|
Megalodon
|
Megalodon (Carcharocles megalodon), meaning "big tooth", is an extinct species of shark that lived approximately 23 to 3.6 million years ago (mya), during the Early Miocene to the Pliocene.[6] It was formerly thought to be a member of the family Lamnidae and a close relative of the great white shark (Carcharodon carcharias). However, it is now classified into the extinct family Otodontidae, which diverged from the great white shark during the Early Cretaceous.
While regarded as one of the largest and most powerful predators to have ever lived, megalodon is known from fragmentary remains, and its appearance and maximum size are uncertain. Scientists differ on whether it would have more closely resembled a stockier version of the great white shark, the basking shark (Cetorhinus Maximus), or the sand tiger shark (Carcharias taurus). Megalodon probably had a major impact on the structure of marine communities. The fossil record indicates that it had a cosmopolitan distribution. It probably targeted large prey, such as whales, seals, and sea turtles. Juveniles inhabited warm coastal waters and fed on fish and small whales. Unlike the great white, which attacks prey from the soft underside, megalodon probably used its strong jaws to break through the chest cavity and puncture the heart and lungs of its prey. 
True story. There is a beach in Florida called Venice Beach, on the west coast, south of Tampa. I grew up in FL, on the east coast, and we locals often referred to Venice Beach as "Fossil Beach" for the large numbers of fossilized sharks teeth that could be found there. So prevalent are these teeth that I myself have found them literally lying in the sand while simply walking down the beach.
Anyhow, we used to drive over there for "fossil hunting" dive trips. These were simply beach dives, requiring nothing more than suiting up and walking into the water, with depths usually no deeper than 15' so you could stay on the bottom as long as you had air in your tanks. During my countless trips to Venice Beach, I had acquired a 5 gallon ziploc bag full of fossilized teeth from practically every known species from that period, including tigers sharks, and Megalodons. I had a large printed card that showed all of the different types of prehistoric sharks teeth that could be found in the area, and I had found examples of every single one of them. However, all of my Megalodon teeth at the time consisted only of fragments and partial teeth, some larger pieces but still broken, until one particular day when I noticed what looked like a black rock in the sand. I brushed the sand away, and revealed a fully intact Megalodon tooth, larger than my hand, it was massive. This tooth was completely intact, still had the serrations completely down both sides, one small chip in one side, and a slight crack about 2" long down the back. It was an amazing specimen. I was around 24 years old back when I found that tooth, and when I came out of the water, there was a crowd of people gathered to see the tooth I had uncovered, along with a local shop owner, who sold fossilized teeth in a kiosk on the beach, actually offered me $500 on the spot for it, which I immediately declined. Sadly, that trip would be the last one I made to Venice Beach, which was something I was obviously unaware of at the time, but sometimes life has different plans. Approximately 2 years after I found that tooth, a friend of mine offered to trade me a 10 week old Chow puppy for my tooth. I really wanted that dog, and since he was a friend, I told him I would do him one better, I'd trade him my entire ziploc bag of teeth, which just sat in a drawer at that point. My thinking was I had found that big tooth simply enough, along with all of the others, that it would not be a difficult thing to replace. Well, nothing could be further from the truth. Not only did I never make it back over to Venice Beach after that, I have since moved away from Florida entirely. My family all still live there, near Cocoa Beach, where most have since retired from their jobs at the Kennedy Space Center, where they had jobs from liquid propellants engineer (fueling the Shuttle) to procurement (buying parts and equipment). The dog, well she has since passed, in 2007, but she was an incredible member of the family for all of the many years that she was with us, and while I have no regrets in making the trade, I still wish I had put more efforts into returning over there, to try and locate another once in a lifetime type of find as I did that day, back in 1991.
