Structural adaptations of the echidna include:
- Long, coarse fur: Insulates against cold and wet environments.
- Spines: Protect against predators and aid burrowing.
- Beak: Long, narrow, and sensory-rich for locating prey.
- Pouch: Females carry young in a fur-lined pouch.
- Limbs: Five digits with long, sharp claws for digging and catching prey.