If ammonite spawns like how it does in other costal and ocean biomes, I should be finding it all over cave walls, but I've been flying around a single-biome stone shore world, and I haven't found a single one at all. Also, when ammonite was first added, it would have a chance of generating on the surface of stone shores, and that was a pretty cool feature as it would add a little variation to the biome. I'm also not sure if this removal was done by choice, or by the bug, but I only posted the suggestion with this bug as there is a possibility that it wasn't an unintended removal. If it was, sorry for the inconvenience.