Megalodon vs. Livyatan melvillei

[sam1]

"..Openly a cetacean enthusiast"
This coming from someone who is actually and openly a megalodon enthusiast, devoting much of his personal time into semi-academic research and studies of megalodon fossils.

Now as for me, I can tell you that cetaceans are not even near the top of my interests. I am merely interested in nature and animals in general.
Honestly, I find, for example, a common swallow or a river-cossing spider more impressive creatures than Livyatan.
As for Livyatan and Megalodon, I simply find the former to be a much more interesting creature.. due to intelligence, reversed evolution and lifestyle. Megalodon is just too straightforward and kind of boring.
Discussing these kinds of topic is just something I feel like doing when having the time.

Can you tell the irony of your premise?

I'll get back to the rest later.

[Life]

Oct 12, 2019 16:54:53 GMT 5 theropod said:

Again, please refer to what I (and others) wrote in the mosasaur discussion. This is simply a major over-interpretation of a fossil tooth mark.

You jump to the conclusion not just that there was a trophic interaction (and not, for example, scavenging) but also as to the nature of said interaction (shark preying on whale, and not the reverse) when there is no evidence of either. Not to mention this claim that the shark "tore through the skull of a large Physeteroid", which is also not exactly realistic.

No need to lecture me on the rules of zoological nomenclature, I work in collections management. Physeter sp. means a species in the genus Physeter. Livyatan melvillei is a species in the genus Livyatan. But besides the point, since their taxonomic assignment appears very doubtful, I was just pointing it out. Proper taxonomic assignment for this specimen would likely be Physeteroidea indet.

That a macropredatory shark would have to deal with ramming and tail slapping from its prey is obvious, and of no concern here. It has already been noted that none of these animals are adapted to ramming to a similar degree as Livyatan or Physeter, or as large for that matter. There is a difference of being tail-slapped or rammed by a 6 m cetothere, or being rammed by a 15 m physeteroid. A difference in body mass, and resulting impact force, by an order of magnitude, for one. This analogy is really rather like saying that because I don’t sustain serious injuries from being punched by a toddler, I would also be almost immune to a punch from a heavyweight boxer.

Same goes for attack on the skull. Because an animal can attack the (far less solid, far smaller, and far less dangerous) skull of a cetothere, that doesn’t automatically mean it could do the same with Livyatan. Which is not just very risky due to the aforementioned ramming abilities of the physeteroid, not to mention a very powerful set of jaws and teeth in its own right, but also an extremely bony target to bite (in fact, likely among the biggest and most solid pieces of bone of any vertebrate in earth’s history).

1. I will address that post when I have sufficient time for the needful. 

2. Take a closer look at the fossil in question (WH023).



You will notice not just one but several cuts on it. One is deep and the remaining are shallower incisions. Deep cut seem to indicate a disabling bite followed by a degree of lateral shaking with the intent to tear off a chunk of flesh (and more) from the jaw structure of the subject. It is possible that this was a follow-on bite to finish off a 'struggling' prey item; initial attack might have been directed towards the chest cavity of the whale to mortally wound it, or some other part which had a disabling effect.

Now, how can you infer from this fossil evidence that Megalodon was actually on the receiving end of this encounter? Does not make sense at all. Have you ever come across a case study in which a 'struggling' shark managed to bite on the jaw structure of a raptorial odontocete in an attempt to escape? You are seriously overreaching in this case. LMAO.

If WE simply assume 'scavenging' in every case of biting imprints then WE can never hope to unmask behavioral patterns of extinct animals. There isn't any debate to be had, and this thread shall be closed because WE do not have much to discuss outside 'superficial conceptual modalities'.

3. My sincere apologies! My intention was not to offend you or question your expertise in these matters. However, refer back to important set-of-revelations in this post: theworldofanimals.proboards.com/post/47816

Possibility of this tooth belonging to Livyatan or a similar type of raptorial odontocete cannot be ruled out. In fact, this assignment is more likely.

