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Post by Grey on May 30, 2013 23:13:53 GMT 5
I also think sometimes that the pack of Brygmophyseter on steroids in JFC is possibly reminiscent of what could have been the interactions between Carcharocles megalodon and Livyatan melvillei. And yes, it does not decrease the level of potency of the whale in this case.
Only, we don't have evidences it was even occasionnally pack hunter...
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Post by creature386 on May 30, 2013 23:16:24 GMT 5
The male great white sharks are mature at 3,5 m for example, whereas the largest females approach 6,5 m... But females don't exceed often 5 m. Sometimes the upper size end can be very high above the average. For example male saltwater crocodiles don't get often larger than 3 m, but they can reach 6 m in length. |
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Post by Grey on May 30, 2013 23:19:23 GMT 5
The male great white sharks are mature at 3,5 m for example, whereas the largest females approach 6,5 m... But females don't exceed often 5 m. Sometimes the upper size end can be very high above the average. For example male saltwater crocodiles don't get often larger than 3 m, but they can reach 6 m in length. Hm, observed females white sharks above 5 m are not uncommon from what I've seen, and this depiste great whites are very rare today. But the point is that mature size range can be vast and that in the case of megalodon, we cannot establish any kind of average for a number of factors. Teeth do not represent skeletons but sharks which had lost teeth at one given moment. |
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Post by Life on May 30, 2013 23:24:02 GMT 5
It shall be noted that great white sharks used to attain very large sizes on average during Pliocene epoch then they do so in current times. Different kind of pressures (specially human interference) have resulted in the decline of this species unfortunately.
But even in current times, several examples of very large great white sharks exist.
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Post by Grey on May 31, 2013 0:06:30 GMT 5
As far as skull morphologies are concerned: extreme size coupled with extreme killing apparatus of C. megalodon suggests that this animal was a big-game hunter in absolute sense. Almost any kind of whale or another giant animal would be potential prey for C. megalodon. In contrast, L. melvillei could be more specialized. I think that reflects the opinion of Bretton Kent who described megalodon as "...a very big generalized carnivore looking for any big hunk of food...". He presumes too that Livyatan may have differences in its diet compared to megalodon based on the differences in the jaws structure. By the way I have hard time to distinctively understand all wat says Chuck Ciampaglio about megalodon bite in this video at around 31.30 ? |
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Post by theropod on May 31, 2013 1:02:15 GMT 5
Still those are large specimens of C. megalodon, probably above average.
What would imo be fair is to take both at the same lenght, since Livyatan's upper figure for average is pretty much the same as a decent-sized C. megalodon.
Are you comparing the most massive jaws of any tetrapod to a gharial? We are not talking about a micropredator or piscivore here!
Gharial jaws are no potent weapon because they are gracile and built to catch small fish. The same is not implied for Livyatan, neither is there reason for it.
Comparing features of jaws built for different killing styles is simply not relevant.
Because these two have different proportions, completely different jaws. Allosaurus could bite the flanks of a sauropod, T. rex could not. Does that mean the former has the more potent bite? Both are simply different in the way their jaws functioned, you know that very well.
Among creatures with the same primary purpose of their jaws, a comparison of jaw volume is helpful. Not if we are talking about a wide-jawed, triangular-toothed shark and a long-jawed, conical-toothed mammal.
