Have a few unidentified objects found on a recent trip to Bracklesham Bay, West Sussex on a full moon low tide.
This one is quite large and heavy, uniform in the coil size and shows no tapering. The outer edges which are not damaged (was protruding from one of the lower beds) have a distinct narrowing and one of the coil ends has pyrite on the core.
Did wonder if it was a mould where the outer shell has worn away as we have quite a few of these but the size is far greater.
Have taken a few photos in the hope that someone may be able to advise what it may be whether it be fossil remains or man made.
I think you're right - it is an internal mould, of a gastropod.
Turritella is common at Bracklesham, but I don't know if they get as large as yours
Here are some internal moulds of Turritella
You'll notice the ratio of mould to gap is not quite the same as yours.
And this is a very nice example of both internal and external moulds of a similar gastropod
That one is unnamed, which is not surprising. It is very difficult to ID reliably an internal mould of any fossil.
But there are other genera in the Turritellidae; and other Cerinthoid genera, which include ones the right shape and size for yours.
Note: there are spiral trace fossils, but I don't think yours is one of them. Here's a classic example
Thank you so much for the reply and the links.
I hesitantly ruled out a burrow type mould due to the sharper edges of the spiral. It was found in one of the major Turritella beds where the shells were quite large but nothing even came close to this find. The shells which were left where they were, were extremely crumbly which added to my reasoning.
Find all this fascinating! Many thanks once again.