A cast of the Xiphactinus, a fanged predator that once roamed ancient seas about 100 to 66 million years ago. Xiphactinus could be as large as 20 feet long.
The first fossil of the Xiphactinus was discovered in Kansas in the 1850s.
Often when fossils of Xiphactinus were found there would be other smaller, fish fossils inside of them.
Image of a fossil of an Xiphactinus at Carnegie Museum in Pittsburgh from James St. John via Wikimedia Commons, CC BY 2.0 Generic
