Talk:Megalodon/Archive 1

Archive 1

Archive 2

Archive 3

Vandalism

I can't seem to find and therefore revert the vandalism on this page. Could one of the editors please do this? It's not on the page anywhere, but appears in the "Related Species" section. Please help!!! 67.189.211.114 02:24, 15 November 2007 (UTC)

The "Related Species" section is now actually situated in the Great White Shark article and not in this article. The "Taxonomy" section already deals with this case and now contains reliable information with proper inline references.

--LeGenD 12:23, 18 December 2007

http://www.enchantedlearning.com/subjects/sharks/glossary/Megalodon.shtml gives its extinction date as about 1.6 million years ago, which rather rules out a sighting in the 19th century... Evercat 21:05, 15 Mar 2004 (UTC)

• "EnchantedLearning.com" is hardly a definitive source, however. -asarkees

http://www.oceans.gov.au/norfanz/new2creatures.htm (2nd to last item on page) says that "This shark went extinct some time between one and 35 million years ago" which extends the time period give on the artile page.

Hey, can someone try to find a better picture than this? It's really not sufficient.

More on time of extinction

The given time frame (5 million to 10,000 years ago) is almost entirely incorrect. Usually this is put at 16 to 1.6 million years ago, and while there are possibly earlier records, palaeontologists are quite unanimous on the time of extinction. See this article for further information concerning more recent claims. Anshelm '77

Relationship to great white

Can someone find out from a proper authority exactly what is the current thinking on whether megalodon is a relative of the great white, or an example of convergent evolution? This article contradicts itself.

To be honest, I think the idea of classifying the Megalodon is a joke at this point. All we have are teeth which closely resemble a great white's (but much larger) and some bones whose form is seemingly ubiquitous among large, predatory sharks. How can this possibly lead to a full classification? How can scientists squibble over convergent evolution and lineage when there is so little evidence? Instead of jumping to conclusions, let's wait until the facts are in; ie, a more complete fossil of the fish is found. Leave the pseudoscience to pseudoscientists.

elasmo.com gives some good insight on the classification. --Anshelm '77 22:34, 7 August 2006 (UTC)

Exaggerated size

"The best-educated estimates of this creature's maximum size range from 55 to 69 feet (about 16–20 metres)" – actually, the typical modern length estimate is 12.2–13.7 m (40–45 ft); still larger than a Whale Shark. Even a more generous estimate by Compagno & Bowman in 1996 put the maximum at 15.9 m (52 ft), with a weight of some 43.5 t (48 sh t) – similar to the average weight of a Fin Whale, though taking both estimates into consideration (one for the average the other for maximum), the size of a Humpback Whale would be more an appropriate comparison. This just to give an idea how an immense creature we're dealing with – even according to the more conservative estimates. Using the length/weight ratio of the Compagno & Bowman estimate would put the weight of the lower estimates at 20–28 t (22–31 sh t), whereas a Great White Shark of the same length would weigh 16–23 t (18–25 sh t) with typical proportions – or 36 t (40 sh t) for the 15.9 m length. The longest measured megalodon tooth I've seen in scientific literature was 168 mm (6.6 in), though I've also seen a photo of a tooth reportedly 181 mm (7 1/8 in) long. The Reconstructing Megalodon link featured in the article provides most of the the size facts quite nicely. --Anshelm '77 20:38, 10 July 2006 (UTC)

Have implemented these dimensions. Can you dig out the references for them, please? - MPF 09:54, 7 August 2006 (UTC)

They're quite difficult to find, as most web pages on the subject could be described as fan pages. The Reconstructing Megalodon page is actually among the better ones, as it does cite its sources. I did find this page rather useful. For once, it gave a formula for determing size based on the teeth (0.96 × tooth length in cm − 0.22 = total length in m [note that the page said tooth length in mm, but that just doesn't work]). It didn't give a weight formula, but based on these two sites the length/weight ratio seems to bee c. 10.8 kg/m³ (where m³ is the cube of the length, not a unit of volume), compared to c. 9 kg/m³ for the great white shark. A length range of 12–16 m would indicate a weight range of 19–44 t (20–30 t is too small a range compared to that of the length). It should also be noted that the given length range is for various maximum size estimates, not a minimum–maximum range; much smaller teeth have been found, though estimates can't be based on just any tooth as the shark had varoius-sized teeth in its mouth.

That link also gave an answer to a question that had puzzled me for a while: if a great white shark's largest teeth are c. 1 % of its length, how did they come up with an estimate of 30 m for a similar species with its largest teeth at 16–17 cm? "In Dean's day, scientists still believed that the living Great White Shark reached up to 35 to 40 feet in length. So it was not unbelievable to estimate "Megatooth" reaching 100 to 120 feet in length when it had teeth three times the size of a Great White Shark.".

--Anshelm '77 00:03, 8 August 2006 (UTC)

This is a contested issue indeed. We can only speculate on the size of a Megalodon on the basis of its teeth but we have never see an actual living adult Megalodon to determine its full length, so no one is 100% perfect in determining the true size of a fully grown Megalodon.

The largest Great White Shark ever caught was a 21 feet long monster with 2-1/2 inch teeth. However there are reports of a 23 feet long White Shark caught as well.

Actually the largest undisputed Great White measured 5.83 m (19 ft 1½ in), and there's some indirect evidence for lengths of up to 6.6–6.8 m (c22 ft). Also, the parameters for determing one species's size are not necessarily applicable for another – especially if they're not closely related, which may be the case with Great Whie and Megalodon. --Anshelm '77 (talk) 18:27, 24 March 2008 (UTC)

Now, if we consider that Megalodon was very similar in structure and appearance to a White Shark and one of the largest Megalodon tooth yet found is 7-1/4 inch in size, then it is not difficult to predict the size of the shark (to which that tooth belongs) and thus that Shark would be over 60 feet in length.

There is a modern recontruction of a Megalodon Jaw (which is not disputed) and this Jaw contains one of the largest Megalodon teeth ever found and all those teeth are real. The size of this Jaw indicates a Shark of over 70 feet in length. This Jaw was constucted by a famous fossil hunter "Vito Bertucci" (also known as "Megalodon Man").

Here is a link: http://www.sharksteeth.com/Megalodon.htm#More

Additional Links: (largest Meg teeth)

Link 1: http://www.lowcountrygeologic.com/news.aspx

Link 2: http://megmawl.com/6inch.html (this link contains at-least three 7.0+ inch teeth for sale)

These huge teeth remind us that this shark could have grown well over 50 feet in length.

I suggest that the maximum size of Megalodon should be edited and put at 60+ feet.

--User: LeGenD 04:04, 6 October 2006 (UTC)

I'm not sure.....in some sharks the size of teeth can be very disproportionate compared to the size of the shark, the cookie cutter shark has the biggest teeth of all sharks in comparison to it's size, and is still a very small shark, and we know this because cookie cutter sharks are still alive, we can't compare this to megalodon because it's extinct, but if something similar is true (and there's no reason why it can't be) megalodon could be much larger than most estimates and the reverse is true that it could be much smaller.

The size of a predator is usually influenced by the size of its prey. Cookie Cutter shark has nothing to do with the case of Megalodon because Megalodon belongs to a different family of sharks and its diet was huge, suggesting the fact that Megalodon must be of considerable size to take on such a large prey.

Anyways! This case have already been solved with best possible information at hand in the main article. Hence further debate is not necessary.

--User: LeGenD 09:52, 11 September 2007 (UTC)

While I have strong reservations on the scientific validity of the sizes of Mr. Bertucci's reconstructions, I noted that two of the above links suggest that the largest C. megalodon tooth measures 194 mm (7 5/8 in). This is considerably more than the 168 mm offered by Compagno & Bowman, so perhaps it should be treated with caution. In any case, applying the formulas above to the 194 mm tooth yields in a length of 18.4 m (60 ft 5 in) and a weight of perhaps 67 tonnes (74 sh t). The heaviest verified Sperm Whale was a 18.1 m (59 ft 5 in) long male weighing 57 t (63 sh t), another one was 18.5 m (60 ft 9 in) long. --Anshelm '77 21:05, 25 September 2007 (UTC)

Actually several 7+ inch Meg tooth have been discovered after year 2000. Compagno and Bowman did not had access to these huge teeth during the time when they published their findings regarding Megalodon. So it is indeed safe to say that Megalodon could grow more then 16 m long. Anyways! You have indeed stated some valid points. --User:LeGenD 04:01, 2 October 2007 (UTC)

I certainly hope those teeth weren't measured like the one in the article's picture – the ruler is held inclined next to the tooth! Based on the picture I'd put the tooth's (vertical) length at c 166 mm (6.54 in – not to be taken too precisely). Not that I really doubt there are teeth of greater size than that mentioned by C & B, however, just as the aforementioned picture demonstrates, any measurement's scientific accuracy needs to be verified before making any conclusions: for example the difference between 168 and 194 mm is quite significant at 15.5 % in length and 54 % in volume (assuming identical proportions); therefore inaccurate – or exaggerated – measurements have a potential of yielding in greatly distorted results. Another matter is that as compelling as it may be to apply the C & B formula to larger teeth, perhaps no greater size should be given than what they came up with, when referring to their work. --Anshelm '77 14:31, 7 October 2007 (UTC)

You cannot deny the fact that some Meg teeth are indeed over 7 inch long. The size of the shark teeth are always measured in "slant" manner and not in terms of "height." The Meg tooth that "Vito" found is indeed "7.25 inch long in slant" and much bigger than what M.D. Gottfried had got in 1996. Hence the maximum size estimate of Megalodon cannot be fixed at 52 feet long. The latest evidence proves that Megalodon would grow bigger than 52 feet and we should always give priority to the latest available evidences. Hence it is indicated in the main article that the Megalodon could grow bigger than what scientists thought in 1996.

--User: LeGenD 02:34, 11 December 2007 (UTC)

If the measurements were taken in the same manner, then there's no problem. But it never hurts to be cautios with measurements taken by non-scientists, a good example can be found here: the longest Saltwater Crocodile skull was once thought to be 98 cm (38½ in) long, but it was later discovered that instead of measuring the skull from snout tip to occiput (back of the head of the upper jaw), they had measured it all the way to the back of the lower jaw, and the proper length of the skull was 73.3 cm (28⅞ in), shorter than the existing record of 76 cm (30 in). Very interesting to note that the maximum acquired by Jeremiah's method is similar to the one calculated by Compagno & Bowman's formula with the 194 mm tooth (18.2 m vs 18.4 m)! --Anshelm '77 (talk) 18:27, 24 March 2008 (UTC)

"In any case, applying the formulas above to the 194 mm tooth yields in a length of 18.4 m (60 ft 5 in) and a weight of perhaps 67 tonnes (74 sh t). The heaviest verified Sperm Whale was a 18.1 m (59 ft 5 in) long male weighing 57 t (63 sh t), another one was 18.5 m (60 ft 9 in) long." Actually, heaviest verified sperm whale was 21 meters long, 72 tons in weight. But there are also reports of 26 meters long ones and 24 meter long ones, those could weigh up to 100 tons at most, still much larger than megalodon. 64 tons megalodon? I hope we agree that Sperm whale per meter of length on average is quite heavier than Megalodon, to verify that, look at the structure of sperm whale and Great White for example, or pictures of megalodon for instance. Now, if 18 meters megalodon weighed 67 tons, then how much exactly could 18 meter sperm whales weigh? Should be at least 80-90 tons. But we do not see 90 tons 18 meters long whale. Also, megalodon preying on sperm whales? You mean juvenile right? If megalodon was indeed as big as you people claim, it would be possible for Sperm whale to ram one (it would be too slow to avoid sperm whale simply because of it's (shark's) size, it is simply biomechanics, something 18 meters long could not move very fast, simply because of resistance of water over large area, let alone manuevre in some manner) and since sperm whales make holes in wooden ships stoving them head on(!), it doesn't seem like Megalodon would stand a chance against a fully grown bull (those bump heads for females). Tooth marks matching those of Megalodon? The whale could be dead allready, and shark was feeding on carcass. Also, it could be another shark. Let us look at some suggestions of why megalodon is extinct: one says that large whales escaped to cold waters, where megalodon could not follow. But Sperm whales were always around in warm waters. Could it not prey on sperm whales then as claimed? Either it could not, or this theory of why megalodon is extinct seems to be flawed. Let us look at another theory of why megalodon is extinct: Orcas. Theory says that Orcas outcompeted Megalodon for prey and probably hunted it as well, seems pretty possible, after all, killer whales take down large whales. However, you do not see killer whales attacking fully grown sperm whale bulls, presumably, because those are too large and agressive. I am not saying that megalodon could not kill sperm whale, it could, but a small one, provided shark is ambushing from behind or side (otherwise it will be detected through echolocation and will be at disadvantage facing sperm whale's so-called "battering ram"). So, in a nutshell, size of megalodon in many sources is greatly exaggerated, with no solid evidence provided for such estimates, and there is no real evidence that really large whales were hunted by megalodon. —Preceding unsigned comment added by 99.231.50.118 (talk) 09:01, 9 December 2008 (UTC)

