order Testudinata vs order Chelonia

order Testudinata and order Chelonia both are nouns.

Word	Noun	Adjective	Verb	Adverb
order Testudinata	Yes	No	No	No
order Chelonia	Yes	No	No	No

As nouns, order Testudinata and order Chelonia are synonyms defined as:

Other synonyms of order Testudinata include Chelonia, order Testudines, Testudinata, Testudines.

order Testudinata (noun)	order Chelonia (noun)
tortoises and turtles	tortoises and turtles