|
Post by theropod on May 20, 2014 16:01:44 GMT 5
So then how will C. megalodon counter the whale's ram? Well, I'm not sure how dangerous the ram will be on an animal of this size, we are currently lacking hard data on that in physeteroids. Judging from small dolphins, it could certainly be deadly to a shark in the right spots, but those may not be so easy to hit. Don't forget accellerating would take some time with animals of this body mass, its not as if they'd reach 50kph in a second. I rather see the cetacean ram as an augmentation to their relatively small gape angles.
|
|
|
Post by Grey on May 20, 2014 21:46:36 GMT 5
I don't think anyone's opinion on how large these animals were respectively was the point... I was just recalling my overall opinion of this epic match. Regarding the ram capabilities, Brett Kent was also suggesting that the ram of the shark would be very effective and could incapacitate a whale even before the first bite. But here too, it'd need more than a few seconds for that such large bodied animals get the proper cruising speed.
|
|
|
Post by elosha11 on Jun 4, 2014 0:58:33 GMT 5
When you are talking about two creatures of this size, a ram from either would have been potentially dangerous. I still think the evidence suggests that Megalodon may have been a bit larger and thus it could certainly have injured a Livyatan sized animal, even if its bite missed its mark. However, I do agree with Theropod that the whale's body shape and basic biology make it more suitable for ramming, and even the a smaller whale could have hurt Megalodon.
|
|
|
Post by elosha11 on Jun 4, 2014 1:01:54 GMT 5
On the other hand, while I'd give the overall ramming advantage to Livyatan, I believe the shape of Megalodon's serrated teeth and overall larger jaws give it a bit of advantage over the relatively more narrow jawed Livyatan, even if the whale had a stronger overall bite force.
I hope new information on both of these species will soon come to light.
|
|
|
Post by Godzillasaurus on Jun 4, 2014 17:44:09 GMT 5
I would definitely give livyatan greater chances in this matchup than the sperm whale at least. It was much better suited for killing large prey animals: it had overall much larger teeth that erupted from both the upper and lower jaw, whereas the sperm whale's maxillary teeth are rudimentary, and most often do not even erupt at all (I have heard of cases where they do, but nonetheless they were still small)
|
|
|
Post by Infinity Blade on Jun 5, 2014 4:56:50 GMT 5
I think we're all aware of that.
|
|
|
Post by creature386 on Jun 6, 2014 18:46:58 GMT 5
Godzillasaurus, I believe it would be better to compare Livytan's teeth with the ones of Megalodon and not with the sperm whale. Especially because they are functionally different.
|
|
|
Post by Godzillasaurus on Jun 6, 2014 22:02:43 GMT 5
The point is that livyatan, despite being closely related, is a far distance from being identical to the sperm whale; at similar sizes with the latter, it would stand a greater chance against megalodon And megalodon's teeth were way different than those of livyatan: they were very similar to those of modern great whites possessing a thin profile and fine serrations. Whereas those of livyatan were considerably thicker and more robust: Really a better analogy for livyatan would be a large pliosaur, which had very robust spike-like dentition and were generally very powerful animals
|
|
|
Post by creature386 on Jun 6, 2014 22:13:01 GMT 5
The functional difference in my post referred to Livyatan/Megalodon actually. It was to say that tooth size is not so important, larger teeth would maybe even be a bit disadvantageous for a shark, as they cannot cut that well. Even though Megalodon relied more on crushing than the modern great white shark, but it is debatable how much.
|
|
|
Post by theropod on Jun 7, 2014 1:09:08 GMT 5
Godzillasaurus: I don’t think anyone here questions that Livyatan’s feeding apoparatus is not comparable to a sperm whale’s. In fact, many extinct physeteroids are much more similar to extant predatory delphinids in that regard. That is neither surprising nor even worth discussing, one is a suction feeder of soft-bodied prey more than 20 times smaller than itself, another is a raptorial macropredator of bony cetaceans. C. megalodon has way thicker teeth than a great white shark: This is not from the most reliable of sources, but it does bring the point across. They are arguably still rather cutting teeth than anything else, but they are way thicker and have lower crowns than a great white’s (a bit of a compromise between cutting efficiency and resistance). As to why they are that robust, that has never been asessed quantitatively so far, but the general consensus is that C. megalodon had a high aptitude at hunting whales, and that it wasn’t too picky in what part of its prey it bit. The more sturdy dentition would have had increased resistance when it impacted bone, which it frequently did→. Compensation for square-cubing is another factor (think of ram feeding; considering the mass is huge and the speed not necessarily much different from extant sharks, the stress may be greater). It makes sense for an animal with such preferences and such size to evolve a sturdier dentition, that way it is less prone to dislodge or break if it more commonly experienced large forces.
|
|
|
Post by Godzillasaurus on Jun 7, 2014 2:56:49 GMT 5
The cutting ability depends on the shape and profile of the tooth, not how large it is. Megalodon was a lot larger than modern great whites, but yet its teeth were still roughly the same size proportionally to its actual jaw size.
I do agree that the ideal food source for the sperm whale would be fish and squid (moderately-sized at best), but is there any indication that it was actually a true suction feeder?
