Pictures: Check out these teeth from the animal world
A new book which looks at the teeth of things like fish, amphibians and reptiles shows the wide range that exist. It looks at how different teeth have evolved for different uses. Here are some of the scariest smiles.
If these scary teeth look pretty sharp, they are! It's because they come from a tiger shark. They are rough around the edges which helps the shark catch and eat its prey. Chomp!
These fish are well known for their teeth. Piranha's teeth are razor-sharp and lock in place when it bites. They get new teeth all the time, each new set takes just a few days to come through and they are replaced about 30 times during their life.
King's College London
These powerful jaws belonged to a fish-eating crocodile, the Gharial. As this skull shows it had more than 100 sharp teeth in its jaws. It used this big bite to catch its slippery prey and then swallow it whole. Snap!
Courtesy Prof. PT Sharpe.
Look at the smile on this guy. This tiger moray has very sharp and spiky teeth. Say cheese!
This is the sucker-like mouth of a sea lamprey. The long fish are known for their good grip and they use their mouths to latch on to their prey. It does not have true teeth, they're made of hardened skin but still look pretty scary.