Paleontologists Fred Smith and Mike Everhart are searching for prehistoric bones on a hillside in the middle of Kansas in 2010. It’s a place where Everhart has previously found bones from a plesiosaur, a giant marine reptile extinct for many millions of years. But on this day the soil yields only tiny bone fragments. Then Smith uncovers what he thinks is a piece of fossilized tree. But Everhart realizes that this is no tree branch. It’s something much more exciting.
In fact, it emerged that what Smith had discovered was actually the first of an array of bones later uncovered. Eventually these included 61 vertebrae, 134 teeth and 23 fish scales. This was no ancient fossilized tree; it was a cache of shark bones dating back more than 90 million years. This shark had swum in the Western Interior Seaway which cleaved North America into two parts during an era known as the Late Cretaceous Period, which lasted from 144 to 66 million years ago.