What are the main differences between bivalves and brachiopods?

Bivalves - Firstly they have two identical valves make up the main shell. They also grow from a few mm to 1m in size such as the giant clam. In order to close the valves, a pair of adductor muscles contract to keep valves closed (leave scars at anterior and posterior). When the muscles relax, external ligament pulls them open. They also have a foot, absent on brachiopods, to aid digging and they use gills to respire. In order to catergorize bivalves, they are put into the Mollusca phylum. Brachiopods - Have one valve (pedicle valve) larger than the other and tend to grow to 2-10cm in length; smaller than the average bivalve. To work the valves, adductor muscles contract to close valves (pair of scars in pedicle valve, 2 in brachial) and then the didcutor muscles contract to open valves (run from cardinal process to floor of pedicle valve). They do not have a foot like the bivalves, but do have a pedicle which aids attachment to rocks. They also use a lophophore to respire rather than gills. In order to catergorize brachiopods, they are in the phylum, Brachiopoda.