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A quick word or two regarding the size of everyone’s favourite extinct shark, Carcharocles (-Megaselachus/Otodus/Carcharodon–why-don’t-other-animals-get-this-amount-of-taxonomic-attention-) megalodon.

As we have learned to expect from something really large and with really scrappy remains (isolated teeth, with vertebrae or more complete dentitions being known in a small number of poorly- or completely undocumented cases), people do enjoy speculating about its size.
Only in this case, people advising the use of conservative methods are often just drowned out (and trolled and bashed into submission) by the internet movement that understandably enjoys the thought of a species of 60ft shark that killed everything in its path with a single bite, aided by the fact that too many of those people mistake scientific’ enthusiasm (or pretty much any statement they can find anywhere, never mind if it’s just a freaking discovery channel documentary they misconstrue as the new principal scientific reference work out there) for some sort of endorsement of their sensationalism.

That isn’t to say that speculating is wrong–we literally would not get anywhere without it in vertebrate palaeontology. And certainly even liberal methodologies have their place, and for very good reasons that I won’t delve into right now.
But that doesn’t mean they are the only ones deserving of that, and it doesn’t mean that place is necessarily to be the most commonly cited and reproduced estimation, neither does it mean the only way to get an estimate that doesn’t get labeled as "too low" should be by making excessive use of wild assumptions to drive up that size figure (which really is precisely how the 20m+, 100t+ figure that’s so common in this case came into being, no offence).
There is a fundamental difference between nitpicking such a figure to represent this animal’s body size in general, and publishing it as a hypothetical (and, as noted by the authors in question, unreliable) estimate (but see below).

That gets even more comical when it gets to discussing how C. megalodon compares to other giant predators. I can’t help but be amused by their confidence in such biased comparisons when representing C. megalodon as an 18-20m critter even though those are the sizes of a handful of individuals in thousands. To jump ahead a bit, there appears to be quite some sensationalism in claims that it is the biggest predator of all time.
Leaving aside the implication of certainty that is expressed in this statement despite the incompleteness of the fossil record (and its fossil record in particular, with most animals people don’t make confident size estimates from teeth), there is a plain and simple lack of data supporting such claims. Certainly it is among the top 2 or 3 contenders, being comparable in size to its contemporary Livyatan melvillei, to the point where it is warranted to not make any statement about which is larger considering the lack of sufficiently complete fossils, and the lack of a sufficiently large sample of the latter’s population.

I don’t have a problem with the thought that 20m megatooth sharks existed, just like how 1t polar bears exist(ed), but this estimate is useless for all (scientific) intends and purposes because it does not base on solid data, and because it doesn’t relate to a normal individual at all (you know, the kind of megalodon that made all those bite marks, the kind you’d expect and fear to swim into if you were a miocene mysticete, in short, the kind that made up the bulk of the adult population of this species).
Those figures represent hypothetical freak specimens, based on more or less reliable hints, and back when this estimate was published it was conceived as such–deliberately basing on the largest (unreliable, and noted as such by Gottfried and colleagues) and most unusually proportioned report of a great white that was available.


Carcharocles Megalodon-backgroundless by theropod1

Life reconstruction, based on the anatomy of the extant great white shark (adapted from Compagno 1984) and accounting for allometric increase in robusticity as per the data outlined below.

So for a less biased picture, conservative methods are in order, especially when the whole matter already has to be based on a handful of teeth.
Keep in mind the actual meaning of "conservative"; not "the lowest", although the word is often used in that sense, even by myself. Yet in principle I am not an advocate of automatically considering the lowest estimate the most conservative.
In fact, it is not unusual for the lowest estimates to be "liberal" of sorts, when special pleading is used in order to produce a minimum estimate, often under the mistaken impression that it would make it more parsimonious (yet being too small isn’t really any better than being too large).
So here, what I mean is the most parsimonious method, the one that keeps biased (e.g. aimed at producing an extreme estimate in either direction) or otherwise poorly supported assumptions to a minimum, the one avoiding to sum up such biases and instead leaving them to cancel each other out if they can not be avoided. In short, the best and most objective estimate. Unfortunately that use of the term will probably not gain popular acceptance, so lets get back on topic.

So is there a way of making this more objective and exercising some caution in this sense? Yes, I think there is.

Firstly, the most important size metric of a species isn’t the size of the biggest thing you can find some tiny fragment of (btw teeth in general are actually tiny fragments, and scientists don’t bother estimating body size from them in many cases). It’s the species average size that’s most important, most objective, and least error-prone, so that’s what I’m most interested in here.
The background is that Pimiento & Balk 2015 actually estimated it fairly recently, and came up with an average of ~10m for 544 individuals of all ages.
But this still isn’t a very good means of comparison; depending on an animal’s reproductive strategy, the number of immature specimens in such a sample can vary, and accordingly species whose social and ecological adult stage is larger can end up smaller (or vice versa). To account for that, one can take the mean size of a subsample, namely all those that are above the mean size at maturity.
Gottfried et al. 1996 estimated mean sizes at maturity for both females and males based on the Great White shark, and the average of both is 11.9m, which is broadly consistent, if not a bit higher, than what would be indicated by the relative size at maturity of C. carcharias (cf. Cailliet et al. 1985, Casey & Pratt 1985, McClain et al. 2015). This figure should hence be appropriate to represent the average size when attaining maturity given that there is an approximately equal number of males and females in the population. In Pimiento & Balk’s sample, the average of individuals estimated to be this long or longer is ~14m.

Now, assume we wanted to know the size of a large megalodon. Not crazy-freaky-outlier-large, but still really large. One such specimen is comes from Denmark, and consists of a huge tooth associated with a number of vertebrae, which means that this specimen is, unlike most megatooth sharks, not a tooth lost by some individual at a random moment of its life, but an actual fossil "skeleton" left the traditional fossil way (i.e. dieing) if that word is appropriate.
Unfortunately there’s no telling whether any of the vertebrae are the largest in the collumn, and there is also vague indication of C. megalodon’s vertebrae being proportioned differently from those of C. carcharodon. So we’re still stuck with a tooth, but at least we have a more substantial specimen that this tooth once belonged to.
The piece of eviscerating awesome in question is 12.6cm wide and 15.8cm tall, with a 11.9cm tall crown. Based on its massive built, slight tilt and size, it is likely to be one of the first three laterals, which include what is often the widest tooth in the dentition.

