Megalodon size

[Grey]

Awaiting for more specimen that's enough for now.

I've not made any body size based on direct sizing.

[theropod]

Fair enough then. I thought you intended do because you did that previously.

[Grey]

There's nothing that wrong at doing it though. Lowry et al. formula is of course more rigorous and from the litterature but after all a large number of size estimates in fossils species are based on direct sizing from smaller relatives or conspecifics, including numerous dinosaurs estimates. The main problem in megalodon remains that the extrapolation is far beyond the known data range as you know. Anyway awaiting for more data, info from the paleontologists I'm in contact with and hopefully perhaps one day the description of the peruvian skeleton(s) or elsewhre, I'm fine with these approx. but reasonnable figures.

I could also consider to have the opinion of Dr. Gordon Hubbell, who truly trust no actual method because of all their respective issues but all things considered, argues that the species may have reached at least 18 m.

[theropod]

Direct sizing is not ideal because it doesn’t make sure the used specimens are typical. Usually, one can certainly argue a random specimen is likely to have typical proportions, but the situation here is obviously more difficult because the specimen does not seem to have them.

A regression on the other hand captures many specimens of the species used for extrapolation and provides a mean value, you used one yourself for the jaw perimeter a few posts back. so that’s one issue less to worry about, and here that’s worth a mint.

All estimates for dinosaurs that I’m aware of base on much better remains and relatives much closer in size. Even Amphicoelias fragillimus is not near as far from the animals used as analogies as a large C. megalodon is from a great white.
Noone ever did the likes of estimating the size of Tyrannosaurus based on a tooth size comparison to Eotyrannus.

[Grey]

The specimen in my opinion has proportions in the normal range of the white shark at this size. I even remark that the upper teeth are just wide by any white shark standard, they fairly fit the size range of that specimen and are even somewhat large. So whatever the actual spacing in it I'm fine with even with I'd like another specimen. Based on the size of the boneclones individual, we need ~20 % added in Lowry's formula. Based on the mean jaw circumference from the graph for a 5.5 m GW, we need ~28 %, fitting the graph but an overestimate based on Lowry (yeilding a ~5.70 m GW). Based on the 5.31 m GW, assuming it has the summed tooth width than in the boneclones individual, around 16 %, and that's probably an underestimate, the 5.31 m GW had most likely a slightly shorter summed tooth width than the 5.50 m individual. But it can be used too.


I use regressions and direct sizing depending the situation.

No one complains about that, I've precised how much larger is megalodon compared to its relative. But I've read accounts of very poorly preserved dinosaurs, pterosaurs and marine reptiles species evaluated in size from small isolated body parts. The problem with megalodon estimates is not restricted to megalodon.

[theropod]

But you have no evidence, you are just guessing that. And that yields you figures considerably greater than anything scientists have indicated, so it is an improbable assumption.
You are also assuming something not actually consistent with the jaw from boneclones itself, while there is a specimen that comes fairly close in Mollet’s plot, one that has a relatively small jaw perimeter for its size. It is parsimonous to assume this is the same specimen.

[Grey]

I'm not guessing anything, I use data from the graph (from Kent), boneclones and the respective size and jaws perimeter of similar-sized individuals. Scientists ? Only Kent gave a range, and it is not impossible he has confused it, even though I've never rejected what he indicates. Now that's you're assuming something you cannot prove that the boneclones individuals is the small mouth from the plot without the shadow of a hint.

[theropod]

Kent never gave a range, and others have hinted at the spacing between teeth as well, I have quoted them numerous times. Kallal et al. assumed the distance between adjacent tooth tips was very close to the width of the teeth. Newbrey et al. used slightly more than 4% in the lower jaw of Cardabiodon.

Anyhow, unless all these sources are wrong, and all great white shark jaws out there are completely inaccurate, it is this specimen that is the outlier, that’s a mathematical fact.

And all these are actually reasonable if you look at great white shark jaws, while your 16-28% are not.

It is far more likely that this is the specimen (which exists anyway!) with the relatively small mouth and the relatively large, but not astronomical spacing, comparable to the ones in the jaws of the specimen. A mere guess, that against better knowledge this specimen had an average overall dentition lenght for its size and that the resulting spacing would also be average does not overthrow this. Period.

An actual basis would be required to cast serious doubts on it.

If there was only this dentition and nothing else, I’d accept it as typical without question. Since all the other data are in disagreement with that assumption, I do not accept it.

[Grey]

Kent gave you a range for GW. It is not impossible that he made some confusion. Your calculation from Newbrey is rather dubious. Kallal et al. is clearly a minimum assumed spacing.

Mines are not realistic ? You're funny.



That's some small spacing right ? Epic sarcasm.