“This means we could simply take the growth curves of the five modern forms and project the overall shape as they get larger and larger – right up to a body length of 16 metres [52.5 feet],”
Megalodon discovery: Scientists reveal giant shark’s astonishing true scale 
Megalodon, Prehistoric Shark, Called 'Apex Predator Of All Time'
Think Tyrannosaurus rex was the ultimate predator? Think again. Carcharocles megalodon, a.k.a. Megalodon, was "probably the apex predator of all time," according to paleontologist Chuck Ciampaglio. The Wright State University professor spoke to the Discovery Channel recently about Megalodon, a long-extinct prehistoric shark whose name literally translates as "big tooth." In the video, Ciampaglio shows the Sharktooth Hill formation in Bakersfield, Calif., which would have been Megalodon's hunting ground more than 2 million years ago. Ciampaglio likens the area to Chesapeake Bay -- full of sharks, marine mammals and fish. However, unlike the Maryland-Virginia bay, the shallow sea was home to much larger predators. Not much is known about the 50-plus-foot shark that once ruled the seas for 25 million years, as just about all that remains of it are its fossilized 7-inch-teeth. But paleontologists are convinced Megalodon would have been above the T. rex on the food chain. "T. rex wouldn't have a chance against this thing," Ciampaglio told the Discovery Channel. "T. rex's head would fit in this guy's mouth." https://www.huffingtonpost.co.uk/entry/m...ri18n=true  *This image is copyright of its original author  *This image is copyright of its original author
School lesson gone wrong leads to new, bigger megalodon size estimate
June 7, 2021 A more reliable way of estimating the size of megalodon shows the extinct shark may have been bigger than previously thought, measuring up to 65 feet, nearly the length of two school buses. Earlier studies had ball-parked the massive predator at about 50 to 60 feet long. The revised estimate is the result of new equations based on the width of megalodon's teeth -- and began with a high school lesson that went awry. Victor Perez, then a doctoral student at the Florida Museum of Natural History, was guiding students through a math exercise that used 3D-printed replicas of fossil teeth from a real megalodon and a set of commonly used equations based on tooth height to estimate the shark's size. But something was off: Students' calculations ranged from about 40 to 148 feet for the same shark. Perez snapped into trouble-shooting mode. "I was going around, checking, like, did you use the wrong equation? Did you forget to convert your units?" said Perez, the study's lead author and now the assistant curator of paleontology at the Calvert Marine Museum in Maryland. "But it very quickly became clear that it was not the students that had made the error. It was simply that the equations were not as accurate as we had predicted." Although the equations have been widely used by scientists since their publication in 2002, the classroom exercise revealed they generate varying size estimates for a single shark, depending on which tooth is measured. "I was really surprised," Perez said. "I think a lot of people had seen that study and blindly accepted the equations." For more than a century, scientists have attempted to calculate the size of megalodon, whose name means "big tooth." But the only known remains of the fearsome shark that dominated oceans from about 23 to 3.6 million years ago are fossilized teeth and a few, rare vertebrae. Like other sharks, the rest of megalodon's skeleton, including its jaw, was composed of lightweight cartilage that decomposed quickly after death. Tooth enamel, however, "preserves really well," Perez said. "It's probably the most structurally stable thing in living organisms." Megalodon sharks shed thousands of teeth over a lifetime, leaving abundant traces of the species in the fossil record. The most accepted methods for estimating the length of megalodon have used great white sharks as a modern proxy, relying on the relationship between tooth size to total body length. While great white sharks and megalodon belong to different families, they share similar predatory lifestyles and broad, triangular teeth serrated like steak knives -- ideal adaptations for hunting large, fleshy marine mammals such as whales and dolphins, Perez said. But these methods also present a challenge: To generate body length estimates, they require the researcher to correctly identify a fossil tooth's former position in a megalodon jaw. As in humans, the size and shape of shark teeth vary depending on where they're located in the mouth, and megalodon teeth are most often found as standalone fossils. So, Perez was ecstatic when fossil collector Gordon Hubbell donated a nearly complete set of teeth from the same megalodon shark to the Florida Museum in 2015, reducing the guesswork. After museum researchers CT scanned the teeth and made them available online, Perez collaborated with teacher Megan Higbee Hendrickson on a plan to incorporate them into her middle school curriculum at the Academy of the Holy Names school in Tampa. "We decided to have the kids 3D-print the teeth, determine the size of the shark and build a replica of its jaw for our art show," Hendrickson said. Perez and Hendrickson co-designed a lesson for students based on the then-most popular method for estimating shark size: Match the tooth to its position in the shark jaw, look up the corresponding equation, measure the tooth from the tip of the crown to the line where root and crown meet and plug the number into the equation. After a successful pilot test of a few teeth with Hendrickson's students, he expanded the lesson plan to include the whole set of megalodon teeth for high school