Sharks have been living on this earth for some 400 million years. There are about 440 species of sharks alive today. Sharks do not have bones, their bodies are supported by a cartilageous skeleton. When a shark dies the cartilagenous skeleton dissolves but its teeth fall to the bottom of the ocean and are covered by sediment. Over the course of thousands of years the tooth becomes fossilized and in the process takes on the color of the type of sediment that it is covered in. Fossilized teeth are usually black, brown or tan to cream in color. Rare colors such as red or blue can also be found.
A shark does not have to die to leave teeth behind. Modern as well as prehistoric sharks continually shed their teeth throughout their lives. At any given time a shark can have from 5 to 15 rows of teeth behind their front chompers. As the front teeth are lost, the next one from the row behind assumes the duty of a frontal tooth. A tooth is usually in service about a week but can be as short a time as 24 hours. If you think about all the sharks that have lived over millions of years each shedding multiple teeth through their lives; that makes for a lot of teeth.
I have a book about fossil shark teeth and I have tried to figure out what some of the teeth Keith and I found might be. It is very complicated as there are so many species of prehistoric sharks. It also turns out, top jaw teeth can look different than bottom jaw teeth. This just adds to the complexity. At any rate, I think the larger serrated ones are likely Great White teeth.
Suspected Extinct Great White Teeth
(Notice the fine serrations along the edges)
These are possibly Lemon Shark teeth
The largest teeth we found are a bit more of a conundrum.
Our larger teeth (unidentified). Suspected Mako Shark
They are large triangular teeth like a Great White, but have no serrations. This type of tooth is characteristic of Mako Shark Teeth. Fossil Mako shark teeth, however, are supposed to be rare on beaches in NC. These teeth were not exactly found on a beach as they came from dirt along the coast, but out of a phosphate mine dig. This certainly could produce fossils from extinct Makos. Some scholars contend that Great Whites of today actually evolved from the extinct giant Makos.
The tooth I would love to find someday is that of the Megalodon. The Megalodon was the largest prehistoric shark and bigger than any modern shark by a lot. It was the largest ocean predator in the history of the world. It lived somewhere between 30 and 1.5 million years ago. There are those scholars who believe the Great White is the descendent of the Megalodon shark. A modern day Great White averages between 7 to 20 feet long. The Megalodon was believed to be 60 feet long. Megalodon teeth can be from 3.5 to 7 inches long. Larger ones can be the size of a person's hand.
Pictures from the Web of a really large Megalodon tooth
Of course it is rare to find an intact Megalodon tooth, but that won't stop me from continuing to look. It was sure a treat to go fossil hunting during our recent vacation back to New Bern, NC. Hopefully we can all do it again on another visit to the area.
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