The Herpetological Journal

pp. 175-186
Authors: Passos, Paulo; Lynch, John D. & Fernandes, Ronaldo

Abstract: The taxonomic status of Atractus sanctaemartae and A. nebularis is revised on the basis of quantitative and qualitative analyses of morphological characters (meristics, morphometrics, colour pattern and hemipenis). Characters used previously for diagnosing Atractus nebularis from A. sanctaemartae are demystified, and the synonymy of these species is proposed. Colour pattern, meristic, morphometrical and scale ornamentation differences originally employed in recognizing both taxa are explained as sexually dimorphic characters, which hold no geographic or phylogenetic basis. Additionally, a new species closely related to Atractus sanctaemartae is described from the Atlantic coast of Colombia. It is distinguished from A. sanctaemartae mainly by having two gular scale rows, slender (62% of body diameter) and acuminate head, snout acuminate in lateral view, dorsum uniformly reddish brown and venter cream with a series of rhomboidal blotches arranged linearly on the lateral portion of the ventral scales. We also discuss putative affinities of the new species and A. sanctaemartae on the basis of shared similarity characters, and comment on the occurrence of strong sexually dichromatic coloration in A. sanctaemartae, unique within the genus.

Keywords: SIERRA NEVADA DE SANTA MARTA, GEOGRAPHICAL VARIATION, SEXUAL DICHROMATISM, TAXONOMY