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Documentary, PaleoWorld PaeoWord S01E06 - Sea Monsters
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AnimalsTranscript
00:05The tranquil shores of the oceans mask an underwater world with a frightening and
00:10violent past. Very real monsters once prowled these depths, then vanished,
00:16leaving behind stunning proof of their existence.
00:23Today, paleontologists discover revelations about the mysterious and nightmarish monsters
00:28that once roamed the seas.
01:04In the ocean, safety has always been an illusion. Death strikes without warning or mercy.
01:11An attack begins with lightning speed. Razor-sharp teeth shred the flesh and pierce the bone.
01:20Incredibly, these predators, like the modern shark, pale in comparison to the creatures that once terrorized the seas.
01:29Imagine a creature larger and swifter than a killer whale and more powerful than a great white shark.
01:36Or an animal with a neck so long it could snatch a bird from the sky.
01:41One of these probably inspired the legend of the Loch Ness Monster.
01:48In Medicine Bow, Wyoming, about 50 miles northeast of Laramie, Robert Bakker is scouring the dirt for a glimpse of
01:57an ancient sea creature called the ichthyosaur.
01:59That's too much. I want a tooth. I've lived a pure life. I deserve a tooth.
02:08These deadly predators glided through the water and caught their prey with a toothy bite.
02:13While dinosaurs ruled the earth from 245 to 65 million years ago, reptiles ruled the sea.
02:23Ironically, their ancestors thrived on land and stalked their prey on four sprawling legs.
02:28But the pressures of survival forced them to adapt to life in the sea.
02:34The reason that these animals went from land to sea probably is simply pressure, pressure of your relatives.
02:42If you're born a reptile, if you're born a lion, you're growing up, you've got brothers, you've got aunts and
02:47uncles,
02:48all of them looking for prey, all of them looking for burrows, for a habitat, for a territory.
02:53It pushes you out. Evolution is a force which pushes outward.
02:58Well, if you're living on land, one way to go out is evolve into the water.
03:03And that's almost certainly why these guys went back into the water at the beginning of the Age of Reptiles.
03:08It became really common.
03:12245 million years ago, at the beginning of what is called the Mesozoic, the Age of Reptiles,
03:18the continents clustered together.
03:22Nutrient-rich water encircled the Earth, creating a global ocean called the Tethys.
03:30These nutrient-rich waters were ideal for the tiniest of sea creatures, the plankton.
03:37In Tethys, plankton multiplied to record numbers, filling the oceans in far greater quantities than now exist.
03:44The abundant plankton provided Mesozoic fish with an almost unlimited food supply.
03:51The fish population exploded to unparalleled levels, setting the stage for a new predator to exploit the bounty of food.
04:00For the first time, reptiles with compact bodies and powerful jaws took control of the seas.
04:10220 million years ago, this beautiful and isolated mountain range of central British Columbia lay at the bottom of an
04:18ocean.
04:20Since 1987, Chris McGowan of the Royal Ontario Museum has been coming here each spring, searching for the first of
04:27the ancient sea monsters.
04:33While most paleontologists chip slowly through the rock, McGowan and his team use harsher methods.
04:47The ground is hard and unmielding. The rock must be removed one layer at a time.
04:52All the while, the excavation team must keep a sharp eye.
04:55A bit of unusual rock may be a significant find.
04:59A clue to the strange and fantastic creatures that swam the ancient oceans.
05:07At first glance, the fragments don't resemble much, but these weathered samples are the fossilized bones of an ancient dolphin
05:15-like reptile called the ichthyosaur.
05:19Everybody knows about dinosaurs. Very few people know much about ichthyosaurs.
05:24Far better animal altogether than dinosaurs. Dinosaurs, they were living on the land. These guys are living in the sea.
05:31The first fossil of a seagoing reptile was discovered in England in 1811, over a decade before the first dinosaur
05:38was introduced to the world.
05:40As it was not wholly a fish, as one observer put it, the creature was named ichthyosaur, which means fish
05:48lizard.
05:50Powerful fin tail and flippers propelled them through the water.
05:53They could achieve bursts of up to 45 miles per hour, the speed of a modern jet-powered boat.
06:00As descendants of land reptiles, they still needed to breathe air, so they had nostrils high on their snouts.
06:07Their jaws, filled with razor-sharp teeth, made them predators to be reckoned with.
06:12Some were the size of a salmon, others as large as a whale.
06:16Their most prominent feature was their large eyes the size of cantaloupes for hunting at twilight or in dark waters.
