Specimens produced by a species of fish whose excrement passes through a spiral valve, giving them a spiral shape. These coprolites are generally attributed to sharks, rays, skates and lungfish. However, other fish such as the coelocanths, bowfins, gars, birchirs and sturgeon also have spiral valves.
Some coprolites of this type may actually be the fossilized contents of the spiral valve itself. These are called cololites. But whether poop or pre-pooped, they are amazing to behold!