; SE/EF 0.91 ± 0.08; HL/HW 1.42 ± 0.09.

Colouration. Dorsal surface light brown to very dark brown, with irregular dark and light flecks or blotches. Dark brown line passing from near tip of snout through upper part of eye to above and forward of ear. Posterior to ear a dark brown band of varying width extends above forelimb becoming less distinct as it proceeds towards tip of tail. This band is broken up by light blotches. Lateral surface usually lighter in colour than dorsum, lessening in intensity towards ventral surface. Usually blotched with dark and light along lateral body wall. No striping on limbs, which follow dorsal and ventral body colouring. Ventral surface red, orange, pink, yellow, white or cream, often lightly speckled with black compared with throat and chin. Fawcett (1970) interpreted the red colouration as sexual in nature; it is absent in immature animals. Throat and chin sometimes strongly mottled in appearance. A white, black-edged “tear-drop” under eye on fifth and sixth supralabial. Upper and/or lower jaws may have denticulate markings. Juvenile colouration is similar to adult except for the belly colour.

Habitat and life history. Oligosoma ornatum is known from throughout most of the North Island (BioWeb Herpetofauna database 2011), but there are no records from altitudes over 600 metres. It also occurs on several island groups off the coast of the North Island, including Little Barrier and Great Barrier Islands, the Hen and Chickens group and the Three Kings islands. It lives among leaf litter, under rocks and logs, or in dense vegetation in man-made and natural environments. One individual was recently found among the roots of a pine tree about 0.5m below the ground in Wellington. It is mostly active at dawn or dusk, seldom emerging far from cover, but will sun-bask near the entrance to its retreat. Young are born in January-February. The life-history was studied by Porter (1987) and Fawcett (1964, 1970). Fawcett found the maximum SVL for his animals was 80 mm. Females matured after their second hibernation when about 19–20 months of age and 60–65 mm SVL; males matured when 15–16 months of age and 50–55 mm SVL. The maximum SVL recorded for this species is 84 mm and maximum weight (for the same animal) was 11.5 g (R. Romijn, pers. comm.). Oligosoma ornatum is currently listed in the New Zealand Threat Classification System as At Risk (Hitchmough et al. 2013).

Figures

FIGURE 2. Ornate skink (O. ornatum) neotype (RE 002457).