I purpose that all predators eventually go extinct and are replaced by prey species evolving into predators. This is because there are far fewer predators than prey, and have far stricter diet requirements. Whenever an ice-age or meteor hits, predators will starve and herbivores will thrive due to their huge populations and lenient diet of plants. Herbivores will fill every niche imaginable and have many more chances to evolve, eventually producing a faux predator that out-competes the real predator and drives it to extinction.

Look at hippos for instance, dangerous animal in Africa, plant eaters that occasionally eat rotted meat, if something shifted in the environment or evolution they could easily outcompete lions.