English: Nangaritza Rain Frog. Spanish: Cutín de Nangaritza.

QCAZ 41710, an adult female from Alto Nangaritza Protected Forest, Las Orquídeas, Tepuy Forest, Zamora Chinchipe Province, Ecuador (4.2620S, 78.6902W, 1809 m), collected by Elicio E. Tapia on April 18, 2009. Figure 38.

(17: 13 males, 3 females, 1 juveniles). All from Alto Nangaritza Protected Forest, Las Orquídeas, Tepuy Forest. Ecuador: Zamora Chinchipe Province: QCAZ 41704–708, QCAZ 41725–726, QCAZ 41728–729, QCAZ 41731–733, adult males, QCAZ 41734–736, adult females, QCAZ 41730, juvenile (4.2632S, 78.6911W, 1843 m), collected by Elicio E. Tapia, Jessica Loe Deichmann, Amable Fermín Jiménez and Holger Braun in April 2009; QCAZ 41709, adult male (4.2567S, 78.6780W, 1820 m), collected by Elicio E. Tapia and Jessica Loe Deichmann in April 2009.

A species of the Pristimantis cryptomelas group with the following combination of characters: (1) dorsal surfaces finely tuberculate; middorsal fold present or absent; head with a middorsal row of two small tubercles; dorsolateral folds absent; thin lateral folds on anterior half of flanks present or absent; skin on venter coarsely areolate; discoidal fold present or absent;) (-shaped postocular folds; (2) tympanic membrane and tympanic annulus prominent, its upper and posterior margin concealed by thick supratympanic fold; (3) snout moderately long, subacuminate in dorsal view, rounded in profile; (4) upper eyelid with subconical tubercles surrounded by several smaller tubercles; cranial crests absent; (5) dentigerous processes of vomers prominent, oblique, narrowly to broadly separated, posteromedial to choanae; (6) vocals slits and white nuptial pads present in adult males; vocal sac not externally expanded; (7) Finger I shorter than Finger II; discs of digits broadly expanded, rounded to elliptical; (8) fingers with lateral fringes; (9) low ulnar tubercles; (10) heel bearing a subconical tubercle surrounded by smaller tubercles; inner and outer edge of tarsus bearing low tubercles; short inner tarsal fold; (11) inner metatarsal tubercle ovoid, elevated five times the size of round outer metatarsal tubercle; supernumerary tubercles numerous; (12) toes with lateral fringes; basal webbing barely evident; Toe V longer or much longer than Toe III (disc on Toe III reaches the middle or exceeds distal edge of penultimate subarticular tubercle on Toe IV, disc on Toe V reaches the middle or exceeds distal edge of distal subarticular tubercle on Toe IV); toe discs smaller than those on fingers, elliptical (Fig. 8C); (13) in preservative, dorsum light to dark brown with darker markings including a scapular W, irregular chevrons and interorbital stripe, or a pattern of longitudinal stripes; head with black or dark brown supratympanic, canthal and labial vertical bars; flanks with oblique pale bars that merge with ventral coloration; posterior surfaces of thighs light brown with or without minute pale flecks; groins with the same coloration as posterior surfaces of thighs or venter; venter and throat cream with different levels of brown mottling (Fig. 39); (14) average SVL in adult females: 29.1 ± 2.7 mm (25.9–32.4 mm; n = 4); in adult males: 18.8 ± 1.1 mm (17.4–20.5 mm; n = 13).

It is most similar to P. cryptomelas, P. gagliardoi, P. muscosus, P. spinosus, and P. versicolor. The postocular folds of P. nangaritza are lower than those of P. cryptomelas, the background color of the posterior surfaces of thighs is light brown instead of black, its body is smaller (Table 5), and males have vocal slits (absent in males of P. cryptomelas). Pristimantis gagliardoi can be distinguished from P. nangaritza by having W-shaped postocular folds (“) (”-shaped in P. nangaritza), smaller tympanum (Table 5), and by lacking vocal slits. Pristimantis muscosus has smaller tubercles on the upper eyelid (round in P. muscosus; subconical in P. nangaritza), lacks tubercles on the inner edge of tarsus (present in P. nangaritza), and have dark brown or black groins. Pristimantis spinosus differs from P. nangaritza in having low cranial crests (absent in P. nangaritza) and black posterior surfaces of thighs with white spots. Pristimantis versicolor is readily recognized from P. nangaritza by lacking postocular folds and having a proportionally larger tympanum (females Z = 2.16506, p = 0.0304 TD/SVL = 4.7–5.9% in P. nangaritza, 5.2–7.2% in P. versicolor; males Z = 3.45394, p = 0.0006, TD/SVL = 5.1–5.4% in P. nangaritza, 5.8–6.4% in P. versicolor).

