A photograph and line drawing (left side) of the fossil dolphin Astadelphis gastaldii. The crescent-shaped line in the line drawing represents the bite of a large shark, with the red portions representing damage done directly to the bone. From Bianucci et al, 2010.

Shark attacks are events of speed and violence. When they have locked on to a prey item sharks seem to come out of nowhere, and though they can be quite gentle with their jaws (as on occasions when they are unsure about whether something is food or not) their ranks of serrated teeth can inflict a devastating amount of damage. They are not the cruel, vicious, or bloodthirsty villains they have often been portrayed