Although it is true that Miracinonyx inexpectatus and the later Miracinonyx trumani were close cousins to Puma, rather than true cheetahs, the oft-repeated hypothesis that the pronghorn evolved as an "answer" to the speed of the American Cheetah is just that, a hypothesis. Miracinonyx - much like the cougar - was a cosmopolitan species which was found in all habitats across North America; fossil remains have even been found in caves of the Grand Canyon, the very last habitat one would imagine pronghorns to be found in. We simply do not know enough about the diet or behaviour of either species of Miracinonyx to assume a close tie to the pronghorn - especially when one considers that the genus went extinct prior to the last of the American Lion and Dire Wolf, when if the theory about megafaunal extinction leaving only the faster and more agile prey species is correct, Miracinonyx should have lasted longer.