Kent said me his old professor said him "LET THE DATA SPEAK". That's what I've done. Mines are deduced from the mean figure of the graph (from KENT) and two very similar sized GW. Not even mentioning that boneclones specimen was revised itself at a more modest measurement of 5.50 m. So it was originally even smaller mouthed when estimated by Hubbell at 5.9 m ?

Content ? I'm not a damn fanboy, I'm just fair with the stuff at hand.

Your argument that it is an outlier would be right if you had another summed width from another individual. But you don't. You're just assuming it because this does not please what Kent indicated you, without retaining that he can have confused the data himself, or not gave the precise range. So give me a break please.

A 5.5 m GW has on average a ~110 cm upper jaw circumference based on Kent's graph, which means that whatever the exact jaw circumference of the GW from boneclones, on a statistical basis it fits this mean figure.

And that's just so funny how much you use Kent's information as written in stone, whereas you have all the time spit on the quotes I reported from him while debatting.
Just as it is so funny how much you argue this GW is an outlier, an abnormally proportioned individual whereas you all the time argue that the first specimen at hand is almost necessarily an average individual. Your obsession with average figures doesn't apply, that's weird.

You're back as an horrible unhonest debatter. I'll keep my findings from now and not even try to discuss with a so much biased guy.

[theropod]

A 5.5m great white has an average toothrow lenght of ~926mm (there’s an actual equation that tells us precisely that, you don’t even have to rearrange it!), that is basically what you have calculated earlier although without using the toothrow lenght itself, so what’s the point?

Now, here we have plenty of evidence suggesting that neither did the boneclones specimen have a dentition actually that long, nor did it correspond to the norm in terms of tooth spacing, and all you responded to that evidence were the following arguments, quoted

• "It is not impossible that he made some confusion." (Well, now please tell me why this is not just "not impossible", but also more likely than that he was perfectly correct. It is possible that the boneclones specimen is the one with the ~98cm jaw perimeter and ~84cm toothrow lenght. Considering the below, that’s even probable.)
• "Your calculation from Newbrey is rather dubious." (Odd enough, my dubious calculation is much more consistent with other sources [but I presume those are all wrong according to you] than yours and you did not give the hint of a hint why it shouldn’t be. Point out my mathematical flaw and I will correct it happily, otherwise, it’s correct until falsified!)
• "Kallal et al. is clearly a minimum assumed spacing." (Where exactly did they state that? It was a generalised statement about lamniform tooth spacing, that couldn’t possibly have been more explicit, as exemplified by their subsequent assumption about tooth spacing.)
• "You know how I consider unreliable these measurements" (And one page later, you produce a picture as an argument, not even measuring it, and ignoring that the roots are embedded in the soft tissue!)

It is not even relevant at all in this case whather one (like me) argues that by default one should expect an individual to represent the norm of the species or not (like you have done, leading to lenghty discussions!). Because as soon as there are reasons why this individual is not normal, that’s obsolete anyway. Now as we see you actually do your own little insults aimed at me me justice in "spitting on" those reasons.

It is also particularly funny that you have repeatedly argued how my methods were too simplistic and how scientists had so much better and more advanced ones (i.e. why I was so wrong and you were so right), when those were not available to us, and now, as soon as they are and you decide their results, for reasons that I cannot comprehend, don’t please you, you suddenly consider those simplistic methods completely valid. I’d like to believe that it’s your opinion about the methods that has changed, and not that you don’t actually have one as long as the results fit your views.

Also, for someone who complained about discussions (Of course, that’s all my fault! ) with me being too long and pointless, it’s curious to be shaping something containing absolutely no novelty (what mean jaw perimeter a great white of a certain size has and what mean toothrow lenght results from that) into some major breakthrough for your understanding, to conclude how fine you are with your own findings.

You did the same that you did before, on a very indirect route full of potential error sources of course.

It doesn’t really matter whether what you do is calculating the estimated total lenght and comparing that to the actual lenght, whether you are calculating the estimated toothrow lenght and comparing that to the summed tooth width, or whether you are looking up the estimated jaw perimeter and calculating the estimated toothrow lenght from that, then comparing that to the summed tooth widths.

You are repackaging your old argument with nothing but statistical noise, to make it look as if it was new. What you have are not data, they aren’t even opinions or guesstimates. They are plainly improbable assumptions based on flawed logic. I am very sorry that questioning of your logic gets you so much on edge.

One would think that in a scientific discussion, it is presupposed that someone keeps at least one eye on whether what he is arguing is still related to the point, and ideally the other one on trying to stick with reality. And being supposedly well past the age of 12, one could also presuppose a certain degree of objectivity and the ability to separate between science and personal dislike for someone. Now, whenever you respond (and I know you will), I would be very pleased if I would not read ANYTHING concerning myself, be it negative or positive.
Focus completely on the argument.

EDIT: The below will not be answered until you have calmed down and apologised. For now, you are on my ignore list. That last post was just too childish and reminiscent of certain youtubers.