There are multiple ways of estimating the size from these measurements. One that is currently very popular is based on individual regressions estimating total length from tooth-crown height in Great White Sharks (Shimada 2001, cited in Pimiento et al. 2010).
Using these regressions for the first three lateral teeth, the mean estimate is 16.8m.
Another method, and one which I personally prefer because it solves a number of the problems associated with using a significantly smaller relative as the sole analogue, is first extrapolating the length of the entire tooth row from the width of the tooth, and then using a regression designed for estimating total length from the length of the tooth row (Lowry et al. 2009, see also Newbrey et al. 2013/in press, and this list of measurements of two cast megalodon dentitions→. That way differences in proportions within the dentition are reduced to the impact of individual, not interspecific, variation, and the resulting estimate assumes them to follow the same trend in terms of relative jaw size.
Even though the literature seemingly suggests significantly less, I went with an interdental spacing of ~15% in addition to the summed tooth widths, because it corresponds to what one can roughly measure in the most widely spaced pictures of great white shark jaws and it is only fair towards the tested hypothesis to use the most optimistic reasonable regression).
Coincidentally this gives us the same mean size estimate for the three positions, 16.8m. Quite funny actually.

It is an intriguing side note (even though it’s another mere coincidence, it pretty much rules out the whole "these figures are different from the official ones" line of criticism I sometimes get, because these are actually the exact figures that were published) that this size estimate also coincides with the highest one estimated by Gottfried et al. 1996 that was deemed reliable, as well as with the biggest specimen from the nursery described by Pimiento et al. (2010). This was hence the highest proper size estimate in the literature for almost two decades. Even now, only less than 3% of all megalodon specimens in Pimiento & Balk’s dataset record the species reaching or exceeding this size, and at most by about 7%, so I find it quite save to assume that this can be considered representative of a very large megalodon.

Length estimates are of course only half of the equation. The most determining factor (though unfortunately highly prone to fluctuations) of the animal’s biology is its body mass. And sure enough, estimating body mass from total length in extant sharks has received almost unparalleled attention as far as size estimates go.
The following is a graph showing 6  [!] different regression equations between total length and body mass for the extant white shark, C. carcharias. In order to avoid biases I’ve applied all of them and marked the mean, maximum and minimum estimates:
Megmass - by theropod1
As apparent from the exponents, most of these studies found positively allometric growth in terms of body mass, i.e. larger sharks get bulkier. From this we can actually estimate the change in body shape, since the component of the weight difference not explained by isometry is necessarily due to a thicker body, i.e. a bigger crosssection. A 5m Great White shark is predicted to mass 1196kg, scaled up to 14m by isometry alone that’s 26255kg, but a 14m shark is actually predicted to mass 29255 (strange coincidence, but not evidence for the existence of the flying spaghetti monster). That’s a difference of 11.4%, so we know a 14m shark has a body crosssection 11.4% larger, since length is out of the picture having already been accounted for in both methods. All we need to do now is take the square root of that, giving us 5.6%, and we’ve got the percentage that it is deeper and wider respectively (assuming it didn’t get disproportionately bigger in one of these dimensions compared to the other, of course).

That is also what my reconstruction bases on, unimaginative as you may call it (since it’s the boring bulked-up great white you almost always see when it’s comes to restoring meg’s body shape), at least it bases on scientific principles. I’m certainly open to other possibilities with regard to its morphology, in the end we all have to accept it is almost completely speculative, it’s just that I have not yet seen any convincing arguments to suggest they are more likely than this (i.e. disproportionately elongated or compact sharks).

So as you can see, the average adult megalodon is predicted to be ~29t in mass, no more than 32t and no less than 26t, and the large specimen from Denmark is expected to be ~52t (within a range from 46 to 57t). The average of the entire population would be ~10t, similar to a very large bull orca (which is impressive enough considering that that average figure corresponds to what is usually a large sub-adult).
And yes, there are a few megalodons that realistically reached or exceeded the 18m-mark (at which length they’d be expected to weigh in at ~64t), and some exceptional fossils do seem to indicate lengths of ~20m (and probably ~89t). But their overall relevance is in no proportion to their size. Consider this; of the 544 teeth in Pimiento & Balk’s sample, none produced an estimate higher than 17.9m, so individuals significantly above that size are obviously too rare for much of a demographic impact. Unless, that is, there ends up being convincing proof that this is a result of some erraneous method, such as a consistent and pronounced sampling bias towards small specimens (very unlikely) or unreliable size estimates (more likely since I am by no means claiming the method always gives us realistic estimates, but currently it seems like if anything the systemic bias here is towards enlarging size estimates).

Most fossil organisms are represented by small samples, and it is likely that they are centered around the average and that "maximum size" remains unknown in virtually all of them. That’s because the likelihood of finding exceptionally large (or small) individuals is typically lower than finding normal-sized ones, and the small number of individuals known for most of them is not in favour of finding such exceptions.
So please guys, when you talk about body sizes, be a bit more precise, differentiate, and don’t mix average, large, small and maximum-sized specimens up all the time, because it does lead to totally unwarranted conclusions.
C. megalodon
is not an 18m shark, nor for that matter is there any species of 18m sharks. Only a species (possibly two if one includes Rhincodon) that occasionally gets that big. There is no species of 1t bear either, and sperm whales aren’t 24m long and don’t weigh 130t, occasional outsized specimens notwithstanding.
This species of shark was big, huge even. Any animal averaging 14m long and close to 30t is positively enormous. It’s nothing except sad that for some people, that just isn’t enough and they have to judge everything by the most extreme examples they can dig up anywhere.

PS: I do realize this looks like a rant, and honestly, it is. I’m sure we all have issues that annoy us, some more than others. That doesn’t mean I am not appropriately impressed by C. megalodon or anything like that, just that I think some people are overdoing it in that regard.
And I am absolutely open to change my mind should future (or presently undocumented *wink*wink*) discoveries or revolutionary new methods change this.

