Smilodon

Smilodon is the cat most people mean when they say “sabre-toothed tiger”, although it was not a tiger at all. It belonged to an extinct branch of the cat family whose ancestors split from those of today’s cats about 20 million years ago. Its upper canines grew up to about 28 cm long, so long that they showed below the lip even when its mouth was shut, and its jaw may have opened more than 110 degrees. It hunted across the Americas for more than two million years and died out at the end of the last Ice Age.

Three kinds of sabre-tooth

There were three species. The earliest, Smilodon gracilis, lived from about 2.5 million to 500 000 years ago and was about the size of a jaguar. Smilodon fatalis, the best-known, lived mainly in North America and was about as large as a lion but more robust, at 160 to 280 kg. The biggest was Smilodon populator of eastern South America, which stood about 1.2 m at the shoulder and weighed 220 to 360 kg, with some individuals probably over 400 kg. All three had short tails and enormously strong forelimbs.

How the sabres worked

A lion opens its jaws to about 65 degrees. Smilodon may have managed more than 110, though a 2020 study gives about 82 to 89 for two of the species; either way it was enough to clear the long canines and drive them into prey. The teeth were flattened from side to side and finely serrated, more like blades than spikes. It probably held its prey down with those powerful forelimbs and killed with a stabbing, slicing bite of the canines. A 2025 study of sabre-toothed predators found that extreme sabres like these pierced flesh with very little force but broke more easily, which fits the older view that the cat had to restrain its victim before biting.

Growing such teeth took time. Young Smilodon kept their milk canines beside the growing sabres for up to 30 months, and a 2024 study found that the baby tooth braced the new one against bending. An adult with fully grown sabres was at least three years old.

Lessons from the tar pits

More than 2 000 Smilodon fatalis have been dug out of the La Brea Tar Pits in Los Angeles, making it the second most common large animal found there. Several of the skeletons have healed injuries, which some researchers take as a sign that injured cats were helped by others in a group, though that reading is disputed. A 2023 study found joint defects in 6 per cent of 834 thigh bones and suggested inbreeding as the species neared extinction, while noting that other causes are possible.

Chemical traces in the bones show what they ate. At La Brea one study found mostly bison and camels, another found more forest prey such as tapir and deer. In the Pampas of South America, Smilodon populator hunted ground sloths, horses and Macrauchenia.

The end

Smilodon disappeared between about 13 000 and 9 000 years ago, along with most of the large animals it fed on; the latest known record is about 8 200 years old. At La Brea, a study published in 2023 used 172 new radiocarbon dates to show that it and six other large species were gone by about 12 900 years ago. The main driver there was a series of large fires in a warming and drying landscape, possibly set off by people as their impact grew.