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Post by Grey on May 31, 2013 1:51:33 GMT 5
[quoteStill those are large specimens of C. megalodon, probably above average. What would imo be fair is to take both at the same lenght, since Livyatan's upper figure for average is pretty much the same as a decent-sized C. megalodon. We don't know the average size in megalodon, and average can be a different measure between mammals and sharks. In sharks, the average can be of about 3 m for one species which does not prevent a reasonnable number of individuals to exceed 5 m. Whereas in mammals, this variation is much less pronounced. And Livyatan is not an obigatory average individual. It can be a slightly smaller or slightly larger individual with the same probability. On the other hand, we don't know the average size for megalodon, and we don't even know for sure its maximum size, depending the teeth, the method, the location... That's unfair to place Livyatan as an average individual, it is a minimal, average and maximum-sized animal at the same time. That's why I compare it with differently-sized megalodon specimens. And at the end, I use equal-sized megalodons (Bakersfield biter, Gatun adult, Calvert reconstructed male...). No I compare one type of elongated, narrow jaws with one type of wide, broad jaws. Of course, the extreme gharial example was to show you the extend of your reasonning. This points that Livyatan was different than megalodon in its biting style and probably in its specific diet. That's not a matter of killing style, that's a matter of devastation made by the jaws. The jaws of megalodon simply can puncture and damage bones much like Livyatan, only it can take off much bigger chunks of flesh each bite than Livyatan can, added to the exsanguination of the prey. Livyatan takes smaller big chunks each bite and cannot bleed its prey to death like the lamniform, despite a bite force possibly rivaling/exceeding the shark jaws. The comparisons with theropods are limited as theropods still share basically a similar skull and jaws plan, not the shark and the cetacean which are totally different. No matter that they kill differently, it does not mean they are as fearsome one and the other. Megalodon's jaws can take more voluminous chuns of flesh, muscles and bones than Livyatan could, and still can bleed the prey to death. |
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Post by theropod on May 31, 2013 2:23:55 GMT 5
We don't know the average size in megalodon, and average can be a different measure between mammals and sharks. In sharks, the average can be of about 3 m for one species which does not prevent a reasonnable number of individuals to exceed 5 m. Whereas in mammals, this variation is much less pronounced. And Livyatan is not an obigatory average individual. It can be a slightly smaller or slightly larger individual with the same probability. On the other hand, we don't know the average size for megalodon, and we don't even know for sure its maximum size, depending the teeth, the method, the location... That's unfair to place Livyatan as an average individual, it is a minimal, average and maximum-sized animal at the same time. That's why I compare it with differently-sized megalodon specimens. And at the end, I use equal-sized megalodons (Bakersfield biter, Gatun adult, Calvert reconstructed male...). The probability for it being a smaller-than-average specimen is just as high as it being a larger-than-average one. Best would be to assume it to be in between, not to be a large individual, or when using it to compare to large individuals, at least not use conservative size figures for it. That wasn't my reasoning. My reasoning was confined to jaws used in predation on large prey items, made to deal mechanical damage. I may not have expressed this clearly enough, sorry. Do extant orcas, in many ways concerning the jaw mechanics supposedly like Livyatan, kill by ripping out pieces of meat? How do they fight similar-sized animals? I doubt the same way as sharks. C. megalodon of course can damage bones through the sheer size and power of its jaw apparatus. Still, if their jaw functioned the same way and required the same adaptions, they would look the same. I do not see why the cetacean should have had a specialized diet. Modern Orcas don't, they are generalists, and it is morphologically and supposedly ecologically similar. If it killed by taking out chunks of meat, the killing metod would include bleeding out of the prey item. Since that is obviously not the purpose of conical teeth like Livyatan's, i agree that it did not do so. It rather crushed some body part of its prey/opponent. Well then, you basically agree with me, these two have different jaw apparata that cannot be directly compared in terms of size or function. Such things reflect payoffs, there is no way you can get better in everything. If C . megalodon bit through bones of large whales, that means it must have logically been a less effective slicer/not as good at letting things bleed out quickly and easily. But a question, how large are the whales Carcharocles is known to have bitten large bones of? I always hear this about cetotheres, <10m in lenght and literally dwarfed by the shark. But you stated it is tought to have disabled the locomotive system in larger whales, much like other slicers would do (komodo dragon vs water buffalo). Doesn't this show the jaw function is different? Of course, more or less robust slicing teeth could bite through decent sized bones, however the way they did that is important, and at what scale. That is the difference between jaws that are slicing-based and ones that are crushing/puncturing-based, even tough the results can be similar if according adaptions occur (from slicing- to crushing-specialist: GWS/komodo dragon?-carcharodontosaurus-C.megalodon|wolf-T. rex-hyaena-raptorial cetaceans/crocodilians). |
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Post by Grey on May 31, 2013 2:56:13 GMT 5
The best IMO is to assume nothing, we simply don't know. And we don't now for sure its size. It could be a small individual if it was nearer to the 13,5 m mark or a larger than average individual if closer of the upper mark.
