Tuesday, January 3, 2017

Twig Anole, Anolis tigrinus

A Tobago Anolis tigrinus
The Tobago Anolis tigrinus Peters, 1863 is a small anole that belongs to the ecomorph group referred to as twig anoles.  The following description is based on Ugueto et al. (2009) On mainland Venezuela females may reach 58 mm and males 55 mm in body length. Head elongate with large, tuberculate scales;  the supraoculars are also large and the supraorbital semicircles are usually in contact, but may be separated by one scale; interparietal and supraorbital semicircles are usually in contact, rarely separated by one scale; a  distinct occipital knob is present. Dorsal scales are small and smooth; 63–97 scales along the middorsal line from axilla to groin; 94–114 scales around midbody; ventrals slightly larger than dorsals, roundish and completely smooth; 57–84 scales along the midventral line between axilla and groin. Dorsal coloration has a lichen-like appearance, changing from brown to mossy green during metachrosis; dark vertebral, rectangular spots, lateral light round, large spots and/or oblique lateral blackish lines are usually present. Dewlap in males large extending close to mid-venter with more or less horizontal rows of single scales; pale whitish anteriorly, pale yellow medially and orange postero-inferiorly with pale scales; females with a smaller dewlap, just reaching between the insertion of arms and  lightly beyond the axilla; with moderately separated, horizontal rows of single scales; pale orangish or grayish with conspicuous (usually horizontally elongated) black spots and pale scales.

Anolis tigrinus appears to be a central Venezuelan Coastal Range-Tobago endemic. However, we also have photographic evidence that A. tigrinus is present on Trinidad. Also see this blog post for more on its discovery on Tobago.

Ugueto GN, Rivas G, Barros T, Smith EN. A revision of the Venezuelan anoles II: redescription of Anolis squamulatus Peters 1863 and Anolis tigrinus Peters 1863 (Reptilia: Polychrotidae). 2009. Caribbean Journal of Science. 45(1):30-51.

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