by Laurie Neilsen
In honor of The Discovery Channel’s Shark Week, here are some common questions asked about shark teeth, and some meaty facts to sink your teeth into.
Q. Why are some shark teeth black and others are tan?
A. The color of a fossil shark tooth is dependent upon the sediment in which it settled. As minerals slowly replace the calcium in the tooth, it changes to the color of the minerals. Color does not necessarily indicate age in a shark tooth fossil. It usually indicates the region from which the tooth was collected. Our fossilized shark teeth are collected from Morocco.
Q. Then how old are these fossil shark teeth?
A. It’s hard to say. A shark tooth takes approximately 10,000 years to become a true fossil. These teeth could be as much as a few million years old!
Q. Why are there only fossils of shark teeth and vertebrae, but not their other bones?
A. A shark’s skeleton is made of cartilage. This makes the shark flexible and fast, and provides buoyancy, precluding the need for a swim bladder like other fish have. Only the teeth and vertebrae of a shark are calcified enough to turn into fossils. Without calcium, the cartilage eventually disappears, and does not become a fossil.
Q. Do sharks have molars?
A. No, sharks do not have molars, incisors, or bicuspids like humans have. Shark’s teeth are all the same shape, but vary in size throughout the mouth. Each species of shark has a different tooth shape, making it easier to identify and sort the fossil shark teeth by species.
Q. Are sharks hunted for these teeth?
A. No, the shark teeth we sell were collected from beaches, not from live sharks. A shark will lose thousands of teeth throughout its lifetime. While the teeth are calcified for strength, they are not as firmly attached in the mouth as our teeth are. Sharks have rows of teeth to provide added grip when they bite their prey, and so they always have replacement teeth ready to take the place of the ones that fall out.
Most sharks live and hunt in coastal waters, though some have been tracked going far out to sea and traveling many miles throughout the course of a year. When the sharks lose teeth while hunting near the shore, these teeth settle in the sediment, fossilize, and sometimes eventually wash up on the beach. Many teeth are also collected by divers close to the shore.
Shark populations are declining because not only are they over hunted, but there have been many man-made changes in their environment. Many shark species are becoming endangered. Sharks are hunted out of fear and misunderstanding, but they are also hunted for trophies, and for their fins. The practice of shark finning – catching sharks just to collect their fins for shark fin soup, and throwing the injured sharks back into the water to drown – is one of the leading causes of the decline in population. For more information on sharks and shark week, visit the Discovery Channel website at: http://www.discovery.com/tv-shows/shark-week.