Echinoderms exhibit both direct and indirect development. Indirect development includes various larval stages that are bilaterally symmetrical and undergo metamorphosis into the radially symmetrical adult. The main larval forms are the Bipinnaria and Brachiolaria in starfish, Ophiopluteus in brittle stars, Echinopluteus in sea urchins, Auricularia in sea cucumbers, and Doliolaria and Pentacrinoid in feather stars. These larval forms are hypothesized to have evolved from a common ancestral larva such as the Dipleurula or Pentacula and share similarities with the tornaria larva of acorn worms, providing