pteridosperm vs seed fern

pteridosperm and seed fern both are nouns.

Word	Noun	Adjective	Verb	Adverb
pteridosperm	Yes	No	No	No
seed fern	Yes	No	No	No

As nouns, pteridosperm and seed fern are synonyms defined as:

pteridosperm and seed fern: an extinct seed-producing fernlike plant of the order Cycadofilicales (or group Pteridospermae)

pteridosperm (noun)	seed fern (noun)
an extinct seed-producing fernlike plant of the order Cycadofilicales (or group Pteridospermae)	an extinct seed-producing fernlike plant of the order Cycadofilicales (or group Pteridospermae)