The cave that held the evidence found is in the United States, a state with the name Kentucky. The cave is known as the Mammoth caves. The cave system travels 420 miles into the earth. This system may be the largest in the world. Now just try to figure the probability of finding 2 different species of prehistoric shark to find in the same location 420 miles deep into the rocky earth. Simply amazing!

“Two prehistoric sea monsters found in the world’s largest cave” – Earth.com

https://www.earth.com/news/prehistoric-sea-monster-shark-fossils-found-in-worlds-largest-cave-325-million-years/