Telmatobius degener Wiens 1993

Telmatobius degener belongs to a clade where there are no proposed synapomorphies supporting the monophyly of Telmatobius, Telmatobiini, Telmatobinae, or Leptodactylidae, though the presumptive synapomorphies for the group are (1) frontoparietals fused posteriorly, and (2) nuptial excresence on Finger 1 only (which are not universal across all Telmatobius). T. degener can be differentiated from its congeners by the following combination of characters: (1) premaxillary teeth absent, (2) tympanum absent, (3) nuptial spines are moderately large, distinctly conical on thumb, (4) dorsal coloration is gray to brown, (5) ventral coloration is yellowish cream with gray speckling, (6) dorsal skin is smooth. T. degener members are small, males reaching 48.9 mm SVL, females reaching 49.6 SVL. The following osteological characters aid in identification: (1) palatine reduced, (2) crista parotica short, (3) otic capsule large, (4) sphenethmoid poorly ossified, (5) jaw articulation at (not posterior to) level of crista parotica, (6) zygomatic ramus of squamosal very short, (7) columella reduced to small spherical nubbin, (8)transverse processes of posterior presacral vertebrae very short and thick. Head is equal to or slightly narrower than the body. Head width is 31.1-34.3% of SVL. Canthus rostralis is indistinct when viewed dorsally and slightly elevated when viewed laterally. Supratympanic fold is weakly developed. Relative length of fingers: III>IV³I>II. Relative toe lengths: IV>III>V>II>I. Color in life is unknown.

Known only from its type locality in the Cordillera Occidental.

The type series were collected in a densely vegetated marsh in an open pasture adjacent to the road. The habitat was very humid Sub-Alpine Forest. Frogs were abundant and active during the day. It is sympatric with Telmatobius thompsoni.

Telmatobius degener is a species of frog in the family Telmatobiidae. It is endemic to the La Libertad Region of Peru and only known from its type locality between Otuzco and Huamachuco, at 3,290 m (10,790 ft) asl. The type locality is in the very humid subalpine páramo. The frogs were active by day and found in pools and running water in a densely vegetated roadside marsh in an open pasture.

The threats to this species are currently unknown, although chytridiomycosis could be a threat.