Elephant birds are an extinct

Extinction

In biology and ecology, extinction is the end of an organism or of a group of organisms , normally a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and recover may have been lost before this point...

 family

Family (biology)

In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...

 of flightless bird

Flightless bird

Flightless birds are birds which lack the ability to fly, relying instead on their ability to run or swim. They are thought to have evolved from flying ancestors. There are about forty species in existence today, the best known being the ostrich, emu, cassowary, rhea, kiwi, and penguin...

s found only on the island of Madagascar

Madagascar

The Republic of Madagascar is an island country located in the Indian Ocean off the southeastern coast of Africa...

 and comprising the genera

Genus

In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

 Aepyornis

Aepyornis

Aepyornis is a genus of aepyornithid, one of two genera of ratite birds endemic to Madagascar known as elephant birds. This animal was the world's largest bird until its extinction, about 1000 years ago.-Description:...

and Mullerornis

Mullerornis

Mullerornis is the smaller of the two genera of extinct elephant birds of Madagascar . Species include Mullerornis agilis Milne-Edwards and A. Grandidier, 1894, and M. grandis Lamberton, 1934...

.
The elephant birds, which were giant ratite

Ratite

A ratite is any of a diverse group of large, flightless birds of Gondwanan origin, most of them now extinct. Unlike other flightless birds, the ratites have no keel on their sternum—hence the name from the Latin ratis...

s native to Madagascar

Madagascar

The Republic of Madagascar is an island country located in the Indian Ocean off the southeastern coast of Africa...

, have been extinct since at least the 17th century. Étienne de Flacourt

Étienne de Flacourt

Étienne de Flacourt was a French governor of Madagascar, born at Orléans in 1607. He was named governor of Madagascar by the French East India Company in 1648....

, a French governor of Madagascar in the 1640s and 1650s, recorded frequent sightings of elephant birds. Also the famous explorer and traveler Marco Polo

Marco Polo

Marco Polo was a Venetian merchant traveler from the Venetian Republic whose travels are recorded in Il Milione, a book which did much to introduce Europeans to Central Asia and China. He learned about trading whilst his father and uncle, Niccolò and Maffeo, travelled through Asia and apparently...

 mentions very large birds in his accounts of his journeys to the East during the 12th-13th centuries.