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

tubercle; subarticular tubercles prominent, round and subconical in section; supernumerary palmar tubercles rounded, large, just slightly smaller than subarticular tubercles; fingers lack- ing lateral fringes; relative length of fingers I < II < IV < III; discs on fingers just slightly expanded, rounded; all fingers bearing pads well defined by circumferential grooves (Fig 12C). Hindlimbs short; tibia length 40% of SVL; foot length 38% of SVL; heel with several small tubercles; outer edge of tarsus with a row of small tubercles (trait more visible in life); inner edge of tarsus bearing a long fold; inner metatarsal tubercle broadly ovoid, about 3x elon- gated and subconical outer metatarsal tubercle; subarticular tubercles prominent, ovoid and subconical in section; plantar supernumerary tubercles ovoid, large, just slightly smaller than subarticular tubercles; toes lacking lateral fringes; webbing basal; discs on toes just slightly expanded, rounded, about same size as those on fingers; toes with ventral pads well defined by circumferential grooves (Fig 12D); relative length of toes I < II < III < V < IV; Toe V slightly longer than Toe III (tip of Toe III barely reaching the penultimate subarticular tuber- cle on Toe IV, tip of Toe V not reaching the proximal edge of distal subarticular tubercle on Toe IV). Coloration of holotype. In life (Fig 10): dorsum, flanks, dorsal surfaces of hindlimbs and arms dark brown with various yellowish white, irregular spots; venter and throat gray, without

spots; iris whitish gray with a dark bronze, broad, median horizontal streak and with fine black reticulations. In preservative (Fig 11): the coloration of dorsum, flanks and dorsal surfaces of hindlimbs became dark gray and the spots light gray; dorsal surfaces of arms, venter and throat became light gray. Measurements of holotype (in mm): SVL 20.1; HW 6.6; HL 6.1; IOD 2.5; IND 2.0; EW 1.6; ED 2.2; EN 1.8; snout to eye distance 2.6; FL 7.7; TL 8.1; FoL 7.6; HaL 4.8; Finger I length 2.2. Body mass of holotype: 0.80 g. Variation. Morphometric variation is shown in Table 1. This species displays an evident sexual dimorphism. The females are larger, and are dark brown with various white, irregular spots and have a dark gray venter (Fig 13A, 13B and 13C). One female (MUTPL 676, Fig 13B) had a whitish orange low middorsal fold. The same individual had very distinctive white lines on the center of the venter and throat, ventral surfaces of hindlimbs and arms. The males have lighter colors of the dorsum that varies from uniform light brown (MUTPL 674, Fig 13E), to reddish brown dorsum and light green and gray flanks (MUTPL 358, Fig 13D). The male MUTPL 356 (Fig 13A) had a bright red coloration of the dorsum and dorsal surfaces of hin- dlimbs and arms and gray flanks. The venter coloration of the males varied from pinkish white to light gray. None of the males had the characteristic white spots of the females. In all speci- mens, the supratympanic fold was black. Advertisement call. The advertisement call of one male from Abra de Zamora was

recorded in in 2017 and of four males from Cajanuma in 2018. Descriptive statistics of the acoustic variables are provided in Table 2 (the detailed information of each of the separate recordings is presented in the S4 Table). Pristimantis samaniegoi has an advertisement call characterized by a call series composed by clicking calls repeated for long periods of time, simi- lar to the calls of P. tiktik and P. vidua (Fig 14). The calls are composed by two short, single- pulsed notes (tonal sounds). The male MUTPL 356 (FUTPL-A-241) had the calls composed by only one note but it is possible that this is actually a recording artifact. Because the males can call continuously for long periods of time, the call series duration is unknown. The calls are characterized by a mean duration of 0.027 s (SD = 0.008), a mean inter-call interval of 0.272 s (SD = 0.027) and a mean call rate of 185.9 calls/min (SD = 25.398). The mean dominant fre- quency of the call was 3140.3 Hz (SD = 144.886), with a mean 90% bandwidth of 2994.4– 3496.2 Hz. The fundamental frequency is not recognizable but 3 to 4 harmonics are visible. 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 26 / 59