00:00 It was the largest fish our Earth had ever seen and its bite was strong enough to crush a car.
00:07 The largest of its teeth found was the length of a remote control.
00:11 It consumed about 2,500 pounds of food a day.
00:16 That's like 3,300 cans of tuna for you.
00:20 The earliest megalodon fossils are from about 20 million years ago.
00:25 But you won't see its skeleton and that's because the mighty Meg had no bones.
00:31 A skeleton made from bones gives most animals their body shape and strength.
00:36 Sharks though come from the same subclass as rays, skates and sawfish and have cartilage instead of bones.
00:43 Cartilage is a tissue that is softer and more flexible than bones,
00:47 but it's still tough enough to shape the body and protect the internal organs.
00:51 Some areas are more flexible since cartilage is weaker and some, like the shark's head,
00:56 are much tougher thanks to calcified cartilage.
00:59 Their snouts though are made of really soft and flexible cartilage
01:04 to work like a bumper in case of a collision with some dangers.
01:08 Who knows if they'd be able to do all this with a heavy skeleton.
01:12 Plus, cartilage makes their jaws more flexible and they can open their mouths much wider than they would with a jaw made of bone.
01:19 Our hero, Meg, was no exception and it had the strongest bite of all living creatures,
01:25 which was also made possible by a skeleton made of cartilage.
01:29 Sharks take full advantage of their cartilage.
01:32 It helps them swim and turn fast while hunting.
01:35 One drawback of this type of skeleton is that it was really tricky for scientists to establish the shape and size of Meg.
01:44 Normally, they would do it using fossilized bone skeletons or their parts.
01:49 With Meg, they had to guess based on the teeth they found and comparisons with living relatives.
01:55 A more recent 3D computer model was based partially on scans of a preserved spine discovered in the 1860s.
02:04 The model showed that Meg was bigger, faster, and even hungrier than scientists had previously thought.
02:11 Looks like an average Megalodon was 52 feet long.
02:15 That's slightly bigger than the height of the Hollywood sign and weighed 10 times as heavy as an elephant.
02:21 There were also much bigger creatures.
02:24 Scientists still aren't sure how the Megalodon got this size.
02:29 The fact that there were bigger and smaller Megs probably has to do with a little something called Bergman's rule.
02:35 It says that the temperature of the surrounding environment affects the animal's body size because they either need to conserve or shed heat.
02:44 The Megalodons that reached cooler waters probably needed more body weight to make sure they survived in low temperatures.
02:51 Those living in warmer waters had to be smaller to avoid burning up.
02:55 If the researchers were correct in their calculations, it also means that Meg reached a cruising speed of over 3 miles per hour, which is much faster than other sharks.
03:06 The still-living Great White Shark can cover a distance of nearly 7,000 miles without stopping, which is 9/10 as long as the diameter of Earth.
03:16 It looks like the Megalodon could have gone much further.
03:20 Megalodons managed to survive on our planet for nearly 70 times longer than humans have.
03:26 They were roaming the oceans for around 20 million years and you could see them pretty much anywhere except near the poles.
03:33 Scientists discovered the most northern fossils off the coast of Denmark and the most southern in New Zealand.
03:39 The reason why there were no Megalodon teeth found in Antarctica is most likely that these adapted to only warm tropical and subtropical waters.
03:49 The younger ones liked to keep to the shores, while full-grown adults preferred coastal areas, but they could easily move into the open ocean as well.
03:59 When our planet went through a period of global cooling and drying and the seas began to freeze around 3.6 million years ago, there was less and less room for Meg to thrive.
04:10 Much of their prey, like smaller whales, seals, and sea turtles, disappeared or relocated to waters that were too cold for our hero.
04:18 And at the same time, the number of its natural competitors, like smaller predatory sharks like the great white shark, and whales increased.
04:27 This shifting food chain dynamics could have been even more dangerous for the Meg than the cold ocean water.
04:34 You're used to seeing them on the big screen as heartless monsters, but these huge sharks were actually loving and caring family guys.
04:42 Scientists discovered several Megalodon nursery areas in Florida, Maryland, Panama, and off the coast of Spain.
04:50 It looks like they gave birth to their young in shallow water environments.
04:54 Then, little Megs would stay there with adults protecting and raising them until they were ready to fight off predators.
05:01 The mighty Meg had 276 teeth in five rows in its mouth.
05:07 Similar to other sharks, it was fast in replacing its worn out or lost teeth.
05:12 With four or five rows of teeth in its mouth, it basically acted like a conveyor belt, able to grow back damaged or missing teeth.
05:20 This means that an adult Megalodon probably would have grown several thousand teeth throughout its lifetime.
05:27 Although the great white shark is often mentioned as Meg's closest relative, they'd hardly be distant cousins.
05:34 The ancestors of today's great white existed at the same time as the Meg, but they weren't best friends and even rivaled each other.
05:43 The great white shark wouldn't win in a head-to-head fight with a Meg, but it was a better hunter using its smaller size and agility to snap up the giant's prey quickly.
05:53 This only left the bigger fish and whales for the Meg, but its food supplies began to run out as the whales swam to the cooler new seas.
06:02 Rather than a great white, the Megalodon is more like a modern bull shark.
06:07 It had a short snout, a flat lower jaw, and huge pectoral fins to support its massive weight and size.
06:15 We also speak of Meg as an extinct giant, but can we be 100% sure it isn't hiding somewhere as we speak?
06:24 After all, we've only explored 5% of our oceans altogether.
06:29 The Mariana Trench is the deepest oceanic trench on Earth, and you could dip the whole of Mount Everest in its deepest part, and over a mile of it would still be above the surface.
06:40 If a Megalodon or two needed a place to hide, that would be the perfect spot.
06:45 It wouldn't be the coziest place to live though, with its cold water and total darkness.
06:50 Plus, the pressure there is 1000 times stronger than at sea level, so if a Meg really were hiding down there, it would have serious issues with its teeth, because calcium would dissolve under that pressure.
07:04 To survive here, it would also need to learn to navigate in complete darkness.
07:09 That means it would have either become bioluminescent or evolved to grow massive eyes like the giant squid.
07:16 If the Meg were still around and true to its dietary choices, it would have to eat smaller fish, and that would be a problem for us humans.
07:25 Especially those of us who love fish that is.
07:28 And the ocean isn't cooling down these days.
07:31 The Megalodon would love its temperature and would thrive and reproduce faster than ever.
07:36 Those giants would create some massive problems for cargo ships and cruising vessels.
07:42 In case you're now scared at the thought of meeting a Megalodon, relax.
07:46 Most scientists don't think it's possible because of our hero's size.
07:50 Most foods that Megalodons like to eat live in shallow ocean areas and not in the deep, deep sea.
07:57 Meg would need to come up for dinner every now and then, and it's kinda hard to miss a creature this big.
08:03 They're both giant prehistoric creatures to us, but the Megalodons and the dinosaurs never actually coexisted.
08:10 The dinosaurs probably died out about 66 million years ago.
08:15 Megalodons seem to have appeared a bit later.
08:18 That's it for today. So hey, if you pacified your curiosity, then give the video a like and share it with your friends.
08:24 Or if you want more, just click on these videos and stay on the bright side.
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