Testing species boundaries within the Atractus occipitoalbus complex (Serpentes: Dipsadidae)

The taxonomic status of Atractus occipitoalbus is revised on the basis of concordance between quantitative and qualitative analyses of morphological characters (meristic, morphometric, color pattern, and hemipenis). Atractus duboisi and A. orcesi are herein resurrected based on the number of ventral and subcaudal scales, number of postocular scales, head shape in lateral view, relative tail length, distinct color patterns, and hemipenial morphology. Additionally, a new species, closely related to A. occipitoalbus, is described from the Andean piedmont of Colombia. The new species, represented by a single female, is diagnosed from the A. occipitoalbus female populations on the basis of number of subcaudals, number postocular scales, and dorsal and ventral color patterns.