This is one half of the Giant Fluted clam’s (Tridacna squamosa) shell. It is a marine creature called a mollusc and is a bivalve, which means that its shell is divided into two parts. The two halves can open and close to protect the body of the mollusc inside. The one shown here is large and heavy so you have to imagine the strength of the muscles and ligaments that allow this to happen.

The shells are joined by a hinge and the fluted shape fits together to form a seal. You can see the leaf-like fluted pattern on the outside. These are called scutes and each fluted layer represents a growth layer. Smaller sea creatures sometimes settle in the hollows of this shell for protection.

These clams are found in the South Pacific and Indian oceans in coral reefs. They are popular as food and are sometimes bred for this market to help preserve the wild species.