The class of Vertebrata that includes the birds.

The class containing birds.

Clade of saurischian dinosaur, placed with the clades Theropoda, Tetanurae, and Avetheropoda, Coelurosauria, Maniraptoriformes, Maniraptora, and Avialae. Colloquially known as birds.

Birds; the class of animals that have wings and feathers, are warm-blooded, and lay eggs.