Final answer:
Living brachiopods are usually found in cold or temperate marine environments with rocky seafloors, due to their preference for attaching themselves to stable substrates with their pedicle.
Step-by-step explanation:
Brachiopods are marine organisms known for their shelled, filter-feeding characteristics and their presence on the seafloor. Throughout history, especially during the Paleozoic Era, brachiopods exhibited incredible diversity. Though their diversity is reduced in the modern era, living brachiopods are typically found in cold or temperate waters. They prefer stable, hard substrates to attach to using their pedicle—a fleshy stalk-like feature, making locations with rocky seafloors more likely places to find them alive or dead.
The shells of brachiopods, with their distinct features such as the brachial and pedicle valves, serve as useful indicators for determining ancient marine environments (or paleoenvironments). The difference in symmetry when comparing brachiopods to bivalves is a key identification feature, with brachiopods exhibiting a vertical plane of symmetry as opposed to bivalves' horizontal plane.