osteostracan vs agnathan

osteostracan and agnathan both are nouns.

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

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

osteostracan: extinct jawless fish of the Devonian with armored head
agnathan: eel-shaped vertebrate without jaws or paired appendages including the cyclostomes and some extinct forms

Other hypernyms of osteostracan include jawless fish, jawless vertebrate.

osteostracan (noun)	agnathan (noun)
extinct jawless fish of the Devonian with armored head	eel-shaped vertebrate without jaws or paired appendages including the cyclostomes and some extinct forms