18 photos of animals with very unusual smiles that are more frightening than delightful (19 photos)
Perhaps, when it comes to unusual and longest teeth, many of you will recall the now extinct saber-toothed tigers. And you would be right; they were record-holders. But even today, animals with very unusual teeth inhabit the Earth, although not all of those in this collection have survived to this day. 
There are also those for whom it is unclear why nature gave them. It is unclear to humans in particular. About dozens of animals were included in this article, and they will certainly impress you with their "smile," although not always a happy one. Some of them might even be frightening, including those of some very cute-looking animals.
Share in the comments which teeth impressed you most. Or have you found a use for them while scientists are still puzzled.
This is what the Babirusa's upper and lower canines look like. 
However, humans still haven't figured out why the animal needs such canines. Judging by observations, it doesn't use them for defense or for obtaining food.
Musk deer live in the Northern Hemisphere. 
Nature has gifted only males with such fangs, which they use to attract females or ward off rivals. This is an unusual decoration.
The mackerel-like hydrolycus, also known as the payara, has fangs that it uses to grab prey. 
The common merganser is a bird with over one hundred and fifty teeth. 
They look quite unusual in the beak, but thanks to their teeth, the merganser catches and holds slippery fish.
The naked mole rat is notable for its protruding teeth. 
Also, 25% of the animal's muscle mass is made up of jaw muscles.
The Cape Cod crucian carp's teeth look rather creepy because they are very similar to human teeth. 
The fish uses them for practical purposes, not decoration. It grinds up hard crustaceans and mollusks, which are the main part of its diet.
This time, the Humboldt squid is surprising. Notice its beak. 
The batagur turtle looks so cute at first glance, but look how it opens its jaw. 
Promachoteuthis sulcus is a species of promachoteuthid Squid 
Scientists have only managed to catch one such squid, namely a German research vessel. The growths on the squid's normal beak have formed unusual teeth, which other squids lack. Again, scientists have not yet been able to explain their purpose.
The dragonfish is a very real representative of the animal world. 
What happens if you look into a penguin's mouth? 
The narwhal has one tooth, but it grows in 2-3 meters 
Crabeater seals filter out krill thanks to this unusually shaped tooth. 
You've probably never looked inside a snail's mouth. Today is the moment of truth: the mouth can hold up to 20,000 teeth. 
The parrotfish chews coral and its teeth remain intact. 
The leatherback turtle also has some very strange features. Teeth 
It's like looking at stalactites. Teeth cover the mouth and esophagus all the way to the intestines.
How do you like the fang-toothed moray eel's teeth? 
From the "Amazing Things from the Past" section — Helicoprion 
This species of cartilaginous predatory fish no longer lives on the planet. They became extinct approximately 280 million years ago. Their spiral teeth helped them hunt soft-bodied prey.
