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

Holotype. BMNH 1947.2.16.11 (formerly 1935.11.3.16), adult female from 15 km East of Loja City, Ecuador, 3000 m, collected by C. Carrio´n. Paratypes. BMNH 1947.2.16.12–14 (formerly 1935.11.3.17–20), a male and three immature females from the type locality. Diagnosis. Lynchius flavomaculatus is a large species distinguished by the following combi- nation of traits: (1) skin on dorsum shagreen (trait more visible in life) and of the flanks smooth; dorsolateral folds absent; low middorsal fold present (trait more visible in life); skin on venter smooth; discoidal and thoracic folds absent; (2) tympanic membrane and annulus distinct; large supratympanic fold obscuring upper and posterodorsal edges of tympanum; one large, elongated postrictal tubercle present; (3) snout short, rounded in dorsal view, slightly inclined anteroventrally in profile; canthus rostralis weakly concave in dorsal view, angular in profile; (4) upper eyelid without tubercles; low, cranial crests present; (5) dentigerous processes of vomers prominent, triangular, with 4 to 5 teeth; (6) males with vocal slits on each side of the tongue and no nuptial pads; (7) fingers long and slender; Finger I longer than Finger II; tips of digits narrow, not expanded, rounded; circumferential grooves absent; fingers lacking lateral fringes; (8) subarticular tubercles prominent, round; supernumerary palmar tubercles large, rounded, smaller than subarticular tubercles; palmar tubercle partially divided into a much larger (inner) and a smaller (outer) tubercles; thenar tubercle prominent, elliptical; (9) ulnar

tubercles absent; (10) heel lacking tubercles; outer edge of tarsus lacking tubercles; inner edge of tarsus lacking tubercles or fold; (11) inner metatarsal tubercle elliptical, about 2x round outer metatarsal tubercle; subarticular tubercles prominent, subconical; supernumerary plan- tar tubercles absent; (12) toes long and slender; Toe V slightly shorter than Toe III; tips of digits narrow, not expanded, rounded; circumferential grooves absent; toes without lateral fringes; webbing absent; (13) in life, dorsum mottled tan, reddish or dark brown, dull greenish gray or yellow; flanks yellow with or without brown spots; venter mostly yellow, with or with- out gray on the throat; throat light gray with yellow blotches; yellow blotches on groin and anterior surfaces of thighs; iris pale green, with a brown median horizontal streak, and fine black reticulations; (14) SVL 34.6–44.2 mm in adult females (n = 31) and 24.0–35.2 mm in adult males (n = 27) [27] (data regarding the SVL contains individuals from several locations, and probably include specimens belonging to other, cryptic, currently undescribed species than L. flavomaculatus). Advertisement call. Unknown. Release call. When caught and manipulated, the female MUTPL 342 emitted low, short, screeching calls (Fig 5), which we interpreted as release calls (calls usually emitted during amplexus or after being touched by other males, when the amplexus is not desired by the amplected individual, [38]), and not distress calls (calls emitted during subjugation by a poten-

tial predator). We base this observation on the fact that the distress call of a similar, unde- scribed, Lynchius species is very different (long, loud shrieking sounds; pers. obs.). We recorded several of these calls in the laboratory, from a 20 cm distance, while holding the female by the sides of its body, in the axillary and inguinal regions, simulating an amplexus (S4 Table). The calls are single-pulsed notes (tonal sounds) characterized by a duration of (range and mean ± SD in parenthesis) 0.026–0.041 s (0.033 ± 0.006, n = 6), a dominant frequency of 2239.5–3100.8 Hz (2555.3 ± 343.088, n = 6) and a 90% bandwidth range of 2153.3–2842.4 Hz (2426.1 ± 295.4, n = 6) to 2325.6–3186.9 Hz (2641.4 ± 343.088, n = 6). The fundamental fre- quency and harmonics are not recognizable. Distribution. Currently, the presence of L. flavomaculatus is confirmed (with DNA sam- ples) only from Parque Nacional Podocarpus (Cajanuma entrance), in a shrub pa´ramo eco- system [44], from about 13 km south to the type locality, Abra de Zamora, in Loja province (Fig 6). Despite intensive searches, we did not find any individuals in the type locality. Based 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 11 / 59