[Grey]

A 5.5m great white has an average toothrow lenght of ~926mm (there’s an actual equation that tells us precisely that, you don’t even have to rearrange it!), that is basically what you have calculated earlier although without using the toothrow lenght itself, so what’s the point?

Yes, what's the point ?

(Well, now please tell me why this is not just "not impossible", but also more likely than that he was perfectly correct.

The data from the graph, that a 5.5 m GW has on average a 110-112 cm jaw circumference suggests something greater than even 15 % of tooth spacing. On average, that's not meaning he's wrong, that's meaning he just POSSIBLY confused the maximum range of spacing. Or also that can mean that something is just wrong in the boneclones data.

It is possible that the boneclones specimen is the one with the ~98cm jaw perimeter and ~84cm toothrow lenght. Considering the below, that’s even probable.)

Never said the contrary, but it remains that we need to prove it instead of argue like you do. It is also possible that the toothrow length of that specimen can be longer than this. And this does not change that this still FITS the mean figure from the graph. On a statistical basis, this GW has a 110 cm jaw circumference. A 84 cm toothrow only yeilds in a 5.13 m GW, a gross underestimate for that individual which was already greatly revised from the original Hubbell's estimate. That does not fit because that toothrow is from a 5.5 m GW. The TL is the factor.

Probable ? You accuse me to make assumptions while you DO assumptions (that I do not strictly reject) ! You're marvellous.

(Odd enough, my dubious calculation is much more consistent with other sources [but I presume those are all wrong according to you] than yours and you did not give the hint of a hint why it shouldn’t be. Point out my mathematical flaw and I will correct it happily, otherwise, it’s correct until falsified!)

Little genius, have you not considered how strange represents only 1 mm of spacing between the LOWER teeth in the great white ? Lower dentition are QUITE spaced. Get it ? Why I say that there's something we may ignore in that calculation from Newbrey ? Your 4 % are dubious because from where Newbrey would bases this data ? 4 % of spacing in lamnids lower jaws ? Yeah right...No there's something unclear in that part.

(Where exactly did they state that? It was a generalised statement about lamniform tooth spacing, that couldn’t possibly have been more explicit, as exemplified by their subsequent assumption about tooth spacing.)

Hey wake up ! Did you ever observed upper anterior teeth in great whites ? Even when there is minimum spacing, there is STILL spacing. Kallal et al. just have suggested the absolute minimum spacing for predicting the size of the teeth and the size of the shark.

(And one page later, you produce a picture as an argument, not even measuring it, and ignoring that the roots are embedded in the soft tissue!)

No need to measure it, you just have to look and be honest at seeing how spaced the teeth are. What the roots have to do with this
You don't even see how so much spaced are the anterior in that GW ? You expect the roots to be 50 % wider than the crowns ? What incredible lack of honesty.

It is not even relevant at all in this case whather one (like me) argues that by default one should expect an individual to represent the norm of the species or not (like you have done, leading to lenghty discussions!). Because as soon as there are reasons why this individual is not normal, that’s obsolete anyway. Now as we see you actually do your own little insults aimed at me me justice in "spitting on" those reasons.

There's no reason to think this individual is abnormal. Even if it is really small mouthed it would not be "abnormal". That's really strange how much the only dentition from boneclones is abnormal ! The UA in that GW at 45 mm wide are already massive for any great white, and the spacing in the actual jaws is very obvious.
And yes you are so obsessed with average figures, even when there is no average data available at all you produce it, but only when they favor your agenda. Here we have an AVERAGE point as data but you ignore it. You just don't accept that this is also a possibility on a statistical basis. And I have to recall you, you little biased genius, that I've never rejected the other possibility you propose, no wonder, that's part of the problem in megalodon estimates, the error bars is based on this. But I have the mean figure as argument. But unhonest as you're, you don't want to include this.

Now as we see you actually do your own little insults aimed at me me justice in "spitting on" those reasons.

I insult you because you're a biased person, who follows his own agenda, is unable to question himself after the contributions of another person except if the contribution fits your personnal likings. Yes, I thought you had improved yourself, but you're just not a honest guy and if you really become a paleobiologist, I'm really afraid of the future credibility of that science.

It is also particularly funny that you have repeatedly argued how my methods were too simplistic and how scientists had so much better and more advanced ones (i.e. why I was so wrong and you were so right), when those were not available to us, and now, as soon as they are and you decide their results, for reasons that I cannot comprehend, don’t please you, you suddenly consider those simplistic methods completely valid. I’d like to believe that it’s your opinion about the methods that has changed, and not that you don’t actually have one as long as the results fit your views.

