
The Helicoprion was a shark-like fish that arose in the oceans of the late Carboniferous 280 million years ago, and eventually went extinct during the early Triassic some 225 million years ago.
The Helicoprion kept growing new teeth throughout its life, but they did not fall out. Instead, the teeth grew in spiral fashion, with new, larger ones being added.
I don’t even know how to feel about this.
This might be the scariest thing ever.