Paleontologists have been finding this one type of fossil everywhere, with millions of specimens being found. 

However, even though these fossils are abundant, they remained a mystery for decades. 

Geologists discovered that these fossils, known as conodont elements, could be used as markers to tell time in the distant past. 

Check out this very interesting video by PBS Eons to learn more about this fascinating fossils and the many ways it has helped us to learn about our planets ancient history. 

Leave a comment to let me know what you thought about this video or anything else that is on your mind.