Ostracodermi vs animal order

Ostracodermi and animal order both are nouns.

Word	Noun	Adjective	Verb	Adverb
Ostracodermi	Yes	No	No	No
animal order	Yes	No	No	No

As nouns, animal order is a hypernym of Ostracodermi; that is, animal order is a word with a broader meaning than Ostracodermi:

Ostracodermi: extinct group of armored jawless vertebrates; taxonomy is not clear
animal order: the order of animals

Ostracodermi (noun)	animal order (noun)
extinct group of armored jawless vertebrates; taxonomy is not clear	the order of animals