Helicoprion Had A Buzzsaw In Its Mouth
Helicoprion's tooth whorl filled its entire lower jaw; the fish had no upper teeth. Scientists theorize that it used its teeth much like a saw blade to slice through prey. It probably ate boneless animals, such as other cartilaginous fish and squid, which explains why fossilized tooth whorls don't exhibit too much wear. Earlier guesses as to where helicoprion's tooth whorl sat on its body ranged from nearly correct to humorously off-base, with some illustrations positioning the whorl on the fish's nose or fins.
from Animal Planet
Key Facts In This Video
Many helicoprion lived in the Phosphoria Sea, which covered what is now southeastern Idaho. (0:21)
See a 3D-printed model of the helicoprion's jaws and tooth whorl: (1:18)
Little wear has been found on fossilized helicoprion teeth, suggesting that they ate boneless prey such as squid. (1:50)