the prehistoric ancestor to a hyiena?

Question

a predator much like a hyiena only bigger and more aggressive

Answer 1

The hyaenids have no fossil record before the mid-Miocene period, about 15 million years ago. It is believed that the family began in Africa and spread through Europe and Asia. They are thought to have evolved from a member of the viverrids. Extinct hyena genera included civet-like tree dwellers and speedy species designed for running down prey, along with even more powerfully developed bone crushing species similar to modern hyena. Fossil examples include the genera Protictitherium, Ictitherium, Chasmaporthetes, Adcrocuta, Pachycrocuta and Percrocuta (of which P. gigantea was the largest Hyena which ever lived}.

Most lines of hyena died out towards the end of the Miocene, possibly due to competition from early canids. The running hyena Chasmaporthetes survived until the first ice ages, and the Eurasian Cave Hyena survived until the end of the last ice age, when they died out along with much of the Eurasian megafauna