I cannot remember which Brachiopod order this living specimen belongs to. I think Terebratulida.
you can tell it is a brachiopod and not a limpet or hipponicid by the ring of hairs extending from around the shell.
Brachiopods, phylum Brachiopoda, are marine animals that have hard "valves" (shells) on the upper and lower surfaces, unlike the left and right arrangement in bivalve molluscs. Brachiopod valves are hinged at the rear end, while the front can be opened for feeding or closed for protection. Two major groups are recognized, articulate and inarticulate. Articulate brachiopods have toothed hinges and simple opening and closing muscles, while inarticulate brachiopods have untoothed hinges and a more complex system...