Fig. 7From: A report on palaeontological excavations and sampling in mudrocks: some guidelinesApplying diluted zapon varnish (= cellulose varnish) to an ammonite (Laqueoceras laqueous (Quenstedt 1856)) on a sediment slab. The shell of the ammonite was dissolved, but the delicate periostracum is preservedBack to article page