A partial taxonomic revision of Atelopus (Anura: Bufonidae) from the central and eastern Andes of Colombia

Abstract

Harlequin toads, genus Atelopus, are a species-rich group of Neotropical anurans. Unparalleled declines and extinctions have hampered a thorough understanding of Atelopus systematics with numerous species only known from few specimens and a single or few localities. Major knowledge gaps particularly remain in the Cordillera Central and Cordillera Oriental of the Colombian Andes. In the central Andes, the names Atelopus angelito, A. ebenoides, and A. eusebianus have caused taxonomic confusion because populations can show vast plasticity, and populations assigned to these names were thought to occur in sympatry and parapatry. The virtual disappearance of all populations has prevented an integrative taxonomic assessment and rendered molecular approaches highly challenging. Based on adult and larval morphology, we propose that these populations correspond to a single polymorphic taxon and establish A. ebenoides as the senior synonym. In contrast, a form from the northern Cordillera Oriental has been considered a subspecies of the latter, A. ebenoides marinkellei. These geographically highly distant populations differ in morphology, particularly in tadpole characters and do not appear to represent conspecifics. We therefore elevate the form marinkellei to species rank and provide detailed morphological redescriptions and tadpole accounts for both A. ebenoides and A. marinkellei.