Somehow this clam ended up exposed on the beach rather than buried in the sand and gravel. It had its shell open a little bit (as it does in the picture) but when I picked it up, it closed up quickly. When I first layed it down, its (surprisingly long) foot came out and moved to flip it over. After that, I moved it again to try and get a picture of it doing that, but it would not move again. Clams seem to have a lot of patience.
Location: Lincoln Street Beach, Sitka, Alaska