They aren't the only ones. Beavers do too! So does the Giant Pacific chiton (world's largest chiton, a type of mollusk).

Pretty useful for animals that have to scrape food off rocks or continually gnaw through something.

I guess Komodo dragons need those teeth to last, whereas sharks are just like "I got a million of these things."

Evolution really fucked up when it came to our teeth, huh?

there's some snail that has an iron sulfide shell

I've got some thoughts that kick up on reading this.

a) Does anyone have some solid reading on this family of lizards?

b) I know a bit about Komodo dragons. I know they tend to eat the dead, and it's believed they gained their title due to looking like dragons and inflicting deadly toxic bites. It was later analyzed (although this is all from memory) that it wasn't as if they had actual poison in their mouths, but instead just carried bacterial that would infect the wounds.

c) In reading up (wiki) on their hunting habits (shred and stalk) it actually does sound more akin to some of the smaller Saurischian hunting habits. As I remember reading about some would slash vulnerable parts of their prey and then stalk them until they succumbed to their wounds. But it's also my understanding that T-Rex had bulbous teeth over these sort of curved like teeth. And acted as a guillotine crushing their prey bones and all over inflicting razor like damage. So I think the article (at least to my understanding) is off the mark there with its comparison.

the article doesn't mention how corrosion is prevented, since iron loves to rust, also doesn't link to a paper which could contain that information