The Ice Age cat commonly known as the saber-toothed tiger is Smilodon. Its name refers to the genus of extinct cats famous for their exceptionally long, curved upper canine teeth.
Smilodon lived in the Americas during the Pleistocene, from roughly 2.5 million years ago until as recently as about 8,200 years ago. Three species are generally recognized: Smilodon gracilis, Smilodon fatalis, and the especially large Smilodon populator. Fossils of S. fatalis are well known from California’s La Brea Tar Pits.
Despite its popular nickname, Smilodon was not a tiger and was not closely related to modern tigers. It belonged to Machairodontinae, an extinct branch of the cat family. The term “saber-toothed” describes a body form that evolved in several unrelated predator groups, so Smilodon was one famous saber-toothed cat, not the only one. Its powerful forelimbs likely helped restrain prey while its canines delivered a deep bite.