4. Fair point; I do not disagree with this view. However, none of the sharks hold a candle to physiology of an adult Megalodon either, and I have already elaborated to you how Megalodon could withstand powerful blows which might break bony structures (extremely robust cartilaginous skeletal structure) as well as being a heavyweight organism in the league of Livyatan or above. Megalodon gives the impression of being a gigantic shock-absorbing organic vessel.

This isn't to say that Megalodon was virtually immune to injuries and/or could endure powerful blows for indefinite period - every living thing have limits in terms of handling punishment. However, it is certain that Megalodon was in the higher end of spectrum in coping with pressures of big-game hunting, it had to be due to its solitary hunting lifestyle.

So livyatan being more potent in ramming than other cetaceans of its time, does not necessarily translate into anything substantial in terms of killing an adult Megalodon in a potential confrontation. And neither ramming a 'well-aware moving target' is easy - the scenario under consideration here as per member sam1.

Still, I'd rather believe that Megalodon is unlikely to risk a prolonged confrontation with a powerful creature such as Livyatan because this is a deadly clash for either party; Megalodon would rather prefer to surprise Livyatan and exercise disabling approach afterwards. Case in point: www.livescience.com/16905-ancient-whale-shark-attack.html

But nothing is certain in case of discussing animals which no longer exist, our knowledge about them will remain limited. Nevertheless, WE can continue to draw inferences from fossilized remains, additional forms of ancient preservation(s), and relevant set-of-observations. And WE can hope to plug some gaps in our knowledge with conventional wisdom at personal capacity.

5. It is possible that this was a follow-on bite to finish off a struggling prey item; initial attack might have been directed towards the chest cavity of the whale in question, or some other part which had a disabling effect.

Do you realize what level of forces Megalodon could produce during its biting activities?

Take a good look at the damage done to following teeth. 





Unbelievable level of bite forces involved. 

Megalodon teeth are among the most tough/robust of biological objects ever. Try to play with these and see what happens.

Wroe et al (2008) actually admitted that their estimates are rather 'underestimates'.

"Feeding behaviors and kinematics are complex in sharks (Motta et al., 2002). A full bite sequence may involve five distinct components: cranial elevation, lower jaw depression and upper jaw protrusion, followed by lower jaw elevation and head depression. Moreover, ram feeding behaviors by C. carcharias may vary considerably depending on factors including the type, size and depth of prey (Tricas, 1985). Modeling presented here is limited to the prediction of mechanical behavior in relation to lower jaw elevation. Some observed behaviors, such as lateral shaking (Martin et al., 2005), might incorporate significant postcranially generated forces. These could amplify readings recorded at the bite points in our model as has been found in some mammalian carnivores (McHenry et al., 2007). Thus, depending on how bite force is defined, it is likely that the total delivered forces experienced by prey are higher than those estimated here."

Megalodon could literally bite through metal and laugh afterwards. It is not unrealistic to assume that Megalodon could bite through extremely bony structures.

[Grey]

Oct 12, 2019 20:16:11 GMT 5 theropod said:

Oct 12, 2019 19:21:08 GMT 5 Grey said:

You didn't tell anything like this but the rebuttal of any argument in favor of the shark makes me think I'd rather be interested, since you're a scholar, in your opinion of the actual outcome. I mean it looks like megalodon was an unadapted organism and that sharks are weak. But there are many anecdotal accounts about the durability and domination of sharks over marine communities and megalodon in particular. Physical attributes are not the only reason to meg domination and longevity as an apex predator, but at the end, it seems reading you, even more than sam1 that is openly a cetacean enthusiast, that nothing in the shark was notably impressive to deal with an odontocete its size. Just like denying the possibility of the shark being possibly larger. So I'm interested in your actual opinion but understand that a bias can always occure even in a neutral mind.
That is why I often revise the question under another angle as we discussed often these past months.

