Urkuphryne, Ortega & Cisneros-Heredia & Camper & Romero-Carvajal & Negrete & Ron, 2025

Urkuphryne gen. nov.

( Fig. 4 View Figure 4 )

LSID: urn:lsid:zoobank.org:act:95EC41FF-368A-4DAC-82D7-BB4F3462B89F

Order: Anura Oppel, 1811 .

Superfamily: Brachycephaloidea Günther, 1858.

Family: Strabomantidae Hedges et al., 2008 .

Subfamily: Holoadeninae Hedges et al., 2008 .

Genus: Urkuphryne gen. nov.

Type species: Urkuphryne merinoi sp. nov. (described below).

Definition ( Tables 2 View Table 2 and 3 View Table 3 ): (1) Larger than its sister genus, Phyllonastes (average adult female SVL = 19.7 mm, adult male = 17.2 mm, Table 4 View Table 4 ); (2) head wider than long, narrower than body, body robust; (3) columella, tympanic annulus and tympanic membrane present; (4) cranial crest absent; (5) finger I <finger II; (6) distal phalanges of fingers and toes rounded; (7) knees and heels without tubercles; (8) presence of inner tarsal fold; (9) fingers and toes lacking circumferential grooves and lateral dermal fringes; (10) toe V <toe III; (11) hand phalangeal formula 2-2- 3-3; foot phalangeal formula 2-2-3-4-3; (12) dark facial mask extending to the groins, triangular cloacal blotch present; (13) thin frontoparietals, longer than wide, big orbital fossae; (14) very prominent premaxillary and maxillary teeth present; (15) large nasal bones, almost in contact with maxilla; (16) zygomatic branch of squamosal shorter than otic branch; (17) large vomers with protruding vomerine teeth; (18) occipital condyles widely separated from each other; (19) prominent medial ridges present in all presacral and sacral vertebrae; (20) urostyle crest very prominent; (21) broadly expanded sacral diapophyses; (22) very large prepollex and prehallux present.

Remarks: Autapomorphies for this genus are the reduction of the distal expansion of the phalanges of fingers and toes ( Figs 7D View Figure 7 , 8 View Figure 8 ), the absence of supernumerary plantar tubercles (Supporting Information, Fig. S20 View Figure 20 ), and protruding vomerine teeth (see ‘ Diagnosis ’).

Diagnosis: Urkuphryne can be distinguished easily from its sister clade, the genus Phyllonastes by (characteristics of Phyllonastes shown in parentheses): (1) tips of fingers and toes subacuminate and rounded (tips pointed); (2) vomerine teeth present (vomerine teeth absent), and (3) larger size ( Table 4 View Table 4 ). Osteologically, Urkuphryne differs from Phyllonastes by having a shorter skull and a slightly broader maxilla, with a broader space between angulosplenials, thinner frontoparietals and larger orbital fossae (broader frontoparietals with smaller orbital fossae), bigger and more conspicuous premaxillary and maxillary teeth (premaxillary and maxillary teeth present but smaller), broader nasal bones almost in contact with the maxilla (nasal bones small, broadly separate from maxilla), vomers large and prominent, bearing protruding teeth (vomers reduced, broadly separated from each other, vomerine teeth absent), prominent medial ridges present on all presacral and sacral vertebrae (low medial ridges present only on presacral vertebrae), very prominent prepollex and prehallux (small prepollex and prehallux), and terminal phalanges rounded in fingers and toes (terminal phalanges expanded in fingers and toes).

Urkuphryne differs from Barycholos by the absence of dorsolateral folds (dorsolateral folds present), by the reduction of the distal expansion of the phalanges of fingers and toes, and by the arrangement of the vomerine teeth (small, oblique, broadly separated, and posteromedial to choanae in Urkuphryne ; and in two long arcuate series extending beyond the choana in Barycholos ). Urkuphryne can be distinguished from Bahius by the absence of circumferential grooves of fingers and toes (both present in Bahius ) and by the presence of an inconspicuous and thin inner tarsal fold (conspicuous, short, tubercle-like inner tarsal fold present in Bahius ). The presence of a tympanic membrane, tympanic annulus, and inner tarsal tubercle differentiates Urkuphryne from Euparkerella and Holoaden (tympanic membrane, tympanic annulus, and tarsal tubercle absent), two genera sequentially sister to Urkuphryne + Phyllonastes + Baryc holos + Bahius .

Content: One species, Urkuphryne merinoi sp. nov.

Etymology: The name refers to the type locality of the type species, ‘Cerro Golondrinas protective forest’ (Golondrinas hill). Urkuphryne is a compound word: Urku means ‘hill’ in the Native American Quichua language, and phryne means ‘frog’.

Distribution: Pacific Basin of Northern Ecuador, western Andean slopes at elevations 2500–2800 m a.s.l.