With their huge teeth, the iconic smilodon, also erroneously called a saber-toothed tiger, is perhaps the best known of several species of saber-toothed cats and cat-like animals. Smilodons lived between 1.8 million and 10,000 years ago. They had many adaptations for life during the ice age, many of which are not found on modern cats.
Paleontologists have discovered smilodon fossils in many parts of North America and Europe. They are the second most common fossil recovered from Southern California's La Brea tar pits. Although sometimes called the saber-toothed tiger, smilodons were not related to tigers, which belong to a different subfamily. Scientists believe smilodons were about a foot shorter than modern lions but weighed almost twice as much. Unlike modern cats such as cheetahs and lions that have long tails that balance them when they chase prey, smilodons had bob tails, suggesting that they ambushed their prey instead of chasing it.
The smilodon's knife-shaped canine teeth were about 7 inches long. Since the species was first discovered in the 1880s, scientists have debated how smilodons used these teeth. One possible use was as weapons since these teeth have an oval-shaped cross section resembling a knife blade rather than a round cross section like the teeth of a modern cat. Smilodon teeth were good for slicing meat but also extremely fragile. Another possibility is that these teeth were used for social display like horns or antlers.
In 2007, researchers from the University of New South Wales and the University of Newcastle demonstrated that the smilodon's bite was only one-third as powerful as a modern lion's bite. However in 2010, researchers at the University of California at Los Angeles showed that smilodon had well-muscled, strong forelimbs. They believe smilodons pounced on their prey and held it down with their powerful forelimbs while delivering a killing bite with their razor-sharp teeth. Smilodons probably hunted large game such as bison and camels and likely became extinct when many of their prey animals died out during the last ice age.
Modern cats, including tigers and house cats, are solitary hunters. However, evidence suggests that smilodon was a social animal. For example, fossils recovered from La Brea tar pits show evidence of arthritis and serious fractures. These ailments would have been crippling, and solitary hunters would not have lived long with them. But many of these bones also show evidence of healing and regrowth, suggesting that the animals lived for a relatively long time after being injured. It is likely that smilodons assisted injured animals or at least allowed them to eat. However, their social lives were not necessarily peaceful. Some fossils have saber-toothed holes in them suggesting that smilodons, like modern lions, sometimes fought each other over food or mates.