Theory on Megalodon size.

It's entirley possible, but haven't jaws been discovered? I still like the concept of the largest, most badass fish to ever live being almost 80 feet long.

@MrHappy, actually, there are bigger fish than Megalodon.

Whales, right? I do believe things like Liopleurodon and Icthiosaurs are classfied as warm blooded, but then again, I'm not sure. Good thing there are opinions, eh? You can think what you want, and I can think what I want.

@Mr. Happy,

Jaws of megalodon haven't been discovered yet. They were custom casts based off of Great White Shark jaws, although the jaws may have been closer to cookie cutter shark jaws.

Also I think whales are the largest swimming animal but not fish cuz they are mammals. Also, lio probably wasn't megalodon sized. While I think Megalodon was 45 ft tops, Lio in my opinion was 40 ft tops. The biggest fish was Leedsycthis I believe.

still, a 40 foot shark is impressive. My thoughts are it was 40-50 feet long, 50 being its max

Actually, there are bigger fish than megalodon

Here it is :

The Leedsichthys

@Carnosaur,

Oh believe me I know its still a giant shark, biggest shark to ever live. I was just saying it might not have been 60-70 ft shark. And I believe the same sizes as you.

@Elite Raptor,

I think I said Leedsycthis was bigger to Mr. Happy as well, such an awesome fish isn't it?:)

Yeah, You're right ! beside leedshyictis, the are also Dunkleosteus, even Xipachtinus ( maybe the xiphactinus is smaller, but it still amazing !)

A lot of hogwash on that thread.

First, there are rigorous publications works made by experts on megalodon, which are used in scientific litterature. There are various methods far more rigorous and serious than the one in the first post. Enamel height, tooth vertical height, crown height measurement, tooth width, jaws perimeter...All these studies yeild various results but globally indicate that largest megalodons exceeded 18 m, perhaps approaching 20 m 

Hence, geek fanboy guess does not count here. I mean, you really think bunch of scientists and sharks experts have not been interested in megalodon studies before you ?

And no, no fish appears larger than Carcharocles megalodon. The latest study on Leedsichthys indicate a largest individual at 55 feet TL and supports that as they got older they were still growing, implying they could reach a bit larger than this (the 55 ft specimen was about 40 years old at the time of its death). 

But Leedsichthys was likely more gracile than Carcharocles megalodon, so there's a great doubt it was heavier.

The total body mass for megalodon proposed in litterature is about 48-103 tonnes, based on the regression known in 75 various white sharks specimens at various life stage.

So sorry if that disturbs some but C. megalodon is most likely the biggest fish of all time (depending the very maximum size in Leedsichthys and Rhincodon), and the largest marine macro-predator in records. Only the Miocene coexisting L. melvillei, at 44-57 feet, enters the same class than Megalodon.

Yes, that shark was bigger than any marine reptile. Don't start with the Liopleurodon myth...bs. The largest pliosaur in record is Pliosaurus macromerus, estimated up to 13 m and 20 tonne (McHenry 2009).

S. sikanniensis was 21 m long and lightly built, thus unlikely as heavy as the lamniform shark.

So no offense, but I 'd advise a bit more of modesty and more research in the REAL scientific works.

Sorry if I sound rude but I really dislike people who aren't able to perform an inch of a research in the available published works about one subject. 

Oh, last thing, there is a megalodon skeleton found somewhere in South America. Not collected or officially announced at now for various reasons. But IT IS larger than 45 feet...

A bit of a scientific material, here's a list of the Megalodons individuals collected in the Gatun Formation. The Gatun Formation is particular in that it was a nursery for Megalodons, which explains a number of specimens collected (teeth) are of modest size. Under 10 m represents neonates and juveniles, between 10 and 14 m, young adult or subadult, and above 14 m definitive adults. Depiste the majority of young individuals, some adults individuals are very large, one reaching almost 18 m.

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One thing to note, is that the method of estimate used in this studys, Crown Height method, gives rather conservative estimates compared to others methods. Still, this shows some individuals reaching colossal proportions.

It's just his opinion Bro. If you don't like, too bad, it's his opinion. I don't agree with it, but I don't call people who's opinion I don't agree with BS.

...you do realize sharks are made of Cartilage right? no bones, whatsoever.  So the "they found a 'skeleton' that was longer then 45 feet" thing is BS.

The whole estimating length off of teeth, and nothing more has always been an issue with me. Teeth vary in size inside the mouth, generally growing smaller towards the back. Even in ,egalodon, they grow smaller as they go towards the sides of the jaws.

Some more scientific stuff can be found below. According to it, a 7 inch tooth would make the length of the shark 55 feet(16.7 meters) long. and those are the largest teeth found.

Megalodon..

A freak individual could very possibly get 18 meters long, but it wouldn't be a very common occurence.

Carnosaur, why are you talking about a subject you clearly not have studied ?

Cartilage, under particular conditions, can be beautifuly preserved, no matter the size of the skeleton. And I know the scientist behind this finding and I've seen private pictures of the shark, and yes, it's bigger than 45 feet.

