Smilodon is an extinct genus of machairodont felid. It is one of the most famous prehistoric mammals, and the best known saber-toothed cat. Although commonly known as the saber-toothed tiger, it was not closely related to the tiger or other modern cats. Smilodon lived in the Americas during the Pleistocene epoch (2.5 mya to 10,000 years ago). The genus was named in 1842, based on fossils from Brazil. Three species are recognized today: gracilis, fatalis and populator. The two latter species were probably descended from gracilis, which itself probably evolved fromMegantereon. The largest collection of Smilodon fossils has been obtained from the Rancho La Brea Tar Pits in Los Angeles, California.