So once again, I ask you to stop making up straw men (a straw man argument means responding to points I never made, e.g.  "megalodon was an unadapted organism and that sharks are weak") and alledging biases, and you respond to that by listing essentially the same strawmen, alledging essentially the same biases once again? That’s just going nowhere.

You know my opinion about the outcome, I have told you numerous times, frequently only on your insistence. Maybe you just cannot understand that not everyone cares so much about the topic of this thread, and potentially more about the scientific issues surrounding it. Just because you like to reiterate that you still favour the shark every few months, doesn’t mean I have to do the same. That is, frankly, putting way too much emphasis on an opinion that is of no real concern or value to anyone else.

If I comment on "Stegosaurus vs T. rex", do you seriously think it is because I care about the outcome of that scenario? No. If I comment on dinosauria101’s size comparison showing a fictional size for Ceratosaurus compared to Daeodon, do I do that because I care about the outcome of a fictional fight between the two? No. This is not the fantasy section. I comment to point out something that can inform people about these animals. I have no problems whatsoever arguing "for" or "against" either "side", but seeing your and life’s posts here, in terms of listing arguments in favour of the shark, I’ve simply had my work cut out for me, and this has been the case since this forum was founded, by and large. Which doesn’t mean I have problems also addressing arguments in support of the whale that I find erraneous, as you will recall, for one as biased as I am, I have spend quite a bit of time voicing my disagreements with sam1 regarding locomotion and respiratory systems.

My arguments adhere to the scientific data, not my preconceived notions of which of these two is "superior".

I am not "denying" the possibility of the shark being possibly larger. I’m just also considering the possibility of the whale being possibly larger as well. Both exist. As you have consistently argued for the shark to be larger, and by and large ignored any or all of my points in criticism of these claims, of course I am more compelled to argue against that then for it (again, I’ve obviously had my work cut out for me arguing for how gigantic the shark is).

Of course I don’t share your opinion that the size of the largest isolated teeth is of any real relevance in answering that question, something we really don’t have to revisit yet again, as there is no new data with any impact on this whatsoever (if anything, the number of Livyatan sp. teeth recently described have reinforced that the specimen is probably a pretty typical size for its species).

That word, "denying" btw, a bit presumptuous, don’t you think? That sounds like I was "denying" evolution, or climate change, or gravity Even for those cases, use of the word "denying" is frequently criticized, despite being somewhat appropriate, because the things (at least the observational basis) being denied really are facts. You can "deny" that organisms change and adapt over time, that the earth is getting warmer, or that masses attract one another. You cannot "deny" a highly speculative size estimate with huge error margins.

But I am not the person here who is calling researchers "idiots" for publishing research at odds with my viewpoints, or not doing research on subjects more in line with my interest, so it’s more than a little puzzling you are busy criticizing me instead. Why is this? I wouldn’t want to go so far as to suggest this is primarily because of our disagreement, or some personal issue, but it seems hard to explain as being less a result of that than any actual bias I am supposed to have shown here.

I’ll give it two days for you to cool down, and suggest you do the same.

Dude, calm down ! The discussion is not that hot-tempered as this. I think we have a kind of misunderstanding rather than a strong disagrement whatsoever.

I have no obsession with this question, it is simply a cool but long-running thread that is sometimes going into circles so I ask for your educated opinion on this, you fairly know I regard your works and observations as valuable. It is just that I specifically ask for a more global view regarding the question rather than going into circles into details.
I know you are objective and mature but I don't remember a post from you where you argued in favor at least in some point for the shark, so my impression was that maybe I simply severely overstate about sharks ?

But no freaking obsession on this. On the contrary, the number of works and analysis you put yourself in this thread make you just as much invested than I am.

As for the teeth of Livyatan found here and there, we can't say more since the size is hardly indicative of anything but it remains that all the described until now are in the same size range but still somewhat smaller than those of the holotype. So I wouldn't say it was necessarily in the typical size, maybe in the large typical young adult of its species ?

[Grey]

Oct 12, 2019 20:50:45 GMT 5 sam1 said:

"..Openly a cetacean enthusiast"
This coming from someone who is actually and openly a megalodon enthusiast, devoting much of his personal time into semi-academic research and studies of megalodon fossils.

