Leontocebus oedipus vs leoncita

Leontocebus oedipus and leoncita both are nouns.

Word	Noun	Adjective	Verb	Adverb
Leontocebus oedipus	Yes	No	No	No
leoncita	Yes	No	No	No

As nouns, leoncita is a hypernym of Leontocebus oedipus; that is, leoncita is a word with a broader meaning than Leontocebus oedipus:

Leontocebus oedipus: South American tamarin with a tufted head
leoncita: small South American marmoset with silky fur and long nonprehensile tail

Other hypernyms of Leontocebus oedipus include lion marmoset, lion monkey, tamarin.

Leontocebus oedipus (noun)	leoncita (noun)
South American tamarin with a tufted head	small South American marmoset with silky fur and long nonprehensile tail