Answer: Bilateral Symmetry
Step-by-step explanation:
Echinoderms evolved from bilateral symmetric species.
Even though adult echinoderms have five-sided or pentaradial symmetry, echinoderm larvae are ciliated, free-swimming species that form in bilateral symmetry making them look like embryonic chordats. Example of echinodermata is starfish.
Bilateal symmetry allows them to move anywhere in the water. That when a predator is trapped by 2 arms, the other arms can be used effectively by continuously placing pressure on the body part to pressurerise the animal to open.
Hence, phylum echinodermata have bilateral symmetry.