Yes, the mollusk in question was a sweet Bay Scollop. In the area the picture was taken it is abundant. A good tasting meal for both birds and humans.Tron, for a wile I was hesitating to comment on your comment ( ) but since here we are community of mix photographers/naturalist I can't resist: We still have to wait for a photo of oystercatcher catching true Oyster (oyster is ambiguous) because the shellfish on that photos is a Scallop (also ambiguous but both groups have very distinctive shells). Not big deal at all but there is that devil in me that always make me uncomfortable when I see miss-identification (and in the same time I hate my photos of interesting/rare for my location birds that are not good at all and it's very painful!).
You're right - it's quite an illusion as I initially thought it was an inside edge in view, where it's really an outer edge view. Escher would be proud! ps - great photo!