Now as for me, I can tell you that cetaceans are not even near the top of my interests. I am merely interested in nature and animals in general.
Honestly, I find, for example, a common swallow or a river-cossing spider more impressive creatures than Livyatan.
As for Livyatan and Megalodon, I simply find the former to be a much more interesting creature.. due to intelligence, reversed evolution and lifestyle. Megalodon is just too straightforward and kind of boring.
Discussing these kinds of topic is just something I feel like doing when having the time.

Can you tell the irony of your premise?

I'll get back to the rest later.

There is no problem with being a cetacean enthusiast, or any enthusiast whatsoever, but it is true that while debatting there can be times where we doubt the neutrality of the other, but this is simply natural.

As for me devoting time in meg; it simply happened to be one of the easiest subject to study from behind a screen. This is simply a mysterious species that needs some investment not only by professionnals to contribute to its knowledge. But don't worry, paleobio research is only the second of my interests currently, simply the older one.

Again, my remark was not meant to be offensive at anyone, I just ask for taking a larger picture in question, this discussion is simply confusive if we focuse on debating while we keep our positions. As for example you admit you consider the giant Neogene shark to represent what you described but at the same time you accepted the (inconclusive) recent paper by Shimada which limits megalodon at 15 m (which would put behind Livyatan?).

And yes, there are even more fascinating subjects. I recognize Briggs Orcas as the most fascinating ultimate marine apex predators since a time for example.
But this here is a subject that can progress nonetheless and is cool in his own right and also allows to allude to other themes regarding biology and ecology knowledge. Everything is not esoteric either.

[sam1]

Oct 12, 2019 22:42:39 GMT 5 Grey said:

Oct 12, 2019 20:50:45 GMT 5 sam1 said:

"..Openly a cetacean enthusiast"
This coming from someone who is actually and openly a megalodon enthusiast, devoting much of his personal time into semi-academic research and studies of megalodon fossils.

Now as for me, I can tell you that cetaceans are not even near the top of my interests. I am merely interested in nature and animals in general.
Honestly, I find, for example, a common swallow or a river-cossing spider more impressive creatures than Livyatan.
As for Livyatan and Megalodon, I simply find the former to be a much more interesting creature.. due to intelligence, reversed evolution and lifestyle. Megalodon is just too straightforward and kind of boring.
Discussing these kinds of topic is just something I feel like doing when having the time.

Can you tell the irony of your premise?

I'll get back to the rest later.

There is no problem with being a cetacean enthusiast, or any enthusiast whatsoever, but it is true that while debatting there can be times where we doubt the neutrality of the other, but this is simply natural.

As for me devoting time in meg; it simply happened to be one of the easiest subject to study from behind a screen. This is simply a mysterious species that needs some investment not only by professionnals to contribute to its knowledge. But don't worry, paleobio research is only the second of my interests currently, simply the older one.

Again, my remark was not meant to be offensive at anyone, I just ask for taking a larger picture in question, this discussion is simply confusive if we focuse on debating while we keep our positions. As for example you admit you consider the giant Neogene shark to represent what you described but at the same time you accepted the (inconclusive) recent paper by Shimada which limits megalodon at 15 m (which would put behind Livyatan?).

And yes, there are even more fascinating subjects. I recognize Briggs Orcas as the most fascinating ultimate marine apex predators since a time for example.
But this here is a subject that can progress nonetheless and is cool in his own right and also allows to allude to other themes regarding biology and ecology knowledge. Everything is not esoteric either.

Alright. No problem.
Now, to clarify the leftovers..if I call your argument ridiculous, why do you instantly find yourself offended and attacked?  
If wasn't a baseless remark, but something I said only after having(along with theropod) addressed the point already fully and you then repeatedly bringing it back despite of that.

