Shark fossils are often found in the mountains of Lebanon. Sharks belong to the cartilaginous class of fish. The skeletons of cartilagenous fish do not contain calcium, but are composed of cartilage tissue. Their only calcium deposits are in their teeth, and sometimes in their spines. For this reason, fossils of sharks" teeth are more commonly found than fossils of their skeletons. The oldest shark fossil so far discovered dates back about 400 million years. As with other living things, this shows that sharks have not changed in hundreds of millions of years. Contrary to what evolutionists claim, sharks did not develop in stages from other species, but came into being all at once with all their structures complete. In other words, they were created.