October 21, 2008

A more fearsome saber-toothed cat.
posted by homunculus 16 years ago
  • Because analyses of fossils from one of these felines suggest that the teeth on its upper jaw meshed with those on its lower jaw to produce a clean, nearly continuous cut, the researchers suggest calling the new morphotype “cookie-cutter cats.” *shudder*
  • The Cookie Cutter Cats used to be my favourite show.
  • I want to address the issue of saber-toothed cats and their bitiness. Saber-toothed cats likely did not viciously engage their prey primarily with these large teeth. They were most likely used to dispatch an already downed prey animal with gouge to belly or throat, if at all. This seems counterintuitive when you see a big cat with fucking great huge teeth coming out of its gob, that it's not primarily a biter, but I'll explain. The image of these things coming at you all bitey is probably wrong. They would rip you up with their claws first. The major predated fauna of the Cenozoic Era in which saber-toothed cats lived were large, heavy, extremely powerful beasts that would be difficult to take down, exposing the cats to serious injury to their teeth and jaws if this was their primary method of attack. Using their teeth in this way on large animal prey would easily break them, as they were by no means stronger than any other animal's teeth, and this would spell death to the unfortunate cat; they would be unable to eat, prone to infection, pain, shock, etc. Fossil records do not show a large number of these animals with broken teeth, therefore this must not have been a primary use of the attribute. QED. So they probably weren't attacking things and mauling them primarily with their big dentures. I would assume they attacked mainly with claws and use of their beefy body weight and musculature (most saber-tooth species were very bear-like in body structure). The development of the enormous canines in these animals is a poser, and has been argued about for over a century. Possibly this trait was not selected for value in hunting, but in display purposes. Animals with large, delicate horns do not primarily use them as weapons, for instance. We may never know. These cookie-cutter cats are obviously a different deal, of course, but I just wanted to hack away at this old chestnut.
  • Well I always thought those teeth looked mighty vulnerable. Scary, but vulnerable. In other news, I dreamed of a kitty last night. I fed it cake.
  • Hank, wouldn't it make more sense that sabre-toothed cats jumped on their prey's shoulders and used this as a vantage to attack the neck, using the teeth in a tearing manner as leopards still do? On the one hand you say that the fauna were large, heavy, and extremely powerful; on the other, you say that the cats attacked with claws and used their beefy body weight. Do you mean that the cats were physically stronger than their prey?
  • That does not follow. I'm implying that their bulk was selected for by evolution to aid their taking down very large prey, not to overwhelm their prey's size or strength. If they jumped on their shoulders and jabbed in the fangs, this could lead to the prey wriggling or shrugging and shearing off these fine enameled protuberances. If they were to put any weight on them, that would open the risk to breakage, however strong the anchorage in the jaw. The breakage risk is along the length of the fang, as some of these animals had 20cm teeth. Their teeth were stronger relative to bite force than modern big cats, but they had nowhere near the bite strength of moderns. This doesn't apply to the cookie-cutter toothed cats, but I note these were also very bulky animals, they were big wrestlers. So presumably that is an indicator of what sort of prey they had evolved to hunt, and the manner in which they did so. Different species of big cats develop different styles of attack, so I'm looking at analogs within that as a model for the sabre-toothed cats. All savanna big cats run down their prey, the difference is in the final encounter. Lions will use their bulk to bring down a prey animal, then strangle the neck with their powerful jaws. Cheetahs will often trip a prey animal, as their body weight is much less and they're physically more delicate, and they often rely on several individuals to hold down large prey that's been downed. Most big cats will attack from the back, try to bring down the prey then attack head/neck. I've heard of mountain lions doing this to humans. I'm assuming that given the physical bulk of the Smilodon, for instance, that they were short distance runners and were social, hunting in groups. Skull structure shows a relatively weak bite, so they are not putting the vice like grip on the neck. Skeletal structure shows a high range of potential movement in the front limbs, thus, maulers. Only when the animal is down and pinned by several cats does the lead animal bite into the neck and sever the major veins, I'm thinking. They had a huge bite though, they could open their jaws twice as wide as a lion. It's difficult to imagine what they did with their teeth during the tackle, if not jabbing them in to hang on. Maybe there's a middle ground there, they had some technique that didn't put stress on the canines. None of this is valid if sabre-toothed cats hunted mice and rabbits, of course ;) The argument has been going on for a long time and I'm not qualified to end it. Maybe if we clone a few sabre-tooths it will be solved. I'm in the camp that says the teeth were display mainly and coup de grace weapons, based upon their potential for breakage. I just can't see my way round that, in my mind, unless someone can prove that their teeth were somehow composed of much stronger bone and enamel than other mammals. It's an engineering issue.
  • Mr. Whiskers always goes at his prey paws-first, so that makes sense to me. I may just have to make "Xenosmilus" his middle name.
  • I think in any future extinct big cat debates, the question should always be 'What Would Mr Whiskers Do'. That should settle it.
  • You can't hide your lion eyes.
  • Interesting comments on why these out sized teeth were especially effective for display. But after seeing all those tooth whitening advertisements on the same ScienceNews page, I've gotta picture a grinning Xenosmilus before and after the movie star dentistry...
  • Ha! You just think they got along. In reality, the saber-tooth cats were hiding in cardboard boxes, and the bear dogs were driving cars.