Osteocephalus deridens

Adult males measure 29–35 mm (1.1–1.4 in) and adult females 44–51 mm (1.7–2.0 in) in snout–vent length.^[4] The snout is rounded in profile and truncate in dorsal view. The tympanum is conspicuous but partly cover by the supratympanic fold. The fingers and the toes are partially webbed. The dorsum is dark tan, with variable markings (irregular dark tan blotches, suffusions of dark tan, irregular light brown spots or flecks, or light brown backward-pointing triangle). The limbs have dark crossbars. The lower surfaces are creamy white.^[2]

Osteocephalus deridens inhabits Napo moist forests at elevations of 200–600 m (660–1,970 ft) above sea level.^[1][4] It occurs in the canopy of primary forest.^[1] Males call usually higher than 5 m (16 ft) above the ground, and the tadpoles develop in bromeliads, often higher than 15 m (49 ft) above the ground.^[1]

This species is difficult to observe because of its arboreal lifestyle. It does not adapt well to anthropogenic disturbance and is threatened by habitat loss caused by agriculture and logging. It occurs in the Yasuni National Park (Ecuador).^[1]