Casuariidae Casuariidae The bird family Casuariidae has four surviving members: the three species of cassowary and the emu. All living members of the family are very large flightless birds native to Australia-New Guinea, though the extinct potential member "Hypselornis" was native to India. The characteristics of the family are those of its members. The fossil record of casuariforms is interesting, but not very extensive. Some Australian fossils initially believed to be from emus were recognized to represent a distinct genus, "Emuarius", which had a cassowary-like skull and femur and an emu-like lower leg and foot. A Pliocene Indian ratite, "Hypselornis", has
Flightless bird 85–92 days while females feed. They can go up to a week without eating and survive only off fat stores. The emu has been documented fasting as long as 56 days. If no continued pressures warrant the energy expenditure to maintain the structures of flight, selection will tend towards these other traits. Many flightless birds are extinct; this list shows species that are either still extant, or became extinct in the Holocene (no more than 11,000 years ago). Extinct species are indicated with a dagger (†). A number of species that are suspected, but not confirmed to be flightless, are