Coiled fossil shell (8)
![Ross](/clue/static/ross-mug.min.png)
I believe the answer is:
ammonite
'coiled fossil shell' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for ammonite that I've seen before include "A victim of Saul" , "shelled to extinction?" , "marine fossil!" , "Type of explosive" , "Type of fossil" .)