Elachistocleis skotogaster Lavilla, Vaira & Ferrari 2003

Diagnosis Elachistocleis skotogaster has belly and legs densely spotted in brown; the dorsal region is uniformly dark brown mottled in black, without light vertebral strip, and the area behind the mouth has an evident fold but a postcommisural gland is absent.

Restricted to the Yungas forests of north-western Argentina, where it is currently known only from the type locality: Los Toldos, Santa Victoria Department, Salta Province, at 1,100m asl (22° 18�S; 64° 40'W) and two more localities in Salta Province. Specimens from Bolivia with spotted bellies that are currently attributed to Elachistocleis ovalis might pertain to this species.

Description of the holotype Adult male; snout-vent length 28.2mm; body ovoid; head triangular in dorsal aspect, proportionally short; head length about 17.5% of snout-vent length, wider than long (head width/head length 1.6); snout rounded and slightly projected in dorsal view, and rounded in lateral view, protruding in a rostrum comprising about 32.8% of the head length; canthus rostralis undifferentiated, rounded, with loreal region slightly concave and moderately sloping; eyes in dorsolateral position, eye diameter/head length 34%; interorbital region flat; tympanum undifferentiated; nostrils oriented subterminally, not protruding, folded and situated almost at tip of snout; internarial distance about 17% of head width; tongue subcircular; choana subcircular, laterally located, broadly separated; head differentiated from the body by an evident postcephalic skin fold, immediately behind the eyes and extending laterally and posteriorly, to reach the insertion of the forelimb. Ventrally, an evident, post-gular (thoracic) fold extends at the level of the insertion of hindlimbs. Dorsal and ventral skin smooth, with small light tubercles slightly protruded; at the lateral region a noticeable skin fold extends from the timpanic region to the hindlimbs insertion; cloacal opening as a longitudinal slit, posteriorly directed. Forelimbs moderate built, without conspicuous details; fingers with rounded tip; relative length of fingers 3 > 4»D 2 > 1I subarticular tubercles simple, rounded to conical; subarticular tubercle formula I(1), II(1), III(2), IV(1); palmar and supernumeraries tubercles absent; fingers without webbing or fringes; prepollex not evident and nuptial pads or cornifications absent; inner metacarpal tubercle oval, smaller than the outer, oval and divided, resembling three palmar tubercles. Hind limbs short; tibia length about 30% of SVL; heels of adpressed limbs slightly in contact; tibio-tarsal articulation does not reach the forelimbs; toes with rounded tips; relative length of toes 4 > 3 > 5 > 2 > 1, without webbing or fringes; subarticular tubercles simple, rounded to conical and slightly prominent; subarticular tubercles formula I(1), II(1), III(2), IV(3), V(2); plantar and supernumeraries tubercles absent; inner metatarsal tubercle suboval; outer metatarsal tubercle absent. Coloration. In life, dorsum dark brown, mottled with black and white spots. Dorsal surfaces of forelimbs with tan mottling. Iris gold, marbled with black and brown. Oval brown blotch at the tympanum region. Yellow spots restricted to the commisural region. Bright orange stripe on hidden surfaces of hind limbs. Irregular bright orange blotch on groin. Venter grey, mottled with dark brown. Throat dark grey, with yellow and black mottling. Chest with some irregular yellowish blotches uniformly distributed. In preservative (70% ethanol): brown changes to grey and orange to whitish; dorsal white spots almost disappear, while the ventral coloration turns into a variegated pattern of grey and cream Variation of the paratypes Most noticeable variations with the holotype refer to body measurements. Morphologicalvariations are: a - Loreal region varies from flat to concave-flat. b - Interorbital region varies from flat to slightly convex. c - Tympanic area varies from flat to slightly concave. d - Post-cephalic fold shows several degrees of thickening. e - Post-gular fold shows different degree of development, from absent to extremely developed. f - Cloaca in two specimens as a subcircular opening instead of as longitudinal slit. g - Lateral fold of the body not evident in two individuals. h - Margins of the fingers can show diverse degrees of thickness. i - Besides body size measurements there are no evidences of sexual dimorphism.

DD. Data Deficient.

Elachistocleis skotogaster (common name: Santa Victoria oval frog) is a species of frog in the family Microhylidae. It is known with certainty only from the Salta Province in northern Argentina. However, the type locality and some later observations are near the border to Bolivia, and it is possible that some frogs from Bolivia currently attributed to Elachistocleis ovalis belong to this species.

Elachistocleis skotogaster is known from its type locality, a subtropical montane moist forest, and another humid montane forest locality. There are acoustic observations of calling males from roadside ponds from further two localities, all in the Salta Province of Argentina. Breeding takes place in temporary ponds.