Oligosoma infrapunctatum ( Boulenger 1887 )

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 : 453-459

publication ID

https://doi.org/ 10.11646/zootaxa.4623.3.2

publication LSID

lsid:zoobank.org:pub:402E9C29-3A36-4A0A-AE8D-5D7B0C335701

persistent identifier

https://treatment.plazi.org/id/0390B574-CB13-2B3F-FF2E-E457FBD0F84E

treatment provided by

Plazi

scientific name

Oligosoma infrapunctatum ( Boulenger 1887 )
status

 

Oligosoma infrapunctatum ( Boulenger 1887)

Figure 3 View FIGURE 3

Synonyms

Lygosoma infrapunctatum

BOULENGER 1887; WERNER 1895; ( Leiolopisma: Boulenger ): SMITH 1937; McCANN 1955

Leiolopisma infrapunctata

(Boulenger): MITTLEMAN 1952

Leiolopisma infrapunctatum

(Boulenger): McCANN 1955; (Boulenger): McCANN 1956; (Boulenger): SHARELL 1966; (Boulenger): WHITAKER 1968; (Boulenger): SOPER 1970; (Boulenger): WHITAKER 1970; (Boulenger): TOWNS 1971; (Boulenger): SCHIPPER 1972; (Boulenger): TOWNS & HAYWARD 1973; (Boulenger): GREER 1974; (Boulenger): ROBB 1974; (Boulenger): BULL & WHITAKER 1975; (Boulenger): GUNDY & WURST 1976; (Boulenger): WHITAKER 1976; (Boulenger): HARDY 1977

Oligosoma infrapunctatum

WELLS & WELLINGTON 1985; GREAVES et al. 2008; CHAPPLE et al. 2009; JEWELL & MORRIS 2008, 2011; TOWNS et al. 2012; BELL 2014

Holotype. 1946.8.16.12 ( New Zealand) (purchased off G. Krefft (sic), date and locality unknown). Loan arranged between the British Museum ( BMNH; London ) and Te Papa, National Museum of New Zealand ( NMNZ; Wellington).

Diagnosis. The specimen’s characteristics clearly distinguish it as a member of Oligosoma ( Patterson & Daugherty 1995) . The specimen is similar to many of the species described in the current paper in overall proportions, scalation and colouration, particularly the ventral speckling. This, and the distinguishing features presented above which exclude other superficially similar species confirm that it is a member of the group of species discussed here as the O. infrapunctatum complex. It can be distinguished from other members of the infrapunctatum complex by the following characters ( Figure 4 View FIGURE 4 a–j)—S-Ear/EF ( O. infrapunctatum 0.8; O. robinsoni 0.9–1.2; O. salmo sp. nov. 1–1.2), MS ( O. infrapunctatum 34; O. auroraensis sp. nov. 30–32), VS ( O. infrapunctatum 83; O. albornense sp. nov. 65–68; O. salmo sp. nov. 59–69), upper ciliaries ( O. infrapunctatum 7; O. albornense sp. nov. 5–6), supraciliaries ( O. infrapunctatum 6; O. salmo sp. nov. 5), supralabial count ( O. infrapunctatum 8; O. auroraensis sp. nov. 7; O. salmo sp. nov. 7), SVL/HLL ( O. infrapunctatum 2.8; O. salmo sp. nov. 3–4.3). The boxplots also show statistically significant differences between O. infrapunctatum and all the other species in this paper.

The AG/SF and SVL/FTL values for O. infrapunctatum are unlikely to have arisen from the distribution of values of O. newmani and O. salmo . The subdigital lamella count is unlikely to have arisen from the distribution of values of any of the other species in this paper, except O. auroraensis . Similarly, for SVL/ HLL, where the only species with a possibly comparable distribution is O. auroraensis . The S-Ear/EF value for O. infrapunctatum is unlikely to have arisen from the distribution of values of any of the other species in this paper.

