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

present; choanae large, oval, not concealed by palatal shelf of maxillary arch; dentigerous pro- cesses of vomers concealed in buccal mucosa but each processes bearing two teeth; tongue 0.5x as long as wide, slightly notched posteriorly, posterior half not adherent to floor of mouth; vocal sac, vocal slits and nuptial pads absent. Skin on dorsum and flanks finely tuberculated (trait more visible in life, Fig 16A and 16C); thin, low middorsal fold starting at tip of snout and ending at cloaca; dorsolateral folds absent; skin on chest, belly, and ventral surfaces of thighs areolate; thoracic and discoidal folds absent (Figs 16B and 17B); cloacal region bordered ventrally by two large, oval, tubercles. Ulnar tubercles absent; outer palmar tubercle prominent, completely divided into a larger (inner) and a smaller (outer) tubercles; thenar tubercle ovoid, larger than the inner palmar tubercle; subarticular tubercles prominent, round and rounded in section; supernumerary pal- mar tubercles rounded, smaller than subarticular tubercles; fingers bearing lateral fringes; rela- tive length of fingers I < II < IV < III; discs on fingers slightly expanded, truncated; all fingers bearing pads well defined by circumferential grooves (Fig 18C). Hindlimbs long; tibia length 46% of SVL; foot length 39% of SVL; heel with several small tubercles; outer edge of tarsus with a row of small, inconspicuous, tubercles (trait more visible in life); inner edge of tarsus bearing a long fold; inner metatarsal tubercle broadly ovoid, about

3x elongated and rounded outer metatarsal tubercle; subarticular tubercles prominent, round and rounded in section; plantar supernumerary tubercles rounded, smaller than subarticular tubercles; toes bearing prominent lateral fringes; webbing basal; discs on toes slightly Fig 20. Relative size of the fingers and toes in Pristimantis colodactylus (MUTPL 388, SVL 20.5 mm), P. muranunka (MUTPL 652, SVL 20.1 mm) and P. matildae sp. nov. (Holotype, MUTPL 731, SVL 20.2 mm). https://doi.org/10.1371/journal.pone.0238306.g020 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 35 / 59