Please try to post relevant material in topics. As explained below, size has little impact on swimming prowess of marine animals. Large marine animals can swim fast (including large predatory sharks). And ramming a moving creature is a challenge because a moving creature can dodge the attack. Sharks are opportunistic predators. They generally tend to avoid getting in to long battles with prey and prefer to ambush them using stealthy approach or when the target is in vulnerable position. An argument can be made that Megalodon was a shark built for fighting large animals but even it was cautious when attacking large animals. Many ripped apart whale flippers and caudal bones have been found with bite marks caused by teeth of Megalodon, as even the teeth were often found lying near such remains. This indicates that Megalodon preferred to cripple a large prey early on during hunting process so that long brawls could be avoided later on and the target could be quickly finished. This shark was an ultimate killing machine and a true marvel of nature. As far as extinction theories are concerned, keep in mind that an "ICE AGE" occured during the late Pliocene after North America and South America joined and the oceanic circulation was fundamentally changed. During Ice Age, Ice sheets spread in all oceans and Ice also covers vast areas of land. Species which thrive in warm environments are doomed in such scenarios. This is why many species of WHALES and DOLPHINES also became extinct during the late Pliocene. Some species of whales that you see today are more recent as fossil records indicate. However some marine animals (including some whales) can live in both cold and warm environments. The Megalodon was destroyed due to changed oceanic circulation, cooling trend in waters which restricted its roaming and hunting space, drying up of warm water breeding areas and shortage of food. Thank the Ice Ages for all this. As far as Orcas are concerned, to date no evidence have been found which could suggest that it outcompeted Megalodon. Competition was never an issue for an APEX PREDATOR like Megalodon. The point is that Orcas can thrive in both warm and cold environments. Also most species of sharks in current times are endangered due to MAN and not due to competition or threat from Orcas. Modern age Sharks were doing fine in the oceans until humans took to the seas and saw them as a threat. So if these sharks could do well under the shadow of Orcas, the much more formidable Megalodon won't have a problem.

--User: LeGenD 12:34, 05 Jan 2008 (UTC)

I am in the middle of making ridiculous argument about size of sperm whale judging by it's teeth myself right now. Let's see if we can make ridiculous assumption like ratio between length of tooth and length of body, and weight of body.99.231.50.118 (talk) 01:45, 11 December 2008 (UTC)Pavel Golikov.

Megalodon and the Orca

Is this right? Where are the sources for Megalodon being meals for Orcas? Even if it is hypothetical.

I agree, this assertion needs a scholarly reference.

This theory is heavily flawed. Megalodon was a dominant predator in its time and it actually "fed" on Whales of various kinds. Megalodons were too large and vicious sharks to be attacked by any predator and let alone a pair of Orcas.

It is a different story when an 11 foot White Shark is attacked and killed by a 25+ footer Orca, but it is an entirely opposite situation when a 50+ foot Megalodon enters the scene.

And there is no evidence that Orcas even existed in the time of Megalodon.

--User: LeGenD 04:04, 6 October 2006 (UTC)

Megaladon died out only lesser than 1 Million year ago, and of course there were already orcas. I can also well imagine that they were a menance to eat least younger megalodons. But it souldn´t be forgotten that there were also other orca-sized and probably even pod-hunting macropredatory whales like Zygophyseter which coexisted whith Megalodon for a long time.

This is truly speculation because it all comes down to specific characteristics of a Megalodon. considering that any assumptions of its size, intelligence, shape, behavior, etc. are not definitive; it could very well be that orcas hunted them and vice versa. We'll never no for sure if they did or not because we have never seen Megalodons or observed them in their natural environment. -Justin Wozniak

Theory of Megalodon being dominant predator is heavily flawed I think. Where is the proof? Where is the proof of 50+ Megalodon? Largest reliable account is 50 foot. If we are always considering largest specimens, let's consider 150 tons sperm whale or a herd of 18 orcas, each weighing 10 tons. Do you know what will they do to Megalodon? Ripp it apart. Or you are going to argue here? Megalodon was UNDOUBLTELY a slow animal (if it is indeed as big as you guys claim) and if you calim it was fast, you will have to admit that it was smaller. Have any of you ever heard of biomechanics? You can be making ANY kinds of estimates of size of animal, but biomechanis specialists will tell you what is the maximum speed with which it can move under water. And guess what... a 40 ton animal simply can't be manueverable and fast like modern shark, water provides MUCH more resistance than air, and the bigger you are, the more resistance. Animal of that size is bound to be rather slow. You can argue with a lot of things, but not with PHYSICS. Henceforth, it is an easy prey for a pod of Orcas, which were known to attack much larger targets and prevail. Please get real. I understand some people here are obsessed with sharks, but please return to reality, Sharks have never been dominant animals, and they are very far from dominant now. Take a single Orca going offensive and killing a great white shark very easily. There is a damn video of that on Youtube, no point to argue. And we are talking about an oversized shark (undoubtely smaller than any big whale) and a POD! of Orcas. No chance. Megalodons were probably avoiding Orcas, much like every animals do this time and probably did back then. Plus, as for dominant predator, there is always Basilosaurus, which averaged 18 tons, but since we here like to press on the size and use maximum estimates, 30-35 meters specimen have been theorized. Those things were slender and long, with big jaws, definitely larger than Megalodon, and judging by it's body, more agile. And remains of sharks have been found inside Basilosaurus. Pavel Golkov.

Megalodon has been presumed to be a dominant predator because its teeth have been found in all the oceans of the world, which indicates wide-scale success for this species and fossil records also reveal that this species preyed upon the largest animals in the oceans (i.e. Whales) and only big and very powerful predators would be able to do that. The size of Megalodon is determined through several factors and in all of them, the physical characteristics of its teeth offer important clues and the largest tooth found so far indicates a 60+ feet size. Now as far as the speed of Megalodon is concerned, keep in mind that several factors will determine it. A) Cartilage skeleton aids buoyancy and reduces the impact of heavy weight on the cruising speed. B) The body characteristics and fins of Megalodon were built for high-speed cruising and reduced friction. The Orcas rule the oceans in these times because of very little competition. Not even Sperm Whales challenge them because they are better adopted to kill prey like Squids and small animals. Now as far as the Great White Shark is concerned, it is noticeably smaller and less powerful than the Orca. The Orca can exceed 25 feet in length and weigh more than 4 tons, while even the largest known Great White Sharks aren't that massive, so it is not a fair competition. And the Great White Shark. which was attacked by an Orca was not an adult individual. It was only 11 feet long, while its attacker was more than 23 feet long. So do you think that it was a fair contest?

And the jaws of an adult Megalodon was surely more massive than even that of a Basilosaurus. See the external links section for more clarification. Also, That 35 m long Basilosaurus specimen is false. Modern estimates of this animal place it in the 60 foot league, which is still very impressive.

--User: LeGenD 12:08, 2 June 2008 (UTC)

A little mistake in your post: It is PRESUMED that it was megalodon's teeth and it is PRESUMED the whale was not dead allready before Megalodon got to it. From that it is PRESUMED that megalodon hunted the whale, and in order for that last assumption to be made, it is PRESUMED Megalodon was large enough. A lot of assumptions. AS far as Megalodon's speed is concerned,... One word "BIOMECHANICS". Animal of the size of Megalodon can not move fast. Actually, what did you mean by fast? Rememeber those T-rex in Jurrasic park catching up with a car at 60 kph? After REAL acientists from university made an analysis, turned out it can hardly make 20 kph, a human would be able to outrun it. Here are some arguments in favor of T-rex being able to run fast: big steps, two legs (Ostrich is one of the fastest animals on earth, with two legs only, and T-rex had much more muscle on his legs) hence it could run very fast. That si speculation on teh same level you speculate about megalodon's speed. But, once again, BIOMECHANICS, SCIENCE tell us different story. And we can affirm nothing that they deny, eny nothing that they affirm :).

So according to you Megalodon was not a GIANT predatory shark and was predominantely a scavenger? Check this video clip to get an idea. The guy in that show answers most of the questions with some reasonable evidence. He showed a ripped apart portion of the pectoral fin of a whale, which was attacked by a giant Megalodon. He even compared the tooth of that Megalodon with that of a Great White Shark to give people an idea that how massive this predator was in real life. Megalodon teeth have been found lying close to chewed up remains of whales by paleontologists. An important thing to consider is that different teeth will leave different kinds of damage imprints on the bones. Shark teeth will leave cut marks in the shape of long lines on the bones. Additionally, it is not simply presumed that how large a Megalodon could grow. The Great White Shark is the closest thing we have to a Megalodon. So systematics used to calculate the size and weight of the Great White Shark have been slightly modified by some scientists to make them applicable to the Megalodon for calculating its size and weight. Also, it is important to know that what particular factors can influence the swimming prowess of a shark:

1. Role of Cartilaginous skeleton in sharks: Shark anatomy is different from that of whales and even bony fish. Its cartilaginous skeleton provides it buoyancy, since it does not have a swimming bladder like bony fish.

2. Role of powerful Swimming Muscles in sharks: Another point is that sharks also possess swimming muscles (RED muscles and WHITE muscles) which heavily influence their swimming prowess and are extremely powerful. The RED muscles provide great endurance and stamina and the WHITE muscles are utilized for achieving high speed swimming.

NOTE: The stamina of large predatory sharks is often foolishly under-estimated. According to a report, a 14 foot Hammerhead shark was able to drag a boat for 12 kms during a struggle with fishermen. Now imagine the power and endurance a 50+ foot predatory shark would possess.

3. Role of Body structure and Fins in sharks: The physical shape and structure of the shark also plays a role in influencing its swimming prowess. Sharks have a streamlined body like that of an Airplane and such a body structure automatically counters friction and drag. The Fins of sharks also play an essential part in determining the swimming prowess of sharks. Sharks have different kinds of fins and each fin have a different purpose but collectively they turn a shark in to an efficient swimming machine. The "Pectoral fins" provide stability and lift while the "caudal fin" provides thrust and plays an important role in helping a shark to attain great speads within short bursts.

4. And interestingly, many predatory sharks are "warm blooded." (including most of the lamnid predatory sharks).

Since Megalodon was a very large predatory shark, it possessed a huge and strong cartilaginous skeleton to support its massive body mass and provide it good enough bouyancy, huge and powerful swimming muscles and fins to provide it with great stamina and good swimming prowess, and a streamlined body to counter friction and drag. It was designed by nature in such a manner that it was capable of hunting and actually did preyed upon "marine mammals (whether large or small)." It was like a Super Great White Shark.

And "Size" does not have much influence on cruising speed of marine animals. If this would be the case, than all large marine animals (including whales) would be slow moving creatures which is not true. Even Blue Whales can swim fast.

--User: LeGenD 08:45, 21 Dec 2008 (UTC)

"The body characteristics and fins of Megalodon were built for high-speed cruising and reduced friction."

Body cahracteristics? Of Megalodon? You mean the ones we do NOT know? Ahhh, I see, assumptions again, with very little evidence, assumptions, you like them, don't you. ;)

Scientists know more about Megalodon than you actually think. The Great White Shark is the closest thing we have to Megalodon in terms of anatomy, so it is not absurd to assume that Megalodon had nearly similar body characteristics.

--User: LeGenD 11:10, 21 Dec 2008 (UTC)

"Not even Sperm Whales challenge them because they are better adopted to kill prey like Squids and small animals."

