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Post by theropod on Jun 13, 2013 21:22:59 GMT 5
The information I read on the thread you contributed a considerable amount of suggests it attacked bony regions, even in large preys, but didn't bite through the bones, and comparable bite marks exist of Allosaurus. Eg. that flipper bone of a large whale in the video, it has deep gauges but is not bitten through. If you think I am overlooking something, post the relevant information, because all I see shows C. megalodon as a slicer, albeit a rather brutal one, not a bonecrusher, and did not crush or slice through large bones in large preys, merely damage them while taking out chunks of meat. Surely, a C. megalodon biting off a cetothere's head is not too different from a great white doing so with a human foot or an Allosaurus with a Dryosaurus.
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Post by creature386 on Jun 13, 2013 22:18:42 GMT 5
White sharks, large monitors and carnosaurs did not bite through the whole skeleton, skull or vertebral column of large preys. Meg did it. That's the differences. That's why I think you don't pay attention to the informations about it. He is aware of the information. We had a discussion about that, where he defined the thing Meg did as "it didn't just slice soft tissue but also bones, which is basically the shark-replacement for crushing, something their tooth and root design is poorly adapted to do". I am not sure, but I believe this could be a possible explanation for the belief that sawing tough bones is more likely: Crushing would require a proportionally greater bite force than the great white shark, but coherentsheaf has shown evidence ( www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0031781#close ) that thicker teeth or a broader skull don't equal a proportionally greater bite force (it could have been proportionally greater though). Slicing through bones is more likely, because it won't need a proportionally greater bite. Why couldn't a modern great white do so? Because the different cranial morphology still gives C. megalodon a mechanical advantage, when compared to the great white. However, I am not sure if the bite marks would support that theory. |
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Post by Grey on Jun 13, 2013 23:22:47 GMT 5
I don't have time to link sources at now.
The gashes found in whales bones are extremely deep. Nothing like seen in white sharks or allosaurs preys. Some very large vertebras are sawed in half. Allosaurs don't perform this.
A cetotherid is bigger and much more robust in its body structure compared to megalodon than a dryosaur compared to an allosaur.
Biting off the tail structure of a large balaenopterid is no easy task.
The white shark avoids hard body parts, megalodon targets them.
No, you do not pay attention to the links and papers if you keep arguing that megalodon's predatory behavior with its preys is similar to what did carnosaurs or white sharks. Sincerely.
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Post by theropod on Jun 14, 2013 0:02:19 GMT 5
The gashes found in whales bones are extremely deep. Nothing like seen in white sharks or allosaurs preys. Some very large vertebras are sawed in half. Allosaurs don't perform this. Again, you must differentiate between "comparable" and "the same" You also have to do so with "not calling something an all-superior killing machine able to do everything as good as a specilaist in that field" and "undermining". First of all, I never said they were the same, merely comparable and neither being qualitatively better at equal size. I said C. megalodon has adaptions allowing it to attack bones more effectively. And that is because its prey is more robust. Secondly, I do not think you are right. A normal-sized Allosaurus is around 8m (some smaller, some larger of course), a Dryosaurus around 4m. Both are not bulky creatures. A cetothere is not larger compared to a megatoothed shark, being ~6-9m as compared to the shark at 15-17m (at least those are the approximate sizes of the specimens in question). It is still a very similar task to severing the tendon on a buffalo leg. Have I doubted that? If you think I am misinformed, the burden of proof as well as the burden to inform me better lies on you, not me. I have done my best, if you are convinced I am not paying attention you have to be more specific about what I am supposed to pay attention to. Seriously, I could say the exact same thing about you and animal jaw apparata, but I explain my points instead of just claiming you were misinformed. It is very very easy to say so, especially if you do not even bring up proof. @creature: Yeah, that's what I stated. A bit too simplified probably, but the point is that if C. megalodon was a crusher like for example T. rex or Livyatan (and no, these two are not the same either, before someone puts those words into my mouth!), its tooth morphology would have greatly changed, towards a puncturing and crushing function, not just got more robust to compensate for commonly larger, more robust prey and "more direct and brutal" (not the wording I would prefer, this makes it sound like this attack style was somehow superior) attack style. That doesn't change the basic function, neither does it mean the animal was somehow able to keep the exact same cutting efficiency while at the same time having a far more robust dentition enabling it to "bite through large bones" (what I see suggests it attacked the soft tissue on these bones, eg. musculature and fascia sensu lato in the flippers or tail in large whales). Bite marks occasionally left by other slicers are similar. That does not mean "the same" and it doesn't mean they are as common, but the general purpose remains a similar one, of course with shifting priorities due to different prey. |
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Post by Grey on Jun 14, 2013 0:08:35 GMT 5
Biting off a massive fluke and cutting a tendon is not exactly the same thing.
