Adult great white shark teeth are pretty fearsome, ringing in at about 2 inches with knife-like serrated edges. But baby great white teeth are just as terrifying, considering they're used to eat their unborn siblings and are shed in the womb.
According to New Scientist, great white shark mothers have been found with baby teeth embedded in their uterus.
The unborn sharks have even swallowed some of their own teeth.
Yum? Well, yes, actually. According to the Florida Museum, shark fetuses may swallow their teeth to gain calcium and minerals from the material.
You know, to make them even stronger than eating their own brothers and sisters does.
Florida Museum notes that sharks eat their fellow embryos in the womb to grow strong. According to The Sun, sand tiger sharks, in particular, devour all but one of their womb-mates. It's what researchers believe is a survival tactic.
The bigger you can be born, the better your chances at thriving in the sea.
LiveScience notes that shark fetuses may also be programmed to eat embryos that come from the sperm of other fathers. Savage.
In any case, they need those teeth, and shark teeth have a unique way of falling out and replacing themselves to keep the shark attack ready at all times.
According to Smithsonian magazine, shark teeth are rooted in cartilage instead of bone, so they fall out after basic wear and tear.
But then a new row of teeth just slides into place.
A great white shark can lose 20,000 teeth in its lifetime — especially when attacking and eating prey.
Sharks have even been photographed losing them mid-hunt.
And the shark doesn't even wait until one pops out to replace its set. New Scientist reports that it's just easier for the shark to be continuously replenishing, and new chompers come in about once a week to keep the set of 300 in tact.
Clearly that process starts before sharks are even born, according to these findings of uterine teeth in great white mothers. But New Scientist reports that this actually complicates earlier science.
Sharks are mostly cartilage and don't fossilize well, so scientists have relied on shark teeth to tell them about history. If any of those recorded fossilized teeth are actually fetus teeth, it throws a wrench into any documented information.
Especially because, according to New Scientist, developing great white shark teeth actually look just like sand tiger shark teeth ...