query: Where were fossils of the Smilodon first discovered?
passage: Smilodon
Smilodon is a genus of the extinct machairodont subfamily of the felids. 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–10,000 years ago). The genus was named in 1842, based on fossils from Brazil. Three species are recognized today: S.gracilis, S.fatalis, and S.populator. The two latter species were probably descended from S.gracilis, which itself probably evolved from Megantereon. The hundreds of individuals obtained from the La Brea Tar Pits in Los Angeles constitute the largest collection of Smilodon fossils.
passage: Machairodontinae
Traditionally, three different tribes of machairodontines were recognized, the Smilodontini with typical dirk-toothed forms, such as Megantereon and Smilodon, the Machairodontini or Homotherini with scimitar-toothed cats, such as Machairodus or Homotherium, and the Metailurini, containing genera such as Dinofelis and Metailurus. However, some have recently regrouped the Metailurini within the other felid subfamily, the Felinae, along with all modern cats.[2] The last machairodontine genera, Smilodon and Homotherium, did not disappear until late in the Pleistocene, roughly 10,000 years ago in the Americas.