students at Delta Charter High School in Aptos, California. Perez expected a slight variability of a couple millimeters in their results, but this time, variations in students' estimates shot to more than 100 feet. The farther a tooth position was from the front of the jaw, the larger the size estimate. After Perez detailed the lesson's results in a fossil community newsletter, he received an email from Teddy Badaut, an avocational paleontologist in France. Badaut suggested a different approach. Why not measure tooth width instead of height? Previous research had suggested tooth width was limited by the size of a shark's jaw, which would be proportional to its body length. Ronny Maik Leder, then a postdoctoral researcher at the Florida Museum, worked with Perez to develop a new set of equations based on tooth width. By measuring the set of teeth from Hubbell, "we could actually sum up the width of the teeth and get an even better approximation of the jaw width," Perez said. The researchers analyzed sets of fossil teeth from 11 individual sharks, representing five species, including megalodon, its close relatives and modern great white sharks. By measuring the combined width of each tooth in a row, they developed a model for how wide an individual tooth was in relation to the jaw for a given species. Now when a paleontologist unearths a lone megalodon tooth the size of their hand, they can compare its width to the average obtained in the study and get an accurate estimate of how big the shark was. "I was quite surprised that indeed no one had thought of this before," said Leder, now director of the Natural History Museum in Leipzig, Germany. "The simple beauty of this method must have been too obvious to be seen. Our model was much more stable than previous approaches. This collaboration was a wonderful example of why working with amateur and hobby paleontologists is so important." Perez cautioned that because individual sharks vary in size, the team's methods still have a range of error of about 10 feet when applied to the largest individuals. It's also unclear exactly how wide megalodon's jaw was and difficult to guess based on teeth alone -- some shark species have gaps between each tooth while the teeth in other species overlap. "Even though this potentially advances our understanding, we haven't really settled the question of how big megalodon was. There's still more that could be done, but that would probably require finding a complete skeleton at this point," he said. Perez continues to teach the megalodon tooth lesson, but its focus has changed. "Since then, we've used the lesson to talk about the nature of science -- the fact that we don't know everything. There are still unanswered questions," he said. For Hendrickson, the lesson sparked her students' enthusiasm for science in ways that textbooks could not. "Victor was an amazing role model for the kids. He is the personification of a young scientist that followed his childhood interest and made a career out of it. So many of these kids had never worked with or spoken to a scientist who respected their point of view and was willing to answer their questions." Leder and Badaut co-authored the study. https://www.sciencedaily.com/releases/20...161015.htm
Megalodon's mortal attack on sperm whale revealed in ancient tooth
The megatoothed shark's serrated teeth left gouge marks. An illustration showing how the attack may have gone down, with a megatoothed shark biting the lower jaw of the sperm whale:  *This image is copyright of its original author Millions of years ago, an ancient sperm whale had a very, very bad day when a megatoothed shark — possibly the fearsome Otodus megalodon or its ancestor Otodus chubutensis, the largest predatory sharks that ever lived — viciously attacked it in what is now North Carolina, a new study suggests. Marks from the attack, preserved as gouges out of the sperm whale's tooth, are the first evidence in the fossil record that megatoothed sharks tussled with sperm whales, the researchers said. "It would seem that these giant sharks were preying on whatever they wanted to, and no marine animal was safe from attacks from these giant sharks," study lead researcher Stephen Godfrey, curator of paleontology at the Calvert Marine Museum in Solomons, Maryland, told Live Science in an email. The single tooth is all that's left of the ancient sperm whale. Study co-researcher Norman Riker, an amateur fossil collector from Dowell, Maryland, found the tooth in what is now called the Nutrien Aurora Phosphate mine, a large phosphate mine in Aurora, North Carolina, in the 1970s or 1980s, when the mine was open to fossil collectors. (Riker, who donated the tooth to the Calvert Marine Museum, died at age 80 in January 2021, the museum newsletter reported.) The researchers aren't sure when this shark-whale brawl occurred. To reach the older phosphate-rich beds, mine workers removed bucketloads of overlying sedimentary rock and dumped them nearby, where fossil collectors could scour them, Godfrey said. The different rock layers — which get laid down over time and so are used to date objects in the layers — got mixed up; because of the mixing, the scientists don't know if the tooth comes from the older sedimentary beds, which would date it to the Miocene epoch, 14 million years ago, or the younger fossils beds, which would date it to the Pliocene epoch, about 5 million years ago. Either way, the tooth falls into the Neogene period (23 million to 2.5 million years ago), he noted. During the Neogene, the Earth's climate was warmer than it is today and, as a result, the North and South Poles had less ice, so sea levels were higher. That's why "coastal North Carolina was covered by a vast shallow arm of the Atlantic Ocean," Godfrey