||Soft-sediment areas dominated by burrowing, clam-like brachiopods, a phylum of animals
with two shells, a stalk-like peduncle, and a tentacular, ciliated feeding organ.
In soft sediment dwelling species, the peduncle and the valves are adapted to burrowing.
In other brachiopod species, the animal is adapted to attach to hard substrate (see
Attached Brachiopods, above). Most brachiopods feed on plankton or on detritus. Brachiopods
may occur in very high densities in some soft sediment areas, including intertidal
areas (particularly on the west coast of the United States).