I understand more some of your points.
Only, when you argue the marks found on allosaurs preys and megalodons preys are similar, you're wrong. The wounds produced by meg on bones, on small or large preys, are far deeper than those produced by allosaurs.
I don't post sources as I cannot these times. You can perform your research. More than lacking attention, I think you just misinterpret some facts.
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Post by theropod on Jun 14, 2013 0:40:49 GMT 5
I misinterpret which facts exactly?
We both seem to comprehend the facts, you just apparently interpret things very differently. I have not questioned that the wounds produced by Megalodon are deeper, read my posts again. I mearly state their nature is similar, and the purpose of C. megalodon's teeth was not specifically to saw through a large whales bones, otherwise it would be adapted for that in a way that would have made it leave more than deep gauges. Therefore it can be concluded the killing strategy when facing large prey items was analogous, albeit not the same.
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Post by creature386 on Jun 14, 2013 1:19:45 GMT 5
@creature: Yeah, that's what I stated. A bit too simplified probably Do you mean my arguments, or your sentence, which I quoted? |
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Post by Grey on Jun 14, 2013 1:20:29 GMT 5
That's where you're wrong. The purpose of meg teeth is specifically at sawing through hard bones. No wonder why it is distinguished from the white shark teeth. It evolved for that kind of feeding.
Yes it is not precisely a bone-crusher in biomechanical terms. Megalodon simply sawed through bones, any bones (where does come from your statement of "most bones" ? I doubt you have evidences of megalodon unable to bite through some particular whale bones).
In the large preys it bitten off the fins and fluke of the prey. I have pics of cetotherids cut in half from the Peruvian desert. One account from Gail Harrington, readable in the meg profile, talks about one skeleton destroyed in half. Accounts of that kind are multiple. In one video talk, Siversson talks about massive vertebras sawed in half, he even shows with his hands the approx. diameter of the vertebras.
In fact, I don't know anymore what is your point at all with this...
Both animals had no problem at deeply damaging bones of their preys. Both in a different fashion. For meg we have numerous direct evidences, for Livyatan nothing but the structure of its teeth is obvious in their purpose. Only the jaws of meg are not only different, they appear to me to be more massive, and as well as slicing through bones of they prey, had an exsanguination potency.
Christian De Muizon recalled Livyatan unlikely to have been able to tackle the largest extant whales. Leonard Compagno suggested megalodon could have done so on the contrary.
At this point, awaiting more stuff, I think we have more likely superior and mightier predator (I mean MORE LIKELY, no definitive opinion here, like often in paleontological fields) in the shape of the shark. My points are clear to me.
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Post by theropod on Jun 14, 2013 16:34:00 GMT 5
@creature: Yeah, that's what I stated. A bit too simplified probably Do you mean my arguments, or your sentence, which I quoted? My sentence is a bit of a simplification, jaw mechanics are a complex field. |
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Post by theropod on Jun 14, 2013 16:46:41 GMT 5
Feel free to post examples of a large (comparable-sized) whale whose large bones have been sawed through. Not sawed at, sawed through. I am open to changing my opinion if you can provide evidence why I should.
All the truly large bones I saw showed gashes, they were not sawed through.
I am not talking about cetotheres, I am talking about whales approximately the same size as C. megalodon. A cetothere, tough large, is nothing compared to a decent-sized Carcharocles.
My point is that Carcharocles had a biting style comparable to other slicers, however it targeted bony regions more frequently and its jaw design allows it to bite and damage them effectively. It is not a bone crusher and I have yet to see evidence for really large bones beign crushed or sawed. This is only the case in small preys (compared to it and its jaws).