said. "These marine waters teemed with abundant sea life." Different views of the ancient sperm whale tooth that show the three gouge marks from the megatoothed shark:  *This image is copyright of its original author Shark versus whale The size and shape of the curved 4.5-inch-long (11.6 centimeters) tooth clearly indicates that it belongs to an extinct sperm whale species, Godfrey said. By using an equation that compares extinct sperm whale tooth size with body size, the researchers estimate this particular whale was small, only about 13 feet (4 meters) long. Today's sperm whales can reach lengths of over 50 feet (15 m), Godfrey noted. Three gouge marks on the tooth show that whatever took a bite out of it had evenly spaced, serrated teeth. Based on the size and spacing of the bite marks and serrations, the only possible culprits are the megatoothed shark O. chubutensis (which lived 28 million to 13 million years ago) and its descendant O. megalodon (which existed 20 million to 3.5 million years ago), the researchers found. "None of the other fossil sharks known from the phosphate mine have teeth large enough and serrations even enough to have left these bite traces on the sperm whale tooth," Godfrey wrote in the email. "Up until now, bite traces by these giant sharks (with a body length of megalodon over 60 feet [18 m] long) have been found on other bones of extinct whales and dolphins, but never on the head or other bones of a sperm whale." The team added that while it's possible the megatoothed shark was scavenging an already-dead sperm whale, it's more likely that that gouge marks were made during a predatory attack. That's because the cut marks were made on the root of the tooth, or the part that was embedded in the whale's jaw. "So before the megatoothed shark tooth could cut into the sperm whale tooth, it first had to cut through the jaw bone of the sperm whale holding the tooth," Godfrey said. "It would seem unlikely that a large shark would target the jaws of a floating or seafloor carcass of a sperm whale. There would be little flesh in return for the effort," he continued. Instead the bite marks "hint at an attack to the head with the goal of inflicting a mortal wound. In other words, if a giant shark is biting your head, it's trying to kill you." The findings shed light on the ancient ecology of North Carolina, said paleontologist Alberto Collareta, of the University of Pisa in Italy who was not involved in the study. Moreover, it's not too surprising that the megatoothed shark bit the sperm whale's tooth, he said. Killer whales, apex predators in today's oceans, are known to eat the meaty tongues and blubbery throats of other whales. "Maybe the sperm whales had some reserve of fat or there was the tongue," that attracted the megatoothed shark, Collareta told Live Science. The study was published online Aug. 9 in the journal Acta Palaeontologica Polonica. https://www.livescience.com/megalodon-sh...ssils.html 
Credit to house of the dinosaur
 *This image is copyright of its original author  *This image is copyright of its original author
We don't want personal issue on public forum. If you guys have some short of misunderstanding, better resolve it in PMs. not in public. Doing this again will result in BAN.
 (09-21-2021, 05:05 PM)Apex Titan Wrote: Megalodon, Prehistoric Shark, Called 'Apex Predator Of All Time' A reflection and a critical analysis: It is always important to get acurate information to make a claim, or at least to check the source of those claims to make sure that is correct or not. Sometimes, preferences make an efect in the conclutions and the sources, like popular news papers help to increase the popular myths or to create new ones. This news article is a good example of it. Taking a critical point of view, the article, which is short, focus in only ONE person, the paleontologist Chuck Ciampaglio, however the editor use this wild phrase from nowhere: "But paleontologists are convinced Megalodon would have been above the T. rex on the food chain". I need to ask, what "Paleontologists"? They only interview one person and the editor (Sara Gates) jump to conclutions with no back up. Interestinlgy, the article was writen in 2012 and completelly ignore the existence of the giant Carcharodontosaurids and Spinosaurus (which were also apex predators of its time) and make a direct comparison with T. rex, which is an animal that do not live in the same habitat, do not hunt the same type of prey, nor live in the same time. Also, because is obviously a very old article it also ignore the existence of the equaly large Livyatan melvillei, described in 2017, and for the wrath of dinosaurs (and other prehistoric reptiles) fans, it disregards the giant reptiles of the Mesozoic like Kronosaurus and Mosasurus, among others, which also surpassed the 10 and 15+ meters long and from which we have complete skeletons from where to draw good conclutions. So clearly there is a gap in the conclutions of this article and we can't take it seriously at all. Finally, and this is the sad part, since they mention Discovery Channel, we know that this is not a serious article at all. It is well know that Discovery is no longer the old good scientific channel that used to be and that they constantly created the false documentaries to increase the audience, one of them about Megalodon, one tv show that was HIGHLY critizice by experts as it created the silly idea that Megalodon still live in our days. It is no coincidence that the article was published in 2012 and a couple of months latter the unfamous false-documentary Megalodon: The Monster Shark Lives was realized in 2013 by the same channel. There is a tendency to increse the mythology of large predators, but there is a point where the reliabily of the