platyrrhinian vs platyrhine

platyrrhinian is a noun but platyrhine is not a noun.

Word	Noun	Adjective	Verb	Adverb
platyrrhinian	Yes	Yes	No	No
platyrhine	No	Yes	No	No

As adjectives, platyrrhinian and platyrhine are synonyms defined as:

platyrrhinian and platyrhine: of or related to New World monkeys having nostrils far apart or to people with broad noses

Other synonyms of platyrrhinian include broadnosed, platyrhinian, platyrrhine, platyrrhinic.

platyrrhinian (noun)	platyrhine (noun)
hairy-faced arboreal monkeys having widely separated nostrils and long usually prehensile tails

platyrrhinian (adjective)	platyrhine (adjective)
of or related to New World monkeys having nostrils far apart or to people with broad noses	of or related to New World monkeys having nostrils far apart or to people with broad noses