Sphenomorphus

Kaiser, Hinrich, Carvalho, Venancio Lopes, Ceballos, Jester, Freed, Paul, Heacox, Scott, Lester, Barbara, Richards, Stephen J., Trainor, Colin R., Sanchez, Caitlin & O'Shea, Mark, 2011, The herpetofauna of Timor-Leste: a first report, ZooKeys 109, pp. 19-86 : 40-42

Genus Sphenomorphus Fig. 19

Common names.

(E) Wedge skinks. *(T) Mamór ai laran ( mamór = skink, ai laran = forest).

Identification.

The genus Sphenomorphus includes wedge skinks of greatly varying sizes and diverse morphologies. The superficially conservative morphology of these skinks is contradicted by a significant number of differences in the details of scalation and coloration. Beyond a recognition based on color pattern (as is straightforward for the species shown in Fig. 19D ), these forms are difficult to tell apart. Sphenomorphus sp. 1 [Ca CMD 445] ( Fig. 19A ) possesses a series of paired dark paravertebral spots running as two lines onto the tail. In both sexes, the ventral coloration is cream, and males possess a black throat. Sphenomorphus sp. 2 [Ca CMD 356] ( Fig. 19B ) has a more diverse pattern of spots on its back, including brown, golden, and black spots in a complex arrangement. The throat is not black in males, and in both sexes the venter is yellow. Sphenomorphus sp. 3 [Ca CMD 415] ( Fig. 19C ) has a dorsal color pattern that is more uniformly brown, with some transverse golden dorsolateral striping. The venter of both sexes is a dirty cream color. Sphenomorphus sp. 4 [Ca CMD 416] ( Fig. 19D ) is easily differentiated from the other forms by its smaller size and by a characteristic black lateral stripe that extends from the eye along the side of the body all the way to the tip of the tail. Its dorsal coloration is more reddish brown than that of the other forms.

Collection and natural history.

We collected four forms of Sphenomorphus at three very distinct localities. In the area around Maubisse at altitudes>600 m, we encoun tered a highland form ( Sphenomorphus sp. 2; Fig. 19B ) that frequently shared its hiding places with night skinks ( Eremiascincus ). A worker at a road construction site gave to us one specimen smaller than typical individuals of Sphenomorphus sp. 2 but of a very similar morphology. That lizard was already injured from rough handling and expired shortly after we received it. Based on the surrounding vegetation, the altitude (>600 m), and several morphological features, we refer this specimen to Sphenomorphus sp. 2 pending the collection of additional specimens and a more thorough analysis. There is superficial resemblance of Sphenomorphus sp. 2 to Sphenomorphus variegatus (Peters 1867), but a further evaluation of museum specimens is necessary to verify any species assignment.

At a second highland locality, in the area of Eraulo (Ermera District) on the western side of the Mount Ramelau massif, we found two distinct forms of Sphenomorphus . One of these, from the Meleotegi River, is a form with very distinctive dorsal patterning ( Fig. 19D ). It was discovered while turning over flat rocks at the edge of the river. Based on its morphology we document this form as Sphenomorphus sp. 4. In the adjacent forest and plantation habitats we collected two specimens of Sphenomorphus sp. 3 ( Fig. 19C ).

The lowland form ( Fig. 19A ) from the dry coastal forest at Loré ( Lautém District) is quite common throughout the habitat. Individuals are most easily found during the daytime on the buttresses and roots of trees or whilst foraging in the leaf litter. This form has strong resemblance to Sphenomorphus florensis ( Weber 1890), but since that species currently has three subspecies aside from the nominate form ( Dunn 1927: Sphenomorphus f. nitidus , f. barbouri , Sphenomorphus f. weberi ) additional comparative work is necessary to determine its exact species affinity. It is also possible that the taxonomy is complicated by the possible synonymy of Sphenomorphus florensis and Sphenomorphusmelanopogon ( Duméril and Bibron 1839); one of the syntypes of Sphenomorphus melanopogon reportedly was collected on Timor. At this time, we prefer to call this form Sphenomorphus sp. 1 ( Fig. 19A ).

Taxonomic comments.

In her seminal work on the reptiles of the Indo-Australian region, Nelly de Rooij (1915) provided species accounts for Lygosoma florense and Lygosoma variegatus , having examined specimens of only the latterfrom Timor. Based on our own examination of various type specimens, the Lesser Sunda species of the genus Sphenomorphus require careful additional investigation in order to confirm their species status and distribution. A revision of Sphenomorphus florensis is currently being conducted by Glenn Shea (in litt.).

Figures

Figure 19. Representative examples of the four putative undescribed species of wedge skinks, genus Sphenomorphus. A Sphenomorphus sp. 1 (USNM [CMD 446], SVL 58 mm, TL 150 mm) from Lore, Lautem District B Sphenomorphus sp. 2 (USNM [CMD 364], SVL 66 mm, TL 185 mm) from Maubisse, Ainaro District C Sphenomorphus sp. 3 (USNM [CMD 416], SVL 69 mm, TL 152 mm) from the Meleotegi River near Eraulo, Ermera District D Sphenomorphus sp. 4 (USNM [CMD 415], SVL 42 mm, TL 92 mm) from the same locality as the animal in C Photos by Mark O'Shea.