Casuariiformes

The Casuariiformes is an order of large flightless birds that has four surviving members: the three species of cassowary, and the only remaining species of emu. They are divided into either a single family, Casuariidae, or occasionally two, with the emu splitting off into its own family, Dromaiidae. The IOC World Bird List and Cornell Lab of Ornithology's Birds of the World both do not recognize Dromaiidae, placing the emu in the family Casuariidae.

Diogenornis is an extinct genus of ratites, that lived from the Middle Paleocene to the Early Eocene (Riochican to Casamayoran in the SALMA classification). It was described in 1983 by Brazilian scientist Herculano Marcos Ferraz de Alvarenga based on fossils found in the Itaboraí Formation in southeastern Brazil. The type species is D. fragilis. It grew to about two thirds the size of the modern greater rhea, at about of height.