I came across this little shell a few years ago while walking the flats at low tide on the Indian River. A hermit crab was inside, which is the norm for this area, so I took a few quick (and not very good) photos and moved on. But it did not match the usual selection of shells I see in this area.
The shell was small, so possibly a juvenile, and young mollusk shells can look very different from adults. The only clue I have is from a link I found while researching the Channeled Whelk where there is a photo at Mitchell Publications containing shells that look similar to this one. They seem to have the very tightly coiled spiral on top.
The partial shell below is a Channeled whelk I found not long ago. I rarely see these pretty bumpy topped shells, in fact this one may have been a first. While researching it, I found the shell identification page linked above, and saw the shell that looks like my gray one listed as a channeled whelk. To me, the image below does not look like the little gray shell, but if the spire had not begun to protrude, I suppose it’s reasonable to link them as the same type of shell.
For now at least, my best guess is that the little gray shell is a juvenile channeled whelk. If anyone knows for certain, I’d love to know what you think.