That's why I basically don't compare strictly the sizes, but the rigorous reconstructions of both. The reconstruction of megalodon jaws simply impress me much more by the quantity of flesh they can engulf, and the fact they are able to slice through muscles and bones with ease.
Also, the sizes of the reconstructions still let me tink that megalodon was slightly larger.
Why again the orcas ?
Orcas and Livyatan are very different. They have been only related to their ecological niches. Pliosaurs too have been related to orcas by their ecological niches. Still, they are not that close in feeding, killing style, there are similarities and differences as well.
Orcas are generalists, but Livyatan has not jaws like an orca, nor its social behavior. They are only compared as apex raptorial marine mammals, that's all, that not means they are similar in all plans.
They are not morphologically similar either. No raptorial sperm whale that I've read about has been described as "orca-like built". The jaws and skull of the orc are also quite wider than the jaws and skull of Livyatan at parity.
Orcas are bigger than the macropredatory sharks, there jaws are larger and wider, and even if it's true, they have been known to have hard time to dispatch some whale flesh.
Interesting but two things.
If it killed by taking out chunks, the bleeding wouldn't be necessary mssive, as massive as with the serrated teeth of megalodon. The serrations and sharpness of the teeth make the bleeding.
Have you a source for thaat killing apparatus of crushing body parts without ripping it ?
That's interesting but I've not read such a thing.
Also, this would not change anything. The parts crushed on the prey are still much smaller than the parts sliced and taken out with the larger, wider and more voluminous megalodon bite.
Why ? Megalodon's teeth are very thick and very robust, recognized able to puncture bones, but the serrations are even thinner than on the white shark teeth.
Check what Cuck Ciampaglio explains at the moment of the video I've indicated just above...
Fin whale-sized (Barnes) and sperm whale-sized (Kent) as I know. Purdy talks about large Pliocene baleanopterids (rorquals).
Megalodon rammed and tried to break the bones of smaller whales, injuring them before consuming them. Another tactic would be to bite off the flippers and tails of larger whales, immobilizing them before going in for the kill.
It could do both, that's what indicate evidences.
I would admit I'm a bit tired of these comparisons and analogies with others animals with differently shaped teeth and always playing with the notions.
We just have to look the design of each teeth in each animal and what the teeth are know to have done in paleontological evidences.
In the case of megalodon, it sliced through flesh, muscles and bones.
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Post by Grey on May 31, 2013 3:34:07 GMT 5
I had asked to coherentsheaf this comparison of the 11 m meg from Calvert scaled up at 16,8 m, the size of the largest adult found in the nursery by Pimiento.  Bretton Kent considered this comparison model as "pretty reasonnable", hinting on the differences of food sources between Livyatan and Carcharocles. Also, it's him who had given me the complet model of the Calvert skeleton that I sent then to coherentsheaf. On this model, Kent said that although it's based on the modern great white, it has a relatively low heterocercal angle, which increases the total size. In other words, the reconstructed lobe is too long, which indicates that these jaws could belong to a shark smaller than 16,8 m... |
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Post by theropod on May 31, 2013 16:57:14 GMT 5
Yes, that's still a rather large megalodon. But I am fine with this comparison, just don't use the lower figures for Livyatan then when it is about total size.
I don't believe in greatly different diet among the two. you could incluse a great white's jaws, it is just as different from the Orca, and the diet of these two greatly overlaps.
