Saturday, May 30, 2026

[Herpetology • 2026] Pristimantis fergusoni • A New spiny frog of the Genus Pristimantis (Anura: Strabomantidae) from the eastern slopes of the Ecuadorian Andes

 

Pristimantis fergusoni 
J. P. Reyes-Puig, Yánez-Muñoz, Ron, Venegas, Ortega, Carrión-Olmedo & C. Reyes-Puig, 2026 
 

Abstract
A new species of rain frog from the upper montane forest of the eastern Andes in the upper Pastaza watershed, Ecuador is described. Pristimantis fergusoni sp. nov. is characterized by its short snout, conical tubercles on upper eyelids and heels, combined with a scarlet colored belly in females. These unique traits differentiate the new species among other Pristimantis of upper montane eastern Ecuadorian Andes. Phylogenetic analyses support its validity and place it within a clade nested with other tuberculated species occurring along the Andean slopes. Pristimantis fergusoni sp. nov. is currently known from only two close localities (Cerro Candelaria and Chamana Reserves) at elevations between 2972 and 3200 m elevation, within the Llanganates-Sangay Ecological Corridor. Data Deficient IUCN status is proposed until new information is available. Individuals were observed at night perched on vegetation in herbaceous and arbustive vegetation of upper montane forest. This discovery contributes to a growing body of evidence identifying the upper Pastaza valley as a hotspot of amphibian endemism and diversification. With this addition, 30 strabomantid species are described for this region in the last decades, underscoring its conservation importance. This discovery highlights the urgent need for integrated taxonomic efforts combining fieldwork, morphology, and molecular data to resolve complex evolutionary relationships within the megadiverse genus Pristimantis, especially in underexplored high-elevation habitats of the tropical Andes. Finally, we provide an updated phylogeny for this clade that clarifies its evolutionary relationships.

Key words: Amphibia, Andean slopes, morphology, Pristimantis gualacenio species complex, taxonomy

Life color and sexual dimorphism in Pristimantis fergusoni sp. nov.
A. Female holotype DHMECN 13318; B. Female DHMECN 19390;
C. Male DHMECN 19388; D. Male DHMECN 19389.
Dorsal and ventral view, respectively. Photographs by J. P. Reyes-Puig.

Pristimantis fergusoni sp. nov.

Live photographs of the new species and comparison with related and similar Pristimantis species from eastern Andes of Ecuador.
A. Pristimantis fergusoni sp. nov., female holotype DHMECN 13318, from Cerro Candelaria; B. P. gualacenio DHMECN 10748, from Area de Conservación Municipal Tinajillas; C. P. bellae DHMECN 4812, from Cerro Candelaria;
D. P. eriphus DHMECN 5209, from Río Zuñag; E. P. incanus DHMECN 11857, from Reventador; F. P. roni, DHMECN 11313, from Sardinayacu; 
G. P. katoptroides QCAZ58900, from Sadinayacu; H. P. inusitatus not collected, from Napo San Isidro; I. P. galdi DHMECN 9640, from Reserva Tapichalaca;
J. P. colonensis DHMECN 6414, from La Bonita; K. P. venegasi MZUTI 6571; L. P. yanezi DHMECN 13309, from Río Zuñag.
Photographs by JPRP, MYM, SRR, Juan Carlos Sánchez-Nivicela, and Patricia Bejarano-Muñoz.


  Juan Pablo Reyes-Puig, Mario H. Yánez-Muñoz, Santiago R. Ron, Pablo J. Venegas, Jhael Ortega, Julio C. Carrión-Olmedo and Carolina Reyes-Puig. 2026. A New spiny frog of the Genus Pristimantis (Anura, Strabomantidae) from the eastern slopes of the Ecuadorian Andes. ZooKeys. 1269: 83-105. DOI: doi.org/10.3897/zookeys.1269.162260 [13-02-2026]