There are so many mysterious that remain here on this planet of ours, and many of them exist in some of the most remote places on the planet.

Case in point: two previously unknown species of prehistoric shark – more than 325 million years old – were discovered in the world’s largest and longest cave system.

Mammoth Cave spans more than 676 kilometers and is designated as a National Park in Kentucky. It is known to be rich in fossils and holds significance for their field of geology, and since it’s stable (for a cave system), researchers are always exploring it for one thing or another.

Recently, the Paleontological Resource Inventory and the National Park Service (NPS) got an unexpected but exciting glimpse into marine ecosystems that existed even before the dinosaurs. What they found were two species that belong to an ancient family of sharks known as the ctenacanths. These species, Troglocladodus trimblei and Glikmanius careforum, are related to modern species and are characterized by defensive cone-shaped spines on their backs.

They likely roamed a now-disappeared seaway that connected what is now North America, Europe, and North Africa. These prehistoric sharks were an important part of the Mississippian period ecosystem. They were around 10-12 feet in length and had forked teeth, suggesting they had a very specific way of hunting prey like other sharks, bony fish, and extinct mollusks.

They apparently stuck to shallower coastal environments as opposed to traversing the deep sea, and their discovery should help scientists learn more about the evolution of sharks.

There are a lot more links in the evolutionary chain of all species than we have yet discovered.

Which is why preserving sites like Mammoth Cave continues to be so important.

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