The saber-tooth tiger is remembered with wonder as a relic of the last ice age, but the truth is both more interesting and more mundane. The giant cat (it was about 5 feet long and 440 lbs) got its nickname from its two 7-inch canine teeth. Scientists have uncovered enough facts about the species to determine some theories about why it went extinct about 10,000 years ago.
The saber-tooth tiger (as it is known in popular parlance, but its official name is Smilodon) is part of the Falidae family that includes every kind of cat living or extinct. It lived in North and South America and is commonly depicted as having lived side by side with man during the last ice age. It is actually much older than that, with fossil evidence dating it to around 1.8 million years ago. A similar but smaller species, Smilodon gracilis, lived 2.5 million years ago. The major hypothesis for its extinction consists of a mix between human hunting and climate change, but each theory has its challengers.
The Smilodon went extinct around the end of the last glacial period in what was known as the Quaternary extinction event. Fifteen kinds of large mammals went extinct in North America during that 1,500 year window, whereas only 33 total went extinct during the past 50,000 years. The saber-tooth had survived previous glacial periods, but this extinction event included changes in temperature and vegetation. It combined to create large consequences throughout the local food chain according to the American Museum of Natural History, which could have ultimately killed off the big cats.
Glaciers were receding across continents around the time of the Quaternary extinction event. Seasons were changing, and rainfall amounts could have altered the condition of local ecosystems. Over a 5,000 year period, the temperature rose more than six degrees, which might have had big consequences for larger animals. If climate change did lead to the Smilodon extinction, then something specific must have occurred that was not present in previous glacial periods. A more esoteric hypothesis is that diseases led to these mass extinctions, but there is little proof of that.
The diet of the Smilodon included bison, deer, and ground sloths, many of which either went extinct or began experiencing population drops about the time the sabre-tooth went away. Bison numbers dropped dramatically as grasslands were transformed into forests. In other words, bison population might have been constrained by the environment. When humans eventually reached North America, they represented further competition for the Smilodon over dwindling sources of food.
The extinction of the saber-tooth tiger also happens to align with the period when humans started to make huge strides in hunting technology. This was around the time of the Clovis tribes, which were known for their projectiles. Humans would not have hunted the saber-tooth tiger for food, but may have killed them for protection or sport. Some researchers refute this hypothesis, asserting that humans did not have the means or the desire to drive other animals to extinction.