Most of you may have heard of Nicholas Steno, a Catholic saint that also was involved in discovering the origin of fossils. His dissection of a shark lead him to realize the origin of fossil shark teeth on areas that were now land.  These were popularly thought of as being petrified snake tongues, which they called "glossopetrae."   https://en.wikipedia.org/wiki/Nicolas_Steno   He published a book of his observations, which included some lovely illustrations of the shark and fossi