subclass Selachii vs Elasmobranchii

subclass Selachii and Elasmobranchii both are nouns.

Word	Noun	Adjective	Verb	Adverb
subclass Selachii	Yes	No	No	No
Elasmobranchii	Yes	No	No	No

As nouns, subclass Selachii and Elasmobranchii are synonyms defined as:

Other synonyms of subclass Selachii include Selachii, subclass Elasmobranchii.

subclass Selachii (noun)	Elasmobranchii (noun)
sharks, rays, dogfishes, skates	sharks, rays, dogfishes, skates