👉 Peridiniida is a group of small, flat-bodied animals that belong to the order Phylum Chordata and are classified as a family within the class Chordates. These animals have a wide range of life forms, ranging from aquatic creatures like fish and frogs, to land-based organisms such as plants and insects. Some notable examples include sea urchins, which are small, squamous animals with large eyes and no backbones; and the jellyfish, which are segmented euk