class Pelecypoda vs Bivalvia

class Pelecypoda and Bivalvia both are nouns.

Word	Noun	Adjective	Verb	Adverb
class Pelecypoda	Yes	No	No	No
Bivalvia	Yes	No	No	No

As nouns, class Pelecypoda and Bivalvia are synonyms defined as:

Other synonyms of class Pelecypoda include class Bivalvia, class Lamellibranchia, Lamellibranchia.

class Pelecypoda (noun)	Bivalvia (noun)
oysters, clams, scallops, mussels	oysters, clams, scallops, mussels