The recent discoveries of the two Cave Lion cubs in Siberia this past summer was truly a fascinating find. It has had me thinking a lot about my visit to the La Brea Tar Pits in Los Angeles and, the long extinct prehistoric cats that roamed the world. In particular those cats from the recent past, that up until about 10,000 years ago called North America home.
One of my personal favorites and best know is Smilodon or Saber-tooth cat and, more than 2,000 individual fossils of these cats were unearthed at La Brea, along with a multitude of other prehistoric species. La Brea is still an active dig site so it won’t be too surprising if the number of Saber-tooth fossils goes up.
La Brea tends to be referenced as one of the best sources for information about the Pleistocene epoch, the time period that spanned from approximately 2.6 million to 11,700 years ago, due to the concentrated and abundant finds of insect, plant and animal life. What is fascinating is that the animal and plant life of this geographical time period, or biota, is said to have been similar to modern ones, however the Pleistocene epoch differed in one big regard – megafauna, distinct and large species like the Saber-tooth cats and Mammoths. While the megafauna did not survive, it is important to note that some of the smaller mammals, like bobcats, coyotes and cougars, who shared this time period with Saber-tooth cats are still with us today.
Since there hasn’t been a ‘fully preserved’ fossil of Saber-tooth cat found, like we have seen with the Cave Lion cubs, we have to rely on artistic interpretation of what the species could have looked like when alive. Depictions of Smilodon vary and they are represented either with faint stripes or markings, rosettes, or a plain tawny colored coat similar to modern Lions.
The fossil evidence shows many of the cats had serious injuries that they ultimately recovered from. The healing of bones indicates they were social and lived in co-operative packs which allowed them time to heal, cats that were solitary and hunted alone would not have managed to survive as well. Researchers have also determined, from examining the structure of the hyoid bones in the throat, that Smilodon could roar. So while the prehistoric cat did share some traits with modern Lions, other anatomical characteristics suggest that it was also different. For one, its build is indicative of an ‘ambush’ predator who waited for its prey to come close before attacking, rather than chasing it down like modern Lions.
The most distinctive feature, Smilodon’s almost 8.5 inch long teeth, were no doubt used for hunting although the jury is still out on how exactly they were utilized. The most widely accepted theory is that the teeth were used to rip or stab the soft belly or throat of the prey. Smilodon’s bite may be the stuff of legends, but research that compared its skull to that of modern Lions showed that their bite was much weaker than first thought. This was due to a smaller lower jaw, which evolved to accommodate the huge upper teeth. In computerized crash tests it was revealed that Smilodon “could not bite a prey that was still on its feet and struggling: the sabers (canines) would have been broken and the cat’s skull would not hold up to the associated forces, while the (modern) Lion’s skull coped easily with this.”
While the bite of a Saber-tooth cat doesn’t stand up to the hype, I think it is still rather impressive and you can tell from the photo above just how impressed I really was. It’s not everyday that you get to put your head inside the mouth of Saber-tooth cat, but if you are visiting the Tar Pits Museum, they are more than happy to oblige. Of course if you would like a more real experience, fur and all, the museum offers something called Ice Age Encounters where you can get close up with a full size life like Saber-tooth cat that moves.
Smilodon, which is part of the Carnivora order that includes species like dogs, cats and bears, was one of many ‘Saber-tooth’ cats that have appeared throughout history and in several evolutionary lineages independently in different parts of the world. It was also one of the more recent Saber-tooth cats to go extinct about 10,000 years ago during the end of the Pleistocene, which was marked by a global ice age. The cats impressive assets, including its heavily muscled frame designed to take down large prey, may have added to its undoing becoming a hindrance when it came to catching quick and more agile animals. It has been suggested, as another reason for the species demise, that as the larger prey animals died out during the Ice Age Smilodon was unable to adapt to catch the smaller prey and soon headed down the path to extinction.
The Saber-tooth cat is still probably the most famous of the prehistoric cats, but it’s good to remember he wasn’t alone. Another lesser known ‘Saber-tooth’ type cat, or Scimitar Cat, also called North America home up to the end of the Pleistocene. However, lesser known doesn’t mean less successful and the Scimitar Cat, or Homotherium Serum, enjoyed even wider distribution in North and South America, Eurasia and Africa.
