. A family of vertebrate animals whose females in a state of nature suckle their young, but when civilized and enlightened put them out to nurse, or use the bottle.
The highest class of Vertebrata. The young are nourished for a time by milk, or an analogous fluid, secreted by the mammary glands of the mother.
Clade of amniotes characterized by hair and mammary glands, among other traits. Descended from synapsid ancestors during the Late Triassic.