I'll have no issues if any of my points is ridiculed with proper arguments..honestly, believe it or not as this will sound cliched ..but I really want to be proven wrong if I am wrong. My interest is learning and getting new perspectives, not being right about something.

I missed to comment on your answer about the Shimada's proportioned meg reconstruction.. 
Well, it does look off, I agree. Although it should look quite different from a full 90° side view and with jaws closed.
I need some sources about the teeth size used for it.

As per your question, do I see livyatan as the "most versatile fighter"..huh, I guess not. Haven't thought about it that way.
But yeah, I definitely see it as a more versatile fighter than megalodon, and I see megalodon as the more efficient and effective killer.

And I already described why I favor it in a head on clash, while agreeing that it would be a relatively rare outcome in itself.

[sam1]

Oct 12, 2019 19:15:43 GMT 5 Life said:

Oct 12, 2019 17:11:30 GMT 5 sam1 said:

I expected you to mention that the sperm whale teeth image Life used for comparison is terrible.
Here, literally from the first page of google sperm whale teeth search.

images.app.goo.gl/X8qxdRRCMjrnxWvG9

images.app.goo.gl/8bVwuyZL1pNuZHM1A

Here is a better view.



Closer look at the rows of teeth:



Of-course, there are different types of teeth in the jaw structure of modern-era P. macrocephalus.

However, the Megalodon-bitten tooth (WH023):-

1. Have a very pronounced crown



2. The tip of crown show intense wear-and-tear from feeding activities



3. Was already massive in size (8.25 inches long), and could grow larger (look at the root structure; underdeveloped)



4. Could be positioned in the upper jaw structure, like this:



Dentition of the Livyatan holotype for reference.



WH023 is absolutely similar to Types H and I in that collection.

Connect the dots.

You cannot rule out the possibility of WH023 being a Livyatan specimen.

Yeah, that's much better.
And yeah I cannot, nor do I want to rule out the possibility, as well as the outcome you're envisioning. No problems with it.

[Grey]

The teeth are available in size here, the second set : boneclones.com/media/PDF/shark-teeth-sizes.pdf

Mouth closed won't change this, there are other pictures of this model available on google. Abd as theropod suggested, is a very heavily built shark. At 15 m, it would be around 70 tonnes. This suggests it is hard to not compact the body with dentition size becoming larger in relation to the body. This suggests that the largest megalodon were really in the gigantic league.

sam1 why the better fighter would not be then the greatest killer ?

[sam1]

Oct 12, 2019 23:40:46 GMT 5 Grey said:

The teeth are available in size here, the second set : boneclones.com/media/PDF/shark-teeth-sizes.pdf

Mouth closed won't change this, there are other pictures of this model available on google. Abd as theropod suggested, is a very heavily built shark. At 15 m, it would be around 70 tonnes. This suggests it is hard to not compact the body with dentition size becoming larger in relation to the body. This suggests that the largest megalodon were really in the gigantic league.

sam1 why the better fighter would not be then the greatest killer ?

Okay, thanks.
So.. what you think would be the average megalodon TL?

Well, the better fighter doesn't usually translate into a better killer, and vice versa. 
For example, a badger is typically a better fighter than a cat, but a cat is a better killer/hunter.
Livyatan's special ramming adaptations(likely a result of intraspecific dynamics but also possibly as an anti-megalodon defensive tool, as speculated by some in the case of p.macrocephalus) give him an extra asset for fighting, but it also isn't ideal for killing. 
Megalodon otoh, has jaws and a bite that are more effective in killing large prey.

[Life]

Oct 12, 2019 23:40:46 GMT 5 Grey said:

sam1 why the better fighter would not be then the greatest killer ?

Mammals have a physiology that facilitate maneuverability by default. While subject to numerous environmental pressures through the ages, Mammalian physiology had sufficient flexibility to facilitate development of intelligence, physical strength, and even gigantism as a coping mechanism.

Livyatan seems to have received an ideal mix of the aforementioned traits by the looks of it (Holotype). This isn't to say that Livyatan will score 10 out of 10 in all aspects of biology; different types of animals feature different types of qualities/adaptations to cope with developments in their surroundings.