–––References:
    Bendix-Almgreen, Svend E. (1983): Carcharodon megalodon from the Upper Miocene of Denmark, with comments on elasmobranch tooth enameloid: coronoïn. Bulletin of the geological Society of Denmark, 32 pp. 1-32.
   Cailliet, Gregor M.; Natanson, Lisa J.; Welden, Bruce A.; Ebert, David A. (1985) Preliminary studies on the Age and Growth of the White Shark, Carcharodon carcharias, Using Vertebral Bands. Memoirs of the Southern California Academy of Sciences, 9 (Biology of the White Shark, a Symposium.) pp. 49-60.
   Casey, John G.; Pratt, Harold L. (1985) Distribution of the White Shark, Carcharodon carcharias, in the Western North Atlantic. Memoirs of the Southern California Academy of Sciences, 9 (Biology of the White Shark, a Symposium.), pp. 2-14.
   Compagno, Leonard J.V. (1984): Sharks of the World. An Annotated and Illustrated Catalogue of Shark Species Known to Date. Part 1 – Hexanchiformes to Lamniformes. FAO Fisheries Synopsis, 125 (4) pp. 1-249.
    Kallal, Robert J.; Godfrey, Stephen J.; Ortner, D. J. (2010): Bone Reactions on a Pliocene Cetacean Rib Indicate Short-Term Survival of Predation Event. International Journal of Osteoarchaeology, 22 (3), pp. 253-260.
    Kohler, Nancy E.; Casey, John G.; Turner, Patricia A. (1995): Length-Length and Length-Weight Relationships for 13 Shark Species from the Western North Atlantic. Fishery Bulletin, 93 pp. 412-418.
Lowry, Dayv; Castro, Andrey L. F. de; Mara, Kyle; Whitenack, Lisa B.; Delius, Bryan; Burgess, George H.; Motta, Philip: (2009): Determining shark size from forensic analysis of bite damage. Marine Biology, 156 pp. 2483-2492.
    McClain, Craig R.; Balk, Meghan A.; Benfield, Mark C.; Branch, Trevor A.; Chen, Catherine; Cosgrove, James; Dove, Alistair D.M.; Gaskins, Lindsay C.; Helm, Rebecca R.; Hochberg, Frederick G.; Lee, Frank B.; Marshall, Andrea; McMurray, Steven E.; Schanche, Caroline; Stone, Shane N.; Thaler, Andrew D. (2015): Sizing ocean giants: patterns of intraspecific size variation in marine megafauna. PeerJ, 3 (715) pp. 1-69.
    Mollet, Henry F.; Cailliet, Gregor M. (1996): Using Allometry to Predict Body Mass from Linear Measurements of the White Shark. In: Klimley, Peter A.; Ainley, David G.: Great White Sharks: the biology of Carcharodon carcharias. San Diego, pp. 81-89.
    Newbrey, Michael G.; Siverson, Mikael; Cook, Todd D.; Fotheringham, Allison M.; Sanchez, Rebecca L. (2013, in press): Vertebral morphology, dentition, age, growth, and ecology of the large lamniform shark Cardabiodon ricki. Acta Palaeontologica Polonica, in press, dx.doi.org/10.4202/app.2012.0047 pp. 1-65.
    Pimiento, Catalina; Balk, Meghan A. (2015): Body-size trends of the extinct giant shark Carcharocles megalodon: a deep-time perspective on marine apex predators. Paleobiology, 41 (3), pp. 479-490.
    Pimiento, Catalina; Ehret, Dana J.; MacFadden, Bruce J.; Hubbell, Gordon (2010): Ancient Nursery Area for the Extinct Giant Shark Megalodon from the Miocene of Panama. PLoS ONE, 5 (5), pp. 1-9.
    Tricas, Timothy C.; McCosker, John E. (1984): Predatory Behaviour of the White Shark (Carcharodon carcharias) with notes on its biology. Proceedings of the California Academy of Sciences, 43 (14), pp. 221-234.
Add a Comment:
 
:iconkirkseven:
kirkseven Featured By Owner Jul 30, 2016
hi theropod

do you know the estimated lengh for the smallest adult megalodon specimen

and is the 16.9 meter specimen on your chart the largest discovered specimen to date?
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:icontheropod1:
theropod1 Featured By Owner Jul 31, 2016  Student Traditional Artist
No and no. The problem is that there aren’t really any means to discern which specimens are adults. It’s just generally accepted to calculate the size when reaching maturity based on great white sharks (i.e. scaling up the ratio between the size when reaching adulthood and overall average size). Depending on whose figures you use, this could also give us somewhat varying results. 10.5m is the value published (Gottfried et al. 1996), and frequently used, for C. megalodon though. I didn’t come up with alternative figures because I didn’t want to spark yet more controversy with certain people, and because data on the size at which great whites mature aren’t that great themselves, but Gottfried et al.’s figures are fairly reasonable based on suggested minimum sizes for adult white sharks that I’ve seen.

No, it’s not the largest ever discovered. There are a few specimens larger than it. I chose this one because it was well-documented in a scientific paper and is hence a "confirmed" specimen, not some sort of large isolated tooth a private collector posted a picture of on the internet or something like that (which applies to the vast majority of specimens likely to be larger than this one). Also it’s a really large tooth with a limited range of possible placements in the dentition, so there’s less room for error than with some small tooth that’s both likely more variable and possibly less accurately placed.
But very roughly, I’d say 18m is a reasonable maximum size for normal intends and purposes, while a few outsized teeth I’ve encountered pictures of could suggest something close to 20m. But 16.8m is already a very large meg.
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:iconkirkseven:
kirkseven Featured By Owner Jul 31, 2016
Thank you.

I guess a 18 meter meglodon would be the equivalent of a 6.5 meter great White?
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:icontheropod1:
theropod1 Featured By Owner Jul 31, 2016  Student Traditional Artist
McClain et al. found a mean length of 3.81m for C. carcharias, while the mean length for C. megalodon estimated by Pimiento & Balk is 10.02m, i.e. meg is on average 2.63 times the size of the great white, but the size distribution of C. megalodon is left-skewed, while that of C. carcharias is normally distributed, so I guess that could be about right.
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:iconpcawesomeness:
PCAwesomeness Featured By Owner May 9, 2016
Nice!

That should discredit that loser shark a bit!
Reply
:icontheropod1:
theropod1 Featured By Owner May 11, 2016  Student Traditional Artist
Err, this doesn't "discredit" C. megalodon in the slightest, it just says things as they are. People running around making up fantasy stories about its size are the ones who discredit it.
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:iconpcawesomeness:
PCAwesomeness Featured By Owner May 11, 2016
Mmmhmmm.

You see, since this thing got owned by the great white shark, I pretty much lost all respect for it, so I apologize if my choice of words is a bit "uncool".
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:icontheropod1:
theropod1 Featured By Owner May 11, 2016  Student Traditional Artist
What do you mean by "got owned by the great white shark"?

Pointing out that there is some biased, sensationalist misinformation about its size has nothing to do with how much I like or respect the animal. It deserves everyone’s respect for being a very successful, long-lasting and gigantic apex predator, among the most impressive ever to exist. It’s not the overpowered, invincible 20m+ killing machine superior to everything else and in every regard. But such an animal simply didn’t exist outside fanboys’ minds.
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:iconpcawesomeness:
PCAwesomeness Featured By Owner May 11, 2016
When baleen whales started to decline, C.megalodon got wiped on the floor by giant sperm whales, orcas, and most of all, the powerful, pleasurable, indestructible... great white shark.