Now you start demonstrating your ignorance about sperm whales. You see, Sperm whales do not prey on the same prey Orcas prey on. Sperm whales prey on squid that can only be found on the bottom of the ocean, sometimes 2000 km deep. Put orca, or megalodon for that matter, to such depths, and see it being crushed within seconds. Sperm whales are extremely well adapted to hunt squid on such depths, something no other animal can do. Orcas and Sperm whales can not challenge each other: they prey primarily on differnet animals. —Preceding unsigned comment added by 99.231.50.118 (talk) 10:04, 9 December 2008 (UTC)

2000 km deep? Which part of the ocean is that much deep? Giant squids lurk at depths ranging between 1000 m to 4000 m. And surprisingly, Great White Sharks are known to reach depths of 2000 m. Megalodon would be able to do even better. Also, Orcas do challenge Sperm Whales in oceans. They seldom attack Bulls but they do attack and kill Cows and juveniles.

--User: LeGenD 11:10, 21 Dec 2008 (UTC)

Sorry for second post, but I forgot to ask some more questions:

1. This has to do with the carniovorous "rule of thumb": the bigger the teeth, the bigger the prey, however, megalodon is said to have same hunting habits or, rather, eating habits, as Great White. Yet we do not see Great White attacking animals larger than itself, only the ones that are smaller. So, the questions is: Why should we conclude that megalodon attacked animals larger than itself (sperm and bigger whales)?

Great White Sharks do attack large animals. Pinnipeds are an important prey item for them and even the "largest members of pinniped family" are attacked by them (e.g. Elephant seals). They even attack sick or dying "whales." In case of Megalodon, whales were an important prey item for it, so why wouldn't it attack large ones?

--User: LeGenD 10:25, 21 Dec 2008 (UTC)

2. Speed of Great White is 15 mph, or 24 kph (http://animals.nationalgeographic.com/animals/fish/great-white-shark.html). Speed of Orca is 30-35 mph (48-56 kph) (that's right, I was surprised too) (http://www.elasmo-research.org/education/topics/r_haulin'_bass.htm), (http://www.thebigzoo.com/Animals/Killer_Whale.asp). You are stating sensible things about boyoancy (sorry for spelling) helping, etc... but Great white is significantly slower than orca, or even a sperm whale. So, why is it that we should think that Megalodon was fast? By all means, it should be slower than Great White (due to size), or in general, significantly slower than Sperm whale. It seems in general, when speed is involved, whales are quite a bit faster than sharks. So, arguments like "built for a kill" etc... are not relevant here, let us use concrete examples and evidence. In fact, if there is one animal that is built for a kill, it is Orca. Actually, if you say megalodon was built for the kill, and it's body resembled that of Great White, then by your own logic, Great white is also built for the kill, yet it is not that fast compared to orcas or sperm whales. I will repeat the question: Why do we think Megalodon was fast?

Not all sources agree with the source you used for quoting the speed of the Great White Shark. It has been known to reach swimming speeds of up to 40 km/hr. However, it is claimed that it is capable of exceeding even 40 km/hr swimming speed, since it possesses a high performance swimming mechanism like that of Tunas. Even National Geographic realizes that Great White Shark can swim very fast. And as mentioned above, size have little impact on swimming prowess of marine animals.

--User: LeGenD 10:38, 21 Dec 2008 (UTC)

3. You did a mistake in your post. According to all sources, Orca was a female, hence it was AT MOST 23 feet, but more likely smaller, 16-20 feet. In other words, not MORE THAN 23 feet, but surely less than that. Also, by the same logic, let us take maximum sizes: at most 100 tons for sperm whale (after all, Nantucket museum claims that 5.5 meters jaw they had belonged to 24 meter long individual. Sperm whale that attacked Essex (don't tell me you do not know about this incident) was estimated at 26 meters). So, taking maximum number - 26 meters for Sperm whale, we also take maximum number for which we have at least some evidence for megalodon - 16-18 meters. Weight - at most 50 tons. Doesn't look like a fair contest either does it? We have taken largest specimens, corresponding ratios would be applicable to smaller ones. —Preceding unsigned comment added by 99.231.50.118 (talk) 02:19, 10 December 2008 (UTC)

Even if it was a female Orca, it was still larger than the sub-adult Great White Shark it attacked. And it was more like a "surprise attack" actually. Also the claimed sizes of those Sperm Whales are still under dispute. As you may know, this issue has been discussed here. And the weight of the 60 foot Megalodon has been calculated at around 70 tons. However, if you are willing to believe the estimates of those Sperm Whales, than do also check information provided in this source, which claims that the Largest Megalodon jaw model represents an individual more than 75 feet long. [NOTE: Do not confuse this model with the one developed by Bashford Dean before WW-II (which is in-accurate), as this jaw model was developed much later by a Meg researcher, Vito Bertucci.]

--User: LeGenD 10:50, 21 Dec 2008 (UTC)

Megalodon is real!

Megalodon is not extinct. I saw one while fishing. It was the most terrifying sight ever. Please take this seriously. We are in danger! Beware the megalodon.

Seriously, shouldn't the comment above be removed?

Megalodon is extinct. It is not hard to accept this fact after-all.

--User: LeGenD 04:04, 6 October 2006 (UTC)

Not true. My father once saw a massive albino shark that once, compared to the boat size (30 ft) once about 70ft long!

there is still a small posibility that they are still alive here is the theory, when the polor seas became to cold megalodons could have swam down as far as 7 miles to the challenger deep where there it is about 90-100 degrees if this theory is right there would be know way the meg could get to the surface because right above the challenger it is about 20-30 degrees which is below freazing so if they left they would freaze to death right away.

Never heard of the term "fisherman story"? —Preceding unsigned comment added by 92.118.191.48 (talk) 03:06, 19 October 2008 (UTC)

The megamouth shark wasn't known to exist until 1976 or so. Who knows what's swimming around down there. For brevity's sake omitting some non-crucial details: 1975, around 600 SSW of Hawaii. Sonar contact. Used every device we had to classify the contact. Even went active (pinged) to get an estimated depth. A very strange contact. Estimated at 3,000 feet or so deep and....moving at approximately 60 mph. Contact was steadily descending and moving away from us. No propulsion noises. Not a "hard" echo as obtained from a metallic hull. We conjectured it was a biological contact. A Giant Squid? Maybe. Sperm whale? Kinda' fast for a sperm whale. Estimating contact size is very difficult. We made a wild guess of approximately 100 feet but was likely more or less than that. Taped the passive and active incoming information and submitted it to the proper folks. Labeled as top secret but that was standard practice (the tape, not the event). Never heard back about it. Much conjecture amongst the sonar gang. Pretty sure it wasn't a man-made craft. Believed to have been a biological. A megalodon? Never will know but there are strange things out there. Ask the submarine guys. Their sonar and vessel's depth allows them to hear some really bizarre stuff. I can't offer proof of what I write but not everything on this Earth has verifiability.Obbop 05:20, 26 November 2006 (UTC)

"Never will know" is not the kind of thing worth writing in an encyclopedia. Publish a peer-reviewed scientific paper on the survival of megalodon and it can be included.Dinoguy2 13:51, 26 November 2006 (UTC)

Well....they could be in the deep water trenches. We don't have technology that can see past 2 ft in that depth. 90% of all unknown species are in the water (remember reading that sentence somewhere. Don't know where though.) Basically...a Meg is like Bigfoot. We can lose a plane in that remote area and using radar we can't find it...so losing an 8 ft monkey isn't too hard when you think about it. Same with meg. How big is the ocean and how bad is our technology down there? For many years everyone thought that the whale shard was extinct and we see how that got debunked. (VRaptorX)

I agree. It is completely plausible that they could still exist. We'll never know for sure unless true evidence comes out. All we have right now is two sides. People who don't WANT it to exist and those who are trying to see the possibilities without being stupid. -Justin Wozniak

Of course. There could be 900ft squid, or Liopleurodon, or mermaids in those trenches too. Therefore, until we have evidence proving beyond a doubt they don't exist, we might as well believe they are there, or at least be open to the idea.

That was sarcasm, by the way... Seriously though, what evidence is there that Megalodon was a deep-sea shark? Examination of the rock strata where its remains are found and what other types of fossils are typically found with them should give us a good picture of where in the ocean it lived. If that picture is something other than deep sea trenches, there is no reason to invoke them when speculating about possible surviving populations. What do you propose they're eating down there? This is a massive animal we're talking about, probably adapted for feeding on other very large animals. Dinoguy2 04:31, 5 August 2007 (UTC)

In the absence of evidence, we'll apply Occam's razor. That a species of 60 foot, carnivorous, coastal shark has gone undetected, doesn't strike me as overly plausible.--THobern 07:02, 24 September 2007 (UTC) —Preceding unsigned comment added by THobern (talk • contribs)

I agree with Dino. I found this statement by Justin to be particularly outrageous; "People who don't WANT it to exist and those who are trying to see the possibilities without being stupid." Since we're getting into loaded statements now, i'll give one of my own. Maybe the division is between people who WANT it to exist and people who use rational thought. —Preceding unsigned comment added by 140.228.26.221 (talk) 19:07, 16 October 2007 (UTC)

It is only rational to admit that megalodon could still be alive. Although the chances are low, still, most of the ocean depths are unexplored. No one knows what lies beneath. With the discovery of live giant squids, the great amount of sea serpent sightings, and recent videos from the bottom of the ocean, it would seem somewhat logical to at least admit that there is a chance that megalodon is still alive. Personally, I believe that there is at least one megalodon still out there. But showing neutrality, it still logical to admit that it and other monsters of the deep are out there. In my opinion, one could easily say that there are chances of creatures like the megalodon and the sea serpent of existing. —Preceding unsigned comment added by WikiFanatic777 (talk • contribs) 05:33, 7 January 2008 (UTC)

There could be living ammonites down there. Or trilobites. Or Hallucigenia. Or aquatic undersea pink unicorns down there too. Doesn't mean we seriously speculate that they actually are there, just because they could be, until there's some shred of evidence to go on. "Personally, I believe that there is at least one megalodon still out there" What if it died of old age by now? ;) Dinoguy2 (talk) 05:38, 7 January 2008 (UTC)

Wow Dinoguy, could you be anymore of a sarcastic boob? Just because we haven't seen it yet doesn't mean it isn't out there. Just look at the coelacanth, that prehistoric fish thought extinct since the time of the dinosaurs, was caught off the coast of Madagascar. Never dismiss possiblility out of hand simply because it has not been seen as of yet.

Carcharocles

Carcharocles = Greek καρχαρος = "jagged" + X-κλης (from X-κλεFης) = "famed for X". Greek καρχαριας = "shark", likely referring to its jagged teeth.

Καρχαροδων = "jagged-toothed" and e.g. appears in Hesiod's Works and Days as an adjective describing a guard dog. Anthony Appleyard 16:43, 22 October 2006 (UTC)

IMPORTANT: Latest research shows that Megalodon has strong ties with sharks belonging to Carcharocles genus. I have updated the section of taxonomy with proper references to make this case very clear for all readers.

--LeGenD 01:22, 15 December 2007 (UTC)

well guys the megladon is real and i know it!! i was eatin by one and now im living inside it and its quite spacey and nice in here. —Preceding unsigned comment added by 24.241.114.29 (talk) 11:07, 28 March 2008 (UTC)

Minor wording confusion

"Still it is important to note that a very old jaw reconstruction (developed by Professor Bashford Dean in 1909) of this shark suggests a size of about 30 m (100 ft) but that jaw reconstruction is now considered to be inaccurate."

-If "that jaw reconstruction is now considered to be inaccurate", then why is this information still "important to note"? Zixor 03:01, 26 September 2007 (UTC)

I think because you may see that size in older or poorly-researched books, and it's important to know where they got it and that it is no longer accepted. Vultur (talk) 17:28, 3 February 2008 (UTC)

Images

Do we really need four pictures of teeth, considering that we have only a single, rather insignificant, artist's rendering? I have a couple of veterbra I found on the English coast, if need be.--THobern 16:35, 29 October 2007 (UTC)

I have added an image in the "Diet" section of the main article, which shows a Megalodon attacking its prey. It seems to be a good addition.

