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Post by Grey on Jun 16, 2013 2:32:08 GMT 5
Again you don't pay attention.
1. Will you check the video by Siversson at the end ? Toward the end of the video, the part about megalodon. The vertebras he talks about are from Aurora.
2. Popular articles as you call them are not necessarily untrue. Also, whatever I provide scientific litterature or something else, you have no problem to reject it.
3. When biting, depending which bones, depending the bite, depending it its feeding, scavengin or an attack, it is NOT NECESSARY that all the bones are deeply shattered. All the T. rex teeth marks do not pierce through the whole bones of its preys. Yes you minsinterpret or don't want to accept.
Edit : are not necessarily untrue.
The teeth of megalodon are extremely robust and known to have sliced through various bones of various sized whales. That sometimes there are only gashes does not mean it has a limitation to bite though the whole bone. You misinterpret that part.
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Post by Grey on Jun 16, 2013 2:54:24 GMT 5
Comparisons of the head shape of Livyatan and Orcinus from the team of Lambert. Not orca-like built but a stocky sperm whale. Not as large as some would expect though still very massive.
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Post by Life on Jun 16, 2013 4:11:29 GMT 5
GreyNice share! --- Ok, time for some visual observations:- Whale vertebra bitten in half: Whale bone with 3 inch deep gash: Whale rib bone segment with puncture like gashes: Another puncture like wound: --- Large (unknown taxon) whale killed by Megalodon? Bite wounds on same whale: --- Also, I shall make this clear that Megalodon inflicted wounds have been observed in all bodily regions of whales. Some attacking strategies have been figured out by experts; Most commonly attacked/bitten regions are: - Ribs (rib-cage) - Vertebra (spine and caudal) - Flippers
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Post by Grey on Jun 16, 2013 4:15:14 GMT 5
You welcome Life.
The problem is that our friend Theropod speculates that all the bones bitten by megalodon should obligatory be entirely sliced...
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Post by Life on Jun 16, 2013 4:20:10 GMT 5
Due to lateral shaking activities, Megalodon could inflict wounds of different nature on the prey; some bones ended up sliced; some bitten in half; some with puncture like wounds; and vice versa! Very terrifying animal.
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Post by Grey on Jun 16, 2013 4:37:07 GMT 5
Wasn't there also the case of a 9 m or so cetotherid devoured from behind in Italy ?
Hönninger once sent me several pics of cetotherids in the 6-10 m range with the vertebral column slashed. I'll try to found them again.
Regarding the presence of deep gashes along with thinner marks, Bretton Kent (2013) :
As a top carnivore, C. megalodon undoubtedly preyed any a broad range of prey. The best available evidence is the presence of large bite marks in marine mammal bones (Purdy, 1996; Renz, 2002; Aguilera et al., 2008). In most cases, the marks are large deep gashes, although in exceptional cases, fine parallel grooving produced by the serrated cutting edges is visible (Figure 15A).
In all cautiousness, I like to list both to be simply similar in power, because of their respective uncertainties. I do not reject any further retractation regarding Livyatan.
However keeping in mind all the suggested possibilities (size, predatory apparatus potency evolutionnary supremacy...), I favor in this case C. megalodon.
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Post by elosha11 on Jun 16, 2013 12:53:46 GMT 5
Life - Great pictures of bitten whale bones, some of which I've never seen before. I will have to add them to the shark bitten whale bones thread when I have the time.
One of the difficulties in determining the effects of Megalodon or Livyatan's bite on whale bones is that the fossils we have are so fragmented. For instance, many whale rib bones that have Megalodon gouges also seem to be shattered or jagged ends. Is this because Megaldon's bite broke the bones as well as cut into them? Or is this simply the erosion of time? Similar question for Livyatan. We know it had a powerful bite, but can we be sure it was focused on crushing bone rather than ripping off sections of meat? For instance, orca have conical teeth like Livyatan and shares certain resemblances in jaw structure. Yet, I've never heard of orcas being described as bone crushers, even with their smaller prey like pinnipeds. Instead they seem to target soft tissues and blubber and use their powerful bite and bodies to shear off large chucks of flesh. So perhaps the functional disparities between the shark and whale's teeth is not as different as has been suggested here. Maybe the key "difference" is not so much cutting v. bone crushing. Instead, the shark's teeth can be described as primarily meant for cutting flesh (but can also grip and cut/brake bone) and the whale's teeth are primarily made for gripping flesh (but can also crush/brake bone and shear off flesh in a cutting action).
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Post by Grey on Jun 16, 2013 13:06:14 GMT 5
It is true that Livyatan as a bone-crusher is an assumption that has not been quoted from the publication or in interviews.
Actually nowhere it has been described by the team as such. The guys are very rational actually. I guess they'd expect direct feeding evidences for that.
But it is understandable, viewing the size and structure of the teeth it could have performed this.
But the truth is that we don't know one single evidence of its feeding habits. Livyatan is truly a Paper Tiger and I'm tired of the endless speculations I can read about it from overenthusiastics amateurs of the internet...
