I used to collect fossils along the Thames river north of London, Ontario, and I will swear there was a rotting marine odor associated with the fossil-bearing layers.
Mary Schweitzer first id’ed it (or at least was first to be brave enough to do it). The first of the FRchive links up there (post #1) links to a post listing topics of her keyword here.
Y’all (most who responded) missed the statement that this was fossilized soft tissue. That means the tissue was replaced with stone. No DNA or other organic material….