Pristimantis chomskyi, Paez, Nadia B. & Ron, Santiago R., 2019

Paez, Nadia B. & Ron, Santiago R., 2019, Systematics of Huicundomantis, a new subgenus of Pristimantis (Anura, Strabomantidae) with extraordinary cryptic diversity and eleven new species, ZooKeys 868, pp. 1-112 : 1

Pristimantis chomskyi sp. nov.

Common name.

English: Chomsky’s Rain Frog. Spanish: Cutín de Chomsky.

Holotype.

QCAZ 47515, an adult male from Tapichalaca Reserve, Zamora Chinchipe Province, Ecuador (4.4730S, 79.1930W, 3366 m), collected by Elicio E. Tapia on September 27, 2009. Figures 10B , 13A .

Paratypes

(11: 2 adult males, 9 juveniles). QCAZ 45670, QCAZ 47733, adult males, QCAZ 45664-669, QCAZ 45677, QCAZ 47730-731, juveniles, collected with the holotype.

Diagnosis.

A species of Pristimantis having the following combination of characters: (1) skin on dorsum shagreen, skin on flanks with large warts, skin on venter areolate to coarsely areolate; discoidal fold absent; dorsolateral folds absent; (2) tympanic membrane and tympanic annulus prominent, its upper and posterolateral margin concealed by thick supratympanic fold; (3) snout short, subacuminate in dorsal view, rounded in lateral view, with or without a small papilla at the tip; (4) upper eyelid lacking tubercles; cranial crests absent; (5) dentigerous processes of vomers low to prominent, oblique, moderately separated, posteromedial to choanae; (6) vocals slits, vocal sac and nuptial pads present in adult males; (7) Finger I shorter than Finger II; discs of digits expanded, rounded to elliptical; (8) fingers with lateral fringes; (9) ulnar tubercles low, diffuse; (10) heel bearing one small low rounded tubercle; inner edge of tarsus with or without a low tubercle or small fold; outer edge of tarsus with or without indistinct tubercles; (11) inner metatarsal tubercle elliptical, elevated, about 4 times the size of round outer metatarsal tubercle; supernumerary tubercles low; (12) toes with lateral fringes; basal webbing on feet; Toe V longer to much longer than Toe III (disc on Toe III reaches or exceeds distal edge of the penultimate subarticular tubercle on Toe IV, disc on Toe V reaches the middle to distal edge of the distal subarticular tubercle on Toe IV); toe discs smaller than those on fingers ( Fig. 7B ); (13) in life, dorsum dark brown to orange; head bears brown supratympanic and canthal stripes; groins, axils and concealed surfaces of hindlimbs dark chocolate brown suffused or not with orange, with or without small cream flecks; venter cream to dusty brown with or without dark markings; iris orange with a faint reddish brown medial horizontal streak and thin black reticulations ( Fig. 13 ); (14) average SVL in adult males: 28.0 ± 4.2 mm (24.0-32.4 mm; n = 3); females: unknown.

Comparison with other species.

Pristimantis chomskyi is similar to P. balionotus , P. gloria sp. nov., P. lutzae sp. nov., and P. multicolor sp. nov. The most similar is its sister species P. multicolor sp. nov. The region above supratympanic fold is more swollen in P. chomskyi . In addition, P. chomskyi has a smaller tympanum (males Z = 2.38157, p = 0.0172, TD/SVL = 4.5-4.7% in P. chomskyi , 4.9-6% in P. multicolor sp. nov.). Pristimantis balionotus can be distinguished from P. chomskyi because it has a tuberculate dorsal skin, lacks basal webbing between toes, and its iris is bronze with a red medial streak (shagreen dorsal skin, basal webbing between toes, iris orange with a faint reddish-brown streak in P. chomskyi ). Pristimantis chomskyi is easy to distinguish from P. gloria sp. nov. by the coloration of the iris (orange with a faint reddish brown streak and thin black reticulations in P. chomskyi ; light silver to cream with wide black reticulations and a red streak in P. gloria sp. nov.) and groins (dark chocolate brown with or without small cream flecks in P. chomskyi ; pinkish to purplish brown with irregular cream to light brown flecks or spots in P. gloria sp. nov.), and the texture of the dorsal skin (shagreen without a middorsal fold in P. chomskyi ; tuberculate to warty with a middorsal fold in P. gloria sp. nov.). Furthermore, P. gloria sp. nov. is smaller (males Z = -2.31490, p = 0.0206, SVL = 24.0-32.4 mm in P. chomskyi , 16.7-24.7 mm in P. gloria sp. nov.), has larger tympanum (males Z = 2.66173, p = 0.0078, TD/SVL = 4.5-4.7% in P. chomskyi , 5.1-6.2% in P. gloria sp. nov.) and smaller eye (males Z = -2.50743, p = 0.0122, ED/SVL = 11.1-12% in P. chomskyi , 11-13.8% in P. gloria sp. nov.), relative to its body length. Pristimantis lutzae sp. nov. differs from P. chomskyi in having a golden to creamy brown iris with a reddish brown streak, a larger tympanum (males Z = 2.45677, p = 0.0140, TD/SVL = 4.5-4.7% in P. chomskyi , 5-5.4% in P. lutzae sp. nov.) and smaller eye (males Z = -2.45677, p = 0.0140, ED/SVL = 11.1-12% in P. chomskyi , 10.3-12.1% in P. lutzae sp. nov.), relative to its body length.

