Final answer:
Phylum Brachiopoda is distinct due to its vertical symmetry, distinct valves in the shell, and the presence of a fleshy pedicle.
Step-by-step explanation:
One distinct feature of the Phylum Brachiopoda is their vertical symmetry, unlike bivalves which have horizontal symmetry. This means that one half of a brachiopod is a mirror image of the other half, but the mirror plane is vertical for brachiopods and horizontal for bivalves. Additionally, brachiopod shells have two distinct valves, with the brachial valve being smaller and having a ridge down the middle, and the pedicle valve being larger and having a valley down the middle. Finally, brachiopods have a fleshy stalk-like structure called a pedicle that some groups use to attach themselves to the seafloor.