Megistotherium is an extinct genus of hyaenodont belonging to the family Hyainailouridae that lived in Africa.
Megistotherium
Comparison of various Early to Middle Miocene hyaenodonts, including the hyainailurids Hyainailouros sulzeri (top) and Megistotherium osteothlastes (center), and teratodontid Dissopsalis pyroclasticus
Hyaenodonta is an extinct order of hypercarnivorous placental mammals of clade Pan-Carnivora from mirorder Ferae. Hyaenodonts were important mammalian predators that arose during the early Paleocene in Europe and persisted well into the late Miocene.
Hyaenodonta
Skull of Hyaenodon horridus