Birds
A class of warm-blooded animals known as the Aves, birds are distinguished by their feathers, toothless beaked jaws, hard-shelled eggs, high metabolic rates, four chambered hearts, and robust yet light skeletons.
A class of warm-blooded animals known as the Aves, birds are distinguished by their feathers, toothless beaked jaws, hard-shelled eggs, high metabolic rates, four chambered hearts, and robust yet light skeletons.