In a remarkable turn of events, a small amphibian species that had eluded scientists for over a century has been rediscovered in the Ecuadorian Andes.
According to a study published on August 13 in the Journal of Zoosystematics and Evolution, the elusive Pristimantis ruidus, or Molleturo robber frog, was first identified in 1922 by George Henry Hamilton Tate during an expedition for the American Museum of Natural History. Tate collected 16 specimens from nearly 8,000 feet above sea level on the Pacific slopes of the Ecuadorian Andes. However, the species vanished from scientific records shortly after.
“Pristimantis ruidus has managed to stay out of sight for more than a hundred years,” the study notes. This changed during a 2022 expedition to the Quitahuaycu Conservation Reserve, where researchers encountered and documented the species for the first time since Tate’s discovery. The team captured two specimens and provided the first photographs of this rare frog.
Described as having a rugged, olive-colored exterior adorned with warty bumps, the Molleturo robber frog features distinctive orange eyes, adding to its unique appearance. The frogs were located among fallen trees and low shrubs along a stream within the reserve. Their appearance includes an olive clay coloration on the back, Verona brown blotches, and an olive sulfur yellow snout with lime green eyelids.
The study reveals that these frogs may spend their days hidden under rocks and their nights in the mountain streams. The rediscovery of Pristimantis ruidus has also shed light on its behavioral patterns. Prior assumptions, based on daytime observations, suggested that the frogs sheltered under rocks. The recent findings imply that they might actually be active on vegetation during the night.
The rarity of sightings since 1922 led researchers to fear the species might be extinct. “The rediscovery of P. ruidus after a century highlights the existence of montane forests that can sustain rare and threatened species,” the researchers assert. “Despite prior unsuccessful attempts to document the species, our findings confirm that a population persists, underscoring the need to protect this critical habitat, one of the last remnants of the West Andean Montane Forest in southern Ecuador.”
The research team behind this groundbreaking discovery includes Juan Sánchez-Nivicela, Diana Székely, Luis Salagaje M., Nicolás Astudillo-Abad, Jaime Culebras, Ernesto Arbeláez Ortiz, and Paul Székely.