Description of the holotype.

An adult male (QCAZ 47515, SC29227). Measurements (in mm): SVL 24.0; TL 12.0; FL 11.6; HL 8.8; HW 9.4; ED 2.9; TD 1.1; IOD 3.3; EW 2.6; IND 2.4; EN 2.4; TED 1.1. Head wider than long, narrower than body; snout subacuminate in dorsal view, rounded in profile, with a small papilla at the tip; cranial crests absent; nostrils slightly protuberant, directed anterolaterally; canthus rostralis slightly concave in dorsal view, rounded in cross section; loreal region concave; upper eyelid lacking tubercles; tympanic annulus prominent, its upper and posterolateral edge concealed by thick, heavy supratympanic fold; tympanic membrane distinct; two prominent postrictal tubercle not surrounded by smaller tubercles. Choanae median, ovoid, non-concealed by palatal shelf of maxilla; dentigerous processes of vomers prominent, oblique, moderately separated, positioned posteromedial to choanae; each vomer bearing several indistinct teeth; tongue slightly longer than wide, not notched, posterior half free; vocal slits slightly curved, positioned at posterior half of mouth floor in between tongue and margin of jaw; small vocal sac.

Dorsal surfaces of body shagreen; dorsolateral folds absent; skin on flanks bearing low rounded warts; skin on chest and belly areolate, that on throat shagreen, ventral surfaces of limbs smooth, ventral surfaces of thighs coarsely areolate; discoidal fold absent. Diffuse ulnar tubercles; nuptial pads present; outer palmar tubercle bifid, as large as ovoid thenar tubercle; subarticular tubercles prominent, rounded; large supernumerary tubercles at base of fingers, distinct; fingers bearing lateral fringes; Finger I shorter than Finger II; discs on fingers expanded and rounded; pads on fingers surrounded by circumferential grooves on all fingers ( Fig. 7B ).

Hindlimbs slender; dorsal surfaces of hindlimbs shagreen; posterior surfaces of thighs smooth, ventral surfaces of thighs coarsely areolate; heel bearing one low and rounded tubercle; outer and inner edge of tarsus lacking tubercles; inner metatarsal tubercle elliptical, elevated, 4 times the size of oval outer metatarsal tubercle; plantar surface with small, low and rounded supernumerary tubercles; subarticular tubercles prominent, rounded; toes bearing lateral fringes; basal webbing between toes III and IV, and IV and V; discs on toes smaller than those on fingers, expanded and rounded; 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 reaches the distal edge of penultimate subarticular tubercle on Toe IV, disc on Toe V reaches the distal edge of distal subarticular tubercle on Toe IV; Fig. 7B ). Coloration of the holotype in life and preservative is shown in Figures 10A , 13A .

Coloration of holotype in preservative. Dorsal surfaces of body and flanks cream covered by minute brown spots evenly distributed; brown supratympanic and canthal stripes; groins, anterior, and posterior surfaces of thighs, shanks and tarsus brown; venter, belly and throat cream suffused with dusty brown irregular spots; belly with dark brown blotches (this pattern does not correspond with coloration in life, probably effect of preservation); ventral surfaces of limbs dusty cream; ventral surfaces of fingers and toes cream ( Fig. 10B ).