--LeGenD 01:19, 20 December 2007 (UTC)

New sections added

I have added a new section called "Megalodon in fiction" in the main article, which is mainly concerned with the various works of fiction about Megalodon. This section would be useful in high-lighting the materials regarding Megalodon that are actually works of fiction and are mean't for entertainment purposes.

--LeGenD 01:57, 14 December 2007 (UTC)

I have improved this section by adding release dates of all the movies and novels mentioned in it and also have mentioned the names of the authors of the respective novels along side them.

--LeGenD 01:57, 22 December 2007 (UTC)

I have further enhanced this section by adding three new sub-sections in it. These are named as "Shows", "Games" and "Misc" featuring Megalodon.

--LeGenD 04:08, 23 December 2007 (UTC)

I have renamed this section as "In fiction and popular culture."

--LeGenD 06:34, 23 December 2007 (UTC)

I have also created a separate section dedicated solely to Megalodon' diet preferences, thus separating this piece of information from the "known physiology" section. The physiology is about physical characteristics of an animal and not its diet.

--LeGenD 04:24, 14 December 2007 (UTC)

I have added a sub-section in the "Diet" section which is dedicated to the the behavior of Megalodon sharks.

--LeGenD 02:00, 23 December 2007 (UTC)

I have separated the "Behavior" section from the "Diet" section now. This change has been made in accordance with the wikipedia based guidance for writing shark articles.

--LeGenD 11:29, 23 December 2007 (UTC)

I have added a new section called "Paleoecology" and have made "Diet" and "Behavior" its sub-sections, because both of these sections are part of the paleoecological studies of the Megalodon, as indicated in the references.

--LeGenD 04:52, 12 January 2007 (UTC)

I have refined or improved the "Known physiology" section by making a sub-section in it, which is dedicated solely to the size of Megalodon.

--LeGenD 09:34, 14 December 2007 (UTC)

The "Known physiology" section has been renamed as "Anatomy and appearance" section and now contains a new sub-section that focuses on the dentition of Megalodon.

--LeGenD 11:17, 24 December 2007 (UTC)

I have also added a "See also" section that contains links of related articles. I have shifted the link of "shark portal" to this section now.

--LeGenD 12:37, 18 December 2007 (UTC)

I have added a sub-section titled as "Educational Videos" in the "External links" section, which is solely dedicated to the best video clips of Megalodon that have been developed by shark experts and are mean't for educational purposes for the audience. This section is an excellent addition in the main article and would allow lots of people to learn about the Megalodon in more realistic manner.

--LeGenD 04:35, 23 December 2007 (UTC)

I have also added a sub-section in the "Relict" section that is dedicated to the famous sightings of supposed Megalodon sharks that took place in early 20th century. This sub-section actually adds more depth to the "Relict" section in terms of details.

--LeGenD 06:36, 23 December 2007 (UTC)

I have added a new section, which is about distribution and range of Megalodon, when it was alive. This information should be provided in any good quality article.

--LeGenD 05:27, 23 December 2007 (UTC)

I have added a "Notes" based reference section in the main article, which deals with the specific points that are relevant and important but needed to be pointed out separately from the remaining content of the article.

--LeGenD 02:11, 14 January 2008 (UTC)

I have added a new sub-section section called "The Megamouth Analogy" in the "Relict" section.

--LeGenD 09:42, 15 January 2008 (UTC)

Title name of this sub-section section has been simplified to "Megamouth analogy"

--LeGenD 04:36, 16 January 2008 (UTC)

Re-structuring of the main article

I have re-arranged the content of the entire main article in accordance with the wikipedia defined article template for sharks. Necessary adjustments in the content also have been made to fit accordingly to the new structure of the main article.

--LeGenD 02:45, 24 December 2007 (UTC)

The entire article update

I have finally updated most of the content (including the references) of the main article. The content now covers most topics concerning Megalodon and contains reliable information.

--LeGenD 08:26, 24 December 2007 (UTC)

I have made some more improvements in some sections of the article. Now all the sections of the article contain updated information.

--LeGenD 05:52, 25 December 2007 (UTC)

Nice work!!! --Stefan ^talk 08:38, 28 December 2007 (UTC)

I have now re-updated some parts of the content by implementing the recent suggestions mentioned below.

--LeGenD 04:21, 14 January 2008 (UTC)

The content has now been further refined, keeping in mind the new suggestions pointed out.

--LeGenD ^talk 07:01, 16 January 2008 (UTC)

The entire content have been revised by me now to ensure that most of the errors have been corrected.

--LeGenD ^talk 04:15, 16 January 2008 (UTC)

The entire article have been re-updated now with proper references.

--LeGenD ^talk 01:24, 17 January 2008 (UTC)

Good article nomination on hold

This article's Good Article promotion has been put on hold. During review, some issues were discovered that can be resolved without a major re-write. This is how the article, as of January 12, 2008, compares against the six good article criteria:

1. Well written?: For the most part, the article is well written and in compliance with the Manual of Style. But there are some issues that need to be dealt with before the article can be considered to be GA. First off, according to the guideline of WP:LEAD, the introduction to the article needs major expansion. A lead section should be a "concise overview" of the entire article. Frequently in the article, the writing uses self-referential language such as "For full details, check "External links" section below." or "from the reasons mentioned above". This inappropriate for encyclopedic writing. If necessary, you may use {{Seealso}} links to other pages, but internal see also mentions within an article are not condoned by the Manual of Style. If someone doesn't find info they are looking for in one section, it is safe to assume they will read other sections in the article to find it. In some cases, the article uses these as if they were references. This is also inappropriate. Inline references should be in a consistent citation format, in this case the footnotes system. All instances of self-referential language need to be removed in order for the article to be GA class. Ones I've caught are present in: Taxonomy, The dispute, Behavior, Extinction hypothesis, Relict, and possibly other places. Another issue is the use of the {{cquote}} template. According to WP:MOSQUOTE and the template instructions, decorative cquotes are never to be used for block quotations, only pull quotes. Please change the format to either {{blockquote}} or <blockquote> formatting. Also note that blockquotes must 4+ lines or multiple paragraphs in length (though I think all of them meet this requirement). Lastly, the article does have a smattering of tiny, single-sentence paragraphs. As part of basic rules of good prose, paragraphs should be at least three sentences, if not more. Unless there is a very compelling reason, single sentence paragraphs should be consolidated in to others.

2. Factually accurate?: The article does a fair job of providing references and inline citations (good job), but there is some work to be done. Most importantly, the article uses megmawl.com as a source several times. If you read the page where they describe themselves, you can obviously see that this site does not meet the definition of a reliable source. As a partially-commercial site written by a hobbyist and that lacks editorial review and fact checking, it falls under the definition of a "questionable source" according to Wikipedia guidelines. The use of this site for verification of scientific facts and theories needs to be undone. According to the criterion of providing inline cites "for direct quotations, statistics, published opinion, counter-intuitive or controversial statements that are challenged or likely to be challenged.." the following areas need to have inline citations.

• "The largest megalodon tooth..." in Size estimation
• The last two paragraphs of the Size estimation section, these refer to the specific work of a person, thus needing a cite.
• In Jaw dentition, "Most shark experts..." without an inline citation, this is also a case of weasel words and needs to be rewritten.
• The second paragraph in Distribution
• Both the first and last paragraphs of Diet. Both of these claim either specific facts or ratios that are likely to be challenged.
• "Some cryptozoologists still suggest.." more weasel words.
• each individual extinction hypothesis needs a cite.

3. Broad in coverage?: Covers all basic points and stays on topic.

• The second paragraph of Relict

4. Neutral point of view?: Mostly gives fair treatment to all significant points of view. However, saying "Hence, Zane Grey actually observed an adult whale shark, but twisted his story." is very POV, and should be removed. Passing judgement on one person's story is not the job of Wikipedia.

5. Article stability? Not the subject of current events or any edit warring.

6. Images?: Images present have the necessary source info and licensing.

Please address these matters soon and then leave a note here showing how they have been resolved. After 48 hours the article should be reviewed again. If these issues are not addressed within 7 days, the article may be failed without further notice. Thank you for your work so far.— VanTucky 00:55, 12 January 2008 (UTC)

Notes

For readability, please place any comments or questions pertaining to the hold below rather than within the body of the review. Thank you!

"The dispute"

Does anyone else think this section should be renamed to something like "Classification dispute"? I think that would sound more encyclopedic as opposed to the current title which sounds like something you'd read in a newspaper.
RMFan1 (talk) 21:36, 12 January 2008 (UTC)
I've gone ahead and made the change but if anyone disagrees you can of course revert it or discuss it here.
RMFan1 (talk) 22:01, 12 January 2008 (UTC)

"The taxonomic debate" sounds more encyclopedic to me. VanTucky 00:14, 13 January 2008 (UTC)

I don't mind what we actually use but would just like to get a little input from others so thanks for yours so far. Now, would you at least agree that the article "The" should be dropped as it is not usually used in section titles? RMFan1 (talk) 18:47, 13 January 2008 (UTC)

Issues that have been resolved

I have tried to resolve several issues that have been pointed out above by the reviewer VanTucky. The details are listed below:

Regarding 1. Well written?:

• As pointed out, I have expanded the introduction part of the article.
• Usage of the self-referential language has been undone by me in all the sections of the article, as suggested.
• I have replaced the "cquote" templates with the blockquote formatting in the Relict Section.

Regarding 2. Factually accurate?:

• I have once again reformed the references of the entire article with the best sources, that I could find. I have also removed all of the references of the Meg Mawl source, as suggested.
• The "The largest megalodon tooth..." based comment in the Size Estimation section have been removed by me because a comment already exists in the same section that appropriately deals with this case.
• The second last paragraph of the Size estimation section now has a proper reference supporting it. However, the last paragraph has been a bit refined by me and so far does not needs a citation, because many sources seem to talk about Gottfried's method for measuring the size of Megalodon and this shows that it is indeed a popular method.
• In Jaw dentition section, the line "most shark experts" has been replaced with "some shark experts."

I have slightly changed and improved the information in this section. LeGenD ^talk 04:32, 14 January 2008 (UTC)

• The information mentioned in the second paragraph in the Distribution section is correct. Things were lot more different during the Miocene epoch from today. More explanation in this regard has been provided in the Extinction hypothesis section.
• The first and last paragraphs in the Diet section contain reliable information. Big Sharks eat lots of things.
• Weasal word removed from the last paragraph in the Extinction hypothesis section.
• Each individual extinction hypothesis now has a cite.

Regarding 4. Neutral point of view?:

• I have removed this comment "Hence, Zane Grey actually observed an adult whale shark, but twisted his ....." from the Relict section, as suggested.

--LeGenD ^talk 05:30, 13 January 2008 (UTC)

Great work so far, but one thing I noticed additionally: the first sentence of Shows asserts the opinion of a specific person. This must have a direct inline citation. VanTucky 01:31, 13 January 2008 (UTC)

I have now provided a citation for the first sentence in the show section. However, that opinion is not of Nigel Marven, so I corrected this mistake. One of the creators of that show actually wrote that story and not Nigel.

--LeGenD ^talk 07:30, 13 January 2008 (UTC)

Article is ready

The article is now up-to-date (with all the above mentioned suggestions being addressed) and is in my opinion ready for GA. So VanTucky, please do post your opinion now!

--LeGenD ^talk 05:02, 14 January 2008 (UTC)

References, writing and speculation

The references used in this article are largely not of a scientific nature, and have not undergone [peer review]]. As such, I do not believe this article should be put forward for 'good article' status, especially when it is compared to other fossil articles that have received good article status (such as Diplodocus, and Stegosaurus prior to going towards featured article status. Examples poor referencing is:

• http://www.elasmo-research.org/
  • Which explicitly states on its warning page that none of the work is peer-reviewed and can say whatever the author wishes.

• http://www.enchantedlearning.com
  • Simplistic site aimed at childern.

No one has used this source as a reference in the entire article.

--LeGenD ^talk 07:35, 14 January 2008 (UTC)

• http://www.lowcountrygeologic.com/SouthCarolina/tabid/53/Filter/104/Page/45/Default.aspx
  • One of two auction sites for buying fossils. The statements they are used to refence are not backed up upon checking.

