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flightless birds having flat breastbones lacking a keel for attachment of flight muscles: ostriches; cassowaries; emus; moas; rheas; kiwis; elephant birds
birds having keeled breastbones for attachment of flight muscles
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fast-running African flightless bird with two-toed feet; largest living bird
large black flightless bird of Australia and New Guinea having a horny head crest
large Australian flightless bird similar to the ostrich but smaller
nocturnal flightless bird of New Zealand having a long neck and stout legs; only surviving representative of the order Apterygiformes
larger of two tall fast-running flightless birds similar to ostriches but three-toed; found from Brazil to Patagonia
smaller of two tall fast-running flightless birds similar to ostriches but three-toed; found from Peru to Strait of Magellan
huge (to 9 ft.) extinct flightless bird of Madagascar
extinct flightless bird of New Zealand
the largest moa; about 12 feet high
the smallest moa; slender moa about the size of a large turkey
warm-blooded egg-laying vertebrates characterized by feathers and forelimbs modified as wings
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