An adult female (QCAZ 41710, SC28142). Measurements (in mm): SVL 32.4; TL 15.5; FL 13.4; HL 12.2; HW 12.1; ED 3.7; TD 1.7; IOD 3.1; EW 3.5; IND 2.5; EN 3.7; TED 1.2. Head longer than wide, wider than body; snout moderately long, subacuminate in dorsal view, rounded in profile; cranial crests absent; nostrils slightly protuberant, narrow, directed laterally with slight dorsal inclination; canthus rostralis concave in dorsal view, sharp in cross section; loreal region slightly concave; upper eyelid with subconical tubercles, those on posterior half larger; tympanic membrane distinct; tympanic annulus prominent, its upper and posterior edge concealed by supratympanic fold; two small prominent postrictal tubercles. Choanae large, circular, not concealed by palatal shelf of maxillae; dentigerous processes of vomers prominent, oblique, narrowly separated, positioned posteromedial to choanae; each vomer bearing several distinct teeth; tongue as long as wide, posteriorly notched; posterior third not adherent to the floor of mouth.

Dorsal surfaces of body finely tuberculate; dorsolateral folds absent; bearing) (-shaped postocular folds; skin on venter coarsely areolate, ventral surfaces of limbs smooth, ventral surfaces of thighs coarsely areolate; weak discoidal fold. Low median ulnar tubercles; outer palmar tubercle bifid, twice the size of ovoid thenar tubercle; subarticular tubercles prominent, rounded; prominent supernumerary tubercles at the base of fingers, slightly smaller than subarticular tubercles; fingers bearing lateral fringes; Finger I shorter than Finger II; discs on fingers broadly expanded, rounded; pads on fingers surrounded by circumferential grooves on all fingers (Fig. 8C).

Hindlimbs slender; dorsal surfaces of hindlimbs finely tuberculate; posterior surfaces of thighs smooth, ventral surfaces of thighs coarsely areolate; heel bearing a medium sized, subconical tubercle surrounded by several smaller tubercles; outer and inner edge of tarsus bearing low tubercles; inner tarsal fold present; inner metatarsal tubercle ovoid, elevated 5 × the size of round outer metatarsal tubercle; supernumerary tubercles prominent at the base of each toe, those on plantar surface distinct, but low; subarticular tubercles prominent, rounded; toes bearing lateral fringes; basal webbing barely evident between toes IV and V; discs on toes smaller than those on fingers, expanded and elliptical; all toes having pads surrounded by circumferential grooves; relative lengths of toes: I < II < III < V < IV; Toe V longer than Toe III (disc on Toe III exceeds distal edge of penultimate subarticular tubercle on Toe IV, disc on Toe V exceeds the distal of distal subarticular tubercle on Toe IV; Fig. 8C). Color of the holotype in preservative is shown in Figure 38; coloration in life is unknown.

Coloration of holotype in preservative. Dorsum light brown with lighter irregular reticulations and a W-shaped scapular mark bordered by dark brown lines; head with dark brown canthal, supratympanic, and labial bars; flanks with cream oblique cream bars bordered by dark brown spots and lines; groins, and concealed surfaces of thighs dark brown with scattered cream flecks; venter cream and ventral surfaces of thighs cream; throat cream with brown mottling; ventral surfaces of limbs dusty cream (Fig. 38).

Coloration of holotype in life. Unknown.

This section is based on 18 specimens of the type series. In preservative, dorsum varies from light to dark brown with darker markings including a scapular W, irregular chevrons, and interorbital stripe. Some individuals have a pattern of longitudinal parallel stripes. Posterior surfaces of thighs are brown with or without minute pale flecks. Groins with the same coloration as posterior surfaces of thighs or venter. Venter cream with varying amount of brown mottling. This variation is shown in Figure 39. Coloration in life is unknown.

Pristimantis nangaritza is only known from its type locality, Alto Nangaritza Protected Forest, Zamora Chinchipe Province, Ecuador, a low vegetation forest with bromeliads, orchids, moss, and Podocarpus trees that belongs to the Eastern Foothill Forest, between 1809 and 1843 m a.s.l. (Fig. 1). Individuals were found active at night on branches, 1–2 m above ground. Calling males were found in April.

We consider it as a Data Deficient species because adjacent areas in Alto Nangaritza Protected Forest are difficult to access and poorly explored.

The specific epithet refers to the type locality of this species, Alto Nangaritza Protected Forest. This protected area preserves native vegetation of the Cordillera del Cóndor and hosts unique geologic formations in Ecuador, called Tepuyes. This reserve is largely unexplored and is currently threatened by the potential opening of roads for mining activities; 80% of its territory is under mining concessions.