Title: The Glaphyromorphus isolepis Species Group (Lacertilia: Scincidae): Diagnosis of the Taxon and Description of a New Species from Timor
Abstract: -The Glaphyromorphus isolepis species complex is diagnosed and its range identified as northern Australia and the Lesser Sunda Islands. A new species in the taxon from Timor is much larger than the only other two species in the Lesser Sundas: G. antoniorum (type locality, Timor) and G. emigrans (type locality, Sumba). These latter two species can only be readily by the number of phalanges in the fourth toe of the manus: five in G. emigrans and four in G. antoniorum. Morphometric and reproductive data are provided for G. antoniorum. Within the Sphenomorphus group of lygosomine skinks (Greer, 1979), there is a small subgroup that is recognizable on the basis of the following combination of derived character states: (1) auricular lobules greatly reduced or absent; (2) infralabials five (vs. six or more) with only one contacting postmental on each side (first two infralabials fused?); (3) limbs relatively short (e.g., rear limb for adults and subadults = 24-38% of SVL); (4) pterygoid teeth absent; (5) the palatal rami of the pterygoids squared off and in medial contact; and (6) palatal rami of pterygoids excluded from infraorbital vacuity by finger-like process from ectopterygoid to palatine. This group occurs in near-coastal northern Australia from South Muiron Island and the Dampier Archipelago (Storr, 1967, 1972) to the southeastern corner of the Cape York Peninsula, and in the Lesser Sunda Islands (Fig. 1). These skinks are terrestrial and cryptozoic in habits, any surface activity generally occurring only in deep shade (G. Shea, pers. comm.), at dusk, or after dark. The group includes six species: Sphenomorphus antoniorum, S. douglasi (including S. brongersmai), S. emigrans, S. isolepis, S. pardalis and one species to be described here as new. The species S. isolepis shows much geographic variation (Storr, 1967, 1972; Shea et al., 1988), some of which may be due to its consisting of more than one species. The lineage represented by all these species appears to be distinct enough to warrant separate generic rank. Although the generic name Mawsoniascincus (type species, Lygosoma isolepis Boulenger, 1897) is potentially available for the group (Wells and Wellington, 1985), this name is currently unavailable due to a case (No. 2531) pending before the International Commission on Zoological Nomenclature to suppress the work. The next available name is Glaphyromorphus (type species: Lygosoma (Lygosoma) punctulatum Peters, 1871) originally proposed by Wells and Wellington (1984) for a group of Australian skinks (inclusive of those considered here) previously included in Sphenomorphus. This work is also part of the same pending case, but in the event of supression, it is available as published by Cogger (1986). Thus we may combine the most recent available generic name with the name of the best-known species and refer to the group as the Glaphyromorphus isolepis group. It should be noted that although Wells and Wellington (1985) distinguished the Glaphyromorphus isolepis group (from what was not specified) on the basis of 11 characters, only two of these are likely to be derived: prefrontals in point contact or separated; and postmental contacts one infralabial on each side. With the description here of a new species in the group, the first of these characters also falls away as a group character. The relationships of the Glaphyromorphus isolepis group are unclear, but may lie with the Calyptotis-Saiphos lineage, a group of small, cryptozoic skinks occurring in mesic habitats along the eastern seaboard of Australia. The two taxa share five derived characters (characters 1 and 3-6) and are geographically contiguous. Ancestrally the Calyptotis-Saiphos group appears to have had two infralabials contacted by the postmental, as seen in Saiphos (Greer, 1983), instead of one-character 2. Three species of the Glaphyromorphus isolepis group occur in the Lesser Sunda Islands: G. antoniorum, G. emigrans, and a new species. Below I describe the new species and provide some notes on G. antoniorum, the only other member of the G. isolepis group sharing its distribution on the island of Timor. Glaphyromorphus timorensis sp. nov. Figs. 2, 3 Holotype. -Naturhistorisches Museum Basel (NHMB) 12794, adult female. Type locality, NiThis content downloaded from 207.46.13.129 on Sun, 26 Jun 2016 07:09:14 UTC All use subject to http://about.jstor.org/terms A NEW GLAPHYROMORPHUS FIG. 1. Map showing the distribution of the Glaphyromorphus isolepis species group. kinki, Timor, collected by A. Biihler and W. Meyer in June 1935. Paratype.-NHMB 12793, same data as holotype. Diagnosis.-Glaphyromorphus timorensis differs from all other members of the G. isolepis species group in the following combination of characters: prefrontals in contact or separated by a medial scale (vs. almost always separated); midbody scale rows 35-36 (vs. 23-32); and paravertebral scales 81-82 (vs. 55-80). Description.-A large, dark brown skink (max. SVL 91 mm) with non-overlapping, pentadactyl limbs, and a diffuse dark brown lateral stripe on the head, neck, and anterior body. Rostral trilobed, nasal lobe broadly rounded and in broad contact with frontonasal, labial lobe angular and not extending beyond level of center of nostril; supranasals absent; prefrontals large, in narrow contact or separated by a medial scale; frontal approximately 1? times as long as wide; supraoculars four, first two on each side contacting frontal; frontoparietals distinct; interparietal distinct, with light parietal eye spot in posterior lobe; parietals meeting behind interparietal; nuchals 0-1 on each side. Nasal with nostril situated slightly ventral of center; loreals two; preoculars two; supraciliaries eight or nine, first three large and contacting first supraocular, last large and projecting medially between last supraocular and first pretemporal; subocular scale row complete but narrowing below eye, presuboculars two or three; postsuboculars three; pretemporals two; primary temporal one; secondary temporals two, upper smaller and overlapping lower; supralabials seven or eight, fifth or sixth in subocular position; postsupralabials two; infralabials five, only the first contacting postmental; mental followed by postmental and three pairs of enlarged chin scales, first pair in medial contact, second pair separated by one scale, each member of third pair divided into two and separated by three or four scales; external ear opening about two-thirds size of eye opening, vertically oval, without lobules; tympanum well recessed. Snout-vent length 89-91 mm; front and rear limbs pentadactyl, approximately 21% and 2930% of SVL, respectively; subdigital lamellae of fourth finger 13-16; subdigital lamellae of fourth toe 20-25, with slight postaxial groove over basal part of digit; inner preanals overlap outer. 373 This content downloaded from 207.46.13.129 on Sun, 26 Jun 2016 07:09:14 UTC All use subject to http://about.jstor.org/terms
Publication Year: 1990
Publication Date: 1990-12-01
Language: en
Type: article
Indexed In: ['crossref']
Access and Citation
Cited By Count: 10
AI Researcher Chatbot
Get quick answers to your questions about the article from our AI researcher chatbot