Eutreptodactylus itaboraiensis gen. et sp. nov., an early cuckoo (Aves: Cuculidae) from the Late Paleocene of Brazil

摘要: Eutreptodactylus itaboraiensis from Late Paleocene karst deposits of eastern Brazil is the oldest and most primitive member Cuculidae known to date. It one fossils that can be placed in a modern family birds. The zygodactyl condition, characterising cuculids, present Eutreptodactylus, but relative rotation trochlea metatarsi IV slight comparison with extant suggesting this bird may not have been an obligate form. Since zygodactyly had developed within Cuculiformes by Paleocene, it follows other order, Musophagidae, must diverged early part Cainozoic.