Melanophryniscus krauczuki Baldo & Basso 2004

Diagnosis Small size; without swelling on snout; dorsal color of head, body and upper surfaces of the appendages uniformly brown; ventral surface of head brown with numerous white spots along the mandibular arch; pupil surrounded by a golden ring; iris gold, finely spotted with dark brown; frontoparietal fontanelle widely exposed anteriorly.

Present in southern region of the Province of Misiones, Argentina and one locality in south of Department Itapua, Paraguay.

Description of holotype Body stout; head slightly longer than wide (head width/head length 0.97), approximately one third of snout-vent length; snout short, truncate in dorsal view, rounded in lateral profile, slightly protruding; nostrils directed laterally, oval, located at anterior terminus of snout; eye large; pupil horizontally elliptical; eye diameter smaller than interocular distance and equal to eye-nostril distance; tympanic membrane absent; parotoid gland absent; maxillae and premaxillae edentate; tongue narrow and elongate, posterior margin entire, free for about two thirds of length posteriorly; vocal sac median subgular; skin of dorsum rugose, scattered with blunt, rounded glandular warts; warts tipped with one to several keratinized spines, lighter in color than the verrucae; dorsal surface of forearms, hands and feet scattered with coni; skin of venter finely granular; lengths of fingers: I , II , IV , III; fingers blunt, short and slightly webbed; subarticular tubercles conical and well developed, divided on finger III; inner metacarpal tubercle oval; outer metacarpal tubercle rounded, four times larger than inner; palmar supernumerary tubercles conical and scattered distributed; smooth, brown nuptial pads on thumb and second finger; length of toes: I , II , V , III , IV; toes webbed; inner metatarsal tubercle conical; outer metatarsal tubercle oval, one and a half times smaller tan inner; subarticular tubercles conical; small supernumerary plantar tubercles scattered in distribution. Color in life: dorsal color of head, body and upper surfaces of the appendages uniformly dark brown; ventral of head dark brown with numerous small white spots along the mandibular arch; pectoral zone dark brown with small white spots, densely crowded on flanks; belly dark brown with large, irregular, bright orange spots; internal surface of forearm and ventral surface of tarsus with small white glands; an orange band on ventral surface of arms and forearms; posterior surface of thighs with a large orange-red spot; palmar surfaces of hands and fingers orange-red; plantar surfaces of feet and toes IV and V dark brown, with orange tubercles; ventral surfaces of toes I to III bright orange; pupil surrounded by a golden ring; iris gold, finely spotted with dark brown. Measurements of holotype (in mm): Snout-vent length 20.00, head length 6.92 , head width 6.74, eye diameter 1.64, interorbital distance 2.10, eye-nostril distance 1.88, internarial distance 1.54, upper eyelid width 1.62, upper eyelid length 2.70, upper arm length 4.32, thigh length 8.06, shank length 7.14, foot length 11.00. Variation The range of measurements (in mm) of adult paratypes are (n = 54), average given in parenthesis): Snout-vent length 18.36-24.20 (20.56), head length 6.06-8.12 (7.06), head width 6.10-8.02 (6.95), eye diameter 1.48-2.10 (1.76), interorbital distance 1.98-2.74 (2.39), eye-nostril distance 1.58-2.36 (1.91), internarial distance 1.32-1.84 (1.56), upper eyelid width 1.32-2.38 (1.73), upper eyelid length 2.26-3.16 (2.72), upper arm length 3.60-5.90 (4.54), thigh length 6.90-9.40 (8.27), shank length 6.52-7.88 (7.09), foot length 10.10-13.80 (11.23). Much variation is observed in color pattern. Dorsally, specimens range from light brown to dark brown. The scapular region is lighter in some paratypes. Ventrally, the size and distribution of orange spots are extremely variable, with some specimens being orange on most of the belly and in part of the pectoral area. Other specimens only show very small orange spots on belly. The gular region varies from dark brown to gray. In dorsal view, the snout is truncate to slightly round. Sexual dimorphism is evident in the snout-vent length, being females larger (21.4-24.2 mm, mean = 22.92, n = 14) than males (18.36-22.59, mean = 19.92, n = 5 67). Mature males have conical nuptial pads on thumb and usually on second finger. Larval morphology Body length about one-third of total length; maximum body width at head level, just behind the eyes; body shape oval, depressed; snout truncate in dorsal view, rounded in lateral profile; ventrally, gular region somewhat concave, abdominal area slightly convex; eyes dorsolateral; nostrils dorsolateral, rounded and protuberant, closer to eye than snout; pineal end organ evident (as a pigmentless spot) between the anterior edges of the eyes; spiracle sinistral; spiracular opening oval, directed posterodorsally; intestinal assa located at left, near the spiracle; vent tube conspicuous, conical; vent opening dextral; caudal musculature becoming narrower gradually toward tip of tail, not reaching the end of tail; myosepts not very evident; tail axis straight (eutiural); dorsal fin slightly deeper than ventral, originating at body-tail junction; both fins with curved margins; tip of tail rounded. Oral disc anteroventral; disc with angular constrictions (emarginate); large rostral gap and medium-sized mental gap; marginal papillae in single row; intramarginal lateral papillae not evident; tooth row formula 2/3; jaw sheaths well developed and keratinized, pigmented distally; margins bluntly serrated; upper sheath wider than high, gently curved; lower sheath smaller, Vshaped. In preserved specimens, skin translucent; dorsum of head light brown, becoming darker posteriorly; venter translucent scattered with melanophores; tail musculature light brown with large unpigmented areas; fins transparent, melanophore rows mark courses of blood vessels. Measurements (range in millimeters, n = 9, average given in parenthesis) as follows: body length 4.28-5.29 (5.01), body maximal width 3.60-4.34 (4.05), body width at eye level 3.18-4.06 (3.62), body depth 2.80-3.60 (3.27), eye diameter 0.56-0.80 (0.73), eye-nostril distance 0.35-0.49 (0.41), interorbital distance 0.74-1.05 (0.94), internarial distance 0.77-1.05 (0.91), tail length 7.31-10.21 (8.57), fin maximal height 1.96-3.18 (2.84), oral disc width 1.82-2.62 (2.11).

DD. Data Deficient.