What two characteristics are present in both a squid and a dolphin but not a jellyfish

There are two major characteristic differences are -

Dolphin and squid are triploblastic while jellyfish is diploblastic,

Dolphin and squid have complex organ systems whereas jellyfish lack it.

Explanation:

Jellyfishes are multicellular, marine organisms of the phylum Cnidaria. Dolphin is a vertebrate organism that belongs to Mammalia. They produce young ones, have complex organ systems. Squids are also marine organism belongs to mollusks. They have 8 arms and tentacles.  

Both squid and dolphin are triploblastic (3 germ layers) and having complex organ systems, while jellyfish is diploblastic (2 germ layers) and absence of complex organ system.

sadness is not good

explanation:

thinking it would be physical characteristics