Monotremes lay amniotic eggs. Monotremes include just the platypus, the short-beaked echidna and the long-beaked echidna.
There are two mammals that lay amniotic eggs. The two mammals that lay amniotic eggs are echidna and platypus.
The primary function of the digestive system is to supply the cells of the body with nutrition. It does this by ingestion, digestion, and absorption. The waste materials that are not used are then eliminated.
jawless fishes
Muscle.
Cnidaria (Hydra, jellyfish, sea anemones, corals, etc.), generally have radial symmetry, although not all sea anemones or corals do.
Echinodermata (sea stars, sea urchins, crinoids, sea cucumbers, etc.) are radially symmetrical as adults, but not as larvae.
Cnidarians
Diploid