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

I only know 1 by far. They both are paraphyletic.

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.