Bivalve .... Desmodont (Desmodont Shell)

Bivalve Molluscs burrow into the sand and mud, digging in with their spade shaped muscular foot. Because they lived in an upright position they have mirrored left and right valves.

Bivalves preferred to live in places where they could burrow into a sandy bottom. Consequentially Bivalves fossils are very common in some sandstones such as the Snapper Point Formation at Merry Beach and much rarer than Brachiopods in muddy sediments such as the Wandrawandian Siltstone at Ulladulla Harbour.