Slender-legged tree frogs

Osteocephalus is a genus of frogs, the slender-legged tree frogs, in the family Hylidae found in the Guianas, the Amazon Basin, Venezuela, Colombia, southeastern Brazil, and north-eastern Argentina. Males are warty, while females are smooth.

Species
There are currently 25 described species in Osteocephalus:
 * O. alboguttatus (Boulenger, 1882)
 * O. buckleyi (Boulenger, 1882) — Buckley's slender-legged tree frog
 * O. cabrerai (Cochran and Goin, 1970)
 * O. camufatus (Jungfer, Verdade, Faivovich, and Rodrigues, 2016)
 * O. cannatellai (Ron, Venegas, Toral, Read, Ortiz, and Manzano, 2012)
 * O. carri (Cochran and Goin, 1970)
 * O. castaneicola (Moravec, Aparicio, Guerrero-Reinhard, Calderón, Jungfer, and Gvoždík, 2009)
 * O. deridens (Jungfer, Ron, Seipp, and Almendáriz, 2000)
 * O. duellmani (Jungfer, 2011)
 * O. festae (Peracca, 1904)
 * O. fuscifacies (Jungfer, Ron, Seipp, and Almendáriz, 2000)
 * O. helenae (Ruthven, 1919)
 * O. heyeri (Lynch, 2002)
 * O. leoniae (Jungfer and Lehr, 2001)
 * O. leprieurii (Duméril and Bibron, 1841) — Cayenne slender-legged tree frog
 * O. mimeticus (Melin, 1941)
 * O. mutabor (Jungfer and Hödl, 2002)
 * O. oophagus (Jungfer and Schiesari, 1995)
 * O. planiceps (Cope, 1874)
 * O. sangay (Chasiluisa, Caminer, Varela-Jaramillo & Ron, 2020) — Sangay casqued tree frog
 * O. subtilis (Martins and Cardoso, 1987) — Brazilian slender-legged tree frog
 * O. taurinus (Steindachner, 1862) — Manaus slender-legged tree frog
 * O. verruciger (Werner, 1901) — Ecuador slender-legged tree frog
 * O. vilarsi (Melin, 1941)
 * O. yasuni (Ron and Pramuk, 1999)