New species of Atractus Wagler, 1828 (Serpentes: Dipsadinae) from Guyana Plateau in Northern Brazil

Abstract

A new species of Atractus is described from Serra do Surucucu, a mountain slope at 1,000 m in the Guyana Shield, State of Roraima, Brazil. This species, only known by females, is diagnosed from all congeners by the following combination of characters: 17/17/17 smooth dorsal scale rows, without apical pits; 200-207 ventral scales; 25-26 subcaudal scales; moderate sized loreal, contacting second and third supralabials; seven supralabials, third and fourth contacting orbit; seven infralabials, first three contacting chinshields; moderate size, 222-388 mm SVL; short tail (7.7-8.8% snout-vent length); dorsal color pattern, in preservative, uniform chocolate to dark brown, with two conspicuous light paraventral lines, and a light incomplete occipital collar; venter immaculate creamish-white; tail uniform black; five maxillary teeth. We compared the new species with all currently recognized cis-Andean Atractus, and its affinities with Atractus alphonsehogei, Atractus caxiuana, Atractus collaris, Atractus gaigeae, Atractus limitaneus, and Atractus zidoki are discussed on the basis of putative morphological synapomorphies. Copyright 2008 Society for the Study of Amphibians and Reptiles.