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

expanded, truncated, about same size as those on fingers; toes with ventral pads well defined by circumferential grooves (Fig 18D); relative length of toes I < II < III < V < IV; Toe V much longer than Toe III (tip of Toe III barely reaching the penultimate subarticular tubercle on Toe IV, tip of Toe V extends to the distal edge of distal subarticular tubercle on Toe IV). Coloration of holotype. In life (Fig 16): dorsum, upper parts of flanks, dorsal surfaces of hindlimbs and arms grayish tan with dark markings; on the middle of the back a large dark X- shaped marking is visible; the head with dark brown interorbital bar, canthal and supratympa- nic stripes; lower parts of flanks, venter, throat and ventral surfaces of hindlimbs and arms pinkish gray; iris bronze with a dark median horizontal streak and fine black reticulations. In preservative (Fig 17): the coloration of dorsum and dorsal surfaces of hindlimbs and arms dark gray, with the dark X-shaped marking evident; venter brownish gray; throat and ventral surfaces of hindlimbs and arms light gray. Measurements of holotype (in mm): SVL 20.2; HW 6.7; HL 6.6; IOD 2.2; IND 1.8; EW 1.7; ED 2.2; EN 1.8; snout to eye distance 2.9; FL 8.8; TL 9.3; FoL 7.9; HaL 5.1; Finger I length 2.4. Body mass of holotype: 0.50 g. Variation. Morphometric variation is shown in Table 1. Except for the female MUTPL 394 (Fig 19B), all specimens had a light interorbital bar flanked by a dark border. This female had the uniquely yellowish tan broad middorsal band, bordered by dark brown dorsolateral stripes

that continue onto the snout and pinkish gray flanks, dorsal surfaces of hindlimbs and arms and venter. Female MUTPL 361 (Fig 19A) had a tan background coloration with dark brown reticulum and the female MUTPL 813 (Fig 19C) had a general grayish coloration with dark markings. Two individuals, MUTPL 813 and 362, additionally had yellowish white spots of different sizes on their dorsum and flanks (Fig 19C and 19D). Several individuals had a large dark X-shaped marking on their back which in case of the female MUTPL 361(Fig 19A), male MUTPL 362 (Fig 19D) and juvenile MUTPL 733 (Fig 19F) is more or less similar to an “hour- glass” shaped marking. The male MUTPL 360 (Fig 19E) had a general dark brown coloration. Advertisement call. Unknown. Distribution. Pristimantis matildae is known only from Abra de Zamora and the Cajanuma sector from the Parque Nacional Podocarpus, about 13 km to the south (Fig 6). We were not able to encounter this species in adjacent areas, with similar ecosystems. However, about 35 km south from the type locality, we found another bromeliad specialist from the P. colodacty- lus subgroup, a genetically and morphologically similar, undescribed species. Pristimantis matildae was encountered at an altitudinal range between 2800 and 3360 m a.s.l. in subpa´ramo (Fig 2B) and shrub pa´ramo ecosystems. Natural history. This is a common species and one of the most abundant species encoun- tered inside of bromeliads. All the specimens were encountered in terrestrial or arboreal bro-

meliads or in their close proximity (perching on the leaves), during the day or night. Similarly to P. colodactylus and P. muranunka, this species displayed the same defensive behavior of rapidly retreating to the water from the bromeliads when threatened. No calling males were heard. Conservation status. Pristimantis matildae is known from only two close localities, from a small area estimated to be less than 50 km2. Nonetheless, we recommend that this species to be categorized as Near Threatened following the IUCN criteria [47], due the fact that it is a rela- tively abundant species and its habitat currently does not face any major threats (because most of the population is situated within a national protected area—Parque Nacional Podocarpus). Remarks. Pristimantis matildae is part of the P. colodactylus subgroup and is closely related to P. colodactylus, P. muranunka and an undescribed species (Fig 7). The genetic distance between P. matildae and its closest relatives from the P. colodactylus subgroup ranges between 5.4–5.8% (P. colodactylus) and 6.6–7.5% (P. muranunka) (S3 Table). 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 36 / 59