The Santiago poison frog, Adelphobates captivus, a species not seen in life since 1929, was recently rediscovered on an expedition to its type locality in northwestern Peru. The colors of this species, previously unknown, consist of a black dorsum with bright red-orange spots and yellow spots ventrally. We provide amendments to the original description as well as the first accounts of tadpole morphology, vocalization, and natural history. A Bayesian phylogenetic analysis suggests Adelphobates captivus and a species originally described as Dendrobates mysteriosus are sister species that form a monophyletic clade sister to Ranitomeya. We propose to clarify the taxonomic status of D. mysteriosus incertae sedis by erecting a new genus, Excidobates, to include mysteriosus and its sister taxon captivus. Members of this genus are distinguished from Ranitomeya by 11 site substitutions in their rrnS and rrnL sequences, well-developed first fingers, and pale spots on the ventral surfaces of the thighs.