American Cheetah, Miracinonyx trumani
Miracinonyx, commonly known as the American Cheetah, is an extinct genus of large cats. It was native to North America during the Pleiotocene era(1.8 million to 11,000 years ago). The American cheetah held at least two species in its genus that are similar to modern cheetahs, including Miracinonyx inexpectatus and M. trumani. Similarities distinguished by bone fragments include a short face and nose for better breathing, and elongated legs used for swiftly hunting prey. These similarities are thought to have occurred not from a direct evolution, but from parallel or convergent evolution.
M. trumani was possibly the most similar to modern cheetahs. It lived on prairies and most likely hunted animals like pronghorn. It is thought that predation by Miracinonyx is what caused the pronghorns to develop such a quick running speed, which is much faster than necessary to outrun modern predators such as grey wolves and cougars.
Another cat in the Miracinonyx genus is the Miracinonyx inexpectatusm, which is actually more similar to modern cougars than cheetahs. It was faster than a cougar because of its slim build, but it had retractable claws and was a skilled climber.
Originally, Miracinonyx was thought to be an early cougar, but was reclassified in the 1970’s as a close relative of the cheetah. That research caused the thought that cheetahs in the “Old World” may have evolved from pumas in the Americas. Research done by Barnett disputes the classification of Miracinonyx by showing that the DNA and morphology (or changes in structure) may have been a convergent evolution from the Puma lineage. It suggests that the genus is most closely related to the Puma and not African and Asian modern cheetahs. This research asserts that the American origin of the cheetah is doubtful; however, it is thought that the cheetah did evolve from a cougar like cat. It is also thought that M. inexpectatus may be an early version of M. trumani.
Image Caption: American Cheetah, Miracinonyx trumani, Extinct megafauna, Pleistocene mammals, Pleistocene extinctions. Credit: Philip72/Wikipedia(CC BY-SA 3.0)