Body Symmetry
Body symmetry of monotremes are bilateral. This means that it is capable of being divided into two parts so that one part is the same as the other.
Body Covering: Platypus
A platypus is covered with dense, brown fur. The fur has two layers, a woolly undercoat and a coarser overcoat. As the platypus dives, the two fur layers trap a layer of air next to the skin, which helps keep the platypus warm and waterproof. Its tail is similar to a beaver tail and is furry and flattened. The tale stores fat.
Body Covering: Echidna
Echidnas are covered with sharp spines on its back and sides. Its underside is covered with hair. The spines protect the animal from enemies. The echidna can roll up into a ball that enemies will leave alone, or they burrow into the ground.There coat is black to brown, and has lighter colored spines.