O. infrapunctatum also has a scale between the prefrontals that is not found in any of the other species in this paper. The O. infrapunctatum type shows some similarity to the undescribed Hokitika population of Clade 2a; they share the additional scale between the pre-frontals and a tendency for the ventral spots to be arranged in longitudinal rows; both features not seen in other members of the complex described here. However, they differ considerably in ventral scale counts (mean of 74 vs 83 in O. infrapunctatum ), AG/SF (mean of 1.6 vs 1.3 in O. infrapunctatum ) and in having 7 supralabials vs 8 in O. infrapunctatum . Similar differences (including the lack of a scale between the prefrontals) exist between other undescribed taxa in the Greaves et al. (2008) paper and this specimen.

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, separated from frontal by a small scale. Frontal longer than broad, shorter than frontoparietal and interparietal together, in contact with 2 anteriormost supraoculars. Supraoculars 4, 2 nd largest. Preoculars, 2, 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 8, 7 th largest. Infralabials 6 (l), 7 (r), several equally largest. Sixth supralabial below centre of the eye. Temporals: 1 primary; 2 secondary. Ear opening round, moderately large (1.8% as percentage of SVL) with several small projecting granules on anterior margin. Suboculars 6, 3 rd and 4 th separated by 6 th supralabial. Mental broader but shallower than rostral. Postmental larger than mental. Chinshields 3 pairs. Dorsal scales largest, weakly striate. Ventral scales and subdigital lamellae smooth.

Adpressed limbs not meeting. Digits moderately long, subcylindrical. Third front digit similar length to the 4 th.

Measurements (in mm; holotype only). SVL 79.8, HL 12.1, HW 7.2, AG 39.3, SF 30.6, S-Ear 14.5, EF 17.4, HLL 29; D-Ear 1.5.

Counts and ratios (holotype only). Upper ciliaries 7; lower ciliaries 10; nuchals 3 pair; midbody scale rows 34; ventral scale rows 83; subdigital lamellae 22; supraciliaries 6; suboculars 6. AG/SF 1.28; S-Ear/EF 0.83; HL/ HW 1.68.

Colouration. Dorsal surface with dark flecking, 6 scale rows wide, grading into pale dorsolateral stripe extending from behind eye to base of tail, becoming indistinct thereafter. This pale stripe extends into brown lateral stripe two or more scale rows wide, notched on upper and lower edges, running from behind nostril through eye towards tip of tail. This band is bordered on each edge by a dark band 1 to 2 half-scale rows wide running above the limbs and becoming indistinct after hindlimb. The lower dark band is bordered below by a pale stripe, 1 to 2 half-scale rows wide running from below the eye, above or through the ear, above the limbs to become indistinct after the hindlimbs. This band is bounded below by a darker band breaking up into a ventral pale colour. Throat, belly and undersurface of tail speckled with darker flecks. Throat grey. Outer surface of forelimbs speckled.

[colour from photos]

Etymology. The Latin name means ‘spotted below’. The currently accepted vernacular name is ‘speckled skink’ ( Bell 2014); however, since this species is not conspecific with O. newmani which is widely known as the speckled skink, ‘Boulenger’s speckled skink’ is suggested for O. infrapunctatum .

Natural History. Despite the various studies of O. aff. infrapunctatum sensu lato by various authors over decades, no studies actually have been undertaken on O. infrapunctatum itself as no extant populations are known today. Hence, this species remains a complete enigma.

Discussion. We unsuccessfully attempted to obtain DNA for sequencing from the type specimen. Based on the morphological differences outlined above (see Diagnosis), we are confident that it is not conspecific with any of the other species described in this paper, or in Greaves et al. (2008). It does share apparently derived characters with the undescribed population of Clade 2a from Hokitika, but also differs substantially in scale counts from the two specimens and one set of photographs of a live animal available from that population (see Diagnosis). Additional specimens may fill the gap in scale counts between these inadequate samples, which would mean that the “Hokitika skink” is O. infrapunctatum . Alternatively, O. infrapunctatum may be extinct or a small population may await rediscovery. There is no doubt that it is at least seriously threatened, if not extinct.

NMNZ

Museum of New Zealand Te Papa Tongarewa

Kingdom

Animalia

Phylum

Chordata

Class

Reptilia

Order

Squamata

Family

Scincidae

Genus

Oligosoma

GBIF Dataset (for parent article) Darwin Core Archive (for parent article) View in SIBiLS Plain XML RDF