This source have not been used for citing scientific facts or theories. It has been used for the purpose of demonstrating that the pliocene period based records of this shark are present. Some people questioned the validity of this claim, so a source was needed to point out the facts to them.

--LeGenD ^talk 07:35, 14 January 2008 (UTC)

• Reference 6 is a dead link

It is properly working. I have checked it.

--LeGenD ^talk 07:37, 14 January 2008 (UTC)

Only reference 1 is scientifically acceptable. Many statements made about C. megalodon are uncited. I high-lighted the first few, but many more statements should have a reference to support them.

In addition to proper citations, writing quality is not high in this article. For example,

• Under extinction hypotheses: "But history shows us that nothing lasts forever and the examples of extinction of pliosaurs and mosasaurs are instructive."
• Under relict: "However interestingly, extremely rare early Pleistocene based records of C. megalodon can still be expected"
• Under behavior: "Its larger size could provide it with certain advantages that other smaller sharks could not enjoy."

Finally under exinction hypotheses that final paragraph is largely pure speculation.

• The polar seas became too cold for the megalodon to thrive in.
• Some species of whales migrated to these cooler regions.
• And many shallow warm water regions dried up at that time, which served as the ideal breeding grounds for the megalodon.
• So, these significant disturbances in the ecosystem caused major problems for C. megalodon and they could not follow the surviving species of whales in the cold regions.
• Hence, the loss of such habitats caused the animal to gradually become extinct, as the species could no longer find enough food to sustain itself.
• The process would have been gradual, leading to fewer C. megalodon individuals, more genetic drift and increasingly isolated populations.

While this does make sense, no evidence for any of this is presented, nor hypotheses by palaeoichthyologists presenting this sequence of events. The last line invoking genetic drift an population isolation can definitly be axed. This article is very far from being ready for GA. Mark t young (talk) 13:00, 14 January 2008 (UTC)

Unfortunately, this is how the whole theory of Megalodon is developed. Basic assumptions are unproven and some are purely speculative, and on them a theory is built which wants to have some credibility to it? Sorry, but serious scientists and researchers require research and not just speculation. Pavel Golikov.

What do you think happened during the Late Pliocene and Pleistocene periods? The correct answer is that some major Ice Ages occurred during these periods, which brought fundamental changes to the ecosystem and geographical conditions of the entire world. The water level around the world shrunk noticeably and many regions that were part of the oceans, actually dried out. Also thick ice covered most regions on the Earth and even the weather became incredibly cold and harsh. Now many species of animals were not able to adapt to such cool environment and dramatic changes in the ecological conditions around the world, which resulted in several mass extinctions and the list includes: Sharks, Whales, Dolphins, Mammoths, Smilodons etc. Now much of this can be learned through research and I think that many people need to do that. The Megalodon was flourishing in an age where oceans covered up to about 80% of the world's surface, food was abundant and temperate water concentrations were immense. When all of this changed, the conditions became unfavorable for the Megalodon. Hence! I have not been speculating over here.

--LeGenD ^talk 07:37, 11 June 2008 (UTC)

References

• Sorry, it is reference 7 that is dead.

• The auction sites are used to back up statements "Although Pliocene based records of C. megalodon are not uncommon, [18]". The auction site claims to have a megalodon tooth from the Pliocene, but 1) there is no evidence that they are in fact Pliocene, or actually megalodon and 2), it is not a reliable source to state that megalodon is not uncommon in the Pliocene, as it makes no claims that they are rare or common. The other auction site again has the same problems. These refences should be removed, and peer-reviewed scientific refernces replace them.

• http://www.enchantedlearning.com, not used as a reference but really not very suitable link for an encylopedia. In addition, the unsubstantiatable comment made by LeGenD about megalodon eating two percent of its body weight clearly came from this website. If it is to be retained then I would recommend a disclaimer.

• www.elasmo-research.org, actually states what I said on its warning page. As such all references made to this site should be removed in accordance with [wiki: Verifiability].

In fact ref 1 and the cryptozoology references that are cited in the correct places are the only ones that are in line with [wiki: Verifiability]. New references should be found prior to GA. Mark t young (talk) 14:56, 14 January 2008 (UTC)

• GA update: it is my initial reaction to fail the article based on the objections to the sourcing Mark has brought up. I don't always agree, but these things need to be hashed out before the article is passable as GA. I'm going to check back at the end of the hold period (the 18th of Jan), and I'd be happy to pass the article if the new issues raised have been satisfactorily resolved. I would also suggest providing citations for the block quotes in the article. Best of luck, VanTucky 04:01, 15 January 2008 (UTC)

The references cited here are pretty silly. They amount to little more than the fantasies of individuals much like those responsible for the majority of this article (perhaps they are one and the same). It is difficult to take seriously an article of this length when the sole source of fossil evidence for the existence of the Megalodon is dental in nature. While one cannot argue that an animal of an approximate size and obvious carnivorous feeding habits didn't exist, hypotheses regarding breeding behavior and predation patterns need to be specifically marked as such. A tooth alone does not support a detailed ecological discussion, however conservative it may be. —Preceding unsigned comment added by 132.236.117.200 (talk) 20:01, 6 June 2008 (UTC)

I think that you need to read the following books and sources:

A) Megalodon: Hunting The Hunter by Mark Renz.

B) Paleoecology of Fossil White Sharks by Robert Purdy.

C) Hell's teeth article in NewScientist Magazine.

And after reading these sources, if you make some constructive contributions in the article than you would have a point.

LeGenD (talk) 07:40, 11 June 2008 (UTC)

Resolving more issues

I have resolved some more issues and details are mentioned below:

• I have removed the link of the source (www.enchantedlearning.com) from the main article, as suggested.
• I have re-checked all the references to see that they all should be properly working. Now all the references provided in the main article are working.
• This comment "But history shows us that nothing lasts forever and the examples of extinction of pliosaurs and mosasaurs are instructive." has been re-written by me and it is now like this: "However, the examples of extinction of pliosaurs, mosasaurs and basilosaurus are instructive."
• The references from the above mentioned "auction sites" (including www.lowcountrygeologic.com) have been removed by me now.
• This comment in Relict section "However interestingly, extremely rare early Pleistocene based records of C. megalodon can still be expected" have been removed by me now.
• This comment under Behavior section "Its larger size could provide it with certain advantages that other smaller sharks could not enjoy." have been removed by me now.

As soon as I resolve more issues, I will notify.

--LeGenD ^talk 04:57, 15 January 2008 (UTC)

• I have provided the citations for the block quotes in a sub-section of the Relict section, as suggested.
• All references from this source (www.elasmo-research.org) have been removed from the content of the main article, as suggested.

--LeGenD ^talk 12:58, 16 January 2008 (UTC)

• The content in the "Extinction hypothesis" now have been modified and at several points, citations have been provided. And the line invoking genetic drift and population isolation have been removed by me, as suggested.
• New sources have been used by me now (including some excellent books) for citation purposes in various sections of the main article.
• Several other corrections have also been made by me in various sections of the article.

--LeGenD ^talk 04:05, 16 January 2008 (UTC)

• I have further refined the introductory information.

--LeGenD ^talk 08:30, 16 January 2008 (UTC)

I have now resolved most of the issues pointed out above by "Mart t young" guy. If a few issues still remain to be addressed than kindly point them out soon.

--LeGenD ^talk 06:51, 16 January 2008 (UTC)

Update on the article

I have finally updated the entire main article, after addressing all the above mentioned issues. However, more opinions would be welcomed.

--LeGenD ^talk 04:05, 16 January 2008 (UTC)

The article is now up-to-date and is in my opinion, ready for GA.

--LeGenD ^talk 08:30, 16 January 2008 (UTC)

Agreed, I've promoted the article to GA. Thanks for your hard work and your patience! VanTucky 04:08, 17 January 2008 (UTC)

Regarding usage of "Undo" option

The main purpose of "undo" option is to prevent vandalism. For simply fixing errors or mistakes in the content, all people are requested to kindly use the "edit" option instead. A revision of mine was recently reverted for just a minor grammer mistake, which is not good. And it should be kept in mind that not all people are proficient in English. --LeGenD ^talk 12:27 21 January 2008 (UTC)

It was me. I thought the Undo could be used when an entire (even though small) change needed reversal. I'll be good in future. Regarding English proficiency, this is the English Wikipedia, where high standards are strived for. If errors are made they will be fixed. BTW, grammer is spelled grammar, don't ask me why. GrahamBould (talk) 19:57, 20 January 2008 (UTC)

Megalodon and whales

I think we need to specify the whales Megalodon preyed on. For what I know Meg prey on primitive whales like cetotheriids which were on average smaller than today's whales. If we don't point that out, reader could think Meg ate whales big modern whales. Bobisbob (talk) 14:15, 19 February 2008 (UTC)

Megalodon actually preyed upon several species of whales. Unfortunately, some species of whales that lived in the Miocene and Pliocene epochs are still unknown and have yet to be properly classified, so we cannot say for sure that exactly what species of whales were attacked by the Megalodon. Hence, simply using the word "whales" seems to be more reasonable choice.

And some fossil records have revealed that the Megalodon did in-fact attacked large whales (that were bigger than Bull Orcas). Here are a few examples:

• The remains of a 30 feet long prehistoric Whale have been excavated from Chesapeake Bay and that Whale was actually killed by a Megalodon. The genus of this whale is unknown.
• A 33 feet long prehistoric but unknown species of Whale have been excavated in Italy and scientists are speculating, after examining its remains that it was probably killed by a Megalodon.
• An ear bone of a Whale shows signs of bite marks from the Megalodon and it is believed that this ear bone probably belongs to an ancient Sperm Whale. For more information, click here CENOZOIC FOSSILS

Also! It is very difficult to estimate the size of a whale from partial remains because many whales that were attacked by Megalodon, were almost entirely eaten.

LeGenD (talk) 12:10, 20 February 2008 (UTC)

When I say large whales I meant 45+ft long whales, and we can know how big the whales were as a species. 33ft? that small for whale standards Bobisbob (talk) 21:53, 19 February 2008 (UTC)

Have you seen an adult Bull Orca from close distance? It is a big animal and a whale that is bigger than this animal, is generally considered to be a large whale. And I have already told you that it is very hard to determine the size of a whale from very few partial remains. Most of the whales that were attacked by the Megalodon were almost entirely eaten. And no marine biologist considers a 10 m long animal to be small, even by whale standards. Try to visualize a Grey Hound Bus in front of you and you will get the picture.

LeGenD (talk) 06:30, 20 February 2008 (UTC)

They may be mostly eaten but we can know the average size of the species. There has to be other specimens that have not been eatne by Meg right? Bobisbob (talk) 02:08, 21 February 2008 (UTC)

Do you the know about all the species of whales that lived in the time of Megalodon? So far, it is clear that: A) an ancient species of Sperm Whale and B) Cetotheriids were among them. But some species of whales that lived in the Miocene and Pliocene periods are of unknown taxon. So my main point remains valid, that Megalodon attacked various species of whales and even the large ones were not safe from it. Also, it should be kept in mind that few fossil records from the Miocene and Pliocene periods can be termed as "significant" but still we have yet to learn a lot about the ecosystem that existed in these periods. As soon as more information will be revealed, I will update the article accordingly. But for now, simply using the word "whales" seems to be better option in the diet section.

LeGenD (talk) 09:35, 21 February 2008 (UTC)

I have now precisely indicated in the "Diet" section that exactly what animals were part of the diet of Megalodon as indicated by the paleontologists. I will continue to update the list, as more findings and information will be revealed.

