Saber-toothed cat,” also called saber-tooth cats or saber-tooth tigers, is a blanket term to describe numerous species of cat or cat-like animals that independently evolved long, impressive and formidable yet fragile canine teeth as long as 20 cm (8 in). Saber-toothed cats evolved in the mid-Cenozoic, about 40 million years ago, and lived up until the late Pleistocene extinctions as recently as 9,000 years ago. The late Pleistocene extinctions, during which many animals were wiped out including mammoths, dire wolves, short-faced bears, and numerous others, is thought to be attributable to human hunters.
Most saber-toothed cats were members of the family Felidae (subfamily Machairodontinae), the true cats, but other saber-tooth cat-like animals were found in the families Hyaenodontidae (hyenas), and Nimravidae (an extinct order of mammalian carnivores), as well as two families of marsupial carnivores. The most famous and prototypical example of a saber-toothed cat was the species Smilodon, which lived in north and south America between 3 million and 10,000 years ago, and of which many fossils have been found.
At 200 kilograms (450 pounds) and with a short tail, powerful legs, muscular neck long canines, and a bear-like build, Smilodon would have been a ferocious predator. Saber-tooth cats have competed with dire wolves and other canine predators over the numerous large prey animals that lived in the Americas during the Pleistocene, such as ungulates and bison. Predators such as the saber-tooths likely contributed to the extinction of the South American "Terror Birds" two million years ago, when the Isthmus of Panama connected North and South America during an event called the Great American Interchange.
Smilodon californicus, a species of saber-tooth cat, is known as the state fossil of California. Thousands of skeletons have been uncovered from the La Brea Tar Pits in Los Angeles. Based on analysis of the fossils, scientists believe the saber-tooth cat's style of killing involved jumping on the back of larger animals and severing the jugular vein. The tough skin and fat layers of animals that lived during this time may have contributed to the evolution of the impressive saber-tooth.