crossopterygian vs lobe-finned fish

crossopterygian and lobe-finned fish both are nouns.

Word	Noun	Adjective	Verb	Adverb
crossopterygian	Yes	No	No	No
lobe-finned fish	Yes	No	No	No

As nouns, crossopterygian and lobe-finned fish are synonyms defined as:

crossopterygian and lobe-finned fish: any fish of the order Crossopterygii; most known only in fossil form

Other synonyms of crossopterygian include lobefin.

crossopterygian (noun)	lobe-finned fish (noun)
any fish of the order Crossopterygii; most known only in fossil form	any fish of the order Crossopterygii; most known only in fossil form