R & C | ICHTHYOLOGY | SHARKS: FACT AND FANTASY

Fossil Shark Teeth

Sharks were swimming in ancient seas more than 450 million years ago; before backboned animals invaded the land. They have existed for about three times as long as did the dinosaurs and over 100 times as long as humans. Fossil shark skeletons are uncommon because they were made of cartilage which is soft and did not fossilize well. Shark teeth are composed of much harder substances and may be very common as fossils.