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

dark flecks; no markings in axilla, groin or on concealed limb surfaces; iris light bronze with a reddish median horizontal streak and fine black reticulations; (14) SVL 16.5–25.8 mm in adult females [9] and 14.0–20.7 mm in adult males [9]. Variation. Morphometric variation is shown in Table 1. The five encountered specimens had variable coloration (Fig 15). Both female MUTPL 311 (Fig 15A) and juvenile MUTPL 732 (Fig 15E) had a dark X-shaped marking on their back (equivalent to what Lynch described as “hour-glass” [9]), but the female had a general grayish coloration with light and dark brown spots and stripes, while the juvenile had a general reddish brown coloration. Both female MUTPL 388 (Fig 15B) and male MUTPL 675 (Fig 15C) had a dark brown middorsal band, but the female had darker flanks and members than the male. The coloration of the male MUTPL 675 is very similar to that of the holotype KU 142151, where the dark brown middorsal band is bordered by light whitish dorsolateral stripes that continue onto the snout (Fig 15C). The col- oration of juvenile MZUA 2491 (Fig 15D) is very similar with that of the male specimen KU 165219 (Fig 3D in [9] and Fig 139 in [25]), with dark brown dorsum and whitish yellow inter- orbital bar and snout. Advertisement call. Unknown. Distribution. For now, P. colodactylus presence is confirmed (with DNA samples) from only a small area in its type locality, Abra de Zamora (Fig 6). The majority of specimens were encountered outside of Parque Nacional Podocarpus borders. We did not encounter this spe-

cies in the Cajanuma sector of the Parque Nacional Podocarpus (about 13 km to the south), which has a similar species composition to Abra de Zamora. The presence of this species in Azuay and Morona Santiago provinces [9] is yet to be confirmed. We consider this highly unlikely, and that it is more plausible that these are different, currently undescribed species. Also, it is almost certain that the animals from Peru [9, 25] are different, undescribed species, taking into consideration the great distance from the type locality. Even Lynch noted some morphological differences between the specimens from the type locality and the ones from central Ecuador and Peru (see Table 1 in [9]). The species was encountered at an altitudinal range between 2800 and 2820 m a.s.l. in a subpa´ramo ecosystem (Fig 2B). Natural history. This species shares the same microhabitat (bromeliads) with P. matildae sp. nov., which dominates in term of abundance. It is a rare species. Between 2016 and 2020, in Abra de Zamora, we encountered only five specimens of P. colodactylus. This is a bromeliad specialist that most likely spends its entire life inside or nearby these plants. The short fingers of the species of the P. colodactylus subgroup (Fig 7) are probably adaptations for the life inside bromeliads, and possibly help to increase the adhesivity of the hands and feet [29]. Four speci- mens were found inside bromeliads (both terrestrial and arboreal) during the day or night. One specimen (MUTPL 675) was found outside, on the leaf of a bromeliad (probably forag-

ing), and when it detected our presence rapidly retreated backwards to the water inside the plant. No calling males were heard. Conservation status. Pristimantis colodactylus is currently categorized as Least Concern [50]. However, this assessment was done by considering the records from the provinces of Azuay and Morona Santiago and from Peru. Based on the available (revised) information we consider P. colodactylus to be Critically Endangered following the B1ab(iii,iv)+2ab(iii,iv) IUCN criteria [47] because: (1) its Extent of occurrence (EOO) and Area of occupancy (AOO) are estimated to be less than 10 km2; (2) it is known from only one location; and (3) its habitat could be severely affected in the near future by deforestation, as it is situated mostly outside a protected area and in the vicinity of a densely populated area. Remarks. Lynch [9] provides a detailed description of this species, including a brief description of the cranial osteology. Our diagnosis concurs with the morphological features described by the author (one small difference would be the coloration of the iris that we found 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 30 / 59