Dibranchiata vs Dibranchia

Dibranchiata and Dibranchia both are nouns.

Word	Noun	Adjective	Verb	Adverb
Dibranchiata	Yes	No	No	No
Dibranchia	Yes	No	No	No

As nouns, Dibranchiata and Dibranchia are synonyms defined as:

Dibranchiata and Dibranchia: comprising all living cephalopods except the family Nautilidae: the orders Octopoda (octopuses) and Decapoda (squids and cuttlefish)

Other synonyms of Dibranchiata include subclass Dibranchia, subclass Dibranchiata.

Dibranchiata (noun)	Dibranchia (noun)
comprising all living cephalopods except the family Nautilidae: the orders Octopoda (octopuses) and Decapoda (squids and cuttlefish)	comprising all living cephalopods except the family Nautilidae: the orders Octopoda (octopuses) and Decapoda (squids and cuttlefish)