staghorn coral vs stony coral

staghorn coral and stony coral both are nouns.

Word	Noun	Adjective	Verb	Adverb
staghorn coral	Yes	No	No	No
stony coral	Yes	No	No	No

As nouns, stony coral is a hypernym of staghorn coral; that is, stony coral is a word with a broader meaning than staghorn coral:

staghorn coral: large branching coral resembling antlers
stony coral: corals having calcareous skeletons aggregations of which form reefs and islands

Other hypernyms of staghorn coral include madrepore, madriporian coral.

staghorn coral (noun)	stony coral (noun)
large branching coral resembling antlers	corals having calcareous skeletons aggregations of which form reefs and islands