What is "class mammalia"

Usage examples of "class mammalia".

Thus, the bat's wing is a most abnormal structure in the class mammalia.

I concluded definitely that it belonged to the vertebrate branch, class mammalia.

It would be a brilliant forgery, done in a nonbiological medium, of a living creature, subphylum Vertebrata, class Mammalia, order Primates, viviparous, bipedal, and having a bicameral brain—.