And that is were I disagree. Both are very different in the primary purpose of their jaws, and considering their different morphology and function any direct comparison of the jaws based on lenght, width or volume is very premature imo
Also, I think I have to stress again that it is simply not possible Carcharocles megalodon was an equally potent soft-tissue slicer and at the same time just as effective agaisnt bones. These are virtually excluding one another. There is a reason for different tooth designs in animals, if there was some "one for all solution", all animals would have that particular jaw and tooth design.
Therefore my poitn still stands, you cannot objectively compare the jaws of these animals, they are pretty much opposites.
Which are opinions, and have no relation to this fight, sicne they are merely about gigantophagy and their respective adaptions towards it or not. Please recall the T. rex-Carnosaur-analogy. One is much more gigantophagous than the other, but you don't favour it at parity because of that, neither do I.
BTW, I think it may be wiser to ask each of the scientists about both animals, not just about one respectively. That would be a much more reliable argument.
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Post by elosha11 on Jun 14, 2013 23:23:41 GMT 5
Grey and Theropod - you both make interesting observations. I actually think your area of disagreement is far smaller than what is agreed upon, whether it be the respective size of the animals or their jaw functionality. Here's my very simplified comparison of their jaws. Livyatan's bite functioned primarily to crush, but in accomplishing that purpose, it could not doubt leave terrible flesh wounds, especially if it increased its force by shaking its prey while biting, similar to an orca. Megalodon's bite functioned primarily to slash and cut but given the thickness and size of its teeth and jaws, it could also heavily damage, slice through, and cut bones, especially as its bite force was amplified as it shook its prey. Both jaws were extremely effective weapons.
Where I tend to believe Megalodon had a more objective "advantage" was in bite volume. The gape, height, and width of Megalodon's bite makes it fairly clear that it had a significantly larger bite than Livyatan. That is truly a measureable, quantifiable difference and I believe gave Megalodon a predatory advantage in that it was likely able to target and incapacitate larger whales than Livyatan would normally tackle. Despite this difference, I do believe Megalodon and Livyatan had a large prey overlap in places they co-existed. In my opinion, just like any predator, Megalodon probably targeted smaller to medium sized prey more frequently than huge animals for many reasons, not the least of which is that the smaller cetaceans and other prey were probably much more populous and available.
Now it is not quite as clear to me that a larger bite translates into a fighting advantage. Livyatan's bite was still very large and could also inflict serious damage and could possibly crush the shark's internal organs it got a good grip (this is of course making a very big assumption that Livyatan's jaws could encompass the girth the shark. However, Megalodon's ability produce catastrophic wounds over a larger surface area may have given it a greater ability to inflict mortal damage in a one bite v. one bite scenario - which of course is not the only way such a conflict may have progressed.
More thoughts to come when I have the time...
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Post by Grey on Jun 15, 2013 0:14:34 GMT 5
Good points Elosha.
Another point : meg and Liv preys were perhaps for most overlapping during Miocene.
Now we have no indications of Livyatan or a similar sized raptorial sperm whales during the Pliocene, when the size of the whales had increased. We don't know exactly when Livyatan vanished but there's no sign of its presence during the Pliocene.
Increasing size of their preys and ecological replacement by delphinids has been proposed for their disappearance.
Meanwhile, meg was still very common and preyed on large advanced balaenopterids...
My posts are limited these times, I'll post some stuff in the weekend.
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Post by theropod on Jun 15, 2013 1:18:27 GMT 5
Agreed with both of the last posts.
The age of them is a good point in favour of the argument of different preys. What I wonder is whether we should not see some sort of adaption in Pliocene Carcharocles, since during miocene the available prey for both seems to have been similar, while the whale fauna was different during the pliocene. Are there any noted differences between Miocene and Pliocene Megalodons?
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Post by Grey on Jun 15, 2013 1:25:12 GMT 5
Only the attacking style.
Once, I had read that Pliocene megs were larger.
But I have posted pics of very large megs teeth from Miocene deposits.
What I wonder is if some megs size was various depending the regions, just like in Ginsu sharks.
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Post by theropod on Jun 15, 2013 1:31:41 GMT 5
I think that's even highly likely. Whales also are different in size depending on the region (compare southern and northern blue whales), and a whale-eating shark ought to adapt to that.
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