Teeth grow smaller towards the back...Yes and ? That's perfectly the purpose of Shimada's method which allows to calculate the size of the shark from any tooth position within the jaws, the method used in the table I've posted in my last post. There are others methods. Whatever, stop to argue by guess. Pubished modern sizes for megalodon depends of the method and the size of the tooth. Gottfried estimated a conservative 16 m for a 168 mm upper anterior and a theoretical max of 20.3 m TL. Pimiento, using Shimada's method, found two 17 m specimen in Gatun, and one at 17.9 m. Mike Siversson, using total jaws perimeter with modern lamniforms as template, estimates that the largest megalodons approached 20 m.

Please, study the subject before arguing anything. I know what I'm talking about and have even access to unpublished yet stuff. 

That's not a matter of opinion but of rigorous approach.  And that's frustrating to bring serious material to posters who just don't care. The graph in my earlier post is from a 2013 publication. So a bit of respect and modesty please.

i edited my post. Give me the link to this study? FYI, i did study the subject, so don't tell me i didn't :)

Can you show me these two 17 meter animals? the study that estimated their length?

Respect is given to those who hand it out, mate. You blatently telling me i don't know anything and you know all is disrespectul.

A freak individual isn't at 18 m as there is a 17.9 m individual in the sample I've posted earlier from the specimens in the Gatun Formation. Estimate used with Shimada's method, which is a conservative method...

Stop to use your guess. There are palontologists who work on it, rigorous and tested methods have been made (Gottfried, Shimada, Jeremiah, jaws perimeter...).

I'm interested in seeing these studies as well, let's see a link. Carnosaur said it about respect.

"i edited my post. Give me the link to this study? FYI, i did study the subject, so don't tell me i didn't :)

Can you show me these two 17 meter animals? the study that estimated their length?

Respect is given to those who hand it out, mate. You blatently telling me i don't know anything and you know all is disrespectul."

Some links among others :

http://stri.si.edu/sites/publications/PDFs/STRI-W_Pimiento_et_al_2013_Sharks_and_Rays_from_Gatun.pdf

http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0010552#pone-0010552-g005

CHRONOCLINAL BODY SIZE INCREASE OF THE EXTINCT GIANT SHARK MEGALODON (CARCHARCOLES MEGALODON)
Pimiento, C., Balk, M., Catalina, Florida Museum of Natural History, Gainesville, FL, United States, 32611; BALK, Meghan, Univ of New Mexico, Albuquerque, NM, United States

Body size influences nearly every aspect of the biology of any organism, from their
ecology to their evolution. One of the most prevalent patterns of body size is the tendency
in many evolutionary lineages to become larger through time (i.e. Cope's Rule).
Paradoxically, larger sizes can confer both ecological benefits and extinction
susceptibility. Although Cope's Rule works at a macroevolutionary scale, microevolutionary trends in body size can help to better understand the causes and consequences of larger sizes. The extinct shark Carcharocles megalodon (Megalodon) is one of the largest marine top predators to have ever existed. Fossil evidence suggests that it lived from 16 to two million years ago, could reach up to 18 meters in length, and had a global distribution. Even though its maximum size is often reported, little is known about
its body size trends through time. A previous qualitative study suggested a static tooth size over time in
C. megalodon. Although tooth size has been considered a reasonable proxy for body size, this hypothesis was based on a limited sample size and likely missed subtle evolutionary changes that can only be detected using quantitative analyses. In this
study, we rigorously assess changes in C. megalodon body size over time. Accordingly, we developed a series of tooth measurements of various museum collections encompassing a wide temporal and geographic range. In contrast to previous studies, we
estimated the total length of each specimen, conducted high resolution statistical
analyses, and found an increase in size through time. This chronoclinal size pattern could
have resulted in a number of ecological adaptations that are associated with higher fitness
(e.g. defense against predation, predatory and mating success, resistance to climatic
variations, greater range of acceptable foods, extended longevity, etc.). Nevertheless, in
the long term, the ultimate gigantic size of C. megalodon could have resulted in a
corresponding number of issues (e.g. increased development time, greater requirement
for food, longer generation time, lower fecundity, etc.), making the species more
susceptible to extinction. The eventual extinction of C. megalodon
could have created new opportunities for other top marine predators to evolve, like the mo
dern lamnids. Our results advance the understanding of the evolution of
C. megalodon and can potentially explain macroevolutionary trends in the Carcharocles clade.

http://www.livescience.com/40920-megalodon-got-too-big-extinction.html?cmpid=514645

ufdc.ufl.edu/UFE0041399/00001/pdf

Two talks about the evolution and dominance of lamniforms sharks, including megalodon and remarks about its size ("mother of all predators") by Dr Mike Siversson : 

http://museum.wa.gov.au/explore/videos/rise-super-predatory-sharks

http://www.youtube.com/watch?v=e4p9EWuVxYQ

Plus, numerous stuff I can only share by mail, accumulated from years of discussions with various experts, including one researcher who indeed found an unofficial unpublished almost complete specimen in South America...

Yes, I know what I'm talking about.

The study about bite forces bases on the estimates of Mike Gottfried.

http://www.bio-nica.info/Biblioteca/Wroe2008GreatWhiteSharkBiteForce.pdf

Guys, I don't want to be direspectful but someone who has read few vague articles about it and made a loosely calculation on teeth he has never studied extensively, without consulting previous works, isn't someone I consider as serious.