Stegocephalia vs animal order

Stegocephalia and animal order both are nouns.

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

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

Stegocephalia: in former classifications a division of class Amphibia comprising all pre-Jurassic and some later extinct large salamandriform amphibia
animal order: the order of animals

Stegocephalia (noun)	animal order (noun)
in former classifications a division of class Amphibia comprising all pre-Jurassic and some later extinct large salamandriform amphibia	the order of animals