Hyainailouridae

Hyainailouridae ("hyena-like cats") is a paraphyletic family of extinct predatory mammals within the polyphyletic superfamily Hyainailouroidea within extinct order Hyaenodonta. Fossil records show hyainailourids arose during the Middle Eocene, although Early Eocene origin is suspected, the family persisted into the Late Miocene. Fossils of this group have been found in Eurasia, Africa, and North America. Originally considered a subfamily of Hyaenodontidae, the group included small species as well as massive predators like Megistotherium. While many were hypercarnivores, others were mesocarnivorous or showed adaptations towards osteophagy.