Lately this blog has been fixated on magnificent saber-toothed mammals. We have featured the extinct saber-toothed whale, a saber-toothed marsupial predator, the little saber-toothed deer, and even the familiar walrus (in reality, a giant saber-toothed seal), but we realize that everyone has really been looking forward to the most famous saber-toothed animal of them all, Smilodon, the saber toothed cat. Smilodon was actually a genus of several large cats, the biggest of which, Smilodon populator, weighed 360 to 470 kg (790 to 1,000 lb) and was larger than modern tigers or lions. In fact Smilodon species are sometimes known as “saber toothed tigers” or “saber toothed lions,” however taxonomists tell us such names are off the mark since the Smilodons belonged to the extinct Machairodontinae genus of felines rather than the familiar Panthera genus of big cats so familiar today.
About two and a half million years ago, Smilodon evolved in North America from an earlier genus of saber toothed cat Megantereon (there were a lot of other earlier genera of saber-toothed cats, not to mention even more genera of saber toothed carnivores which were not exactly felines—the whole story is complicated). During the Great American Interchange with South America the big predators invaded South America at the same time armadillos were making their way up into North America. Yikes, that’s a pretty lopsided exchange.
In addition to long razor sharp teeth, Smilodons possessed immense neck and forelimb muscles. Using the muscles of their front torso they would pull down and pin the great grazing metafauna of the American plains. Prey animals almost certainly included bison, tapirs, deer, American camels, and ground sloths. Additionally Smilodons might have opportunistically killed juvenile mastodons and mammoths. To dispatch such large prey Smilodons employed their fearsome canine teeth with which they bit through the prone creatures’ necks.
Paleontologists have collected a great deal of fossil evidence concerning Smilodons, which suggest that the big cats were sophisticates social predators like today’s lions or wolves. The number and nature of saber-toothed cat fossils recovered from tar pits suggests that Smilodon prides would converge together on prey animals caught in the petrochemical ooze–only to become trapped themselves. Also some fossilized smilodons have shown evidence of badly broken bones healing—a rarity in carnivores which is generally only possible for pack/pride animals which can (sometimes) rely on a support network.
Thanks to their size, ferocious appearance, and highly characteristic teeth, Smilodons have a special place in human culture to the extent that few other extinct animals do. The Flintstones had a pet smilodon named “Baby Puss” which evicted Fred from his house in the title sequence and the moral struggles of Diego the saber tooth constituted the moral hook of “Ice Age” a cartoon movie. Ironically for all of our apparent fondness for the great cats, it seems that human migration into the Americas may have been the downfall of the great cats (which vanished 10,000 years ago) but whether their extinction was the result of humans overhunting their prey, shifting climate, or some other factor remains an open question.