Tiger Shark Tooth Necklace

Sharks loose and grow teeth throughout their entire lives. Their teeth are specialized versions of the little "teeth" in their skin, the dermal denticles. Quite recently engineers realized that by reducing the amount of turbulence these denticles greatly reduce the drag on a shark as it glides through the water. This discovery is now used to create rough surfaces on e.g. airplane wings! If you look into a shark's mouth, you can see row after row of teeth. Note that the flatter side of a tooth is the part that faces outwards.
Tiger sharks have pointy teeth, with very long and curved roots Tiger shark teeth have one large crown on the anterior side, and many small serrations on the posterior side. This shark evolved in to the modern day tiger shark.