Adult: Species description based on Ibanez et al (1999) and Savage (2002). Small, delicate frog with large eyes. Adult males have a spine at the base of the thumb. Males to 20 mm, females to 23 mm. Dorsal: The dorsal surface is green and rather smooth, without any spots or markings. Ventral: Ventral surface transparent and all organs are visible. Heart covered with a white membrane and appears white. Eye: Iris greyish ivory with black reticulations. Extremities: The feet are moderately webbed.
Breeding season: Males may be found calling throughout the rainy season (May to October-November, Savage 2002) Egg: Eggs of Teratohyla spinosa are laid on the underside of leaves (Starrett 1960). Clutches of 18-25 unpigmented eggs are laid in a single layer, encased in jelly (Starrett 1960). Embryos change from green to yellow to gray at hatching (Starrett 1960). Tadpole: Tadpole has a narrow elongate body, with a long, thin tail (Savage 2002). Coloration is brown, but the tadpole appears red or pink due to large concentrations of hemoglobin in the blood (Savage 2002). Some dark spots present on the tail (Savage 2002). The ventral surface is lighter, with a dark stripe down the center (Starrett 1960). The mouth is oriented ventrally and tadpoles probably have 3 lower and 2 upper teethrows (Savage 2002 but see Starrett 1960). One of the upper teethrows is limited to a small segment on either side of the mouth (Starrett 1960). Centrolenid tadpoles are fossorial, living in the low-oxygen environment under mud and leaf litter in stream bottoms (McDiarmid and Altig 1999).
Habitat: Humid lowland forest to 800 m. Call: A creep creep, repeated at intervals (Savage 2002). Type locality: Los Diamantes, one mile south of Guápiles, [Cantón de Pococí, Provincia Limón,] Costa Rica
Diagnostic description: The dorsal skin is dimly glandular. The back is solid color or with some large dark or light, or heavily stained black spots. Usually without enlarged parotid glands, but if present. Head lacking ridges. No dorsal fold in the head; without fleshy fold on the roof of the mouth. The belly is transparent in living specimens, which will allow the internal organs. Green Bones in live specimens. The maximum standard length of adult males is 20 mm, females 23 mm.
A conspicuous lack tarsal tubercle, and the leg lacks tarsal fold. They have legs with five toes; no two elongated inner tubers, such as shovels, with a free margin. Without a pair of fleshy protrusions on the dorsal terminal finger region. They have a small digital groove, which separates the upper surface of the finger and bearing, at least in the two outer fingers and toes of the foot. Ventral disk lacks. The fingers are usually membranes; intercalary cartilage present between the last phalanges of the fingers. The talus and calcaneus are fused. The terminals are fastened straight or T or Y have vomerine teeth. The snout between upright and rounded profile. The posterior margin of the forearm lacks a fleshy fold. They have a free or a thorn prepólica prepolex.
Habitat: They live in very humid tropical forests.
Food: They feed on small insects like flies and crickets.
Behavior: They are nocturnal and arboreal.
Distribution in Costa Rica: In humid and lowlands of the Atlantic slope, and south of the Pacific slope, between 20 and 560 m. Lift (Savage 2002).
Distribution outside Costa Rica: It is through the Caribbean and Pacific Slopes of Costa Rica to Ecuador.