Rheidae is a

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

of flightless

ratite Ratites () are a polyphyletic group consisting of all birds within the infraclass Palaeognathae that lack keels and cannot fly. They are mostly large, long-necked, and long-legged, the exception being the kiwi, which is also the only nocturnal ...

birds which first appeared in the

Paleocene The Paleocene ( ), or Palaeocene, is a geological epoch (geology), epoch that lasted from about 66 to 56 mya (unit), million years ago (mya). It is the first epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), ...

. It is today represented by the sole living

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

'' Rhea'', but also contains several extinct genera.

Taxonomy

Order Rheiformes (Forbes, 1884) Furbringer, 1888 heimorphae Bonaparte, 1849; Rheae Forbes 1884ref name="mikko"> * Family † Opisthodactylidae Ameghino 1895 ** Genus ?†'' Diogenornis'' de Alvarenga 1983 (Late Paleocene) – possibly a member of

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, wit ...

instead. ** Genus †'' Opisthodactylus'' Ameghino 1895 (Miocene) – rheid? * Family Rheidae (Bonaparte 1849) Bonaparte, 1853 ** Genus †'' Heterorhea'' Rovereto 1914 (Pliocene) ** Genus †'' Hinasuri'' Tambussi 1995 ** Genus '' Rhea'' Brisson 1760

References

{{Authority control Ratites Bird families Birds of South America Extant Thanetian first appearances Taxa named by Charles Lucien Bonaparte Notopalaeognathae