doliolum vs urochordate

doliolum and urochordate both are nouns.

Word	Noun	Adjective	Verb	Adverb
doliolum	Yes	No	No	No
urochordate	Yes	No	No	No

As nouns, urochordate is a hypernym of doliolum; that is, urochordate is a word with a broader meaning than doliolum:

doliolum: free-swimming oceanic tunicate with a barrel-shaped transparent body
urochordate: primitive marine animal having a saclike unsegmented body and a urochord that is conspicuous in the larva

Other hypernyms of doliolum include tunicate, urochord.

doliolum (noun)	urochordate (noun)
free-swimming oceanic tunicate with a barrel-shaped transparent body	primitive marine animal having a saclike unsegmented body and a urochord that is conspicuous in the larva