information is sacrificed by the rating, and this is what this type of articles and channels had done in the last years. There is no such a thing as the "apex predator of all times", because we have not a clear idea of the hunting techniques, prey type and the speed and agility of the large predators in the different eras. Even worst, there is still no concensus about the real size of Megalodon and we need to add that there is plenty of evidence that support that this shark was NOT a giant version of the great white shark, but the people that study it insist in using it as the main comparsion. Interesingly, they results are allways different and contradictory, even using the same modern animal as model! It is really confusing. Definitellly, this article from Sara Gates is no different from the tons of news papers that exagerate the conclutions of scientific studies and at the end, when you read the real papers, it shows something completelly different. It came to my mind the article about the scaled skin of the T. rex, all the news saying that T. rex did not had featers, but they omited the HUGE fact that the skin patches were smaller than a tumb! The same authors accepted this fact and a critical review of the paper showed innacuraciones in they claims. Now, about the images, the first one shows a white shark attacking "something", because that thing is definitelly not a whale. With no scale in the image, most fans use it to claim that Megalodon hunted whales of its same size, but like I explained in other topics, no marine animal surpassed the 10 meters in those days, most of them were between 4 to 7 meters, only Livyatan and Megalodon surpassed the 15 meters. The second image is anachronic, as no orca (Orcinus orca) lived in the time of Megalodon. This is like the images that shows giant white sharks (poor copies of Megalodon) hunthing giant sperm whales (Physeter macrocephalus), in a time where sperm whales of that species did not existed at all. The only species related with the modern orca was Orcinus citoniensis that measured about 4 meters long (only one specimen found) and the sperm whales of its time measured a maximum of about 6-7 meters at the most. I we could make deep analysis of all those news articles, we will found that fiction is killing the true, all in the name of entertainment. (12-30-2021, 04:43 AM)GuateGojira Wrote:(09-21-2021, 05:05 PM)Apex Titan Wrote: Megalodon, Prehistoric Shark, Called 'Apex Predator Of All Time' I agree with some of your points, they make sense and I know Discovery channel has lost its credibility and is known for making several fake documentaries or "mockumentaries". But I think what that article means by calling Megalodon the 'Apex predator of all time' is that for its ecosystem, compared to other marine and terrestrial apex predators, the Megalodon was the most dominant and greatest apex predator of its domain. Even more dominant and formidable than the T-Rex was for his environment. Thats what I think they mean by saying that. Of course you can't compare a land-based apex predator to marine apex predators. Different environments/terrain, different type of prey, challenges, enemies etc.... Based on numerous scientific documentaries I've seen (not on Discovery) throughout the years on prehistoric marine predators, I've consistently seen many marine biologists, scientists, and experts widely acknowledge and regard the Megalodon to be the most formidable and greatest marine apex predator that ever lived. The 'King of the Sea' like many call it. No one mentions the Livyatan Melvillei, to be honest with you, I've seen none. There's no doubt that the Livyatan whale was a formidable apex predator in its own right, but marine predator experts and biologists seem to widely agree that the Megalodon, overall, was THE ultimate marine apex predator that ever lived. Megalodon is considered to be the largest apex predator that ever lived too, and possessing the most powerful biteforce of any marine/terrestrial predator of all time. Also, there's nothing unreliable about the other articles I posted. What's wrong with 'ScienceDaily' ?? Thats a website where all the latest research and science news is posted. The other article from 'Livescience' also reported factual information. Whats the problem? While I agree with you that there's no such thing as the "Apex predator of all times", I definitely think though, that the Megalodon was the greatest marine apex predator of all time. I know you'll probably disagree with me, but this is my view based on many scientific documentaries and sources I've seen. Lastly, there's no way of knowing how Megalodon looked like, period....as no human being has ever seen one. Its impossible to know. It could have resembled a giant great white shark, or maybe not. We'll never know, its all speculation. (01-03-2022, 09:19 PM)Apex Titan Wrote: I agree with some of your points, they make sense and I know Discovery channel has lost its credibility and is known for making several fake documentaries or "mockumentaries". But I think what that article means by calling Megalodon the 'Apex predator of all time' is that for its ecosystem, compared to other marine and terrestrial apex predators, the Megalodon was the most dominant and greatest apex predator of its domain. Even more dominant and formidable than the T-Rex was for his environment. Thats what I think they mean by saying that. Of course you can't compare a land-based apex predator to marine apex predators. Different environments/terrain, different type of prey, challenges, enemies etc.... I will like to touch a couple of points here. 1 - You say that Megalodon was more dominant and formidable than T. rex. There is no such a thing, check that in the habitat and timeframe of T. rex (late Cretaceous