Shark teeth are covered in fluoride which makes them cavity-resistant. A study published in the Journal of Structural Biology in 2012 discovered that the enamel on sharks teeth is actually made up of a chemical called fluoroapatite. Fluoroapatite is resistant to acid produced by bacteria so this means that shark’s teeth don’t decay. Also, most sharks (not all) continuously lose and replace their teeth with new ones throughout their lives. So if you were going to try to make a living as a shark-dentist, business would be slow!
Speaking of slow…
Sharks have been on earth for over 420 million years – that is 200 million years BEFORE the first dinosaurs existed. That is a looooooong time. In that time, lots of different types of sharks have evolved and they have all grown the perfect teeth to suit what they do. Here is a look at a few different types of shark teeth:
Great White sharks have fairly flat, very triangular teeth for tearing and cutting.
Tiger sharks have angled, serrated teeth that sit sideways in the jaws. The shark clamps down on its prey with around 3000lbs of force and shakes its head from side to side, cutting and slicing. Even the tough shells of turtles, its favourite prey, are not enough to withstand these teeth.
The Sand Tiger shark (also known in some areas as Ragged Tooth sharks or ‘Raggies’) has sharp, thin dagger-like teeth for catching fast, slippery fish with extra ‘prongs’ like forks. The teeth are curved slightly inwards, towards the mouth, so once it has hold of a fish – there’s no escape!
The biggest shark teeth ever belong to the Megalodon, which lived alongside the dinosaurs but became extinct around 40, 000 years ago. In fact its name means ‘Big Tooth’. The biggest teeth ever found have been over 7 inches (that’s around 18cm) long!
The Megalodon was not the only giant in the ocean at the time. As formidable as it was, it is very likely that it was prey to other, larger creatures at the time. Still – nothing that has ever lived on land or at sea has been as big as the Blue Whale which you can still see today.
Perhaps the strangest shark teeth ever belong to Helicoprion – another extinct, prehistoric shark. Fossils have been found of its strange, spiral-like teeth that are so bizarre, people still cannot agree on exactly how it must have looked. Below are some artists impressions of what the Helicoprion may have looked like:
If you want to know more about shark teeth – check out this great article from shark expert Joshua Moyer. Josh is an ichthyologist specializing in the evolution, biodiversity, and morphology of sharks.