LeGenD (talk) 01:47, 23 March 2008 (UTC)

Megalodon fan-kids are going crazy these days. In times of Megalodon, sperm whales for example were MUCH larger than now. Estimates exist of up to 150 tons. Megalodons weighed at most 40 tons. There is NO WAY Megalodon could kill even a whale of 100 tons. Sperm whales have been known to ram ships head on and not only survive but sink ships, and then to swim away with scratches on head. Head on collision with Megalodon and shark is DEAD (especially considering sharks have VERY fragile bodies, hell it has no bones, what are we talking about). Could megalodon avoid collision? NO, because at 40 tons, you are simply TOO slow to move that fast. Sperm whale has sonar and can detect megalodon very far away. So, yeah, before posting nonsense, shark fans better check some facts. The situation is identical to Similodon fans claiming similodon could kill Megatherium, which is as much of an absurd as a claim that Megalodons preyed on sperm whales. On calfes, sure, but very unlikely on adult males (adult females were in herds, and attack on a herd would be total suicide for a shark). there is no point talking about significant records or any kind of proof. Shark fans wil come in and change the article all they want, that is how it usually happens. Also, some funny things: "An ear bone of a Whale shows signs of bite marks from the Megalodon and it is believed that this ear bone probably belongs to an ancient Sperm Whale." Ear bone of PROBABLY sperm whale killed PROBABLY by a Megalodon. There we go, from that we claim right away that Megalodon preyed on sperm whales? I am sorry, but first, I would like to hear some reasons of why is this a sperm whale's earbone and most importantly, a purely speculative claim that it (unknown whale as for now) was kiled by a Megalodon? Why not Basilosaurus? Also, as been noted here, many whales existed of which we do not know. What makes it true that the earbone is of unknown species of whale and not of sperm whale. How do we know it was of adult sperm whale? THere is A LOT of speculation about Megalodon, and unfortunately, this article begins to suck them in, not without shark enthusiasts though. From purely hypothetical and unprooved statements, things are inferred as if they are proven deductively and treated as truth. 99.231.63.253 (talk) 05:31, 19 April 2008 (UTC)PAvel Golikov.

Looks like as if a few Sperm Whale fans are getting worried. Seriously dude! There are some signs and clues that led several scientists to believe that Megalodon did attacked Sperm Whales. And you can never know that how much powerful and deadly Megalodon was in real life. However, according to a great analysis conducted by Dr. Kent, Megalodon was clearly built for the kill. Also, watch a video called "Big Tooth: Dead or Alive" in which scientists show that how Megalodon attacked Sperm Whales. And not surprisingly, the famous scientist Robert Purdy also found signs of Megalodon stalking Sperm Whales and large Baleen Whales in some regions around the world. He pointed out that where these whales headed, they were closely pursued by some adult Megalodon individuals. He mentioned this in his article known as "Paleoecology of the Fossil White Sharks," which has been published in various books. And not all Sperm Whales weighed 100 tons and such estimates for even the large bull Sperm Whales are often considered to be exaggerated. Hence, sorry to disappoint you but these scientists know better about these animals than you do and you better stop thinking that Sperm Whales are invincible or something. Just because a predator does not exists today that is large enough to challenge it, it does not means that some giants of the past weren't capable of doing so.

LeGenD (talk) 12:30, 14 May 2008 (UTC)

I do not in any way think sperm hales are invincible, I just think that people shouldn't exagerate the size of megalodon without proper evidence. we DO have evidence of sperm whales weighing 100 tons (not 150 maybe) but we in no way have any evidence of Megalodon weighing half that size, and even if it did, how exactly would it kill 100 tons sperm whale? Challenge? You mean head on? Are you saying that a shark without proper bones could challenge an animal weighing twice as much, that can seriously damage metal ships or sink wooden ships head on? That seems a little bit of an exageration, don't you think? Built for the kill? What is that supposed to mean? So are orcas, so is sperm whale, so is dolphin, so is any predator. Sperm whale and in general any other fans ARE indeed getting worried, because without any solid scientific evidence, the size of this shark is blown out of any sensible proportions. Videos showing how megalodon attacked sperm whales? but wait a second, this article mentiones 60-foot shark weighing 20 tonnes. Hmmm, do you accept this estimate? Seems like you are quote mining, taking only the evidence that fits your point of view. Do the show how it would take down an 80 tons sperm whale for instance?

You do seem to think that large Bull Sperms are virtually invincible. Do you judge the power of an animal by its weight? Its a bad thing to rely upon. Many predators are usually designed and armed in such a manner that they can kill much heavier prey than themselves. Additionally predators do not necessarily challenge powerful prey head-on. They tackle them by utilizing stealthy means (if opportunistic) or use co-ordinated approach (if small and not solitary) and scientists have found evidence of Megalodon employing stealthy hunting approach against large potential prey. Some fossil records have provided useful insights regarding hunting behaviour of Megalodon. They revealed that Megalodon preferred to cripple a large prey first by ripping apart its propelling structures before proceeding to kill and feast on it at leisure. Once a whale would be crippled, it would become a sitting duck. And using terms such as "without proper bones" are utterly ridiculous to rely upon in a scientific debate. The strength of the cartilaginous skeleton is determined by level of its "calcification." A heavily calcified cartilaginous skeleton is as strong as a bony skeleton and would be able to tolerate and hold a very large & heavy body mass with ease in-conjunction with providing good flexibility and aiding bouyancy in very large sharks. Sharks have been able to reach extremes among fish in various aspects of biology due to some very good reasons. As far as Dr. kent is concerned, he showed through his research that Megalodon could easily rip apart large bodied animals, as it could bite through even the tough bony portions of large prey. It's dentition was very robust and teeth were very strong, large, and serrated. In-addition to these traits, a team of scientists recently showed through their research that Megalodon was also capable of exerting incredible bite force (More than enough to crush bones and damage steal). So armed with such a devastating jaws, ripping through tons of flesh and bones won't be difficult for Megalodon. It was designed by nature to accomplish such a task as it was an active predator of whales. And several factors are used to determine the size of a prehistoric shark. The first step is to determine that to which group of sharks does a prehistoric shark belongs and which extant shark is its closest living relative by looking for similarities among the bones and after a match is found and linkage is established, the rest of the mystery can be solved. Megalodon' physical attributes closely match with those of the Great White Shark as fossil records have shown. So systematics used to determine the size and weight of the Great White Shark also become applicable to the Megalodon after minor adjustments. In-fact remains of a Megalodon were found in Belgium which revealed that Megalodon might have a more liberal TH to BL correlation than observed in Great White Sharks. So scientists do not just speculate but use available data (e.g. 1. Fossils & 2. Close Living Relatives) to determine the proportions of prehistoric sharks. Some fossil records of Megalodon indicate that it could grow to more than 18 m long. And as far as weight of the Megalodon is concerned, a team of famous scientists mentioned a method to determine the weight of large predatory sharks (extant or extinct) with high accuracy in their research work in 1996. Check a research work called Determining the size and skeletal anatomy of the extinct megatoothed shark (Source is Great White Sharks: The biology of Carcharodon Carcharias) for more information in this regard. So I use that scientific method to determine the weight of the Megalodon with respect to its size and do not make random guesses like some people or sources make. And an adult Megalodon can defeat any sperm whale by employing its stealthy attacking approach and formidable hunting traits. A sperm whale is also surface breather like all other whales, and this weakness can be easily exploited by a highly opportunistic predator like Megalodon. It only takes common sense and research to figure these things out.

LeGenD (talk) 07:50, 20 Dec 2008 (UTC)

"And not surprisingly, the famous scientist Robert Purdy also found signs of Megalodon stalking Sperm Whales and large Baleen Whales in some regions around the world. He pointed out that where these whales headed, they were closely pursued by some adult Megalodon individuals."

Do you realize how stupid that sounds? I think you misunderstood something. How could he find signs of megalodon STALKING anything? What kind of evidence could possibly suggest that? Trick question: Did megalodon follow baleen whales in to northern waters? Shark nowadays also follow sperm whales, Jacques-Yves Cousteau mentiones it in his observations. He actually describes a lot of sharks feeding on dead calf after the herd leaves. They possibly prey on sick, old, dead or simply for leftovers (squid). Why couldn't Megalodon do the same?

The word stalking also refers to "hunting." By carefully examining the fossil records and their distribution and drawing parrallels with modern age eco-system, ancient eco-systems can be reconstructed with high accuracy. To find out that whether a prehistoric animal was killed via hunting or was simply scavenged upon, paleontologists try to determine that how it was attacked and which portions of its body were targeted during the attack by carefully observing the signs of damage inscribed on its bones. Some parts of the body of an animal can be considered as high value targets by predators because by damaging such parts, it becomes easy to subdue the animal (e.g. Attack on propelling structures of the victim would indicate that the predator was trying to cripple it.). Ripped apart propelling structures and even caudal bones of some large whales have been found with bite marks left by teeth belonging to Megalodon. These fossil records show that Megalodon crippled those whales by ripping apart their propelling structures and damaging their tails during the hunting process. Additionally, Megalodon teeth have been found lying close to chewed up remains of whales in several regions of the world. So such fossil records reveal that whales were stalked (hunted) and preyed upon by Megalodon and that they (whales) were an important prey item for this giant shark. Paleontologists also observe the modern age kin of prehistoric predators to gain some useful insights regarding their probable behaviour. Robert Purdy is the first scientist to attempt to reconstruct the ecology of Megalodon and he made many expeditions for his research to make it as credible as possible. Also every predator is also a probable scavenger and Megalodon was also no exception to this rule but this does not means that it predominantly relied upon scavenging. Also it is not necessary that what current predatory sharks do, Megalodon also strictly functioned according to their life-styles. Dr. Kent' research specially opens new horizons in the mystery surrounding the behavior of the Megalodon. And the physical traits and capabilities of the prehistoric predator should also be kept in mind, as they can influence its behaviour. There must be a logic or a good enough reason behind Megalodon growing so large and possessing a very robust dentition (with large serrated teeth) and capable of exerting devastating bite force. In lay man terms: "It evolved big to eat big." And I would recommend you to go through the research work of Robert Purdy before passing judgements. It is very informative and interesting.

LeGenD (talk) 09:58, 20 Dec 2008 (UTC)

One more point: Some scientists you mentioned seem to be doing exactly what you do, that is, looking at evidence that suites their point of view (most scientists do that actually, except for mathematitians). Maybe we should look at the general picture, with all facts accounted for. Rememeber those BBS Walking with Dinosaurs videos? Easily proclaimed Leupleirodon weighing 150 tons. Later was found out that it was not nearly as large. Same thing here. Tell me, in which universities your scientists work? Was what they said checked against biomechanical principles? Everyone can make vidoes, but very few can prove. Also, regarding the sources, the article uses as sources fan based sites, which I think is not really good. References like "Hunting the Hunter" seem to be just anotehr sensationalist articles never confirmed by real scientists. —Preceding unsigned comment added by 99.231.50.118 (talk) 09:37, 9 December 2008 (UTC)

I have tried to keep the this article as fair and unbiased as possible as it is meant to educate the masses. You can notice that all the controversies surrounding the taxonomy and anatomy of Megalodon have been mentioned in the main article. The problem is that people need to distinguish between content which has some credibility (supported by some sort of evidence) and the content which lacks any credibility: such as "guess-works" (unproven and not supported by any kind of evidence) and massively disputed. And most scientists mentioned in the main article are very conservative in their works and know a great deal about sharks, as they are called "shark experts" for a reason. One should spend some time and go through their research works before judging them. And the "Megalodon: Hunting the Hunter" is a book written by a paleontologist who consulted many experts on the subject. Another thing is that it is wise to use common sense in-conjunction with self-research and even consult some experts (if possible) before proceeding to make amends in any encyclopedic topic or reconstructing them. As far as my knowledge is concerned, I am involved in research works on sharks. But not all people know a great deal about sharks. Some even try to portray Megalodon (An APEX SUPER PREDATOR with over 17 million years of life-span of existance) as a "failure" even when the fossil records paint a different picture by relying on unproven content and opinions of some cetacean fans. This should be avoided.

LeGenD (talk) 05:35, 20 Dec 2008 (UTC)

Legend, you seems to mention many times evidence that Megalodon preyed on large whales. Can you list a full list of this evidence please. And quotes to be precise. Will be much appreciated. —Preceding unsigned comment added by 99.231.50.118 (talk) 02:38, 10 December 2008 (UTC)

Up till now, hundreds of remains of whales have been found which became victims of the Megalodon. However, very few whales have been successfully identified among them as of yet. Though, whales (which can exceed 10 m in length) have been attacked by Megalodon as some fossil records have revealed. The list includes: Right whales & Brygmophyseter.

LeGenD (talk) 06:0, 20 Dec 2008 (UTC)

Evolution of Megalodon

I have added a cladogram representing the "hastalis hypothesis," which shows that the great white shark is more closely related to I. hastalis than the Megalodon. This is an excellent addition in the article, making it more clear for the readers to understand about the new perception of the scientists regarding the evolution of the Megalodon.

