Fifty years after: A taxonomic revision of the amphibian species from the Ecuadorian biodiversity hotspot Abra de Zamora, with description of two new Pristimantis species

Natural history. This is a rare or hard to detect species. Lynch [9] described the species with only two specimens and only four more specimens were collected afterwards, in 1984 by W.E. Duellman, all from the type locality. Aguirre Mendoza et al. [52] found only seven indi- viduals through 21 sampling days, from December 2009 to April 2010, in Parque Nacional Podocarpus (Cajanuma sector). We encountered two females and a subadult, all during one night of our ongoing fieldwork carried out in this area since 2018. All specimens were encoun- tered during the night, perching on the vegetation (on leaves of Neurolepis sp., Valeriana sp. or of bromeliads) at 10 to 40 cm above the ground. No calling males were heard. Conservation status. Pristimantis percultus is currently categorized as Endangered based on criteria B1ab(iii) [53]. We suggest maintaining this category because, its Extent of occur- rence (EOO) and Area of occupancy (AOO) are estimated to be less than 50 km2, it is known from only two locations and it is possible that there is a decline in the number of locations or subpopulations. Remarks. Lynch [9] provides a detailed description of this species. Our diagnosis concurs with all the morphological features described by the author, to which we add descriptions of the characters that are more evident in life. The diagnosis provided herein is based on two specimens from the original description (KU 166057, 166058), two adult females (MUTPL 810, 812) and one subadult (MUTPL 811) collected from about 12 km south to the type locality.

Pristimantis percultus is part of the P. phoxocephalus group, and is closely related to P. chomskyi, P. andinogigas, P. atratus and P. multicolor. However, its exact kinship to these spe- cies remains non-resolved (Fig 21). The genetic distance between P. percultus and its closest relatives ranges between 3.3–3.7% (P. chomskyi) and 4% (P. multicolor) (S3 Table). Pristimantis balionotus (Lynch, 1979) (Fig 25) Eleutherodactylus balionotus Lynch, 1979 Eleutherodactylus (Eleutherodactylus) balionotus: Lynch and Duellman, 1997 Pristimantis balionotus: Heinicke, Duellman, and Hedges, 2007 Pristimantis (Pristimantis) balionotus: Hedges, Duellman, and Heinicke, 2008 Pristimantis (Huicundomantis) balionotus: Pa´ez and Ron, 2019 Common English name. Speckled Rain Frog (This is a newly proposed name as it is more appropriate than the previous one, “Crest Robber Frog”). Common Spanish name. Cutı´n de lomo manchado Etymology. Greek, meaning speckled back, in reference to the predominant color pattern. Holotype. KU 142136, an adult female from 13.5 km E Loja, at the crest of the Cordillera (Abra de Zamora) between Provincia Loja and Provincia Zamora-Chinchipe, Ecuador, 2800 m, obtained on 22 July 1971 by William E. Duellman. Paratypes. KU 142135, KU 142137–44, collected syntopically with the holotype. Diagnosis. Pristimantis balionotus is a medium sized species distinguished by the following combination of traits: (1) skin on dorsum tuberculated (in life the skin tuberculated texture is more evident); skin on venter coarsely areolate; discoidal fold weak; dorsolateral folds absent;

(2) tympanic annulus evident and tympanic membrane differentiated, its length about 49% of the length of eye; supratympanic fold present; (3) snout subacuminate in dorsal view, rounded in profile; canthus rostralis weakly concave in dorsal view, rounded in profile; (4) upper eyelid bearing several small tubercles, similar in size and shape with the ones from the dorsum, about 88% IOD in females and 84% IOD in males; cranial crests absent; (5) dentigerous processes of vomers prominent, oblique, ovoid, separated medially by distance equal or lower than the width of processes; each processes bearing 2 to 4 teeth; (6) males with a subgular vocal sac and vocal slits; nuptial pads absent; (7) Finger I shorter than Finger II; discs on fingers broadly PLOS ONE Taxonomic revision of the amphibian species from Abra de Zamora PLOS ONE | https://doi.org/10.1371/journal.pone.0238306 September 10, 2020 44 / 59