Out at the Cerro Colorado site in the Peruvian desert, a team of paleontological researchers uncovered the skull of a 12 million year-old relative to the modern sperm whale. While it was similar in size to the sperm whale, which is now the largest of all the toothed whales, the Leviathan melvillei (as the researchers named it in honor of Moby Dick) has much more massive teeth located on both upper and lower jaws whereas the sperm whale has a much smaller, somewhat vestigal set only on its lower jaw.
The teeth of this whale were 36 centimeters long (that’s 14 inches for Americans) and 12 centimeters (5 inches) in diameter, giving it the largest bite of any tetrapod yet found according to the researchers, who believe that this animal had a diet including small baleen whales (the group of whales that the world’s largest animal, the blue whale belongs to), whose remains have also been found in Peru around that time. Here’s a photo of the find taken from the supplemental materials:
So, at a quick glance, it looks like I could easily fit my whole body inside this creature’s jaws. For a more detailed account, see Ed Yong’s post on the topic or “The jaws of the Leviathan” video done by Nature or the original article.