👉 Cycadeoidea is a group of animals that belong to the order Cnidaria and are known for their unique adaptations in aquatic environments. These animals have specialized structures, such as gills, that allow them to extract oxygen from water through diffusion. Additionally, they have a high metabolic rate, which means that they require a constant supply of energy to maintain life and activity levels. Cycadeoidea also includes the following families: Cnidaria (including the sea cucumbers,
