amniotic sac vs mammalian

amniotic sac and mammalian both are nouns.

Word	Noun	Adjective	Verb	Adverb
amniotic sac	Yes	No	No	No
mammalian	Yes	Yes	No	No

amniotic sac (noun)	mammalian (noun)
thin innermost membranous sac enclosing the developing embryo of higher vertebrates (reptiles, birds and mammals)	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

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