Ammonite

Not what it appears to be

This is an ammonite, not a snail! Ammonites from the Lower Chalk are very distinctive and evolved into a range of bizarre forms. In this case, rather than developing as a flat spiral like nearly all other ammonites, it coiled into a spire, like a snail. It is thought that these ammonites may have been filter feeders, or that they bumbled along just above the sea bed picking up food.