branchiopodan vs subclass Branchiopoda

branchiopodan and subclass Branchiopoda both are nouns.

Word	Noun	Adjective	Verb	Adverb
branchiopodan	Yes	Yes	No	No
subclass Branchiopoda	Yes	No	No	No

branchiopodan (noun)	subclass Branchiopoda (noun)
aquatic crustaceans typically having a carapace and many pairs of leaflike appendages used for swimming as well as respiration and feeding	primitive aquatic mainly freshwater crustaceans: fairy shrimps; brine shrimps; tadpole shrimps; can shrimps; water fleas

branchiopodan (adjective)	subclass Branchiopoda (adjective)
of or relating to or characteristic of the subclass Branchiopoda