Pelycosauria vs animal order

Pelycosauria and animal order both are nouns.

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

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

Pelycosauria (noun)	animal order (noun)
edaphosaurus; dimetrodon	the order of animals