Possible Clues:

• A nitrogenous fertiliser made from animal wastes
• Fossil obtained from old nomadic tribesman
• Crazy inmate hiding Medical Officer's fossil
• Fossil mollusc
• Fossil, a little one with day inscribed
• A little creature, one day buried, to become a fossil
• Prince quits pantomime when dressed as a marine fossil!
• Common fossil
• A special moment in which one’s collected fossil
• Coiled fossil shell of extinct mollusc