tomium

The tomium is the sharp cutting edge of the beak of a bird or turtle.

The tomia (singular "tomium") are the cutting edges of the two mandibles.

The upper jaw has a blunt unnotched, nonbucuspid tomium.

E. imbricata is easily distinguished from other sea turtles by its sharp, curving beak with prominent tomium, and the saw-like appearance of its shell margins.

The front end of the skull is unknown, but there would have been a sharp bony ridge (tomium) at the end of both upper and lower jaws, as seen in other ankylosaurs.

Instead of teeth, the leatherback turtle has points on the tomium of its upper lip, with backwards spines in its throat to help it swallow food and to stop its prey from escaping once caught.