What is an order of birds in which the wings are small, rudimentary, or absent, and the breastbone is destitute of a keel. The ostrich, emu, and apteryx are examples called?

ratitae — An order of birds in which the wings are small, rudimentary, or absent, and the breastbone is destitute of a keel. The ostrich, emu, and apteryx are examples. (Webster's 1913.)

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