Answer :
Answer:
Class Bivalvia
Explanation:
Members of class bivalvia from phylum mollusca are often confused for members of phylum brachiopoda. They look similar because both of them have two shells which are generally made of calcite. The shells also have radial ribs. They are also found in the same shallow marine environment.
However some differences can be found on close inspection. The valves (shells) of bivalvia are same or symmetrical but the two valves of brachiopoda can have different shapes and size. The bivalves have right and left valve symmetry but in brachiopoda they have top-bottom (dorsal-ventral) structure.