Also, a smaller (and significantly less overblown) shark, Hybodus, as well as horseshoe crabs of the genus Limulus, lasted longer. Where is their recognition?
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:icontheropod1:
theropod1 Featured By Owner May 11, 2016  Student Traditional Artist
That there are some species that lasted longer does in no way diminish that C. megalodon itself lasted for over 15Ma.
And afaik xiphosurids and hybodus DO get recognition for their longevity, if not for much else.

The heyday of giant sperm whales was many millions of years before the extinction of megatooth sharks, and in case you didn't notice, they are just as extinct as Megalodon now. Not that they weren't very serious competitors, but if anything they wiped the floor with each other. There is only a single pliocene Orcinus fossil, and it's not exactly an impressive animal (or species, from what we know). It seems that Orcinus started thriving later, after Carcharocles went extinct, and it certainly doesn't look like it wiped anything with the shark. Great white sharks whiping the floor with C. megalodon...mind explaining how? Megalodon had been coexisting with similar sharks for millions of years.
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:icontheropod1:
theropod1 Featured By Owner Edited May 13, 2016  Student Traditional Artist
I had already read it, it doesn't change any of the things I wrote. There’s no "wiping the floor" with anything here, whether competition was a major factor in its demise or not doesn’t make this creature any less awesome. It’s strange how people just don’t get that. Instead they either fashion it into some sort of "attack" on C. megalodon, like you, or inadvertedly reinforcing that argument by treating it like some sort of religious sacrilege, because neither seems to understand how competition works or that it doesn’t mean anybody is saying their beloved/hated animal is stronger or weaker.

Animals die out at some point, and 15+Ma is a lot longer than most species survive. Competition is a factor in most of these extinctions, if there was none, there would practically always be enough to eat, so sure, competition was likely a factor in C. megalodon’s extinction as well. That doesn’t diminish the animal itself in any way, both haters and fanboys should try to wrap their mind around that.
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(1 Reply)
:iconmegalotitan:
Megalotitan Featured By Owner Jan 15, 2016  Hobbyist Traditional Artist
I haven't read the whole thing, but I have a suggestion for the reconstruction: I do think that you should make the snout blunter.
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:icontheropod1:
theropod1 Featured By Owner Jan 16, 2016  Student Traditional Artist
Thanks. I didn't write about that point in there, but whether it should or should not be restored with a blunt snout tip remains a contentious issue. Godfried and colleagues restored it with such a morphology in 1996 (though that model was also more extremely proportioned in other regards, because its jaws are proportionally larger than a great white's) while more recently Kent restored it with a pointed nose for hydrodynamic reasons.
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:iconmegalotitan:
Megalotitan Featured By Owner Jan 16, 2016  Hobbyist Traditional Artist
Okay. Speaking of Megalodon, would it be possible that all teeth assigned to Megalodon would be actually different genera? Because I have a suspicion that all huge shark teeth assigned to Megalodon can be splitted into several species and/or genera.
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:icontheropod1:
theropod1 Featured By Owner Jan 17, 2016  Student Traditional Artist
Hmm, what do you mean by "all teeth". As in "to equal parts" or as in "some of them"?
It’s certainly possible that a few presumed megalodon teeth could be misidentified specimens from a related taxon like C. subauriculatus, especially since that taxon is both very large and converges on a similar morphology in its adult stages, and because most megalodon teeth have probably never been examined by a real scientist. However I don’t think this happens that frequently, otherwise it would throw up the question whether these species can be distinguished on the basis of their anatomical characteristics at all.

If you mean "C. megalodon as we know it doesn’t exist and consists of a mixture of various other sharks", then no, that can be confidently ruled out.
There are at least three complete associated dentitions that show the range of tooth morphology of this species, so we can infer that all those types of teeth belonged in the same animal’s jaws.
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:iconmegalotitan:
Megalotitan Featured By Owner Jan 17, 2016  Hobbyist Traditional Artist
I mean like most teeth can be referred to Megalodon itself, but other teeth can be referred to other species and/or genuses of sharks. But it seems you are right and I'm wrong.
My prehistoric shark knowledge is fairly poor, so I think I'm wrong most of the time.
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:icontheropod1:
theropod1 Featured By Owner Jan 20, 2016  Student Traditional Artist
I see how one could get that impression, it’s a valid point to question the phylogenetic affinities in something with a fossil record only composed of isolated teeth. The problem with this is that C. megalodon is actually known from more than  that, it’s merely not well publicised (or, for that matter, properly described in most cases).

For example the only scientific description of a complete associated megalodon dentition is in Japanese and there is no translation. There are other, even better specimens, but they are in private hands and the owners are content with letting them sit in their collections, only partially igured or described on inofficial websites, despite their scientific importance.
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:iconcenozoic-studios:
Cenozoic-Studios Featured By Owner Dec 1, 2015
That reconstruction of is hideous and horribly inaccurate. It's doesn't even reflect a real shark or ANY of the formulas you used. 

If you're going to use another scientists' formula to estimate size and weight you can't afterwards use your own depiction with different and clearly inaccurate proportions.
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:icontheropod1:
theropod1 Featured By Owner Edited Dec 1, 2015  Student Traditional Artist
I was going to write a sincere response but I had the sense of checking out your profile and posting history first. I think linking comments of yours such as this one make clear why.
Also I think everything has already been already explained elaborately enough for an intelligent being to understand it–and an objective being to admit it.
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:iconcenozoic-studios:
Cenozoic-Studios Featured By Owner Dec 1, 2015
I've been following your posts as well. You clearly have a bias against this shark

All my points were correct. Megalodon outlived Livyatan for millions of years. Livyatan DID have a thin lower jaw relative to the upper jaw if you paid attention to the dimensions of the skull. Livyatan Fed exclusively on medium sized whales from what they've gathered. So where's the issue with the comment?

Your problem is that you're creating unrealistically thin reconstructions with terrible proportions that have no basis in reality to go along with another scientist's formula. A real megalodon wouldn't have looked identical to a scaled up great white shark which is EXACTLY what you did here. You literally scaled up a great white shark taking 0 consideration in to the increase of bulk that a real megatooth shark would have had.
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:icontheropod1:
theropod1 Featured By Owner Dec 2, 2015  Student Traditional Artist
The issue with that comment is that it started with "lol bull shit on so many levels. Let me drop some knowledge on you real quick.". In fact, while it’s longer, it started out very similar to the zero-content troll comment you made here.

C.megalodon outlived Livyatan. Both myself and coherentsheaf are well aware of that, and it has no bearing on the accuracy of either of our drawings.

