As currently defined, Pristimantis subsigillatus is a species of the P. lacrimosus species group distributed in the Chocó of Colombia and Ecuador, from lowlands to Andean foothill forests. Upon re-examination of the holotype of P. subsigillatus, we conclude that the populations currently ascribed to P. subsigillatus are not conspecific with the holotype. Instead, the holotype is conspecific with one of the syntypes of P. latidiscus, a species described four years before from a nearby locality. To avoid the ambiguity in the application of the binomen Hylodes latidiscus, we designate a lectotype. As a result, P. subsigillatus becomes a junior synonym of P. latidiscus. The misidentified populations represent an undescribed species which we describe based on morphological, bioacoustic, and genetic data as Pristimantis milpe sp. nov. The new species has one of the widest distributions among Chocoan Pristimantis and is unusual for having sexual dimorphism in coloration. It is most closely related to Pristimantis degener from which it diverged in the late Miocene and is morphologically distinct. The fact that such a common species remained "invisible" to taxonomy highlights the importance of correctly establishing the link between the name-bearing types and natural populations. Finally, we discuss how taxonomic treatments of Pristimantis during the second half of the 20th century often made this non-trivial error.