Answer: Sponges, echinoderms, vertebrates, and chordates.
Protosome is the clade or group of animals in which the first opening in the embryo becomes the mouth. It represents all those animals that have a true body cavity and which share common ancestry. They include annelids, mollusks and arthropods. Sponges, echinoderms, vertebrates, and chordates do not develop as a protosome.