Despite the popular nickname Saber Tooth Tiger, these ancient felines were not tigers at all. Evidence suggests that unlike tigers, Simlodons were social animals that hunted in packs, much like today’s lions. They also had the muscle mass and physical bulk that’s more comparable to a bear today than that of a tiger. It’s also very unlikely that their coat was striped like a tiger, but rather probably dappled like a bobcat or plain like a today’s lions given the habitat in which they lived. They would not have needed to blend in with thick forest or jungle like a tiger, but rather blend in with open tundra and grasses.
from How Stuff Works:
Naturally, saber-tooth cats are known for their distinctive teeth — two very long canines that extended well past the bottom of the jaw. These canines were about twice as thick from front to back as from side to side, so they resembled very thick, somewhat curved knife blades. In Smilodon fatalis, adults’ saber teeth could measure up to 7 inches (18 centimeters) long. That’s about as long as the average man’s hand from the wrist to the end of the middle finger.
But the cats’ teeth weren’t always so big. Saber-tooth cats had deciduous baby teeth, just like people and many other mammals do. The cats lost their baby teeth, including a set of miniature saber canines, before they entered adolescence. In order to reach the necessary length, their adult canines grew at a rate of about 8 millimeters a month for more than 18 months. Today’s tigers’ teeth grow about this fast, but the canines of saber-tooth cats grew for a longer period of time than tiger teeth do.
The sheer size of a saber-tooth cat’s canines can make it seem like eating or attacking prey would be a problem. But saber-tooth cats had the ability to open their mouths very wide to make up for the extreme length of their teeth. Smilodon fatalis could open its mouth up to 120 degrees wide. This let the cats take big bites, although, according to computerized tomography (CT) scans, they used those big bites for soft flesh, not thick bones. The cats’ skulls weren’t designed to handle the pressure of biting through bone. They also weren’t designed to provide anchors for the amount of muscle needed to hang on to struggling prey for a long time. That’s one reason why saber-tooth cats tended to aim for the throat or abdomen instead of the bonier parts of their prey.
The legs and bodies of this carnivore were short and squat, made up of muscle mass. This cat would have weighed between 600 and 700lbs, while the modern lion only weighs up to 500. Saber-tooth cats also lacked the long tail that today’s lions use for balance. This may have made saber-tooth cats stronger but less agile than most of today’s big cats.The lack of a long tail is also one reason why scientists don’t call them saber-tooth tigers or saber-tooth lions.
The social patterns of this cat aren’t quite known. Scientists believe they hunted in packs and were drawn to prey by the distress calls of dying animals in the La Brea Tar Pits. Smilodon Californicus is one of the most common specimens found in the pits. Also, several specimens have been found that had severe injuries, however the animal seemed to have lived for a long time with the injury. This suggests Simlodons may have lived in packs and cared for their injured peers – sharing food with those unable to hunt. Living in groups also may have aided the cats in defense against Short-Faced Bears and Dire Wolves. Smilodon Californicus probably preyed on a wide variety of animals including wild bison, ground sloths, camels, horses, and deer.
Modern big cats kill mainly by crushing the windpipe of their victims, which may take a few minutes. Smilodon’s jaw muscles were probably too weak for this and its long canines and fragile skull would have been vulnerable to snapping in a prolonged struggle or when biting a running prey. Research in 2007 concluded that Smilodon more probably used its great upper-body strength to wrestle prey to the ground, where its long canines could deliver a deep stabbing bite to the throat which would generally cut through the jugular vein and / or the trachea and thus kill the prey very quickly.