Heterostraci vs animal order

Heterostraci and animal order both are nouns.

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

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

Heterostraci: extinct group of armored jawless fishes or fish-like vertebrate; taxonomy is not clear
animal order: the order of animals

Heterostraci (noun)	animal order (noun)
extinct group of armored jawless fishes or fish-like vertebrate; taxonomy is not clear	the order of animals