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| Pristimantis paganus Loza-Carvajal, Yánez-Muñoz, Quilumbaquin & Ortega-Andrade, 2025 |
Abstract
Pristimantis, a genus of direct-developing frogs within the family Strabomantidae, comprises 617 recognized species, making it the most species-rich genus of vertebrates worldwide. This group include 264 described (43% of the world) species in Ecuador, being one of the countries in the region with the highest rate of species description, greatest diversity and endemism. In this study, we analyze the phylogenetic position and describe a new Pristimantis species from the Colonso Chalupas Biological Reserve and Llanganates National Park in northeastern Ecuador, using phylogenetic, genetic, morphological, and geographic evidence. Additionally, we propose a new subgenus within Pristimantis that includes the Pristimantis prolatus and Pristimantis bicantus species groups. Our results indicate that the new species and related species form a well-supported group with significant genetic divergence based on the 16S rRNA gene (average uncorrected p-distance = 2.8–7.5%), within the Pristimantis bicantus species group. Morphologically, the new species is characterized by a black to dark-gray dorsum and marbled venter (less intense or brown in males), being endemic to the Guacamayos mountain range and the Llanganates region in the northeastern Andean foothills of Ecuador. We emphasize the importance of including topotypic specimens to analyze and compare species groups to delimiting species, like Pristimantis.
Keywords: Integrative taxonomy, Cryptic diversity, Pristimantis paganus sp. nov., Pristimantis prolatus group, Pristimantis bicantus group, Cryptomantis gen. nov.
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| Pristimantis paganus sp. nov. Holotype in life DHMECN 16810, adult female, SVL = 27.2 mm. (A) Dorsal view; (B) frontal view; (C) lateral view; (D) ventral view. Photographs by Mario H. Yánez Muñoz. |
Pristimantis paganus sp. nov.
Suggested common English name: Amazonian pagan rainfrog
Common name in Spanish: Cutín pagano Amazónico.
Diagnosis. Pristimantis paganus sp. nov. (Figs. 2–7) is a member of the subgenus Cryptomantis and P. bicantus species group, characterized by the following combination of characters: (1) dorsal skin finely granular with dorso-laterally aligned flattened warts, areolate venter, discoidal fold present and visible posteriorly, dorsolateral folds weak and discontinuous in females, continuous in males; scapular W-shaped fold in males; (2) tympanic membrane and tympanic annulus present, round, horizontal diameter of tympanum equal to 38% of eye diameter, antero-dorsal margin with a supratympanic fold and large subconical postrictal tubercles; (3) snout short, subacuminate in dorsal view, rounded in profile with slightly flared lips; (4) upper eyelid with at least three to four large rounded tubercles surrounded by several small rounded tubercles, two subconical tubercles behind each eye; no cranial crest; (5) dentigerous processes of vomers, oblique in outline each process with 3–8 teeth; (6) vocal slits absent; no nuptial pad and no vocal sac; (7) Finger I shorter than Finger II; broad, expanded disks dilated with circummarginal grooves; (8) fingers with thin lateral cutaneous fringes; (9) subarticular tubercles, present, prominent; hyperdistal subarticular tubercle, present; ulnar tubercles absent; (10) heel with one subconical tubercle; outer edge with two flattened tubercles, tarsal fold absent; (11) inner metatarsal tubercle oval in females 3 times larger than rounded outer metatarsal tubercle; supernumerary tubercles absent; (12) toes with thin lateral fringes present, interdigital membrane absent, Toe V longer than Toe III; (13) The distinctive coloration of females, characterized by a uniformly black dorsum and black markings on a cream to pinkish-cream background on the flanks, belly, and throat, distinguishes this species from its congeners and other Pristimantis species inhabiting the eastern montane forests of Ecuador; (14) adult males, SVL = 17.20–21.5 mm (mean = 19.6, n = 13), females SVL= 24.8–29.8 mm (mean = 29.6 mm, n = 6), (Tables 2, 3, S3).
Etymology. The specific epithet is from the Latin word “paganus”, an adjective derived from “pagus”, which refers to the inhabitants of the forest or village, far from civilization and towns, referring to the remote and unexplored sites where this species inhabits, in the montane cloud forests at the Colonso Chalupas Biological Reserve and Llanganates National Park, northeastern flanks of the Andes in Ecuador.
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| Habitat and specimens of Pristimantis paganus sp. nov. (A) Cloud forest with epiphytic plants, type locality, Colonso Chalupas Biological Reserve; (B) female, DHMECN 19962; (C) paratype, male, DHMECN 15602; (D) paratype, adult female, DHMECN 17222. Photographs: Jorge Brito (A), Keyko D. Loza-Carvajal (B), H. Mauricio Ortega-Andrade (C), Zane Libke (D). |
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| Representative species of the subgenus Cryptomantis. Subclade A-Pristimantis prolatus species group: (A) Pristimantis ganonotus DHMECN 16961, Colonso Chalupas Reserve, Napo; (B) P. burtoniorum DHMECN 14479, Paratype, Mayordomo Reserve, Tungurahua; (C) P. prolatus DHMECN 11564, Topotype, Río El Reventador, Sucumbíos; (D) P. c.sp. 1, DHMECN 15674, Colonso Chalupas Reserve, Napo. Subclade B-Pristimantis bicantus species group: (E) P. c.sp. 2, QCAZ 70020, Llanganates National Park, Napo; (F) P. marcoreyesi, DHMECN 13833, Tungurahua volcano, Tungurahua; (G) P. paganus sp. nov. DHMECN 15606, Colonso Chalupas Reserve, Napo; (H) P. tungurahua, DHMECN 14428, Vizcaya Reserve, Tungurahua; (I) P. sacharuna, QCAZ 52496, Zúñag Reserve, Tungurahua; (J) P. c.sp. 3, QCAZ 51553, San Antonio de Juval, Cañar; (K) P. nelsongalloi, DHMECN 5223, Zúñag Reserve, Tungurahua; (L) P. bicantus, DHMECN 12359, El Reventador, Sucumbíos; (M) P. c.sp. 5, QCAZ 52489, Sangay National Park, Morona Santiago. Photo credit: Gustavo Pazmiño, Bioweb (E); Santiago Ron, Bioweb (I), Bioweb (J, M); Keyko D. Loza, Carvajal (A); Mario H. Yánez Muñoz (B, C, F, H, K, L); H. Mauricio Ortega-Andrade (D, G). |
Conclusions:
We described a new species, Pristimantis paganus, from the Colonso Chalupas Biological Reserve and Llanganates National Park, northeastern Ecuador. Furthermore, we define a new subgenus, Cryptomantis, within Pristimantis that includes the Pristimantis prolatus and Pristimantis bicantus species groups. Our results indicate at least five Candidate species within Cryptomantis. We emphasize the importance of including topotypic specimens to analyze and compare specios groups to delimiting species, like Pristimantis.
Keyko D. Loza-Carvajal, Mario H. Yánez-Muñoz, Walter Quilumbaquin and H. Mauricio Ortega-Andrade. 2025. Vast Cryptic Diversity in Direct-developing Frogs Pristimantis (Anura: Strabomantidae): A New Subgenus and the Description of A New Species from the eastern Andes of Ecuador. PeerJ. 13:e20512. DOI: doi.org/10.7717/peerj.20512 [December 17, 2025]