Livyatan had a narrower lower jaw than upper jaw. Many animals do (e.g. T. rex…), and this is not a limiting factor on its predatory potency, it actually helps the bite generate shear stresses.

Give me a source stating that Livyatan "Fed exclusively on medium sized whales".
There is no direct evidence whatsoever for its diet, ergo an artist is free to depict it doing anything biologically possible, and certainly without having someone make rude and unprofessional remarks because of it.
The only scientific note on its diet (from Lambert et al.’s description paper) is that it mostly fed on medium-sized baleen whales. That has nothing to do with it being inferior, it applies to megalodon too. The reason is that most baleen whales during the Miocene were mid-sized by modern standards.
Certainly two adult Livyatan hunting cooperatively would be physically capable of taking on a megalodon and winning, especially by ambush.

As far as I can tell, I don’t actually have a problem.
This megalodon is necessarily based on the proportions of a white shark, but its robusticity is consistent with the allometric scaling trends. There is literally no better data available.
Yes, I did take consideration to the increase of bulk that a megatooth shark would have had. This increase in bulk suggests that an 18m megalodon would be ~14.5% heavier than an isometrically scaled 5m great white shark of the same length, and accordingly 7% deeper and wider. If you measure the drawing, you’ll find that reflected there.
It’s not my fault that some people have unrealistic ideas in their heads as to what a real white shark looks like (possibly from watching too many bad cgi megalodons…).

Your problem is that you feel insulted as soon as megalodon isn’t depicted as an invincible hulk of a shark. But for all we know, it wasn’t, get over it.
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:iconcenozoic-studios:
More like you don't wish it to be depicted as an invincible hulk and do everything to get people to underrate it. 

I agree that two or more Livyatans may have been able to take on megalodon by surprise, just as Two Megalodons could kill a Livyatan under the right circumstances, but this is a giant raptorial sperm whale we're talking about, and giants don't operate in pods. There would be no benefit. This is even reflected in the modern world. If you look at female sperm whales, they remain in pods with their youngs but the bull sperm whales operate solitary. They only regroup to mate, respond to distress calls from pods, or other social behavior, but never to hunt cooperatively. This is because they're capable on their own and hunting in pods would be detrimental to their success. Livyatan similarly would most certainly have been the same in this regard.

A note on the drawing with 2 livyatans hunting a "megalodon". That picture was clearly drawn by a biased artist. The Livyatans lower jaw was depicted extremely robust contrary to the actual fossil, and the shark was puny, especially it's mouth that is supposed to have far greater bite radius than a livyatan at parity. This is clearly not reflected and the drawing is very flawed.

Your depiction of megalodon does not take inconsideration the increase in bulk despite your claims. So you have 1% bulk added to the the body, but where's the 900% missing from the caudal peduncle?

And what's up with that tiny head? Even after numerous jaw reconstructions since the first one in 1909, the common consensus is that the average mature megalodon could fit 5+ individuals in it's mouth. Your depiction can't even fit 2.

Using the great white shark as the basis of your scaling was your biggest mistake because everyone knows that Megalodon was NOT the extinct great white shark, and all fossil evidence indicates that. In fact the great white shark, for a time literally coexisted with Megalodon. There was almost 0 chances that megalodon would have been an exact clone of the great white shark with the 1% increased bulk as depicted by you. They had clearly different ancestries.

The other mistake you made was assuming that all the teeth were all anterior teeth of the shark, therefore leading you to believe that a majority of the population would have been 11m individuals. I bet you didn't even take in to consideration that they may have been smaller tooths that fell off a larger shark.

Megalodon thrived for 25 million years and surely the Cenozoic whale hunter did not look as ridiculous as you presented in your efforts to prove that at parity livyatan was heavier than megalodon which is also improbable, considering a 12 meter sperm whale is 16 tons and your proposed malnutriotioned megalodon at party was 29t. I don't believe, even if the bulk was increased dramatically to fit livyatan's build, that it's bulk would surpass or catch up, if hypothetically your proposed malnutritioned 12m, 29t estimate was correct.
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:icontheropod1:
theropod1 Featured By Owner Edited Dec 3, 2015  Student Traditional Artist
More like you don't wish it to be depicted as an invincible hulk
Absolutely! I don’t wish any animal to be depicted in a hyperbolic, inaccurate fashion!

giants don't operate in pods[…]This is because they're capable on their own and hunting in pods would be detrimental to their success.
Sperm whales are suction feeding, specialized, deep-diving teuthivores. They aren’t a viable ecological analogy for Livyatan. That bull sperm whales wouldn’t benefit from hunting cooperatively for squid that’s 1/100th it’s own size doesn’t mean another animal its size couldn’t benefit from it, especially if it went after a large and dangerous prey.

Orcas do benefit markedly from pod hunting, even when they go after seals or penguins, and they certainly use it to good effect when attacking larger whales (see for example Pitman et al. 2001).
I’m not saying that Livyatan must have hunted in pods, what I’m saying is that if you personally disagree with that notion you should be polite about it and not make it look as if your opinion was a fact, or behave like a troll once someone disagrees.

A note on the drawing with 2 livyatans hunting a "megalodon". That picture was clearly drawn by a biased artist.
It was drawn by one of the two or three least biased people I know.

The Livyatans lower jaw was depicted extremely robust contrary to the actual fossil, and the shark was puny, especially it's mouth that is supposed to have far greater bite radius than a livyatan at parity. This is clearly not reflected and the drawing is very flawed.
It’s as if every single time I see someone claim something like that about a drawing they haven’t actually done any research to support their claim.

First of all, who sais they were at parity? The artist stated in the comments that the depicted megatooth shark corresponded to a ~10m individual ("median extrapolated length from a recent study by Piemento et al."). A shark that size would be expected to have a total upper tooth-row length of ~1.69m (Lowry et al. 2009) and an upper jaw circumference of 198cm (following Kent’s 1999 assumption that the tooth-free space adds 17%). Assuming the toothrow approximates a half-circle, the corresponding anteroposterior length of the jaw would be a little over 0.6m. That seems quite right, if anything the depicted shark is actually a little bigger than that.

Secondly, Megalodon is not supposedd to have a greater bite radius at parity, for tthe simple reason that Livyatan doessn't have such a thing as a bite radius. The term doesn't make the slightest sense for something not at leasr roughly circular. In a jaw the shape of Livyatan's, what do you define as the radius? Length? By that metric,, it's far larger than megalodon, actually larger than the biggest megalodons. Half the width? By that measure it's probably smaller, yes. You are comparing apples and oranges here.

