Prehistoric Big Cat Discussions

[smedz]

Any discussions relating to prehistoric big cats can go into this thread. I made this thread because I feel like it would be a good place for anyone with a theory relating to prehistoric big cats can share it here. 

[smedz]

The Great Cats of The Woods 

    Big Cats have always captured our imaginations, and have also stroke fear into the hearts of those who lived with them. With living cats, the lion and tiger capture most of the imagination. When it comes to extinct felines, no cat captures our imaginations more than Smilodon. Or to be more specific, Smilodon fatalis. But he was not alone, as he coexisted with another cat that would have rivaled him in size and power, Panthera atrox, or the "American Lion". Both coexisted with each other for millions of years, and it's pretty rare to find two massive cats living in the same ecosystem. The theory in the past was that Smilodon, P .atrox, and the Dire Wolf coexisted on the plains, all competing for the same prey such as horses, camels, and bison. However, a new scientific study has debunked this theory. Past studies on these animals diets were done with isotopic analysis of the bone collagen. This new study on the other hand involved isotopic analysis of the teeth enamel because it is now known that tooth enamel is more reliable than bone collagen because it is isn't as prone to being messed with in the fossilization process. With this, the experts found that Smildon and P .atrox were more forest dwellers and hunted animals like deer and tapirs while dire wolves were hunting on the plains for horses and bison. But how did these two massive cats coexist with each other for so long? Well, lets look at the situation shall we?

    In an ecosystem, there is what's called the Competitive Exclusion principle which says that no two species can have the exact same niche in the exact same place at the exact same time. But if enough resources exist in an ecosystem, a niche can be somewhat shared. But a question that must be answered is were these cats social or solitary?

Smilodon

    Regarding to whether this animal was social or solitary has been the subject of debate over the years. In recent years however, it appears experts have begun abandoning the idea of Smilodon being a solitary animal. One big piece of evidence of the cats being social is the high number of healed injuries on the bones that have healed. These injuries included crippled pelvises, dislocated elbows, broken legs and other injuries that would have prevented these animals from hunting. Despite this, the animals lived long enough for the bones to heal. On the other hand, some argued against the sociality of Smildon. One argument was that Golden Eagles which are solitary are also a very common find at Rancho La Brea, so just because a species is a common find does not mean that species was social. But just because one species isn't social does not mean another common species wasn't social. Another argument was that the small brain of Smildon was not consistent of a social life. However, research has found that tigers, relative to body size, have a larger brain than lions! Now this does not mean tigers are smarter by any means, but what it does mean is that there is no correlation between brain size and social life in cats relative to body size. The final argument was that cats used metabolic reserves to heal quickly without eating and can survive with access to water. Now, analysis of the wear patterns of the teeth of healthy Smilodon and injured Smilodon showed that healthy cats munched on flesh and bone while injured cats ate the softer parts of a carcass. Meaning that the injured cats were eating after all.

    So it's very safe to say that Smildon fatalis were social animals. How big the packs were is anyone's guess. But there is one thing that's a bit off. The habitat. In open plains and grasslands, there are many advantages for big cats at least the size of lions to live in groups. But Smilodon fatalis was a forest cat, so why would it need to be social? The answer may have been because of cubs. Smilodon cubs could take up to 22 months to get most of their adult teeth, and the massive canines would take up to 3 years or more to get to their full size. Not only that, but it may have taken Smilodon cubs longer to learn how to safely hunt bug prey without breaking their canines. Living in groups would have allowed for cubs to develop more slowly because of the bigger safety net, and with a number of threats around, that would have comes in handy. In other words, Smilodon fatalis may have lived in groups just to protect their cubs.


Panthera atrox

    I no longer believe Panthera atrox to have been a social animal. But I'm going to explain why. American Lions aren't nearly as frequent at the tar pits as Smilodon and Dire Wolves. P.atrox occurrency at La Brea is 2.6% while Smilodon occurrency is 33.3% and dire wolf occurrency is 51.2%. Likely meaning that P.atrox wasn't as social because social carnivores were more likely to react to distress calls because they had the better backup. But P.atrox being solitary would have known the tar pits were a good place to encounter the groups of Smilodon and so they normally stayed away. On the other hand, coyotes and Gray Wolves aren't common at Rancho La Brea and they're social, but you also have to remember that they coexisted with Dire Wolves on the plains and dire wolves were bigger and more powerful than both of the smaller canids and most certainly would have killed them when given the chance. So avoiding the tar pits meant avoiding the larger canid.

    Then there's the habitat of the American Lion, which was forest. In forested environments, big cats have no need to be living in groups as they can easily hide their kills from scavengers and cover for hunting isn't an issue. But what about protecting cubs? You might be thinking "But didn't you just say Smilodon probably lived in groups to protect their cubs?" Yes, but Smildon cubs probably took longer to develop and being in a group would have allowed that. Pantherine cats on the other hand don't have this problem. But for a modern day example, think of the Amur Tiger. Here is a list of animals in the Russian Far East that would be more than happy to kill tiger cubs.


1. Other tigers
2. Brown Bears
3. Asiatic Black Bears
4. Wolves
5. Amur Leopards
6. Eurasian Lynx
7. Dholes (Historically)

These tigers live with many tiger cub killers, and they do not live in groups and they are forest cats. Therefore, and this is my strict opinion, it is more than likely that Panthera atrox was a solitary animal, probably with a social structure like a tiger with one male controlling a big territory that overlapped with those of several females.


The Relationship

As with all wild cats, these two would not have liked each other. With Smilodon being the social cat and Panthera atrox being the solitary cat, the pantherine would have avoided areas where the sabertooth hunted for fear of encountering a pack. But there may have been times when a P. atrox could have caught a lone sabertooth off guard from ambush, but in general, Smildon would have been the dominant cat.

www.sciencenews.org/article/saber-toothed-cats-smilodon

journals.plos.org/plosone/article?id=10.1371/journal.pone.0052453

www.sciencedaily.com/releases/2009/09/090911145030.htm

www.smithsonianmag.com/smart-news/fossils-reveal-why-coyotes-outlived-saber-toothed-cats-180972826/

www.ncbi.nlm.nih.gov/pubmed/12697957