Siderite Dubiocoprolite

It may have been slow moving, but it's definitely not a snail.  Rocks such as this are commonly thought to be the fossilized feces of female turtles that come ashore to lay their eggs.   However, without the presence of inclusions, it is unclear whether these are actually coprolites. Siderite "coprolites" such as this can be found in most rock shops. Just be aware that they may not be coprolites.