LeGenD (talk) 01:47, 23 March 2008 (UTC)

The Article re-update

Many portions of the content of the megalodon article have been updated, improved and tuned by me now. Some changes in the content of the article can be obviously noticed, but they are according to the wikipedia guidelines for writing articles.

LeGenD (talk) 05:35, 5 April 2008 (UTC)

I have made some more more important modifications to the content of the main article. It should be noted that:

• Reference no. 1 is now the book called "Megalodon: Hunting the Hunter."
• And reference no. 2 is now the cryptozoology article by Ben S. Roesch.

So people should not be confused.

LeGenD (talk) 01:08, 6 April 2008 (UTC)

Moved Page

I moved the page because two movies with that name (Megalodon) exist and many books as well. I made a re-direct page and moved this here. If you think the name should be Megalodon (prehistoric animal) then change it to that. I was unsure if I should get that specific with the title. - Prede (talk) 07:23, 6 April 2008 (UTC)

The animal is the WP:PRIMARYUSAGE in my opinion, so it belongs here. I've moved the disambiguation to Megalodon (disambiguation). Gimmetrow 19:22, 6 April 2008 (UTC)

I'm fine with that. This idea is better then mine. We just needed a disambiguation page, and we have one now. ^.^ - Prede (talk) 19:26, 6 April 2008 (UTC)

Diet

The 1 tonne of food a day would only represent the largest of Megalodons. Perhaps we need a less extreme figure? --THobern 01:59, 10 April 2008 (UTC)

It has been estimated that Megalodon needed to eat at-least one-fiftieth of its weight of food per day. Now the 52 feet long Megalodon weighed more than 50 short tons. And 50 short tons = 100,000 lb. Now one-fiftieth of 100,000 lb is 2000 lb. Hence this line "more than 2000 lb of food" does makes sense. And keep in mind that 52 feet long Megalodon is not even close to the largest individuals (that were more than 18 m long) and would eat even more.

LeGenD (talk) 10:50, 10 April 2008 (UTC)

I have to argue with that. 52 feet, despite what some very unreliable sources might say, is probably the greatest size it could have reached. I fairer estimate is 14 metres, despite media hype to the contrary.

--THobern 08:26, 11 April 2008 (UTC)

I probably should have checked up on this before doing a scale chart, but it appears the 18m estimate is from the secondary literature. Can anyone provide actual scientific papers that generated these estimates? What is the largest estimate that has been published in a peer-reviewed source and has not yet been refuted?

I find it particularly troubling that the entire discussion of Cliff Jeremiah's method (the cite for the method itself, the cite for it's wide acceptance without mentioning particular studies that have baked him up, etc.) uses a single (secondary or possibly tertiary) source. Dinoguy2 (talk) 10:08, 11 April 2008 (UTC)

Why the largest? Why not the most commonly accepted amongst credible scientists in the relevant fields? --THobern 00:29, 12 April 2008 (UTC) —Preceding unsigned comment added by THobern (talk • contribs)

Are there enough estimates for one to be more commonly accepted than others? I still haven't seen sites for any size estimates period. It sounds like you guys are more familiar with the lit than I am, so if you could provide some recent cites that include size estimates I'd much appreciate it. (I asked about the largest in this case to see if the 18m estimate had actually been published in something other than the book which seems to form the basis for most cites in this article). Legnd claimed in the article that the 18m estimate and the methods used to generate it are widely accepted. If this is not true the article needs to be changed ASAP with some primary sources disputing or ignoring those estimates. Dinoguy2 (talk) 05:46, 12 April 2008 (UTC)

How can you go on and declare that the statement I posted in the article is not true without even reading the book? Here is a hint: Read the chapter: "A Dentist's Nightmare" in the book called "Megalodon: Hunting the Hunter." Cliff Jeremiah' method is highly appreciated and accepted by his pears. And not a single person disagreed with his conclusion. Not a single!

LeGenD (talk) 05:46, 12 April 2008 (UTC)

While I admit that I am far from expert, I was under the impression that modern estimates were far more conservative than the 60 foot model. Size it has been claimed, would be limited to 14 odd metres by problems, that the Shark would incur past this point, with oxygen absorbtion. --THobern 08:16, 17 April 2008 (UTC)

Latest research places Megalodon back in the 60 foot league. Have you properly read the details mentioned in the "Size Estimation" section? Every point has been made clear in it. The 52 feet size estimation is based on a 6.61 inch long Megalodon tooth and keep in mind that some people have found even bigger Megalodon teeth after 1996. Hence, this issue does not even warrants any further debate. Also, keep in mind that I have read most "Megalodon" books that have been cited in the article and they are the best ones among all. Hence, I know this stuff well. And claims such as huge sharks having respiratory issues are baseless and unproven. Modern sharks do not represent the physical systematics of the prehistoric Megalodon. For example, a huge Basking shark has less than 140 vertebrae in its body. However, Megalodon had over 200 vertebrae in its body.

LeGenD (talk) 08:16, 17 April 2008 (UTC)

I have read the section, but it is not the only material I have read. But let's not debate size. Most teeth found are less that 5 inches, suggesting that few Megalodons would reach 50 feet. I think we should revise the diet section to give a more conservative average diet figure. --THobern 02:24, 19 April 2008 (UTC)

The problem is that most of the teeth that we found on shallow water regions or beaches or even on the dry lands, belonged to juvenile individuals. It makes no sense for huge adults to roam in such shallows in search for food because huge animals (including large whales) seldom roam in coastal waters due to the threat of getting breached and stranded. This is why we seldom get to find huge Megalodon teeth in such regions and oceans are too big for excavations. So you can't say for sure that few individuals actually got about 50 feet long or even more.

LeGenD (talk) 12:57, 14 May 2008 (UTC)

Any scientist who seeks the opinions of fruit, is highly suspect...--THobern 00:57, 17 May 2008 (UTC)--THobern 09:20, 16 May 2008 (UTC)

Can you be more specific here?

How many large whales you see roaming in shallow waters on daily basis? They seldom visit shallow regions because they can get stranded on coasts or beaches. Their huge size becomes a disadvantage in such locations. Hence, the adult Megalodon individuals were also vulnerable in such regions.

LeGenD (talk) 11:50, 19 May 2008 (UTC)

You also have to remember that the seas extended much farther inland than they do nowadays.--THobern 01:08, 18 May 2008 (UTC) —Preceding unsigned comment added by THobern (talk • contribs)

It is a matter of common sense dude! That's why we find Megalodon teeth on dry lands as well.

LeGenD (talk) 11:35, 19 May 2008 (UTC)

My point exactly. That is why it is not necessarily fair to say that we don't find larger teeth, as the larger sharks lived farther out to sea.--THobern 06:22, 20 May 2008 (UTC) —Preceding unsigned comment added by THobern (talk • contribs)

Photo

Megalodon jaws on display at the National Aquarium, Napier, New Zealand.

I've just uploaded this picture. Not sure it's exactly encyclopaedic but it gives a good idea of scale ... Jasper33 (talk) 12:36, 27 May 2008 (UTC)

A different Megalodon

An article on cryptozoology.com apparently says that megalodon was not a massive, whale-crushing predator after all. It turns out that all of the whale puncture marks in their vertebrae were just fractures from natural causes. Megalodon's teeth were only designed for slicing small fish, and its bite force was rather weak. Megalodon was only about 30-50 ft, and it was much more closely related to the leopard or reef shark than the great white. Should I add this (I'll even ref the article)

Elasmøsaurus (talk) 20:29, 10 July 2008 (UTC)

That article can spark controversy at a massive scale, so I will not recommend you to use it in the main article. Also! The information provided in that article can be easily debunked by carefully examining the available evidences.

1) Watch this documentary:

Video: Sample of The Perfect Shark Documentary (2006)

The guy in it clearly shows the evidence of Meg attack on a whale.

2) Study this article: Hell's teeth (1999)

You will get all the answers you need. The Megalodon was in-fact a whale-crushing predator, as scientists prove it in the above mentioned sources.

LeGenD (talk) 02:15, 11 July 2008 (UTC)

Guidance regarding exceptional claims are covered at WP:REDFLAG. Also, references from a cryptozoological website need to be considered on the light of guidelines at WP:FRINGE. Mark t young (talk) 16:50, 11 July 2008 (UTC)

All right, it won't be added to the article...

and how is a cryptozoological website unreliable for a reference?

Elasmøsaurus (talk) 00:18, 12 July 2008 (UTC)

The information provided in a cryptozoological article must be supported by reliable sources or concrete evidences and not just based on unproven assumptions, before being considered as reliable. The article that you were referring to mostly contains incorrect and misleading information as I have shown above. Our main purpose should be to portray facts.

LeGenD (talk) 07:50, 12 July 2008 (UTC)

That and cryptozoology sites tend not to deal with research, more with unrelated, superficial parallels that are used to imply a false conclusion.--THobern 23:45, 23 July 2008 (UTC) —Preceding unsigned comment added by THobern (talk • contribs)

Keep in mind that megalodon had straight teeth rather than curved teeth. Curved teeth are found in great whites and are suitable for gripping onto prey. Stright teeth are weak and more suited to eating fish. 76.191.186.43 (talk) 00:57, 9 August 2008 (UTC)

The teeth of Megalodon are razor sharp and serrated just like that of Great White Shark, but they are even more robust. Also a recent scientific research has concluded that Megalodon packed a tremendous bite-force. See the "external links" section for more details.

LeGenD (talk) 05:42, 21 August 2008 (UTC)

Pronunciation

Hi, the pronunciation seems a bit wacky. The first description was made on 2008-01-17 by LeGenD, who mentioned meg-la-don.[1] He then wrote the IPA as [mɛɡlɑːdɒn], which puts the stress on the second syllable, like meg-LAH-don.[2]

I haven't tracked further changes, but by 2008-04-28 the article had a different guide, MEG-a-la-don. The IPA still matched meg-LAH-don, so there was a mismatch between the two pronunciations given.

On 2008-04-30 the IPA was changed,[3] but this IPA does not make much sense. It uses a reduced vowel in the third syllable but marks it as having secondary stress.

So... we currently have a minor problem. We give two different pronunciations in two different ways, and one of them does not make sense.

Well, does Megalodon have different pronunciations? How is it pronounced? Descriptions, please. If you answer here, I'll tidy them up and add them to the article. Thanks. --Kjoonlee 07:42, 30 July 2008 (UTC)

According to this source, the word Megalodon is often pronounced as meg-la-don. However, BBC suggests that this word is generally pronounced as meg-a-la-don. You should also watch some Meg related documentaries, to see that how various scientists spell the word Megalodon. The "external links" section of the main article will be useful in this case. Hope this helps.

LeGenD 02:25, 04 August 2008 (UTC)

MEGALODON vs. LIOPLEURODON

My 7 year old son INSISTS that liopleurodon is the largest animal (living creature) to ever exist. There are claims that Megalodon is the "largest predator" to ever live and then that Liopleurodon is the "largest carnivore"... so which is it??? Is there a difference? Can anyone explain/expand so that I can have a well-informed discussion with my 2nd grader? Thanks, Gail

Liopleurodon was the largest predatory marine reptile to ever live, estimated to be somewhere between 23 and 50 feet in length, depending on age and species, though some mosasaurs, such as Tylosaurus rivaled it in length, if not mass. The ancient whale Basilosaurus exceeds Liopleurodon in size, having an average length of 60 feet. Megalodon was the largest predatory fish ever, with the largest individuals estimated to be up to 60 feet in length. So, you could say that Liopleurodon was the largest predatory reptile to ever live in the sea, while Megalodon was the biggest predatory fish ever to live in the sea, and that Basilosaurus was the largest predatory whale ever to live in the sea, though, none of them would have ever met, as they all lived and died out at different times.--Mr Fink (talk) 20:04, 31 July 2008 (UTC)

Liopleurodon was a large pliosaur, but no larger than Pliosaurus, Kronosaurus, Megalneusaurus or Brachauchenius, all of which could exceed 10 metres in length. The large mosasaurs, such as Tylosaurus, Mosasaurus and Hainosaurus reached lengths of 14 or more metres, exceeding the size of the large pliosaurs. However, for the largest marine reptiles you have to look at the ichthyosaurs. Some, such as the shastasaurs reaches lengths of almost 25 metres. That makes the large ichythosaurs larger than ancient whales such as Basilosaurus (~18 m long) and C. megalodon (12-18 m long). Hope that helps Mark t young (talk) 20:15, 31 July 2008 (UTC)

So to answer your question :) Liopleurodon would have been around the same size as the lower size estimates for an adult C. megalodon. That being said, a much larger pliosaur from Norway has been discovered, that is probably 15 metres or so in length. But as it isn't named, we don't know if it is Liopleurodon, Pliosaurus or something new. If it is a 15 m or so long Liopleurodon, then Lio and mega would have been around the same size.