06:24The ichthyosaurs were the first to exploit the abundant food supply in the oceans.
06:31At first, none challenged their domination.
06:33They harvested the seas, feasting on squid and giant ammonites, a shellfish three feet in diameter.
06:41But ichthyosaurs may have had an appetite that also included each other.
06:48For a few years people debated whether this was evidence of cannibalism, but it's quite sure that these are real
06:54individuals that belong to the animal containing them.
06:59They are in fact babies, and there's one famous specimen where there's an offspring actually in the process of being
07:06born at the time of death.
07:09I think actually this was a post-mortem birth.
07:12This happens with animals where after they've died, they decompose, the gas pressure in the abdomen pushes the fetus out.
07:22Since reptiles lay eggs, evidence of live birth shows how well adapted to life in the water these one-time
07:29land dwellers had become.
07:31Though they still needed to breathe air, baby ichthyosaurs were born underwater.
07:37With each new generation, the basic design of the ichthyosaur was also beginning to change.
07:42Over 100 million years, they lost their stocky reptilian shape and evolved a sleeker, more streamlined silhouette.
07:50It's the bullet-shaped, built-for-speed design that nature reproduces with a bottlenose dolphin.
08:02The reason for the change was new competition.
08:06Other reptiles retreating from the land wars where the dinosaurs were moving into the ocean.
08:12They would bring with them new ways of hunting and killing.
08:15The battle for the seas was just beginning.
08:23For centuries, sailors returned from voyages with fanciful tales of sea monsters.
08:28Even Hollywood has tried to cash in on our hunger for the absurd.
08:36It's the size of a dinosaur, and ten times more terrifying.
08:45Behind these stories lies a grain of truth.
08:49Monsters as large and deadly as any legend prowled the seas.
08:58For centuries, the quarries of Holzmaden, Germany, have supplied limestone for pavement and construction.
09:04But they have also yielded a more valuable commodity.
09:08The fossils of more than 3,000 ichthyosaurs.
09:14160 million years ago, a large inland sea covered much of what is now Europe.
09:19This quarry rested at the bottom of a lagoon, similar to the one in British Columbia.
09:35When a sea creature died, gases from decomposition lifted its body to the surface.
09:41The carcass would wash ashore, disintegrate, or be eaten.
09:45But every once in a while, a body sank to the sea floor.
09:49There, during a long sedimentation process, it would undergo several stages of fossilization,
09:56until the bones petrified into the limestone that is now called the Poseidon slates.
10:03Over the years, the Poseidon slates of southern Germany have surrendered spectacular finds.
10:09The Museum HALF, located in nearby Stuttgart, exhibits some of the best.
10:16They include the marine reptile plesiosaur.
10:19Bob Bakker thinks they are one of the most important creatures of the Mesozoic.
10:27These plesiosaurs are actually the reason the Age of Reptiles is called the Age of Reptiles.
10:33It was these giant marine, ocean-going reptiles found in the 1790s that gave people a hint that the oceans
10:42were ruled by these blizzard relatives.
10:46Nearly all of the plesiosaurs and other giant reptilian monsters of the ocean are found in continental interiors,
10:54what are called cratonic sea waves.
10:57These are shallow bodies of warm water that covered thousands of square miles
11:01in the middle of North America, in the middle of South America, in the middle of Australia.
11:05We think of continents as dry places. That's true today.
11:09In the past, that's not true.
11:11The continents were hosts, were holding up these immense areas of shallow, very rich marine habitat.
11:18The plesiosaurs began their successful domination of the seas 190 million years ago, as reptiles continued their journey into the
11:28oceans.
11:31Weighing five tons, about as much as an elephant, plesiosaurs had a large body crowned by a small head.
11:38Unlike ichthyosaurs, plesiosaurs kept their hind legs, which may have proven an advantage in shallow water.
11:48Plesiosaurs are what I call double penguins. Go to a zoo or an aquarium, watch penguins swimming around.
11:53They have one set of flippers, right? Just one set. One flipper on either side.
11:57They're incredibly fast and maneuverable.
12:00Plesiosaurs have flippers in the front end and the back end.
12:03They're the only animals ever to have evolved which combine the shoulder and the hips into this four-flippered configuration.
12:12They must have been incredibly fast and maneuverable, with huge eyes, very visual predators.
12:18This guy is a big-headed plesiosaur. Some of them will get heads four feet, five feet, ten feet long.
12:26Able to swallow something the size of a killer whale today, whole.
12:32One of the most successful sea reptiles, over two dozen species of plesiosaurs have been catalogued.