in North America) there was no other predator that matched its size and power, no other, in fact the nich for middle sized predators was occupied by juvenil T. rex! The next predator in the food chaing will be Dakotaraptor with only 350 kg (compare that with the 9 tons of Rex). In the case of Megalodon, it had a competitor, it was Livyatan, which matched its size and mass, so there were two predators in the same enviroment and based on this, T. rex will be more "dominant" from your point of view. In fact, the case of Megalodon will be more like Spinosaurus and Carcharodontosaurus, two big similar sized predators sharing the same area. 2 - About the documentaries, please check that Megalodon is known to science since 1667 and described several times, reconstructed, and even we have movies of it. It covers all the popular media and there are even crepy-theories about it. On the other side, Livyatan was discovered and described until 2010, there is a difference of 343 years! There is no doubth about why Megalodon is in the mind of people and Livyatan not. About documentaries, the serious ones at least and not the youtube videos made by fans and they computers, all of them are before 2010, there is not a single documentary, for prehistoric marine mammals, made after that date (as far I know). Now you see, is not that scientist ignore Livyatan, is that they don't knew about it and now that the interest for scientific documentaries is almoust lost, I doubth that anyone will made a new documentary for TV or Cinema. Ask to any people about Megalodon and anyone will tell you about the giant shark, but ask about Livyatan and I bet you that no one, except for prehistoric-fans like us, will tell you what it is. 3 - Again, Megalodon is no longer considered the largest apex predator, not in all the educated circles at least. Also, there are no studies about the bite force of Livyatan, so we can't say that Megaldon bites the harder. Even worst, did not you that the studies of Megalodon bite force are estimations made on assuptions, don't you? We don't have the skull of a Megalodon so those bite force studies should be take like a grain of salt. 4 - I did not say ANYTHING about the ScienceDaily or the Livescience article in my previous post. Can you please read it again? Also, those news reports are not always 100% accurate, is much better to read the original papers. I will like to read the paper that LiveScience refer of, because it is very weird that they created an entire history based in just one tooth! Something there do not look right. And about ScienceDaily, I am not surprised that we have new size estimations, in fact I will not surprised if Megalodon was smaller or bigger than all those estimations in the dozens of documents about it. What the fans need to take in count is that all those measurements are estimated from the tip of the nose to the tip of the tail tip, probably like on these two forms, the TOT or the TLn:  *This image is copyright of its original author  *This image is copyright of its original author That means that these sizes depends of how is the reconstruction of the shark and as we know that Megalodon had an heterocercal tail, is possible that great part of that length belonged to the tail flip. That means that the hipotetical maximum size of 20 meters long for Megalodon could be about 16 meters in PRC size and that is using the TLn measurement, if we use the TOT form, then the 20 meters Megalodon will be about 15 meters in the PRC length. Finally, remember that they are using a white shark in this example, so using a real heterocercal shark like the basking shark or the sand tiger shark, the tail flip will be bigger and the difference larger too. 5 - The point of view of a particular person may be biased towards the likes of the person, so I am not going to touch that part. However, while we had more than 300 years of papers, documentaries, movies and crepy-pastas about the mytical Megalodon, I am not surprised that it will take time to acept the fact that it was not the "undisputed king" of sea. We don't know what other species are yet to be discovered, Livyatan is a great example. 6 - While there is no form to know how Megalodon looks like at 100%, I will not say that there is no way at all. In fact, using relatives like Cretolamna appendiculata, which is very well conserved, we can get a good idea of how Megalodon could look like. Besides, we can't discard that maybe, in the future and with a HUGE luck, someone could found a complete mandible, or maybe an asociated mandible-spine fossil. Who knows........ (01-21-2022, 11:52 PM)GuateGojira Wrote:(01-03-2022, 09:19 PM)Apex Titan Wrote: I agree with some of your points, they make sense and I know Discovery channel has lost its credibility and is known for making several fake documentaries or "mockumentaries". But I think what that article means by calling Megalodon the 'Apex predator of all time' is that for its ecosystem, compared to other marine and terrestrial apex predators, the Megalodon was the most dominant and greatest apex predator of its domain. Even more dominant and formidable than the T-Rex was for his environment. Thats what I think they mean by saying that. Of course you can't compare a land-based apex predator to marine apex predators. Different environments/terrain, different type of prey, challenges, enemies etc.... Hello Guate, I have a question, regarding the similar weights of the Livyatan and the Megalodon, don’t you think that the Livyatan is only estimated to have weighed as much as the Megalodon because it had a skeleton made of bones while the Megalodon had a cartilageous skeleton?? And the cartilaginous skeleton could allow it to have better manoeuvrability despite their huge size? I’m just guessing