planorbis

Nice find. What size is it? I would be interested to know what you have preserved it with. Normally the matrix is prone to crumbling when dry and often turns to a slushy clay when wet.

Ta kosmo,

its about 6 inches, just got artists varnish on it.

A lovely piece there, Neil. It's Caloceras johnstoni - as it has the strong ribbing which Psiloceras typically don't have, although Psiloceras plicatulum does show faint ribbing.

Edit: After re-reading your description I've noticed that you haven't actually named the specimen, you may have just named the zone that it has come from? I do apologise if this is the case - if not then you now have the ID.

Joe

Thanks Joe.

Classic!