The Scyphozoa are an exclusively marine class of the phylum Cnidaria, referred to as the true jellyfish (or "true jellies"). It may include the extinct fossil group the Conulariida, whose affinities are uncertain and widely debated.

The class name Scyphozoa comes from the Greek word skyphos (σκύφος), denoting a kind of drinking cup and alluding to the cup shape of the organism. Scyphozoans have existed from the earliest Cambrian to the present.

Scyphozoa. Retrieved November, 05 2021, from en.wikipedia.org/wiki/Scyphozoa.