Although nowhere near rivaling the largest living species of whale -- the blue whale -- the largest extinct whale that's been discovered is known as Leviathan melvillei. The name is in homage to Herman Melville, the author of "Moby Dick," as it's thought this extinct species was fearsome and ferocious. It lived in the oceans of our planet roughly 12 to 13 million years ago.
The fossilized skull of Leviathan melvillei was found in a coastal desert region of Peru -- an area once covered by ocean -- in 2010. Scientists had previously found large fossilized teeth, which suggested there was a extinct whale species they hadn't yet discovered, but hadn't come across any further evidence than that. The team that discovered the creature was led by Olivier Lambert, a paleontologist from the Museum National d'Histoire Naturelle in Paris.
The skull that these paleontologists discovered was 10 feet long. Although the entire skeleton wasn't found, it's estimated that Leviathan melvillei measured roughly 60 feet in length. There were still teeth remaining in the fossilized skull, and some of these measured up to 14 inches long, suggesting that this whale was a fierce -- and somewhat scary -- predator.
Although it's impossible to be completely certain what Leviathan melvillei ate, experts believe that smaller whales, such as baleen whales, were probably its main source of food. The wear lines on this whale's teeth are vertical, and there's a big gap in the skull that would've held a large jaw muscle. Due to these attributes, it's safe to say Leviathan melvillei bit its prey, much like the killer whale, rather than sucking it in, like sperm whales and many other large whales.
Although not a direct ancestor of today's sperm whales, Leviathan melvillei was definitely related to them, more likely as a distant cousin. Although they were roughly the same size as modern sperm whales, there are several evolutionary differences between them. For instance, sperm whales have no teeth in their top jaws. They have no need for them, since they suck in squid and other prey as they swim along, rather than hunting for and biting their dinner.