Coloration of holotype in life. Based on studio photographs. Dorsal surfaces of body and flanks orange-hued brown covered by minute chocolate brown spots evenly distributed; brown supratympanic and canthal stripes; groins, anterior and posterior surfaces of thighs, shanks and tarsus chocolate brown; venter yellowish cream covered by chocolate brown spots coinciding with areolation pattern; throat orange suffused with brown; ventral surfaces of thighs, shanks, and tarsus reddish orange suffused with brown; plantar and palmar surfaces orange; iris orange with a faint reddish brown medial horizontal streak and thin black reticulations ( Fig. 13A ).

Variation.

Based on the 12 preserved specimens of the type series and photographs from eight individuals. Variation in life and preservative is shown in Figures 13 , 14 . Coloration in life is given in parenthesis. Dorsum and flank coloration vary from brown to brownish cream (dark brown to orange). Dorsal markings may be absent or present as longitudinal stripes or dark blotches evenly scattered; one individual has a pale blotch on dorsum. All individuals have brown supratympanic and canthal stripes; some also have dark interorbital stripe and labial bars. Color of groins, armpits, dorsal surfaces of thighs, concealed surfaces of thighs, shanks and tarsus is dark brown (dark chocolate brown, suffused or not with orange, with or without small cream flecks), few individuals with small pale flecks; dorsal surfaces of thighs and groins can have irregular pale spots. Limbs bear scattered small dark spots arranged or not as transversal bands. Venter varies from cream to dusty brown with or without dark markings (orange, cream, or dusty brown, with or without darker flecks or mottling). The iris is orange with a faint red medial streak and thin black reticulations. Sclera varies from white to light blue.

Distribution, natural history, and conservation status.

This species is only known from the type locality, Tapichalaca Reserve, Zamora Chinchipe Province, Ecuador at 3366 m a.s.l ( Fig. 1 ), which corresponds to the Paramo biogeographic region. All individuals were found at night inside bromeliads, mostly of the genus Puya . Tapichalaca Reserve is adjacent to Podocarpus National Park (northward) and Yacuri National Park (southward). Both areas are unexplored and represent potential habitats for this species. Therefore, we assign P. chomskyi to the Data Deficient Red List Category ( IUCN 2017).

Etymology.

The specific epithet is a noun in the genitive case and is a patronym for Noam Chomsky, US born theoretical linguist and one of the most cited modern scholars. Chomsky is the founder of modern linguistics. He developed the concept of "universal grammar," an innate cognitive capacity, shared by all humans, which allows to learn and communicate through complex speech. Chomsky was professor at the Massachusetts Institute of Technology between 1950 and 2017. He is currently professor at Arizona State University.

Figures

Figure 1. Distribution of Pristimantis, subgenus Huicundomantis. Records are based on specimens deposited at the Museum of Zoology, Pontificia Universidad Catolica del Ecuador (QCAZ). Locality information is shown in Suppl. material 2.

Figure 7. Palmar and plantar surfaces of Pristimantis atillo sp. nov., Pristimantis chomskyi sp. nov., Pristimantis gloria sp. nov., and Pristimantis jimenezi sp. nov. Photographs of left hand and foot of the holotypes A Pristimantis atillo sp. nov.: QCAZ 42500, male B Pristimantis chomskyi sp. nov.: QCAZ 47515, male C Pristimantis gloria sp. nov.: QCAZ 57201, female D Pristimantis jimenezi sp. nov.: QCAZ 45170, male. All specimens are shown at the same scale.

Figure 10. Holotypes of Pristimantis atillo sp. nov. and P. chomskyi sp. nov. Photographs of preserved holotypes of A P. atillo (QCAZ 42500, male) and B P. chompskyi (QCAZ 47515, male). Dorsal view on the left, ventral view on the right. Specimens are shown at the same scale.

Figure 13. Color variation in live individuals of Pristimantis chomskyi sp. nov. A QCAZ 47515 (holotype, male, SVL 24.0 mm) B QCAZ 45669 (juvenile male, SVL 21.4 mm) C QCAZ 45665 (juvenile female, SVL 19.7 mm) D QCAZ 45666 (juvenile female, SVL 21.9 mm). Dorsal view on the left, ventral view on the right.

Figure 14. Color variation in preserved individuals of Pristimantis chomskyi sp. nov. A Dorsal view of (from left to right): QCAZ 45670 (male), QCAZ 47731 (juvenile female), QCAZ 45667 (juvenile male), B Dorsal view of: QCAZ 45669 (juvenile male), QCAZ 45670 (male), QCAZ 45666 (juvenile female) C Ventral view of specimens in (A) D Ventral view of specimens in B See Suppl. material 2 for locality data. All specimens are shown at the same scale.