Great whites too are not very picky as to where they would bite something. When they rip apart animals like seals and sea lions, that is basically what they do, rip it to shreds:
So thus, great whites too seem to impact bone when they hunt, and megalodon probably hunted in the same way, or at least very similarly.
|
|
|
Post by Infinity Blade on Jun 7, 2014 2:59:39 GMT 5
Uh, you also read the fact that C. megalodon's teeth are proportionately thicker than a great white's too right?
|
|
|
Post by Godzillasaurus on Jun 7, 2014 3:01:58 GMT 5
Yea, I read it. And I have known that for quite a while. Nonetheless, the two tooth morphologies were still very similar, and the two animals likely hunted similarly.
|
|
|
Post by Grey on Jun 7, 2014 3:13:36 GMT 5
Megalodons teeth are LOT thicker and more massive than those of GWS at parity size, it's particularly obvious. Large teeth are approaching 4 cm in thickness, I've seen a peruvian one exceeding 7.5 cm of thickness. Bretton Kent has longly studied the biomechanics of sharks teeth, he explains clearly here why megalodons teeth are not alike GWS teeth and that they didn't kill similarly : www.discovery.com/video-topics/other/dinosaur-videos/prehistoric-washington-dc-mega-shark.htmThat's a dead end to compare megalodons teeth with Livyatan teeth. One had long rooted, cylindrical crushing teeth, one single set for its life. The other has short rooted teeth, easily replaced all its life, with long blade able to slice into even bones. Not even comparable, but both efficient at killing large preys.
|
|
|
Post by theropod on Jun 7, 2014 3:30:31 GMT 5
It is not so simple. Toothrows like those of sharks effectively function like a serrated blade or saw, with every tooth constituting one serration (that is, itself, also serrated in most cases). Serrations reduce the perpendicular (downward) force necessary to perform a cut, but increase the drawing force necessary. The taller the serrations, the more extreme this gets, i.e. the ratio of bite to shaking force that is found in sharks would not work any more. Obviously the relative tooth size does play a role for the cutting action, because it has to match the other traits of the jaw apparatus. A megalodon certainly could not have used teeth twice as long effectively, all else being equal. There is a reason teeth used for a certain purpose are usually proportioned similarly relative to the lenght of the toothrow. With cutting teeth acting in the fashion described above, you’ll see they are all in roughly the same lenght range, irrespective of the clade (be it lamniform, varanid or carnosaur). They can be a little taller or lower, e.g. as with C. carcharias and C. megalodon, based on specific differences, but they are generally all in the same ballpark. Taxa that have greatly increased tooth lenghts ( e.g. Ceratosaurus, Machairodontids, Thylacosmilids) probably also used them differently, and accordingly have altered jaw morphologies. There are certain differences you can observe (as already outlined, likely related to robusticity, such as some teeth being proportionally shorter), but it is in the same general range as far as that is concerned. Not just indication, it is a fact that Physeter macrocephalus is a suction feeder. www.aquaticmammalsjournal.org/index.php?option=com_content&view=article&id=335:functional-morphology-of-the-sperm-whale-physeter-macrocephalus-tongue-with-reference-to-suction-feeding&Itemid=113That type of behaviour is the reason for its highly unusual anatomy compared to extant raptorial cetaceans or its raptorial relatives such as Livyatan. I do realise that-hence why I noted other, size-related factors and the fact that this wasn’t really quantified. But it looks like C. megalodon had an increased tendency to target relatively bony areas even in large prey. I do agree with that, I think it is almost inevitable that C. megalodon would hunt at least somewhat similarly, given the broadly similar functional morphology and requirements of the two. Both are likely ambush hunters (pursuit or pod hunting seems unlikely) and they both kill violently and using their sawlike dentition, by taking out large chunks from their prey or literally tearing it to pieces (again, bite marks are evidence of this biting mode). So both these animals obviously encounter bone while biting prey (in case you have a few weeks of spare times, you can read the whole thread and you’ll see that I have provided evidence of that myself. Great whites have been recorded biting into turtle shells and taking human legs off). I just think (based on the ocurrence of fossil bite marks, among which you commonly find rather massive ones) there is a difference in the frequency of contact with large and robust bone that would offer considerable resistance to the teeth (that’s why there are so many ghashes known on these bones), and it is frequent ocurrences that animal tend to adapt to. Hence that is likely at least part of the reasons for a more robust but generally similar dentition. Not the sole reason, since part of it is certainly allometrical (see for example Snively et al. 2006→ and Testin et al. 2011→ for the allometric scaling of tooth bending strenght and proportions in theropods), but part of it. I think you are gonna agree that this field is in need of some objective science. It is horribly understudied, as much attention as meg gets otherwise, no quantitative asessment and comparison of its jaw and tooth function, or any scientific survey of bite marks attributable to it, seems to have ever been attempted. PS: Actually, there are no large predators that totally avoid bone in the fashion some pseudo-scientific documentaries or fanboys want to make you believe. So don’t assume I was claiming GWS totally avoided bone when biting prey–they do not, and neither does any other macropredator that I’m aware of. GWS have been known to saw through sizeable bones itself, it just doesn’t do that very frequently, which reduces the need for specific adaptions of its dentition.
|
|