12:40The most distinguishing trait is the length of its neck.
12:43Those with stocky, porpoise-like necks are known as pliosaurs.
12:47This is a short-necked plesiosaur, called a pliosaur.
12:53Big one. Top predator in the system. Compact body.
12:59With a tail, with a bit of a fin for a rudder.
13:03And forceps of flippers, like penguin flippers.
13:10From the side, its large head looked like a crocodile's.
13:14Big eyes made for sharp vision.
13:16With its streamlined body and powerful flippers, the pliosaur was a virtual torpedo,
13:22cruising and maneuvering underwater at speeds up to 35 miles an hour.
13:28130 million years ago, in the early Cretaceous period, pliosaurs grew to incredible size.
13:35The largest was the chronosaur.
13:38This frightening species found in Australia was 50 feet long.
13:42Its head was 12 feet.
13:44Its jaws were large enough to engulf a cow.
13:50While the wide-mouthed pliosaurs grew bigger, the long-necked plesiosaurs grew longer.
13:54At 60 feet, the largest was Elasmosaurus.
13:59Its 40-foot neck was a cunning new weapon.
14:02Like a snake, it could strike out and ambush a hapless fish.
14:08Unlike ichthyosaurs, that had lost the ability to leave the oceans,
14:12plesiosaurs may have spent part of the time on land.
14:15Their bone structures exist, and they were amphibious.
14:19Their anatomy was similar to that of modern sea turtles.
14:22They had a wide, broad body over a bony, armored stomach region.
14:27With their strong hind legs, they may have crawled onto land to lay their eggs.
14:33This ability to escape to land for short periods may have been their only defense against another monster.
14:39For an even more deadly foe lurked in the sea 130 million years ago.
14:46This skull belonged to Mosasaurus Maximus.
14:49The Mosasaurus was more than a match for the plesiosaurs.
14:54If there was ever a dragon, this was it.
14:57From head to tail, it was 40 feet of sinew and brawn.
15:02The culmination of millions of years of adaptation gave the Mosasaurus a dreadnought design.
15:08This was not just survival of the fittest.
15:10This was survival of the deadliest.
15:12Evolutionary pressures created a monster designed for speed and killing.
15:21Bill Gallagher of the New Jersey State Museum is duly impressed by this titan of the seas.
15:27It was the king of the ocean in the late Cretaceous seas.
15:31It was the biggest, nastiest thing in the marine realm.
15:34It was undoubtedly the Tyrannosaurus rex of the seas.
15:40The skulls of the Mosasaurs were equipped with long pointed teeth with sharp edges.
15:46As if this weren't enough, double hinges allowed it to flex its jaws wider,
15:51momentarily dislocating them in order to bite off an enormous chunk of flesh or to swallow its prey whole.
15:58Its powerful jaw muscles could then slam shut, sealing the fate of the Mosasaurus prey.
16:05But that's not all.
16:07Inside the mouth and in the back of the head region are these series of teeth on the separate pterygoid
16:17bones.
16:17So it not only had this set of outside teeth, but positioned inside the skull was an additional set of
16:23teeth.
16:23It was sort of the alien of its time.
16:35Powered by its long flexible tail, it propelled itself through the water like an eel,
16:40steering with its four paddle-like flippers.
16:44What did a Mosasaur eat? Anything it wanted.
16:47It fed on plesiosaurs, ichthyosaurs, sharks, and on anything else unfortunate enough to cross its path.
16:54Their flippers and tails often bear the scars of attacks from their own kind.
17:00Mosasaurs evolved a variety of sizes and shapes, from the agile 16-foot platycopus to the intimidating Mosasaurus maximus that
17:09stretched 40 feet.
17:12The deep offered no protection for prey.
17:14The Mosasaur could dive 100 feet down and more.
17:18So well-adapted and highly efficient were the Mosasaurs that their strange disappearance near the end of the Cretaceous has
17:26puzzled scientists.
17:27What could kill so splendid a killing machine?
17:32Some suggest a change in climate may have disrupted the food chain, but Bob Baca disagrees.
17:38The most fascinating thing about these sea monsters, the most puzzling thing, is they're linked to the land predators.
17:46These are the top predators in the ocean, plesiosaurs.
17:49The top predators on land at the same time are dinosaurs, things like T-Rex and its ancestors.
17:55They didn't see each other.
17:56They're living thousands of miles from each other, not the same habitat, but they're linked like this in evolutionary history.
18:02When evolution hit T-Rex, it and all of its relatives went extinct.
18:08Evolution was hitting the plesiosaurs, and they were all going extinct.
