order Ephemerida vs Ephemeroptera

order Ephemerida and Ephemeroptera both are nouns.

Word	Noun	Adjective	Verb	Adverb
order Ephemerida	Yes	No	No	No
Ephemeroptera	Yes	No	No	No

As nouns, order Ephemerida and Ephemeroptera are synonyms defined as:

order Ephemerida and Ephemeroptera: the order of mayflies or shadflies (Ephemeroptera, Ephemerida)

Other synonyms of order Ephemerida include Ephemerida, order Ephemeroptera.

order Ephemerida (noun)	Ephemeroptera (noun)
the order of mayflies or shadflies (Ephemeroptera, Ephemerida)	the order of mayflies or shadflies (Ephemeroptera, Ephemerida)