that a similar sized whale with a bony skeleton might not be able to move with as much manoeuvrability. What do you think? (01-22-2022, 08:13 AM)LonePredator Wrote: Hello Guate, I have a question, regarding the similar weights of the Livyatan and the Megalodon, don’t you think that the Livyatan is only estimated to have weighed as much as the Megalodon because it had a skeleton made of bones while the Megalodon had a cartilageous skeleton?? About the weight, as far I know there is not an "official" estimation about the weight of Livyatan, the only figure available of 57 tonnes came from Villafaña et al. (2014) and they do not provide any evidence of what method they used to calculate it. Indredibly in that same document they state a size of 30 meters for Megalodon (bigger than the blue whale!) and a weight of over 100 tons (completelly ridiculous), and several other whales were escalated as the same size as modern blue whale even when we know that were not even close to the 15 meters long, so those estimations are definitelly not reliable at all. However, based on its size and compare it with modern sperm whales, I think that 57 tonnes is a reliable figure for a cetacean of 17 meters like Livyatan, but as we don't know if this animal was slender or bulkier, it is just an educated guess. I have saw other estimations between 50 to 60 tonnes, but all of them are from people in the web, non from a published paper. Now, while we can have a more or less good idea of the weight of Livyatan, with Megalodon is a more speculation that other thing, I mean, we only have dentition and the analogous that was used in the past to estimate its weight was the white shark which now we know it was incorrect. So while we still use the estimation of 13 - 59 tonnes for Megalodon, that maybe different if they use other shark species for comparison. When I checked orcas and white sharks of the same length, the cetacean was always the heavier, so that can give you an idea with the Pliocene giants of the sea. About the maneuverability, that is more related with muscles than skeleton itself, I think. However we can compare dolphins and sharks and both are very fast and strong, so personally I don't see any difference, maybe is more related with internal mechanisms and energy usage (I maybe wrong on this), but that is another history. Now, as we don't have modern analogous of the same size as the prehistoric beasts, we can use the orca and the white shark (for size and ecological place only), and like I said before I found that at the same size the orca is heavier, and while the shark is faster in short turns, orca is stronger overall. So all depends of the situation, but if someone think that these two animals (Megalodon and Livyatan) chase each other like "Tom and Jerry", that is just a silly supposition from fans with no base, they were competitors for sure but probably both of them targeted smaller prey (well, all prey on that time was smaller than them!  ) and probably they avoided each other.
Sea predators:
I was navigating in the web when I found the following comparative image:  *This image is copyright of its original author Since the beggining I identified the source of the marine reptiles but the image of the orca, white shark and Livyatan is grossly exagerated and that of Megalodon is the constant incorrect copy-paste of the white shark. So, I decided to make my own comparative image using the images from several artists and escalate them with the correct measurements available in litterature, here is the result:  *This image is copyright of its original author The image is self-explanatory, I quote the sources of each measurement that I used for all the beasts and I used the same grid for the uper images, each grid is 1 meter. Those from Randomdinos and Slate Weasel are they own escalations, so that is why you will see discrepancies between them for the same specimens. There are only two points that I will like to mention: 1 - The skull of the Tylosaurus "Bruce" is mentioned at 180 cm, but I remember (and I saw it in youtube just to confirm) that the skull was actually measured at about 190 cm (6 ft 23 in). So I don't know if Randomdinos used a paper to quote his size or maybe is because the skull was measured from its side and not from the middle of the skull. 2 - The holotype specimen for Shonisaurus sikanniensis was presented at 19.6 m by Randomdinos, but the paper of Nichols and Manabe (2004) says that the speciment measured 21 m, just like the webpage of the Royal Tyrrel Museum. So, for pure curiosity and used his image and escalated to the 21 m (in red) and there is no significant difference. Now, what I need to admit is that none of the giant marine reptiles is a match to Megalodon, in size issues at least. The giant Ichthyosaurus were more like whales, so the only predator that match the size of Megalodon is Livyatan. Othe thing is that none of this animals is a match for the blue whale, in both size and weight, and even when there is an estimation for a giant Ichthyosaurus at 26 meters, as you can see part of that length will be of the tail which is not as muscular as that of the whale. So, from my point of view, mammals still rules in the sea. There are many other comparative images in the web, but I an not sure of what sized they use and if the escalations are correcto, so I suggest caution if you want to use them.
Recent studies & research (2021-2022) show that Megalodon was even larger and more formidable than previously thought. This giant shark reached 20 meters in length, occupied the absolute highest trophic level than any other marine predator of all time and was so massive, it could completely devour the largest killer whales in just five quick bites, and swallow a large great white shark whole!
