Eusmilus bidentatus. Illustration and photo-reconstruction of an Eusmilus, an ancient species of Nimravidae, standing on a fallen tree trunk menacingly baring its teeth. Eusmilus (true ) is a prehistoric genus of the family Nimravidae, subfamily Nimravinae, endemic to North America, Europe, and Asia during the Late Eocene-Early Oligocene epochs (37.2-28.4 mya), existing for approximately 8.8 million years. It had developed long teeth and looked like a sabre-toothed cat, but was actually a so-called false -tooth. Most were leopard-sized and rather long-bodied and short-legged compared to modern leopards. Some reached 2 metres long. A single specimen was examined by Legendre and Roth for body mass and was estimated to have a weight of 50 kg.