branchiopodous vs branchiopod

branchiopodous is not a noun while branchiopod is a noun.

Word	Noun	Adjective	Verb	Adverb
branchiopodous	No	Yes	No	No
branchiopod	Yes	Yes	No	No

As adjectives, branchiopodous and branchiopod are synonyms defined as:

branchiopodous and branchiopod: of or relating to or characteristic of the subclass Branchiopoda

Other synonyms of branchiopodous include branchiopodan.

branchiopodous (noun)	branchiopod (noun)
	aquatic crustaceans typically having a carapace and many pairs of leaflike appendages used for swimming as well as respiration and feeding

branchiopodous (adjective)	branchiopod (adjective)
of or relating to or characteristic of the subclass Branchiopoda	of or relating to or characteristic of the subclass Branchiopoda