These branchiopod crustaceans (not a clam) show up in the geologic record 400 million years ago, today they can still be found in nearby seasonal “vernal” pools. They nibble on algae and filter feed along the bottom, in turn they are a favorite snack for many creatures including the Tiger Salamander. The eggs (called cysts) are visible under their shells, when a pool dries up the adults die but the eggs can lay in wait for years until enough water returns for them to begin the cycle over again.
