A New Distribution Record and Updated Conservation Assessment of the Endangered Maranón Poison Frog, Excidobates mysteriosus (Amphibia: Dendrobatidae)

Abstract. Excidobates mysteriosus (Myers, 1982) is a species of poison frog (family Dendrobatidae) endemic to Northern Peru and one of the more enigmatic species of the family. It was described in 1982 from a single specimen originally collected in 1929 (Myers 1982). This species remained undocumented in life until R. Schulte (1990) rediscovered it from near the type locality of Santa Rosa de La Yunga, Cajamarca department, Peru. Although E. mysteriosus was initially suggested to belong to the Oophaga histrionica group based on its color pattern, large size (SVL 26–29 mm), and osteology, later molecular phylogenetic work placed it in the genus Excidobates (Twomey & Brown 2008). The species is easily recognizable due to its distinctive white “polka-dot” pattern (Fig. 1A) and has become an emblematic species of Peru’s exceptionally diverse but threatened amphibian fauna (Jarvis et al. 2015). Here, we report a population of E. mysteriosus from a new locality and provide an updated model of suitable habitat to reevaluate this species’ conservation status.