Eons | PBS How a Supervolcano Made the Cenozoic’s Coolest Fossils | Eons WKNO Published January 4, 2024 at 4:00 AM CST Facebook Twitter LinkedIn Email One of the most dynamic, transformative, and potentially dangerous features in North America is also responsible for some of the continent’s most amazing fossil deposits. It’s a supervolcano we now call Yellowstone.