This nice coprolite was sold by U.K. dealer as a dinosaur coprolite. Because of its spiral structure, we know it is most likely from a large fish like a shark, ray or another fish species with a spiral valve. Misidentification is common with coprolites, so always beware.
However, misidentification was not the only problem with this coprolite. Either the original collector or the dealer had used glue/consolidant on it. This made it difficult to remove the matrix. I could have just loosened the matrix a little at a time by brushing it with acetone. But since there were no signs of cracking and this spiral type is fairly common to the area, I thought I would try a little experiment. I completely submerged the sample in acetone for about 5 minutes to see if I could dissolve some of the glue. I had used this process with coprolites comprised of apatite (which is much harder), with some success. However, this particular specimen ended up a gooey, crumbled mess. Unlike fossilized bone, use of glue or stabilizers/consolidants on coprolites is not a good idea. Always remember: NEVER put glue on fossil poo!