Phasmatodea vs class Hexapoda

Phasmatodea and class Hexapoda both are nouns.

Word	Noun	Adjective	Verb	Adverb
Phasmatodea	Yes	No	No	No
class Hexapoda	Yes	No	No	No

Phasmatodea (noun)	class Hexapoda (noun)
in some classifications considered a suborder of Orthoptera: stick insects; leaf insects	insects; about five-sixths of all known animal species