aquatic vertebrate vs craniate

aquatic vertebrate and craniate both are nouns.

Word	Noun	Adjective	Verb	Adverb
aquatic vertebrate	Yes	No	No	No
craniate	Yes	No	No	No

As nouns, craniate is a hypernym of aquatic vertebrate; that is, craniate is a word with a broader meaning than aquatic vertebrate:

aquatic vertebrate: animal living wholly or chiefly in or on water
craniate: animals having a bony or cartilaginous skeleton with a segmented spinal column and a large brain enclosed in a skull or cranium

Other hypernyms of aquatic vertebrate include vertebrate.

aquatic vertebrate (noun)	craniate (noun)
animal living wholly or chiefly in or on water	animals having a bony or cartilaginous skeleton with a segmented spinal column and a large brain enclosed in a skull or cranium