mammalian vs class Mammalia

mammalian and class Mammalia both are nouns.

Word	Noun	Adjective	Verb	Adverb
mammalian	Yes	Yes	No	No
class Mammalia	Yes	No	No	No

mammalian (noun)	class Mammalia (noun)
any warm-blooded vertebrate having the skin more or less covered with hair; young are born alive except for the small subclass of monotremes and nourished with milk	warm-blooded vertebrates characterized by mammary glands in the female

mammalian (adjective)	class Mammalia (adjective)
of or relating to the class Mammalia