18:13In the whole history of dinosaurs, there are six extinctions, major ones.
18:17Every time the land is hit, the ocean is hit.
18:20Top predators on land, top predators in the ocean.
18:23It's very hard to think of a single environmental event which will wipe out a top predator in the open
18:28ocean,
18:29and a top predator living at three or four or five thousand feet somewhere in a mountainous terrain.
18:34But it happened again and again and again.
18:37Climate won't do it.
18:39Change in rainfall, change in heat, change in summer drought, that won't do it either.
18:43Some people say meteorite strikes will do it.
18:45There's no evidence of meteorite strikes through most of the age of reptiles.
18:50So it has to be something else.
18:56Oddly, it may be the smallest of sea creatures that did these monsters in.
19:02Around 75 million years ago, a mysterious catastrophe shattered the delicate ecosystem.
19:10As the continents drifted, the ocean currents changed.
19:14The plankton population crashed.
19:17As they began disappearing, so did the fish and squid that fed on them.
19:22The mosasaurs and the plesiosaurs that depended on this bounty also began to disappear.
19:27The large seagoing reptiles were starved into extinction.
19:32Their ignoble demise left room for smaller creatures to reclaim the oceans.
19:37But the oceans were not necessarily a safer place.
19:40The hunting grounds were ripe for a new killer.
19:44Bigger and deadlier than any that went before it.
20:12In the movie Jaws, a great white shark held hostage a New England resort town.
20:18Measuring 20 feet, the shark was large enough to terrorize millions of moviegoers.
20:26But some 25 million years ago, a relative of the great white prowled the waters.
20:33Although the extinct shark Megalodon dwarfed the great white, a clear family resemblance is undeniable.
20:45While remains of these monsters have been found the world over, Dr. Michael Gottfried of the Calvert Marine Museum has
20:52been hunting shark fossils on the shores of the Chesapeake Bay.
20:56The Megalodon, or the Megatooth shark, as we sometimes like to call it, grew to over probably about 50 feet
21:02in length.
21:02We estimate from the size of the teeth on the Megalodon, comparing them to the size of the living type
21:07of great white shark, that it reached at least 52 feet in length and probably something over 50 tons.
21:13In human terms, that's about the size and about as big around as a greyhound bus and about the weight
21:19of about seven or eight Tyrannosaurus rex dinosaurs.
21:22They're sort of the epitome of predatory shark evolution, the biggest, baddest sharks that ever lived.
21:29His model of this giant is one-eighth the size of the actual shark.
21:34A single tooth from the mouth of this giant shark measures six inches long and five inches at the base.
21:42The Megalodon teeth are incredibly sharp, and not only do they have a very sort of razor-sharp edge right
21:48along the tooth, but they're serrated like a steak knife.
21:51So not only could they slice just because of the sharpness of the edge, but they could saw back and
21:55forth with this serrated edge to cut through meat and even bone.
22:00And they found the tips of these bits of these teeth broken off in whale bones.
22:04So we know that they were capable of biting right through the skin, right through all the muscle, right into
22:09the bone.
22:14The jaw of the Megalodon spanned almost six feet, more than enough to swallow a dolphin or a man in
22:21one gulp.
22:23Why these monsters got so big has remained an intriguing mystery.
22:28One answer may be that they fed on large creatures such as whales and dolphins.
22:35Unfortunately, other questions may never be answered.
22:38Sharks are largely cartilage, which doesn't fossilize.
22:42Teeth and vertebrae such as this make up the few remains of Megalodon.
22:47It is doubtful that much more will ever be found.
22:52The limited fossil record does not reveal what happened to these giant sharks.
22:56They may have become too large and outmaneuvered by smaller, more agile sharks.
23:01Or the larger animals they preyed upon could have retreated to colder waters out of the Megalodon's reach.
23:07Whatever the cause, most paleontologists believe they finally died out some two million years ago.
23:22Gone forever are the monsters of the Mesozoic, which fuel our nightmares and fire our imaginations.
23:30The dolphin-like ichthyosaur, the long-necked plesiosaur, and the horrific mosasaur have turned to dust.
23:38Their fragile fossils, coaxed from the ground, bear witness to their once awesome dominion under the sea.
23:49Gone too are the huge and menacing sharks that followed.
23:54The streamlined terrors whose descendants ruled the seas today.
24:05Rocks hold clues to the Earth's subtle, relentless changes over eons,
24:10and to nature's constant refinement of the creatures that inhabit the Earth.
24:39So the vantage lot at the temperature.
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