Cephalaspida vs Osteostraci

Cephalaspida and Osteostraci both are nouns.

Word	Noun	Adjective	Verb	Adverb
Cephalaspida	Yes	No	No	No
Osteostraci	Yes	No	No	No

As nouns, Cephalaspida and Osteostraci are synonyms defined as:

Cephalaspida and Osteostraci: extinct group of armored fish-like vertebrates; taxonomy is not clear

Other synonyms of Cephalaspida include suborder Cephalaspida, suborder Osteostraci.

Cephalaspida (noun)	Osteostraci (noun)
extinct group of armored fish-like vertebrates; taxonomy is not clear	extinct group of armored fish-like vertebrates; taxonomy is not clear