A common frog found in the Chocó forests of western Ecuador and southern Colombia has finally been recognized as its own unique species after being misclassified for over 100 years. Scientists at the Pontificia Universidad Católica del Ecuador (PUCE) identified the species, now named Pristimantis milpe, by comparing 19th-century specimens from the Natural History Museum in London with living populations in the region. This comparison revealed that the frog had been incorrectly grouped with a different species for more than a century. Pristimantis milpe inhabits an area of over 67,000 square kilometers, stretching from sea level up to 1,200 meters in elevation. This range includes dense, humid forests in both Ecuador and Colombia. The frog is notable for its unique nighttime call, which sounds like a "click." Males typically call from elevated positions on leaves of shrubs and bromeliads, several meters above the forest floor. Additionally, the species shows sexual dimorphism, with females displaying more vivid coloration around their groin and thighs compared to males. The findings were published in the journal ZooKeys and emphasize the role of natural history collections in resolving taxonomic mysteries. These collections, often containing specimens gathered over many decades, can provide crucial data for modern scientific research. The discovery of Pristimantis milpe highlights how even common species can remain misclassified for long periods, underscoring the importance of revisiting historical records and specimens. This research also serves as a reminder of the value of preserving and studying historical biological samples. By using these older collections, scientists can compare past and present data to better understand biodiversity and the evolution of species over time. The identification of Pristimantis milpe not only corrects a long-standing error but also contributes to the broader effort of cataloging and protecting the world’s diverse wildlife.