Your depiction of megalodon does not take inconsideration the increase in bulk despite your claims. So you have 1% bulk added to the the body, but where's the 900% missing from the caudal peduncle?
They only exist in your head, and as I already wrote I added over 14% in bulk, and that’s exactly what the only objective data that have been put forth so far suggest. Can’t you read?

And what's up with that tiny head? Even after numerous jaw reconstructions since the first one in 1909, the common consensus is that the average mature megalodon could fit 5+ individuals in it's mouth. Your depiction can't even fit 2.
Lol, consensus?
Show me the paper that "consensus" was established in then, and the various papers that have agreed with it.

The average mature megalodon is about 14m long (data from Pimiento et al. 2015, confer the average megalodon in general, which coherentsheaf stated was similar in size to the one in his drawing, which is 10m long), that corresponds to an upper tooth-row length of ~237cm and a total upper jaw perimeter of 278cm.
Assuming, again, that it was roughly the shape of a half-circle (remember that that’s a rough approximation), in a straight, line measured parallel to the anterioposterior axis, the jaw would be 89cm long and about twice that width (177cm).
The lower jaw would be somewhat smaller than that (tooth-row length predicted to be 183cm), so that means the entire jaw’s height, even at an exaggerated gape, will be well below 2m–unless the jaw was relatively narrower and thinner, in which case it could be taller, but would also be more constricted in terms of width.
So you think those 5 people are supposed to stand side by side on 1.8m of jaw width (which is a little less than the estimated greatest skull width of the Livyatan holotype at 197 btw)?

It’s not my depiction that has a tiny head, it’s you who is accustomed to seeing 3m megalodon jaws, which, if they existed at all, would only belong to the very largest specimens.

Using the great white shark as the basis of your scaling was your biggest mistake because everyone knows that Megalodon was NOT the extinct great white shark, and all fossil evidence indicates that. In fact the great white shark, for a time literally coexisted with Megalodon.
I know all that, it has no bearing on the fact that it’s the best analogue. If you think it isn’t, name me a better one. You’d like a megalodon depicted based on a whale shark, perhaps? Or on a basking shark?

There was almost 0 chances that megalodon would have been an exact clone of the great white shark with the 1% increased bulk as depicted by you. They had clearly different ancestries.
Yes, they did. So how is it you feel so sure that it should be bulkier than the 15% bulkier great white that I depicted, and not less bulky? Because there’s at least an equal chance that it would be less bulky than predicted by great white scaling equations, you know? Yet you only focus on your fantasies of it being even more robust than the only real data suggest.

The other mistake you made was assuming that all the teeth were all anterior teeth of the shark, therefore leading you to believe that a majority of the population would have been 11m individuals. I bet you didn't even take in to consideration that they may have been smaller tooths that fell off a larger shark
This just proves that you haven’t even read my posts, let alone the papers it bases on.
One of the studies I cite, the one the 14m adult average bases on, used a unique scaling equation for every tooth position (from the largest anterior teeth to the smallest posteriors), and used those on a sample of 544 megalodon teeth from all over the world. The average size they found was 10m. The average only counting individuals above 11.8m was 14m.

The other method I used based on an tooth that was presumably an anterior lateral (L1-L3). I extrapolated the summed width of all teeth based on the size of that tooth for each of the possible positions and used the results to estimate total length based on Lowry et al.’s formula for estimating total length from the length of the tooth row. Then I took the mean of the results, which was 16.8m.

You should really make it a habit to read more thoroughly before criticising something, then I wouldn’t have had to repeat it. It seems like all you really did was look at the images, not even reading the caption, and taking one clance at the graph and dismissing it because it seemed too complicated for you. That’s not science, it’s childish behaviour. If you can’t comprehend what someone did, be quiet and try to understand, or ask. Don’t act as if you could tell them they didn’t do it right when you don’t even know what they did.

Megalodon thrived for 25 million years and surely the Cenozoic whale hunter did not look as ridiculous as you presented in your efforts to prove that at parity livyatan was heavier than megalodon which is also improbable, considering a 12 meter sperm whale is 16 tons and your proposed malnutriotioned megalodon at party was 29t. I don't believe, even if the bulk was increased dramatically to fit livyatan's build, that it's bulk would surpass or catch up, if hypothetically your proposed malnutritioned 12m, 29t estimate was correct.
…And more yet, you didn’t even bother to read the text that’s IN THE F***ING image itself, otherwise you’d know my "proposed malnutriotioned megalodon" is 14m long. And had you read the rest of my very elaborate, very easy to follow explanation, you might have been able to notice that being ~29t at that length it’s almost 12% heavier than it would be if it was just an upscaled great white (which would mass only ~26t).

––Refs:
Kent, Bretton W. (1999): Speculations about the Size and Ecology of the Extinct Lamnoid Shark, Parotodus benedeni (le Hon). The Mosasaur, 6 pp. 11-15.
Lowry, Dayv; Castro, Andrey L. F. de; Mara, Kyle; Whitenack, Lisa B.; Delius, Bryan; Burgess, George H.; Motta, Philip: (2009): Determining shark size from forensic analysis of bite damage. Marine Biology, 156 pp. 2483-2492.
Pimiento, Catalina; Balk, Meghan A. (2015): Body-size trends of the extinct giant shark Carcharocles megalodon: a deep-time perspective on marine apex predators. Paleobiology, 41 (3) pp. 479-490.
Pitman, Robert L.; Ballance, Lisa T.; Mesnick, Sarah I.; Chivers, Susan J.: (2001): Killer Whale Predation on Sperm Whales: Observations and Implications. Marine Mammal Science, 3 (17) pp. 494-507.
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:iconcenozoic-studios:
Cenozoic-Studios Featured By Owner Dec 3, 2015
"Sperm whales are suction feeding, specialized, deep-diving teuthivores. They aren’t a viable ecological analogy for Livyatan. That bull sperm whales wouldn’t benefit from hunting cooperatively for squid that’s 1/100th it’s own size doesn’t mean another animal its size couldn’t benefit from it, especially if it went after a large and dangerous prey. Orcas do benefit markedly from pod hunting, even when they go after seals or penguins, and they certainly use it to good effect when attacking larger whales"

Because the White Shark is the greatest analogy for Megalodon? It's strange that you think a suction feeding sperm whale is not a good analogy for Livyatan while you're absolutely certain a seal eating opportunistic wimp of a shark is the perfect analogy for an experienced whale killing megatooth shark.

Big dolphins are not a good analogy for their behavior. Let's not forget that not every orca is a 10m bull, just as not every Meg is a 20 meter giant. The average individual is 5-7 m, far smaller than livyatan. Hunting in pods would actually benefit them because they don't have the weaponry or size to take out something like a whale.

