ostracoderm vs agnathan

ostracoderm and agnathan both are nouns.

Word	Noun	Adjective	Verb	Adverb
ostracoderm	Yes	No	No	No
agnathan	Yes	No	No	No

As nouns, agnathan is a hypernym of ostracoderm; that is, agnathan is a word with a broader meaning than ostracoderm:

ostracoderm: extinct fish-like jawless vertebrate having a heavily armored body; of the Paleozoic
agnathan: eel-shaped vertebrate without jaws or paired appendages including the cyclostomes and some extinct forms

Other hypernyms of ostracoderm include jawless fish, jawless vertebrate.

ostracoderm (noun)	agnathan (noun)
extinct fish-like jawless vertebrate having a heavily armored body; of the Paleozoic	eel-shaped vertebrate without jaws or paired appendages including the cyclostomes and some extinct forms