The Saber-toothed Cat

A Smilodon fends off the vulture-like Teratornis at what would later be called the Rancho La Brea tar pits, situated in Los Angeles, California (Painting by Charles R. Knight)

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.

Smilodon fatalis (reconstruction/specimen at the Page Museum)

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.

Smilodon by Knight

The Irish Elk

Irish Elk (Painting by Charles R. Knight)

Megaloceros giganteus was the largest deer to ever exist.  The huge animal would have stood 2.1 meters (over seven feet) tall at the shoulders and had antlers more than 3.65 meters (12 feet across).  During the Late Pleistocene (the glacial epoch immediately prior to the Holocene) the giant deer ranged from Lake Baikal in northern Asia across all parts of Europe down into northern Africa.

In English, Megaloceros giganteus, is more commonly known as the Irish Elk, a name which is something of a misnomer since the creature lived across broad swaths of three continents and was not actually very closely related to elk and moose.   The name was originally adopted because many nearly perfect fossils of the Megaloceros were found in the great peat bogs in Ireland.  So perfect were the skeletons that a misguided biological theorist, Thomas Molyneux, used the remains as evidence that no species ever went extinct (a question which was at the forefront of science at the end of the eighteenth centery).  Molyneux believed that the Irish Elk skeletons were actually those of large moose or elk and that divine providence would never allow an animal to disappear forever from earth.   Unfortunately Molyneux was completely mistaken.  The great zoologist, Georges Cuvier comprehensively proved that the Megaloceros was very distinct from living Moose and Elk and was therefore gone from the world.  It is strange to think that there was a time as recent as the nineteenth century when natural philosophers argued about whether extinction was possible or not.

A painting of Megaloceros giganteus, from the Lascuax caves (at least 10,000 years old).

Although the Irish Elk coexisted with humankind for a long time, sadly something went awry and the great beast went extinct at least 7,700 years ago.  Strangely, overhunting by humans was probably not the reason the Megaloceros died out.  However the actual reason for the extinction of the magnificent mammal has been a long standing cause of dissent among paleontologists.  An obsolete school of thought held that the creatures’ antlers became so immense  that the beasts could no longer hold their heads up.  A likeminded school of thought believed the antlers (which grew larger and larger in response to female’s preference for a mate with big antlers) left the animal unable to compete with smaller and more nimble competitors.  A new theory concentrates on the amount of calcium and phosphate necessary to grow such stately and humungous antlers.  As vegetation changed in response to the end of the ice age, the poor Irish Elks could not get enough of the proper nutrients and began to suffer like old ladies from osteoporosis.  A final answer to the mystery is still outstanding.

Irish elk (Megaloceros giganteus) RIP

Extinct Turkeys

Turkeys have been widespread and successful since the early Miocene (23 million years ago).  Since their robust bones fossilize quite well, a number of extinct turkeys are known to paleo-ornithologists (including two genera which do not exist today, the “Rhegminornis” and “Proagriocharis”).

The best known of these vanished turkeys is the Californian Turkey, Meleagris californica, which died out about ten to twelve thousand years ago as the ice ages ended and human settlements became common.  The Californian turkey had a shorter beak and a stockier build than contemporary turkeys but it was a similar creature and probably shared many of the habits and vocalizations familiar to us.  Its remains have been discovered profusely in the tar pits of southern California, where it must have been preyed on by the great carnivores of that Pleistocene.  Californian turkey bones have also been found in camp middens of ice age humans, whose love of succulent turkey dinners may have combined with climate change to usher the poor birds to extinction.