"doesn’t mean another animal its size couldn’t benefit from it, especially if it went after a large and dangerous prey."

The only competition I imagine livyatan would have are other toothed whales, none of them would pose great danger. Other than C. Megalodon of course. But other than that there was absolutely 0 reason a bull livyatan would operate in a pod for reasons other than mating. These are not dolphins. At an average size of 6meters, the pod forming orcas needed to form pod to take out 10+meter whales. Livyatan had the dentition and size that orca lacks to kill whales on their own.

"It’s not my depiction that has a tiny head, it’s you who is accustomed to seeing 3m megalodon jaws, which, if they existed at all, would only belong to the very largest specimens."

It's definitely your depiction. Compare it to every single scientific depiction of megalodon.

"So you think those 5 people are supposed to stand side by side on 1.8m of jaw width (which is a little less than the estimated greatest skull width of the Livyatan holotype at 197 btw)?"

In a rush and don't have the time to confirm your measurements, which I will do so later. But I do believe so actually. Livyatan's skull was longer yes but only 2 meters of the entire skull were part of the lower mandible. And it's gape was very limited. At most only 1 persons can fit inside at a time. Megalodon even at 14meters could fit 3+ people, having the advantage of thrusting jaws, higher gape, and bigger bite radius.

"Yes, they did. So how is it you feel so sure that it should be bulkier than the 15% bulkier great white that I depicted, and not less bulky? Because there’s at least an equal chance that it would be less bulky than predicted by great white scaling equations, you know? Yet you only focus on your fantasies of it being even more robust than the only real data suggest."

Because its illogical. Look at their teeth at parity. Meg has bulkier teeth. That's no way to estimate an animals bulk yes, but consider this. A giant shark that constantly needed to hunt can't have a peduncle like that, I doubt it would even be able to swim 5mph with that. Megalodon almost certainly needed to have bulk in the peduncle to compensate it's gigantic size and raptorial lifestyle.

And why are you so certain that it looked exactly like a great white shark with 1.5% bulk in the body and 0% in the peduncle? The Great white shark lived with megalodon. I've heard of convergent evolution but they had different ancestries. Megalodon is part of the megatoothed sharks which were far more impressive hunters than the seal eating Carcharodon carcharias, which again was swimming with Meg, therefore throwing off your entire argument because evolution wouldn't let that happen from two clearly different ancestries.

"They only exist in your head, and as I already wrote I added over 14% in bulk, and that’s exactly what the only objective data that have been put forth so far suggest. Can’t you read?"

If they only exist in my head, then explain why Gottfried and every other scientifically plausible reconstruction of Megalodon has it. And why you decided to stray from the rest of the scientific community and create a malnutriotioned great white shark with 0% increased peduncle from proportions of a seal eating shark that lived with Meg. They all took in consideration the obvious fact that a giant shark that hunted fast active whales on a daily basis needed a strong propulsion system. Why is this so hard to grasp?
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:icontheropod1:
theropod1 Featured By Owner Edited Dec 3, 2015  Student Traditional Artist
Because the White Shark is the greatest analogy for Megalodon?
Once again, if you know a better one, enlighten me.

It's strange that you think a suction feeding sperm whale is not a good analogy for Livyatan while you're absolutely certain a seal eating opportunistic wimp of a shark is the perfect analogy for an experienced whale killing megatooth shark.
The seal-eating opportunistic wimp happens to be one of the, probably the most macropredatory shark. "Those seals" (assuming that you are referring to sea lions) aren’t that small compared to the relative size of the average cetothere as compared to C. megalodon, not to mention great whites do take on far larger prey including elephant seal, young right whales, beaked whales etc. etc.

You are seriously comparing the ecological analogy of a teuthophagous suction feeder to that of the largest extand macropredatory chondrichthyan to C. megalodon? There isn’t even a comparison here. C. carcharodon isn’t only the best analogue there is (again, name me a better one for Frak’s sake if you think there is one!), its also a far better ecological analogue for C. megalodon than P. macrocephalus is for L. melvillei. Like it or not, the latter’s modern ecological analogues are macroraptorial delphinids, whether Livyatan hunted in pods notwithstanding (I don’t have strong feelings about that issue itself, we might never know, and it isn’t even a question of exclusively solitary vs exclusively social hunter).
That’s not my invention, the analogy was made by Lambert et al. at the time they first described it.

Big dolphins are not a good analogy for their behavior.
They are the best there is. They and Livyatan are both raptorial predators, they both go/went after large prey, there are clear parallels in their tooth and jaw morphology. Again, not my invention, read the description paper if you don’t believe me. Physeter is a specialized deep-sea predator adapted for suction feeding and commonly lacking a functional dentition, that preys on animals orders of magnitude smaller than itself. There’s no reason its ecology should have anything to do with Livyatan, while there’s every reason to assume that of raptorial delphinids does.

Let's not forget that not every orca is a 10m bull, just as not every Meg is a 20 meter giant. The average individual is 5-7 m, far smaller than livyatan. Hunting in pods would actually benefit them because they don't have the weaponry or size to take out something like a whale.
That has nothing to do with it, a 6m orca would still have very little difficulty dispatching a penguin on its own–yet they hunt them in pods. Even orca populations that exclusively eat fish hunt socially and benefit from it, as do orcas hunting small seals. Pod hunting behaviour is not restricted to prey items that would be challenging or dangerous prey for a single orca.
And I’ll wager it’s probably your opinion that a lone Livyatan wouldn’t be able to accomplish the feat shown in coherentsheaf’s drawing, so this in itself would be a reason worth hunting cooperatively by your logic.

It's definitely your depiction. Compare it to every single scientific depiction of megalodon.
I’m pretty sure you’ve seen exactly one of them in your entire life, probably not even looked at it properly (let alone the underlying research, to check under what conditions the reconstruction applies), and if you would bother reading what I wrote you’d know why mine looks different than Gottfried et al.’s skeletal. Had I relied on their methods, my megalodon would be quite a bit shorter. Yes, with proportionately bigger, more massive jaws, but not larger jaws in absolute terms.

But I do believe so actually.
Well, good for you, but I don’t care. You claimed it was consensus, so prove it.
As far as I know there is no such thing as a scientific consensus on how many people fitted in C. megalodon’s mouth, much less how that compared to Livyatan (whose actual gape you don’t even know, but odontocetes are seamingly less gape-limited than sometimes thought, judging by the Pitman et al. account I posted in my last post).

The average megalodon’s jaws do not dwarf those of Livyatan at all, as you’d have us believe, in fact they are only differently shaped with Livyatan’s jaws being considerably longer but narrower.