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Post by theropod on Jun 16, 2013 14:08:13 GMT 5
^We might even do, but have not yet realized they are actually from a Livyatan. But obviously, these physeteroids were not particularly common, otherwise one would find a few more fossils of them. Livyatan being a bone crusher is the only viable inference from its feeding apparatus. There simply was no functional analysis beyond it being a macropredator in its description paper. @life: Very nice compilation, thank you a lot for posting! Probably the best collection of megalodon bite marks I've seen so far. Grey: Please, give me the exact time! I cannot find these vertebrae you are talking about. I hope you realise the soft tissue structure of Livyatan, exactly like Carcharocles megalodon, is largely speculative? What about popular articles talking about 20m Livyatan then? Since many pages, the only scientific paper brought up was not even relevant to the topic and brought up by me. And it is not me who is making the claims that have to be supported. I am not suggesting it must have sliced through every single bone in order to be called a bone slicer. But one would expect at least some large whale bones sliced given the abundance of fossils if it really used this tactic to kill large whales. Sometimes? From what I see that is not just sometimes, but nearly always. Ghashes are the norm, sliced-through parts are present but not that frequent, and I have yet to see bones of a large prey item sliced through. @life has posted the evidence. 5 fossils showing bite marks of c. megalodon, one of them sliced through but lacking any data on the fossil's size, the rest showing deep scratchmarks. I have already explained why the Triceratops sacrum was probably a feeding site. Yes, some megalodon bite marks undoubtedly are too, but I doubt you will find mere feeding wounds on the flippers, and even then, if it was able to slice through large bones why not saw the flipper off? The evidence is pointing towards an attack style on large animals primarily similar to extant or extinct slicers, with some degree of bone-damaging-potency. Very different from Livyatan in which it is the other way around. We may just have terminology-related difficulties here, tough massive ones. And I think you should have a closer look at the attack styles of other slicers. it is not true that they avoid bony regions or killed slowly or are any less brutal than crushers. That Megalodon was quick and brutal doesn't exclude it being primarily a slicer.
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Post by Grey on Jun 16, 2013 14:19:23 GMT 5
Theropod, the other video in the link of the appropriate thread. Not that one.
Makes no sense. We have the skull, they know where was the tissue and flesh on the animal. I'm talkig for the skull. Or any soft tissue structure in any fossil is speculative then.
You confuse popular articles and popular scientific articles. The article by Gail Harrington is valuable, she has performed several reports with Klaus Hönninger as well. The articles provided about megalodon here are all valuable.
I don't want and I don't have to continue that discussion about the teeth and bones, you have the sources, pics, video and even the quote I've posted from the not yet published chapter from Kent.
Also, I'm tired of all these unformal formulas. Megalodon had no problem at damaging any bones, its teeth were not rounded and deeply rooted like those of rex by example, but adapted to survive impacts through bones. There's really no dicussion to have here.
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Post by theropod on Jun 16, 2013 14:29:06 GMT 5
But the other file is an mp3, which is an audio file.
To some extent, it is. of course less so if the postcranium is known too. That is very relevant to the cervical area's soft tissues, and those are the main difference between the reconstructions of Livyatan and Orcinus, and the one you certainly also had in mind, or not?
"Popular scientific" refers to things like WWD, at least in my language. Not really any difference between it and popular int erms of credential. The article on Livyatan in question, I remember, was written by a geologist. who exactly decides which articles are valuable and which aren't? Same goes for documentaries, most if not all have scientific consultants, but the example of COTD shows that does not guarantee accuracy in the slightest. Would you also use "the truth about killer dinosaurs" as a source?
And about all of them you have apparently a very different view than me. That's OK for me, I just hope it is for you too...
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Post by creature386 on Jun 16, 2013 14:29:09 GMT 5
Pictures of supposedly bitten through vertebrae lack scalebars. Not always, here we have an idea of the bone size: www.calvertmarinemuseum.com/cmmfc/newsletter/CMMFC_Newsletter_2004-04.pdfFascinating Fossil Finds This year’s Fossil Club trip to Lee Creek Mine, North Carolina proved to be a good one for me.Although impressive shark teeth were hard to come by, I found a short segment of Rorqual (baleen whale, Balaenopteridae) rib that preserves what appears to be healed Carcharodon megalodon bite marks (Figure 2). Three swellings on the surface of the bone mark the location where the C. megalodon teeth impacted the rib. The swellings form a gentle curve along one side of the bone. The apex of adjacent swellings are about 2 ¼” apart, a dimension that would correspond to the distance between the tips of the impacting megalodon tooth. This dimension also gives us a close approximation to the maximum width of each tooth. I do not yet know if the offending megalodon teeth were anterior or lateral teeth. The close encounter with C. megalodon was not fatal for the whale however. The periosteum responded to the injury by forming these swollen bony calluses. I expect that an x-ray of the rib segment will show how the bone within reacted to the trauma.Judging from what they wrote about the distance of the bite marks, it seems like this ruler measures in inches.
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Post by theropod on Jun 16, 2013 14:32:15 GMT 5
^Thats obviously a nice example of a large whale's bone not bitten through, and of a whale even surviving the attack on its ribcage.
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Post by Grey on Jun 16, 2013 14:38:55 GMT 5
No, the link to the Wester Australian Museum I say.
No, we have the skull, they know how it was shaped in life. The body shape has a limited impact here. Also, in the Nature video, Lambert justly explains that the whole body is overall simiar among all cetaceans, this is the shape of the skull which is important. And fortunately, they've found the skull and know how it was shaped. I don't even know what's the problem here too.
The articles are valuable and serious. No matter the quality of the show, I take the lines and sentences from the specialists themselves. If the line is confusing I contact them at the end. In any case, the sources here are reliable.
I know exactly what I'm talking about. And here too, I don't know why you insist to debate on this. The sources, pics, articles and quotes are here. Big bones deeply damaged. Period.
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Post by Grey on Jun 16, 2013 14:41:51 GMT 5
^Thats obviously a nice example of a large whale's bone not bitten through, and of a whale even surviving the attack on its ribcage. The whale was reported much larger.
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