tamarin vs marmoset

tamarin and marmoset both are nouns.

Word	Noun	Adjective	Verb	Adverb
tamarin	Yes	No	No	No
marmoset	Yes	No	No	No

As nouns, marmoset is a hypernym of tamarin; that is, marmoset is a word with a broader meaning than tamarin:

tamarin: small South American marmoset with silky fur and long nonprehensile tail
marmoset: small soft-furred South American and Central American monkey with claws instead of nails

tamarin (noun)	marmoset (noun)
small South American marmoset with silky fur and long nonprehensile tail	small soft-furred South American and Central American monkey with claws instead of nails