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Post by theropod on May 31, 2013 17:13:45 GMT 5
The best IMO is to assume nothing, we simply don't know. And we don't now for sure its size. It could be a small individual if it was nearer to the 13,5 m mark or a larger than average individual if closer of the upper mark. Well, that would definitely include one being larger. How large this specimen is compared to the rest of the population doesn't depend on its size estimate, but on the comparative size of the remains. We unfortunately don't have other remains for now, unless you include other isolated teeth. If it was 17,5m, above-average individuals would likely be even larger than that, if it was 14m, below average-ones would be even smaller. That's why I basically don't compare strictly the sizes, but the rigorous reconstructions of both. The reconstruction of megalodon jaws simply impress me much more by the quantity of flesh they can engulf, and the fact they are able to slice through muscles and bones with ease. You are free to think that. However I do not think the two killing apparata can be compared this way. Why again the orcas ? Orcas and Livyatan are very different. They have been only related to their ecological niches. Pliosaurs too have been related to orcas by their ecological niches. Still, they are not that close in feeding, killing style, there are similarities and differences as well. They are close in terms of morphology of the skull and teeth, indicating a similar killing-style. Orcas are generalists, but Livyatan has not jaws like an orca, nor its social behavior. They are only compared as apex raptorial marine mammals, that's all, that not means they are similar in all plans. The jaws are very similar. We don't know about the social behaviour. Interesting but two things. If it killed by taking out chunks, the bleeding wouldn't be necessary massive, as massive as with the serrated teeth of megalodon. The serrations and sharpness of the teeth make the bleeding. Have you a source for that killing apparatus of crushing body parts without ripping it ? That, or otherwise suffocating, has always been the purpose of cinocal teeth. Taking out a chunk creates a wound. of course with conical teeth you cannot take out chunks in a very effective way, that's way crocodilians do not kill by letting their prey bleed to death. That's interesting but I've not read such a thing. Also, this would not change anything. The parts crushed on the prey are still much smaller than the parts sliced and taken out with the larger, wider and more voluminous megalodon bite. Volume is not that important in this regard. it matters little to your healt whether just your spine or your whole ribcage is crushed, since it is not about bleeding and tissue-damage but about damaging some vital structure. Why ? Megalodon's teeth are very thick and very robust, recognized able to puncture bones, but the serrations are even thinner than on the white shark teeth. Check what Cuck Ciampaglio explains at the moment of the video I've indicated just above... I know they are sharp. but the ticker a tooth is, the harder it is to slice whith it. Fin whale-sized (Barnes) and sperm whale-sized (Kent) as I know. Purdy talks about large Pliocene baleanopterids (rorquals). You mean these are the ones it bit the tails off? Megalodon rammed and tried to break the bones of smaller whales, injuring them before consuming them. Another tactic would be to bite off the flippers and tails of larger whales, immobilizing them before going in for the kill. It could do both, that's what indicate evidences. Both are used in different cases. It would use the raw size and power of its killing apparatus to simply bite right through smaller preys, and would behave more careful, like other slicers, with larger prey. Analogies are the key to how these two compare. Unfortunately we don't have fossils of whales predated on by livyatan, but there are certain rules and payoffs that apply to all jaws. An animal that kills by slicing tries to bleed large prey to death or can of course simply bite through smaller prey. A crusher specifically targets the bones, even very robust ones, but is not good at taking out chunks of meat or causing excessive bleeding. |
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Post by DinosaurMichael on May 31, 2013 17:18:24 GMT 5
I think Megalodon would win.
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Post by Grey on Jun 1, 2013 21:41:54 GMT 5
I will respond later but really I rest my case and you need to understand some traits in megalodon biology.
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Post by theropod on Jun 1, 2013 22:35:04 GMT 5
Do you mean me? I too rest my case, but I think I have udnerstood the relevant biology quite well. C. megalodon kills by taking out gigantic portions of meat with sharp-edged saw-like teeth and killing either through blood-loss, shock or damage to the internal organs.
Livyatan probably kills by gripping and crushing some vital strucutre with its conical teeth, but certainly not by ripping out chunks.
And if volume was the determining factor for a bite's potency, I guess all predators would develop jaws with the main aim to maximize it, which is not the case.
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