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Class of animals scientifically known as the Mammalia. They are primarily characterized by the presence of mammary glands in the female which produce [[milk]] to feed their young.

'''Mammals''' are a class of [[vertebrate]] animals scientifically known as the Mammalia. They are primarily characterized by the presence of [[mammary gland]]s in the female which produce [[milk]] to feed their young, which (except in the case of the [[Monotremes|Monotremata]] which lay eggs), are born live. Mammals are warm-blooded and most are hairy.

The first true mammals appeared in the early [[Jurassic]].

The first true mammals appeared in the early [[Jurassic]].