Casuariiform

casuariiform, (order Casuariiformes), any member of a group of large, flightless birds that includes two families native to Australasia. The family Dromaiidae, made up of the single living species of emu (Dromaius novaehollandiae), is found only in Australia, whereas the family Casuariidae, made up of three species of cassowaries (Casuarius), is restricted to northern Australia, New Guinea, and nearby islands. Of the two groups, the emu is far better known, both biologically and popularly, being exhibited in zoos around the world. The common characteristics of emus and cassowaries are described in this article; however, most authorities place casuariiforms with ostriches, rheas, kiwis, and others in order Struthioniformes.

The emu was first identified by European explorers in 1788, more than a century after the first cassowaries had been seen by Europeans; in 1697 a Dutch navigator, Willem de Vlamingh, had seen the emu’s footprints in western Australia and had attributed them to a “Kasuarius.” Cassowaries first became known to Europeans in the 17th century—there was a published reference to a “Casoaris” in 1658—when the Portuguese and Dutch colonized the East Indies. Both names, emu and cassowary, were originally applied to cassowaries; the emu was known as the New Holland or New South Wales cassowary until the early 19th century, when the name emu was gradually transferred to it. By the late 19th century about 11 species of cassowaries were recognized, but greater understanding of variation within species has reduced the number to three: the double-wattled, or southern, cassowary (Casuarius casuarius), the single-wattled, or one-wattled, cassowary (C. unappendiculatus), and the dwarf, or Bennett’s, cassowary (C. bennetti).