Celatiscincus euryotis (Werner, 1910)

Sadlier, Ross A., Smith, Sarah A. & Bauer, Aaron M., 2006, A New Genus for the New Caledonian Scincid Lizard Lygosoma euryotis Werner, 1909, and the Description of a New Species, Records of the Australian Museum 58 (1), pp. 19-28 : 21-22

Celatiscincus Sadlier, Smith, & Bauer, n.gen.

Type species. Lygosoma euryotis Werner, 1909:271.

Diagnosis. The following suite of apomorphic characters in combination will distinguish Celatiscincus from all other genera in the Eugongylus group of Greer (1979): frontoparietal scales fused; naris positioned in a single large nasal scale, with no evidence of scale or postnasal suture; anterior loreal reduced, either contacting upper labials narrowly, or present as a semilunar scale failing to contact upper labials; contact between lower eyelid and adjacent upper labials interrupted by the presence of complete subocular scale row; parietal scales each bordered by a single enlarged upper temporal scale and 2 (rarely 3) equal sized nuchal scales no larger than the surrounding dorsal scales; lower eyelid with an obvious, centrally located semitransparent disc; ear lobules barely distinguishable from blunt conical scales around upper, lower, and posterior edges of ear opening; premaxillary teeth 13; atlantal arches of first cervical vertebrae fused to intercentrum.

The genus sharing the greatest number of derived features with Celatiscincus is Sigaloseps. However, Sigaloseps lacks the elevated number of premaxillary teeth and has each parietal bordered by an enlarged upper secondary temporal and transversely enlarged nuchal scale, rather than an enlarged upper secondary temporal and two (or more) smaller equal sized scales seen in Celatiscincus. Further, Sigaloseps has smooth body scales, whereas Celatiscincus has keeled body scales. The polarity of this latter character has yet to be determined. Comparison to the two closest outgroups: New Zealand+Australian Eugongylus group species and Eugongylus + Emoia + Leiolopisma (based on genetic evidence—Smith, 2001) would indicate smooth scales are the pleisiomorphic state at the level of the New Caledonian radiation.

Etymology. The name Celatiscincus is derived from celatus, the Latin for concealed and scincus, a Latinized version of a Greek word for lizard, particularly applied to skinks or other “shiny-scaled” lizards, and alludes to the isolation of the ranges of the constituent species and the fact that the identity and affinities of these taxa remained “hidden” to systematists for so long. The name is masculine.

Recognized species. Celatiscincus euryotis (Werner, 1909); and Celatiscincus similis n.sp. Sadlier, Smith, & Bauer.

The two species of Celatiscincus are similar in overall appearance. They are small in size with long tails and relatively long limbs, and share the same basic configuration of head scalation that includes: prefrontals moderately large and moderately to widely separated; frontoparietals fused; interparietal distinct; parietals each bordered by a single large upper secondary temporal and two (rarely three) equal sized scales no larger than the surrounding dorsal scales; nasals well separated; loreals two, anterior narrowly contacting labials, occasionally present as a semilunar scale failing to contact the labials; supraciliaries usually 7; upper labials usually 7; a complete subocular row between preocular and pretemporal scales; primary temporal single; lower secondary temporal single; tertiary temporals two; postlabials two; lower eyelid with an obvious, centrally located semi-transparent disc. Both species are sexually dimorphic in adult colour (see Bauer & Sadlier, 2000, pl. 18C–F), and adult females of both species typically have a

1 Only in the Australian genus Niveoscincus as proposed by Hutchinson et al. (1990) are both conditions present. However, although the generic diagnoses provided for Niveoscincus and other genera proposed by Hutchinson et al. are based on morphological characters, the framework within which these diagnoses were formulated was determined by immunological data alone. As such the morphological data do not provide an independent test for the monophyly of groups identified by the immunological study.] The species euryotis and its sibling species from the north of the Grande Terre shares some apomorphic characters with Sigaloseps Sadlier, but none in particular, or even all in combination, are sufficiently compelling to infer a level relationship that would suggest they are congeneric.

narrow, white hip stripe (dark-edged above) that extends over the hindlimbs and along basal portion of tail that is not present in adult males.

Diagnoses and descriptive data for Celatiscincus euryotis have been published by: Werner (1909, as Lygosoma euryotis); Sadlier (1986, as Marmorospha × euryotis); and Bauer & Sadlier (1994, as Marmorospha × euryotis); and Bauer & Sadlier (2000, as “Lygosoma” euryotis). However, the species accounts of Sadlier (1986) and Bauer & Sadlier (2000) were composite, including information from specimens from both the Isle of Pines and from the north of the Grande Terre. We here redefine C. euryotis and diagnose and describe a second member of the genus to accommodate the mainland New Caledonian populations previously subsumed within C. euryotis.