The American lion, also known as the North American lion or Panthera leo atrox, was a species of big cat that roamed the continent during the Pleistocene epoch. This magnificent predator was closely related to today's African lion, but due to its unique physical and behavioral traits, it earned a host of different names. Synonyms for the American lion include the cave lion, the Alberta lion, the Southern jaguar, and the Sierra Nevada lion. These names reflect the different regions where these animals hunted and made their homes. While the American lion is now extinct, its legacy lives on in the rich history and folklore of North America.