About the size of a Lion, Homotherium was lighter in body had long forelimbs, a long neck, and relatively short, powerful hind limbs and large nasal openings. These physical characteristic indicate that, unlike Smilodon, it was fast, agile, probably chased its prey more, and could even climb trees. Another trait which differed from most cats, is it could see well during the day. Homotherium had shorter upper canines, but they were flat, serrated and longer than those of any living cat – its incisors and lower canines were the perfect tool to both puncture and grip. Tigers (Panthera tigris) are the only living cat to have comparably large incisors, which aid in both lifting and carrying prey.
In North America Homotherium serum existed up until the late Pleistocene and remains have been found at various sites between Alaska and Texas. In the southern parts of its range it co-existed with Smilodon while in the northern parts it was the only species of Saber-toothed cat.
When you start to examine how many different species of prehistoric cats lived it is easy to see how they are thought to be some of, if not the most, successful and perfect predators to ever exist. It is pretty amazing to think that up until the very recent past a multitude of fascinating prehistoric cats ruled North America.
- Xenosmilus Hodsonae, another Saber-tooth cat with a highly muscular body, that is more muscular than any other cat alive or dead. Only two fossil specimens from the same location are known, unfortunately this means it cannot be accurately determined, in the fossil record, when the cat first appeared and went extinct.
- Pleistocene North American Jaguar (Panthera onca augusta) was much larger than Jaguars today. It came to North America from Asia during the Pleistocene via the Bering Land Bridge and their range included virtually all of North and South America except for the extensive open grasslands, deserts, and mountainous areas. After the last Pleistocene extinction event, Jaguars became extinct in the northern parts of their range until they were only left in the tropical forests of Central and South America.
- Miracinonyx (American cheetah) is actually thought to have been descended from Cougar-like ancestors. Miracinonyx inexpectatus was built more like a cougar, but more graceful and faster while still retaining some of the strength of a Cougar. It also had fully retractable claws which likely aided it in climbing. Miracinonyx Trumani had an even lighter build and was most similar to the modern Cheetah with only partly retractable claws that could be used to gain more traction on the ground while running.
Last but certainly not least is a cat that has caused a wee bit of prehistoric controversy among Paleontologists ever since it was first dug up – the American Lion (Panthera atrox). This American Lion is not to be mistaken with today’s Mountain Lions, which are quite often referred to as ‘America’s Lion’.
On one side research states that Panthera atrox is descended from an earlier form of Jaguar around 150,000 years ago. Studies using the skull of the cat reference that “Panthera atrox shared more in common with Jaguars than Lions or other big cats.” However, there is also support for the idea that Panthera atrox occupied an “intermediate place between a subgroup of Lions/Leopards on the one hand and, Tigers/Jaguars on the other.” So it wasn’t a type of giant North American Lion, but perhaps close a type of giant Jaguar. Confused yet?
Then there is the consensus that Panthera atrox is a Lion. In a study done by zoologist Ross Barnett and colleagues they reported that Panthera atrox “formed a distinct genetic cluster among prehistoric Lion populations which became genetically isolated around 340,000 years ago.” They also made a point to highlight that samples taken showed a strong correlation “with modern Lion data” that would rule out any connection between Jaguars and Panthera atrox.
Truth in labeling? Adding to the confusion, the plaque at the Tar Pits Museum labels Panthera atrox as Naegele’s Giant Jaguar.
The American Lion is thought to have descend from the Cave Lion who possibly entered Alaska from Siberia during the second-last glaciation period, then as the ice from the last glaciation period spread (about 80,000 to 10,000 years ago) they eventually became isolated. Fossils have been found in the Yukon as well as in Edmonton, Bindloss and Medicine Hat in Alberta.
While researchers may not fully agree on how to classify this prehistoric cat, they do know that Panther atrox did not fully behave, based on fossil evidence, like modern Lions. Standing beside the exhibit the argument seems to become irrelevant when you see just how big the cat was. I tried to imagine what it would have looked like when alive and what an impressive, surreal and frightening sight it would have been. Personally I am leaning towards Lion, although it is fun to think Jaguars were once this big.
Will the original American Lion give up its secrets? Who knows, but their fossils continue to be discovered as recently seen in an ancient sinkhole in Wyoming. where researchers are hoping to find fossils as far back as 100,000 years. The site which had gone unexplored in over 30 years, is looking to be another hot spot full of small and large Ice Age-era prehistoric mammals such as the American Lion and American Cheetah. The sinkhole is believed to have opened up 25,000 years ago, and much like La Brea, it acted as a trap luring many unsuspecting creatures to their fate. Perhaps these new finds will also help shed some light on the mystery of America’s great prehistoric Lion once and for all, either that or just give us something else to ponder.