How to Tell If Shark Teeth Are Old

Sharks continually shed and grow new teeth throughout their lives. A tooth may only last in the shark's mouth for 10 days, meaning it sheds approximately 1,800 teeth each year. The teeth range from 1/8 of an inch to three inches and, in rare cases, even larger, depending on the type of shark. Though it is difficult to tell the exact age of shark teeth without testing them in a lab, there are a few ways to tell if they are old.

Things You'll Need

  • Geological map
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Instructions

    • 1

      Note the color of the tooth. Modern shark teeth are usually white, and fossil teeth that have been permineralized, or filled in with mineral deposits, are usually darker colors, like black and brown.

    • 2

      Identify where the shark tooth was found. Teeth found at the beach or in the ocean are likely newer because live sharks are continuously shedding teeth. Teeth found in a river or creek where sharks do not live have traveled a greater distance in the water over a longer period of time, usually making them older.

    • 3

      Determine the age of the sediments the tooth was found in. Look at a geological map that shows where different aged sediments can be found. Compare these locations with the location where the tooth was found to estimate the age of the shark tooth.