Simbakubwa

Simbakubwa kutokaafrika is an extinct species of giant hyaena-like mammal. It was in the order Hyaenodonta. It was originally classified as a creodont. It lived during the early Miocene and was found in Kenya.
The type specimen had been sitting in the Nairobi National Museum for many years until two American palaeontologists took an interest in it. It was got from deposits dated to be 23 million years old. The animal must have been huge, perhaps up to 1,500 kg (3,300 lb) in weight. It might have been bigger the modern polar bear in size.
Paleoecology.
Africa in the early Miocene was much more forested than today, and even the area which is now Kenya would have had much less grassland. Therefore, instead of the run-and-chase routine of most carnivores today, the emphasis would be more on stealthy stalk-and-pounce methods.
Teeth of this species show it did not have the crushing molars of modern hyaenas. What it did have here huge carnassials for slicing flesh. "Simbakubwa" was probably a specialist hunter and scavenger that preyed on creatures such as rhinoceroses and early elephants.
"Simbakubwa" was a straightforward flesh-eater, and one of the largest mammalian carnivores ever found.