- The feeding zooids use retractile tentacles, called the lophophore, to filter feed and have a U-shaped gut for digestion.
- In Australia, for example, marsupial herbivores the size of a rhinoceros, kangaroos nearly 10 feet tall, and carnivorous lion-like forms with shearing teeth and retractile claws all roamed the landscape.
- Like scaphopods, bivalves have a retractile foot which they use to burrow.
- The morphology of the middle and distal phalanx in Tapocyon exhibits a retractile claw condition, supporting this as the primitive condition for Carnivora / Carnivoramorpha.
- The habit of felids to use primarily their forelimbs to capture prey is supported by the anatomy and function of their retractile claws.