Have you ever collected sharks from Kansas? That may sound very strange, being as how Kansas is about as far away from any modern ocean as you can get. In fact, the geographic center of the contiguous United States is located in Kansas. So how do sharks get there?

Kansas was not always in the center of the continent, and the coasts were not always where they are today. In fact, 100 million years ago the shape of North America was very different. What is now Kansas was part of the continent, but it was under an enlarging epicontinental sea, a sea that laps onto the continental shelf or its interior.

There are few examples of epicontinental seas today, but Hudson Bay is one. During the Late Cretaceous time period, the last period from the Age of Dinosaurs, the epicontinental sea spread over the entire mid-section of North America, connecting the Gulf of Mexico with the Arctic Ocean, dividing the continent into two main landmasses.

With the sea waters came sea creatures, including sharks and giant fish. From the fossil evidence of their teeth we can tell a great deal about their diversity and lifestyles. There were small, scavenging sharks that specialized in crushing up shelled mollusks. There were mid-sized sharks, in the 8-10 foot range, that scavenged on larger carcasses and fish. And there were large sharks, much like our modern-day Great White Sharks, that were able to attack very large prey.

And there were plenty of large things in the sea to select from. In addition to the sharks, the Kansas seas were alive with giant marine lizards called mosasaurs, and other reptiles called plesiosaurs. The mosasaurs are close to modern snakes, and like snakes had elongate and sinuous bodies. They propelled themselves through the water with powerful whips of their tails, and guided their movements with paddle-like limbs. The species of mosasaurs ranged from modest 10 feet to giant sea monsters over 40 feet long.

The plesiosaurs were an entirely different group of reptiles that lived in among this mix. They came in two basic forms: long-necked and short-necked. The long-neck beasts have been described as looking like a snake threaded through a turtle, their bulky bodies and paddles resembling a sea turtle, while their long snakey necks wreathed out in front of them. The “Loch Ness Monster” has been described as looking like this, just to give you an idea. The short-necked forms were much heavier in body plan, and ate much larger prey.

All of these beasts have been preserved in the rock formations of western Kansas and are on display in many museums. Some of them are found in toy dinosaur sets, although nothing mentioned here is a true dinosaur. But that is another story.