Miracinonyx, also known as the American cheetah, was a prehistoric species of big cat that lived in North America during the Pleistocene Epoch. Though commonly referred to as the American cheetah, this species was not closely related to modern cheetahs and exhibited several unique morphological adaptations. Some synonyms for Miracinonyx that have been used over the years include the "saber-toothed cheetah", "long-legged cheetah", and "false cheetah". These synonyms reflect the similarities and differences between Miracinonyx and modern cheetahs, as well as the long process of identifying and classifying this extinct big cat species.