Livyatan have the necessary physical characteristics that would enhance its 'physical strength' and affiliated expressions such as great size and corresponding musculature, and the spermaceti organ. As such Livyatan could be really good at contending with other lifeforms. Livyatan is also gifted with a very impressive killing apparatus which facilitated its hunting prowess in conjunction with its great physical strength (macropredatory possibilities). However, once again, 'very impressive killing apparatus' does not suggest that Livyatan will score 10 out of 10 in this aspect of biology.

Therefore, Livyatan can be the better fighter but not necessarily the greatest killer.

[sam1]

Oct 13, 2019 1:25:19 GMT 5 Life said:

Oct 12, 2019 23:40:46 GMT 5 Grey said:

sam1 why the better fighter would not be then the greatest killer ?

Mammals have a physiology that facilitate maneuverability by default. While subject to numerous environmental pressures through the ages, Mammalian physiology had sufficient flexibility to facilitate development of intelligence, physical strength, and even gigantism as a coping mechanism.

Livyatan seems to have received an ideal mix of the aforementioned traits by the looks of it (Holotype). This isn't to say that Livyatan will score 10 out of 10 in all aspects of biology; different types of animals feature different types of qualities/adaptations to cope with developments in their surroundings.

Livyatan have the necessary physical characteristics that would enhance its 'physical strength' and affiliated expressions such as great size and corresponding musculature, and the spermaceti organ. As such Livyatan could be really good at contending with other lifeforms. Livyatan is also gifted with a very impressive killing apparatus which facilitated its hunting prowess in conjunction with its great physical strength (macropredatory possibilities). However, once again, 'very impressive killing apparatus' does not suggest that Livyatan will score 10 out of 10 in this aspect of biology.

Therefore, Livyatan can be the better fighter but not necessarily the greatest killer.

Dont want to look biased now, but this post is a classic..the kind of stuff internet is made for.

[dinosauria101]

Oct 13, 2019 1:25:19 GMT 5 Life said:

Not to nitpick but is this in absolute terms or in comparison to other animals?

[Grey]

What do you guys think about the recent "downsizing" of megalodon ?

[dinosauria101]

Oct 13, 2019 3:49:47 GMT 5 Grey said:

What do you guys think about the recent "downsizing" of megalodon ?

I think it's not to be taken for gospel but certainly must be considered

[Grey]

A simple consideration regarding meg's "titles" is that if megalodon's feeding apparatus was really up to 4.5 times, for the largest, the size of the feeding apparatus of a 5 m white shark, it would mean a bite volume unmatched when you know (but I couldn't find a source) that a typical great white shark is said to be able to take 14 kg of flesh in one gulp, I mean perhaps the capacity to take out more than 2 tonnes of organic material. Is Livyatan or another macropredator approaching this scale ?

Maybe I'm wrong because of some perception but I don't think Livyatan's holotype bite really approaches this one in terms of "gargantuan".

Unless, it happens, even for the most unlikely reason, that otodontids got downsized. But I doubt about that presently.

The latest reported size of the Belgian specimen is 11 m. Since this is potentially a better specimen than even the dentitions and if published that could present an almost certain size for a meg specimen.
This specimen has its widest vertebra 155 mm, scaled up to the 230 centra from Denmark would then suggest a minimum of 16 m for the owner of this centra.

This would simply confirms for adult megalodons a normal size of at least 16 m since there is no reason the Danish centra comes from an exceptionally large specimen just like the Livyatan holotype.

As for Livyatan, Jaime Bran told me he used an equation from a paper about fossil cetaceans by Pyenson 2011 and used for physegeroids an equation giving Livyatan holotype about 16 m.

I think this is the most likely although we can always be surprised in either way. But I doubt Livyatan much smaller-headed than its relatives.

[dinosauria101]

Well, I agree. Sharks have very large mouthgapes in all dimensions. The same cannot be said for whales.