class Hexapoda vs order Thysanura

class Hexapoda and order Thysanura both are nouns.

Word	Noun	Adjective	Verb	Adverb
class Hexapoda	Yes	No	No	No
order Thysanura	Yes	No	No	No

class Hexapoda (noun)	order Thysanura (noun)
insects; about five-sixths of all known animal species	firebrats, silverfish, machilids