The results do not fit my view, they roughly fit the estimates Siverson made for the largest megalodons. I've not rejected what you propose, at all, but instead of playing between a 0 and 15 % of spacing, I prefer to use a mean figure, the mean figure in the Parotodus graph and the mean figure that may have used Newbrey, Siversson and Kent for their respective works. I use scientific data you joke. That's not "fiting my view"., I'm FAR more objective, neutral, modest and honest than you, especially in that field.

Also, for someone who complained about discussions (Of course, that’s all my fault! ) with me being too long and pointless, it’s curious to be shaping something containing absolutely no novelty (what mean jaw perimeter a great white of a certain size has and what mean toothrow lenght results from that) into some major breakthrough for your understanding, to conclude how fine you are with your own findings.

Indeed your fault, you have an incredible talent to transform interesting discussions in boring debates. I've almost never any pleasure reading you, your conception of all of this is just lame. Your lines are long, boring, it needs a great motivation to respond them. Your professors may fall asleep when reading your copies.

I have a the mean jaws circumference of 5.5 m GW+I have the summed tooth width of one 5.5m individual=I can LEGITIMATELY make a figured deduction from these datas. And I'm welcome to any other details from other GW. If that does not please you, then bite me.

It doesn’t really matter whether what you do is calculating the estimated total lenght and comparing that to the actual lenght, whether you are calculating the estimated toothrow lenght and comparing that to the summed tooth width, or whether you are looking up the estimated jaw perimeter and calculating the estimated toothrow lenght from that, then comparing that to the summed tooth widths.
You are repackaging your old argument with nothing but statistical noise, to make it look as if it was new. What you have are not data, they aren’t even opinions or guesstimates. They are plainly improbable assumptions based on flawed logic. I am very sorry that questioning of your logic gets you so much on edge.

Statistic just matters, a 5.5 m GW has on average a 110 cm upper jaw circumference. So either in the absence of another data or not, I can fairly use this summed width from a 5.5 m GW at boneclones. That assumption is reasonnable as it enters the mean figure. Bite me.

One would think that in a scientific discussion, it is presupposed that someone keeps at least one eye on whether what he is arguing is still related to the point, and ideally the other one on trying to stick with reality. And being supposedly well past the age of 12, one could also presuppose a certain degree of objectivity and the ability to separate between science and personal dislike for someone. Now, whenever you respond (and I know you will), I would be very pleased if I would not read ANYTHING concerning myself, be it negative or positive.
Focus completely on the argument.

There's no scientific discussion with theropod, there's only boring discussions.

I've read the first discussions on the German board, nothing has changed ! "30 m Pliosaurs are hogwash !" "No they aren't !"...NEVER HONEST.

[creature386]

Apr 2, 2014 20:30:45 GMT 5 Grey said:

(And one page later, you produce a picture as an argument, not even measuring it, and ignoring that the roots are embedded in the soft tissue!)

No need to measure it, you just have to look and be honest at seeing how spaced the teeth are. What the roots have to do with this
You don't even see how so much spaced are the anterior in that GW ? You expect the roots to be 50 % wider than the crowns ? What incredible lack of honesty.

The roots have something to do with it because their width is included in most tooth width figures you read.
It is possible to see the roots in your picture and they are a lot wider than the crowns.

[Grey]

Apr 2, 2014 20:47:29 GMT 5 creature386 said:

Apr 2, 2014 20:30:45 GMT 5 Grey said:

No need to measure it, you just have to look and be honest at seeing how spaced the teeth are. What the roots have to do with this
You don't even see how so much spaced are the anterior in that GW ? You expect the roots to be 50 % wider than the crowns ? What incredible lack of honesty.

The roots have something to do with it because their width is included in most tooth width figures you read.
It is possible to see the roots in your picture and they are a lot wider than the crowns.

No that's misleading because there is the shaped flesh which seemingly increases the size of the root, just look at complete teeth out of the flesh, roots are not that massive either, and we can still see here that there is some clear spacing between the roots.

[theropod]

And→ this→ is→ the→ huge→ spacing→ between→ adjacent→ teeth→, roots that "very nearly abut"→ (all except the two A1s of course), all with markedly less spacing than the famous boneclones jaw→. Some touch, some have a little spacing in between, but it is slight.
As I explained, this has biomechanical reasons.

[Grey]

Apr 2, 2014 21:20:42 GMT 5 theropod said:

And→ this→ is the huge→ spacing→ between adjacent→ teeth→, roots that "very nearly abut"→ (all except the two A1s of course), all with markedly less spacing than the famous boneclones jaw→. Some touch, some have a little spacing in between, but it is slight.
As I explained, this has biomechanical reasons.

I see a clear spacing in all these dentitions. And this does not change at all my point, have you measured these spacing, the width of the teeth, the toothrow length, the perimeter in these jaws ? No.

Are they from juveniles or adults ? Of which size ?

Find a dentition with details from a GW of similar size then I have no problem to progress. In the mean time move on.