The research also indicates that no creature, no matter what size, (including other large predators) were safe from the megalodon. It was the undisputed top apex predator of the ocean and dominated and ruled the ocean, preying on all animals, even other large predators. Megalodon Sat Higher Up The Food Chain Than Any Other Ocean Predator Ever Everything was a catch of the day to the megalodons. The megalodon – aka megatooth shark, Otodus megalodon – was a mighty beast that once roamed the ancient oceans. They were larger than any other predatory sharks at the time, reaching a whopping 16 meters (52 feet). For comparison, the current biggest predatory fish in the ocean are female white sharks, averaging 4.5 meters (15 feet). Unfortunately for them (but fortunately for many marine animals), the megalodon went extinct 3.6 million years ago. In a new study published in Science Advances, scientists revealed that the megalodon occupied the highest trophic level (the position of an organism in a food web) than any other ocean predator, living or extinct. https://www.iflscience.com/megalodon-tee...hain-64167 What did Megalodon eat? Anything it wanted — including other predators New Princeton research shows that prehistoric megatooth sharks, the biggest sharks that ever lived, were apex predators at the highest level ever measured. A team of Princeton researchers has now discovered clear evidence that Megalodon and some of its ancestors were at the very highest rung of the prehistoric food chain – what scientists call the highest “trophic level.” Indeed, their trophic signature is so high that they must have eaten other predators and predators-of-predators in a complicated food web, say the researchers. https://www.princeton.edu/news/2022/06/2...-predators https://www.science.org/doi/10.1126/scia...ookieSet=1 https://www.science.org/doi/10.1126/sciadv.add2674 The extinct shark Otodus megalodon was a transoceanic superpredator: Inferences from 3D modeling We used an exceptionally well-preserved fossil to create the first three-dimensional model of the body of this giant shark and used it to infer its movement and feeding ecology. We estimate that an adult O. megalodon could cruise at faster absolute speeds than any shark species today and fully consume prey the size of modern apex predators. A dietary preference for large prey potentially enabled O. megalodon to minimize competition and provided a constant source of energy to fuel prolonged migrations without further feeding. Together, our results suggest that O. megalodon played an important ecological role as a transoceanic superpredator. Hence, its extinction likely had large impacts on global nutrient transfer and trophic food webs. https://www.science.org/doi/10.1126/sciadv.abm9424  *This image is copyright of its original author Ancient megalodon was so massive it could've snacked on killer whales, scientists say We're going to need a bigger boat — maybe something like a cruise ship. Scientists recently discovered just how massive an ancient shark might've been. It is freaking staggering. The otodus megalodon — you know, the infamous meg you've likely heard of — was so large it could have snacked on orcas, colloquially known as killer whales. That's according to a new study, published in Science Advances, that made a 3D model of what the shark likely looked like by using an "exceptionally well-preserved fossil." In short, and I'm taking some liberties here, the researchers concluded the megalodon was an absolute unit that was the unquestioned master of the entire ocean. "We estimate that an adult O. megalodon could cruise at faster absolute speeds than any shark species today and fully consume prey the size of modern apex predators," the researchers wrote. Just how big the megalodon was is pretty difficult to comprehend. The shark, which cruised Earth 23 to 2.6 million years ago, likely could've swallowed a large great white in a single bite. Researchers think a large megalodon grew up to 20 meters long. That's a shark nearly the size of an 18-wheeler. It could eat the largest current-day killer whale (around 26 feet) in five quick bites, one of the researchers wrote. The new 3D model was an important step forward in researching the megalodon, which has remained somewhat of a mystery to scientists. Their bodies were largely made of cartilage, which means fossils — except for massive teeth — are rare. But now we have a better picture of just how massive, and impressive, the ancient animals really were. https://sea.mashable.com/life/21190/anci...ntists-say In a new 3D modelling study published this week in Science Advances, we show that the giant extinct shark, Otodus megalodon, was a true globetrotting super-predator.  *This image is copyright of its original author It was capable of covering vast distances in short order, and could eat the largest of modern living super-predators, the killer whale, in five gargantuan bites. It could have swallowed a great white shark whole. Based on other isolated fossil vertebrae, it’s likely the largest megalodon grew to 20 metres in length. We further determined that the Belgian specimen’s maximum gape was around 1.8 metres and that its stomach could have held 9.5 cubic metres of food. This suggests it could have entirely consumed the largest of living killer whales (around 8 metres) in just five bites. Hypothetically, it could have eaten another iconic super-predator, the Tyrannosaurus rex, in just three bites. As for great white sharks, a megalodon could have swallowed a large one whole. Results from our analysis of energetics suggest that having eaten a big killer whale for breakfast, this megalodon could have travelled around 7,000km before needing to feed again. In short, our results show that megalodon really was the super-predator it’s been cracked up to be, and more. No creature, no matter its size, was safe from the jaws of this super shark. Its extinction likely sent tremendous cascading effects through marine environments of the time. https://theconversation.com/ancient-mega...als-188749 Faster than today’s sharks and swallowing them whole Not only was the otodus megalodon big but it was fast for its size. It was capable of reaching speeds of 10.3 m/s, allowing it to travel great distances across the ocean in a short amount of time. The research showed that it could swim seven times faster than the largest sharks of today such as the whale shark.  *This image is copyright of its original author It’s teeth have been measured to be up to 18 centimeters long. This allowed it to chow down on species in similar size to the humpback whale and blue whale, the biggest mammal on Earth today. It could eat a killer whale in just five bites and swallow a great white shark whole. https://www.esquireme.com/news/extinct-m...enhungrier |
| Users browsing this thread: |
| 1 Guest(s) |