However, which one had the most mass is unknown. So, even if they were the same length one could be far larger than the other! Mark t young (talk) 20:33, 31 July 2008 (UTC)

THANK YOU soooo much! Very helpful info and I am extremely excited to share this with my little guy. How fantastic to have this answered SO fast!!! Thanks again! GailSimons (talk) 01:43, 1 August 2008 (UTC)Gail

Also keep in mind that while some shastasaurs reached over 20m, they probably did not weigh as much as modern sperm whales. So while it's correct to say they were the longest, they were not really the "largest" carnivores of all time--toothed whales are. Especially if you count filter-feeders like baleen whales among "carnivores." Baleen whales are both longer and heavier than shastasaurs. Dinoguy2 (talk) 04:58, 1 August 2008 (UTC)

As Dinoguy2 reminds, mass is the all important factor whether an animal is "larger" than another, especially underwater where the limitations imposed by gravity are far less. If you isometrically scale an animal up (keep all its dimensions like length, width and height constant) then a 4 metre Liopleurodon is a quarter of the mass of a 8 metre long one. Thats why length is a nice way to compare closely related animals, but usual not so in more distantly related ones. My suspicions are the same as Dinoguy2's, that the toothed whales are the largest marine carnivores of all time (although the fossil record could always surprise us, as it often does). Mark t young (talk) 22:55, 1 August 2008 (UTC)

I think that you mean one eighth of the mass.--THobern 11:13, 4 August 2008 (UTC) —Preceding unsigned comment added by THobern (talk • contribs)

Possible Megalodon Video?

Looks very real and not like other dipictions, wait til near the end to see the whole animal (audio and text in the Japanese language). [4].--Sonicobbsessed (talk) 01:37, 5 August 2008 (UTC)

Somehow I think that evidence that the Megalodon isn't extinct wouldn't come from a Japanese game show.
There's no point of reference for the scale, and we don't know where the footage is from; if it's off the coast of Japan, a basking shark is possible, though a sleeper shark (as per the YouTube commentary, though that's hardly a reliable source) isn't out of the question if it's from the Greenland area. Basically, this is just evidence that large sharks exist, a fact that isn't in dispute. EVula // talk // ☯ // 01:52, 5 August 2008 (UTC)

The footage was taken in Suruga Bay, Japan during the 1989 National Geographic Society/Tokyo Broadcasting System/Toba Aquarium expedition. Camera operator was Emory Kristof. The big shark is a c.23 foot (based on the 60cm bait cage) female Pacific Sleeper and has absolutely nothing to do with megalodon.

Source = Doubilet, D., E. Kristof, and E. Clark. 1990. Suruga Bay, in the shadow of Mt. Fuji. National Geographic 178(4):2-39. Ozraptor4 (talk) 17:42, 22 December 2008 (UTC)

i actually would like to see it cited at some place in the article mentioning the "relect" belief,though for some unholy reason there isnt one now. —Preceding unsigned comment added by 68.153.118.160 (talk) 20:43, 4 November 2008 (UTC)

Greenland sharks have been recorded to lengths of nearly 8 meters, a similar size to that of the shark mentioned in this video. C. megalodon was a stream-lined mackerel sharks. This is, I believe, a carchariniforme, is similar to a Greenland shark, or it may be a related species. It isn't C. megalodon.

However, this also raises and interesting point. If C. megalodon is still alive, then it wouldn't be C. megalodon any more. It would have evolved into a new species altogether, if it did survive this long, and adapt to benthic sea life.Spotty11222 (talk) 01:40, 14 January 2009 (UTC)

Most POWERFULL Bite force

According to several studies the Megaldon had a 10 ton bite force almost 3 times that of the T-rex...Most powerfull of any known animal ever:http://www.livescience.com/animals/080804-sharks-bite-power.html —Preceding unsigned comment added by 209.67.178.213 (talk) 23:19, 26 August 2008 (UTC)

Undue weight issues

What's with the huge section (and sentences in the lead) about supposed sightings. They're based on tertiary (if not more distant), word of mouth sources. This does not belong. OrangeMarlin ^{Talk• Contributions} 06:22, 28 August 2008 (UTC)

Agree and was about to remove it but I see that you did it, and good improvements! --Stefan ^talk 01:11, 30 August 2008 (UTC)

Couple of points

I remember reading (? New Scientist) that Megalodon's killing method was different from that of the Great White: the Great White goes for soft underbellies; Megalodon had more robust teeth in proportion to its size, and quite often went for the prey's spine, and whale fossils of the time with chunks bitten out of the spine and rib cage were cited - Megalodon as a chondrichthyian T. rex.

I'd change the order, and cover anatomy and lifestyle before taxonomy. That's consistent with the use of cladistic analysis, which is based on lots of anatomical details. -- Philcha (talk) 12:34, 29 August 2008 (UTC)

Vandalism

Leading section has been blanked, but reverting it also brings back some older vandalism in the section. I seem not to be skilled enough to handle the reverting process. Could someone else do it, please. Jokinen | Talk 13:15, 6 November 2008 (UTC)

Extinction hypotheses

Pardon me for being so frank, but I'm surprised that section "Extinction hypotheses" passed FA review:

• The first para lacks citations.
• None of the rest of the section shows any connection between the extinction of C. megalodon and that of pliosaurs, mosasaurs, ichthyosaurs or Basilosaurus.
• The final para simply restates the contents of the bullet list, except that it omits the restriction of breeding grounds.
• The bullet list is introduced by "Some notable climatic shifts are:" But the bullet list does not cover multiple climatic shitfs, it presents a domino effect of 1 shift.
• Much of the language looks, well to be honest, pretentious. The same content could be presented more concisely and clearly in less high-falutin' language. --Philcha (talk) 13:56, 6 November 2008 (UTC)

Allow me to point out a few things:

This is a GA class article and not an FA class article as of yet.

• A citation has been added to the first para in the "Extinction hypotheses" section.
• Some reasons behind the extinction of Basilosaurus are similar to those behind the Megalodon, so its example has been used in the sense of being instructive to possible mechanism involved.
• The final para is a summary of the the major reasons behind the extinction process of the Megalodon. You wish to make some corrections than please do so.
• The major climatic shifts and some major geological changes around the world, which took place due to the Ice Ages are both responsible for causing massive disturbances in the eco-system favorable for the Megalodon, which led to its extinction.

I will see later that how the content in this section can be further improved.

--LeGenD (talk) 22:24, 8 November 2008 (UTC)

Sorry about the FA / GA confusion.

The source cited for the para about Basilosaurus mentions only cooling and no other mechanism for Basilosaurus's extinction. In addition it does not mention Megalodon, so bringing in Basilosaurus looks very like WP:SYN. I'm no rulebook-thumper (I've had a few "vigorous" discussions with WP:fundamentalists), but my general knowledge of paleontology makes me ask, "Why is Basilosaurus more relevant than e.g. the Ordovician–Silurian extinction event, for which cooling and sea-level regression are favoured causal mechanisms. Put it another way, would readers' understanding of the extinction of Megalodon really be reduced if that of Basilosauruswere removed?

I'm happy with the bullet list format for the chain of events. I think any additional material from the final para should be incorprated into the list, so that readers understand each step before moving on to the next. --Philcha (talk) 14:23, 18 November 2008 (UTC)

I have further improved the content in this section with some re-adjustments. The content now more clearly focuses upon two major factors behind the extinction of Megalodon: (1. Climatic upheavels and 2. Shortage of food). The chain of events and there impact are more clearly defined now. Your opinion would be appreciated.

----LeGenD (talk) 02:40, 24 December 2008 (UTC)

Caption for "teeth" image

The caption for the "teeth" image seems to put the cart before the horse - C. megalodon is the star of the article and the image. It would also make more impact if it explained "Carcharodontosaurus". --Philcha (talk) 14:00, 6 November 2008 (UTC)

I have modified the comments representing the "teeth image" according to importance and relevance level of animals with respect to this article. However the word Carcharodontosaurus has been linked to its article, so an explanation may not be necessary for this animal, as the over-all comment for this image might become too big. However an additional reply from you will be appreciated.

--LeGenD (talk) 16:51, 18 November 2008 (UTC)

I've edited it, as I think "large carnivorous dino" is more relevant to Megalodon than "from the Sahara" is. However you're currently doing most of the work here, so I'll accept your judgement. --Philcha (talk) 14:09, 18 November 2008 (UTC)

Intro

I believe the fact that 18 million to 1.5 million years ago is mentioned twice so close to each other makes the introduction seem wierd. Maybe we could construct the sentence to use the species existance only once. Enlil Ninlil (talk) 09:19, 9 December 2008 (UTC)

I tried to fix it. --Stefan ^talk 12:51, 9 December 2008 (UTC)

It is good now, I will try and contribute something asap. Enlil Ninlil (talk) 06:16, 10 December 2008 (UTC)

Cryptozoology?

Reference 2 is Cryptozoology. Are you serious? It is a pseudoscience. The fact is noted even on Wikipedia itself. I strongly suggest that this reference being deleted, since cryptozoology is not considered anything serious by biologists and zoologists, REAL sciences. —Preceding unsigned comment added by 99.231.50.118 (talk) 02:32, 10 December 2008 (UTC)

Yes but the information come from the first 2 paragraphs is referenced by what seems to be scientific authors. Enlil Ninlil (talk) 06:23, 10 December 2008 (UTC)

Well, I guess so. I will look up what kind of source it is.--99.231.50.118 (talk) 09:21, 12 December 2008 (UTC)Pavel Golikov.

Extiction theory

I added some critisizm that exists to some of the current theories mentioned in the article, I also added a theory about Orcas outcompeting or possibly hunting megalodon. It is a valid theory and I think should be mentioned.--99.231.50.118 (talk) 09:19, 12 December 2008 (UTC)Pavel Golikov.

Just because a hypothesis is mentioned in a few sources, it does not becomes credible unless proven by some credible evidence such as "fossil records" and accepted by the entire scientific community as true. This theory is not credible and heavily disputed so I removed it. To date, no evidence have been found of Megalodon being a prey of Orcas. Check the "Megalodon and the Orca" section above for more details. For example: Some argue that Megalodon would still be alive and lurking in deep waters but due to lack of evidence, we do not accept this hypothesis as true.

--User: LeGenD 08:20, 14 December 2008 (UTC)

Can you both put your sources here for verification? Enlil Ninlil (talk) 12:34, 24 December 2008 (UTC)

Recently added content moved here for work

Moved the following from the lead. It needs verification and rewriting if it is to be used. Doesn't belong in lead section. Vsmith (talk) 14:14, 20 December 2008 (UTC)

In the book Great Shark Stories by Peter Goadsby - with a foreword by Ron & Val Taylor - published around 1979, he recounts a story of Sri Lankan fishermen working from their boat at night, being chased by a 100ft Great White. This had some people wondering. The late famous Prof JLB Smith in his book Sea Fishes of Southern Africa writing about the 'extinct' gigantic Carcharodon megalodon states that is ONLY presumed extinct. Was this a megalodon or a monster Great White? What in 2002 took the body of a a hooked Great White off Kenya in a single bite, leaving a head that alone weighed 1500lb?

Sounds like a myth or exageration to me. Enlil Ninlil (talk) 09:47, 5 January 2009 (UTC)

Archive

I think some of the older sections can be archived now. The talk page is too long. Enlil Ninlil (talk) 09:47, 5 January 2009 (UTC)

Archive 1

Archive 2

Archive 3