class Reptilia vs subclass Lepidosauria

class Reptilia and subclass Lepidosauria both are nouns.

Word	Noun	Adjective	Verb	Adverb
class Reptilia	Yes	No	No	No
subclass Lepidosauria	Yes	No	No	No

class Reptilia (noun)	subclass Lepidosauria (noun)
class of cold-blooded air-breathing vertebrates with completely ossified skeleton and a body usually covered with scales or horny plates; once the dominant land animals	diapsid reptiles: lizards, snakes, tuataras