10 Terrifying Extinct Cetaceans

Basilosaurus isis
This giant creature, originally called "king lizard," lived 40 million years ago. De Agostini Picture Library/De Agostini/Getty Images

Bees buzz around a series of domestic hives in early 19th-century Mississippi. Wedged between the hives are the gigantic vertebrae of an ancient sea creature. So ubiquitous are these bones during this era that Mississippians and Alabamans routinely use them as furniture. They even stick them in their fireplaces to prop up logs. Curious about the strange bones, a local judge decides to send some samples to a well-known anatomist [source: Zimmer]. Believing that the fossilized vertebrae belong to a massive dinosaur, the anatomist decides to call the species "Basilosaurus," meaning "king lizard." He's right about the size but wrong about the dinosaur thing.

Basilosaurus isis was a mammal — a whale that lived about 40 million years ago. Its front legs had evolved into flippers, and it had some stubby hind feet that would've been no use on land. But at 50 feet (15 meters) in length, slithering through the water like a giant eel with terrifying rows of sharp, curved teeth for ripping sharks to pieces, it would have been one of the most dangerous predators lurking in the oceans of the late Eocene [source: Gingerich].