Because its illogical. Look at their teeth at parity. Meg has bulkier teeth.
First you’ll have to define parity, because this does not apply to an estimate based on jaw perimeter (where its jaws are scaled to the same size, and the teeth are actually proportionately shorter).

That's no way to estimate an animals bulk yes, but consider this. A giant shark that constantly needed to hunt can't have a peduncle like that
Says who and on the basis of what biomechanical analysis, and how come that neither do Cethorhinus and Rhincodon have exceptionately deep caudal peduncles, nor do large whales have exceptionately wide ones?

And why are you so certain that it looked exactly like a great white shark with 1.5% bulk in the body and 0% in the peduncle?
And why do you have such an annoying dislike for reading properly? It’s 115% as bulky as a great white of equal length, not 1.5%.
I am not certain of that at all. It’s both possible that it was bulkier and that it was less bulky. I’m assuming that it was that bulky because that is what the best and only available data suggest.

I've heard of convergent evolution but they had different ancestries.
Which are now extinct and have left behind no more than C. megalodon itself did. Convergent evolution is the best we have, and there are reasons why C. megalodon has been predominantly classified as a species of Carcharodon until recently. It has produced a very similar functional morphology, because the animal that has it is a mammalian-prey specialist as far as extant sharks go, and still one of the largest macropredators in the ocean only rivaled or exceeded by Orcinus and Pseudorca.

Megalodon is part of the megatoothed sharks which were far more impressive hunters than the seal eating Carcharodon carcharias, which again was swimming with Meg, therefore throwing off your entire argument because evolution wouldn't let that happen from two clearly different ancestries.
"My entire argument" is perfectly fine until you can show me a better analogy for reconstructing C. megalodon’s body shape. And no, your imagination doesn’t count as an analogue.

But let’s look at what your proposed alternative would be, just making everything we don’t know up based on our personal biases.
You: Oh hey, I think the great white is a bad model for C. megalodon, it doesn’t look bulky enough
Me: Can you give me a better way of reconstructing its body shape?
You: I’m just gonna make it up entirely in my head, who needs an analogue for unknown parts of its anatomy if we can simply make it the largest and bulkiest possible?
Me: You need to take the best analogue available, otherwise all you are doing is biased speculation.
You: But the great white is a whimpy seal-eater!
Me. If you think so, give me a better analogue then!
You: NO! I WONT! I just wanna keep making up the shape me feelings tell me is best!
And yet you criticise others, who have been far more true to the actual scientific data, based on what you personally have made up?

E.g. you believe (for questionable reasons, but that’s not the point) that Livyatan was an exclusively solitary hunter. Fair enough, maybe it was, maybe it wasn’t. The truth is actually that we can’t tell, so it’s valid to favour either. But what do you do then? You treat your opinion as a fact even though you have LITERALLY NOT A SINGLE PIECE OF EVIDENCE and call everything else BS, regardless of whether it was actually based on far more elaborate research than your opinion.
People having a different opinion isn’t what I’ve got a problem with, irrespective of how wrong or biased I think they are (because I don’t judge an opinion by what I think about the person who holds it, lucky you). You can believe C. megalodon was superior to Livyatan all you want, and for whatever reason you want, I don’t need you to agree with me. But my tolerance stops at the point were you start trying to force it on others by making a bunch of comments insulting people ("bull shit on so many levels") and then "informing" them of what you think is the one and only real truth ("Let me drop some knowledge on you real quick"), especially if in the process you reveal how little research you actually did to get to it.

If you don't like the drawing, you have three options. Make a civil, scientific argument against it, shut up, or make your own drawing according to your liking. You'll notice that most people will happily let you exercise your artistic freedom all you like here, without attacking you because your depiction isn't the most scientifically likely. I've seen all sorts of megalodon depictions that I find unrealistic, that doesn't mean I'm gonna start making "this is bullshit" comments likke you do.
What I did here was back up that depiction with scientific arguments. It's your choice, you are free to express your feelings as to what it rather looked like,, or you can make scientific arguments for it, but don't confuse one for the other.

If you aren’t able to behave like an adult about them, best just keep your opinions to yourself.
If they only exist in my head, then explain why Gottfried and every other scientifically plausible reconstruction of Megalodon has it.
These reconstructions may sometimes (for reasons already explained, or sometimes precisely for reasons not scientifically plausible) have somewhat deeper caudal peduncles than mine, but I guarantee you that outside of your imagination there is no shark in the world that has a caudal pedunkle 900% bulkier than the one I drew.

First of, increasing the depth of the caudal peduncle makes no sense. That may not have reached your ears yet, but unlike whales, sharks move their tails from side to side. As a consequence, that is the direction in which the caudal peduncle has to have its greatest second moment of area and the largest moment arms for muscle pull–based on this alone, the ideal shape is wide and shallow, not deep. Added to that, it is also optimized to be hydrodynamic, because the shark does not want to waste energy moving lots of water with the peduncle without a benefit for propulsion–having a large lateral surface area is what fins are for.
That is why large whales have very deep caudal peduncles (good leverage and good stiffness combined with small friction in dorsoventral direction), while large sharks have very wide ones (good leverage and good stiffness combined with small friction in lateral direction). Logical enough for you?
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:iconspinoinwonderland:
SpinoInWonderland Featured By Owner Dec 3, 2015
"More like you don't wish it to be depicted as an invincible hulk

Maybe because Megalodon ISN'T an invincible hulk? No animal is.



That picture was clearly drawn by a biased artist. The Livyatans lower jaw was depicted extremely robust contrary to the actual fossil, and the shark was puny, especially it's mouth that is supposed to have far greater bite radius than a livyatan at parity. This is clearly not reflected and the drawing is very flawed.

Because all megalodons were totally the same size and that none of them can be small individuals Hahahahaha. No.
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:iconcenozoic-studios:
Cenozoic-Studios Featured By Owner Dec 3, 2015
"Because all megalodons were totally the same size and that none of them can be small individuals"

You missed the part with the lower jaw. Point still stands
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:iconspinoinwonderland:
SpinoInWonderland Featured By Owner Dec 3, 2015
Livyatan's jaw wasn't the part I had issue with.
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:iconfragillimus335:
Fragillimus335 Featured By Owner Sep 23, 2015  Hobbyist General Artist
I'd call it an average note.  ;)
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:icontheropod1:
theropod1 Featured By Owner Edited Sep 24, 2015  Student Traditional Artist
In sum it’s probably an above average note, considering I dealt mostly with the larger part of the population…Wink/Razz
Sort of hard to avoid that unless you want to make people really angry at you.
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