Print Eyewitness Signatory with airSlate SignNow

Print eyewitness signatory

[Music] [Music] tyrannosaurus rex the largest meat-eater ever to walk the earth one of the hundreds of dinosaurs that have been reconstructed and well not exactly brought back to life dinosaur has only come back to life in the movies and they've been dead for 64 million years before humans appeared on earth or on the menu if anything it's been the human imagination that's fed on dinosaurs with taste ranging from green and comic to the global and serious game of paleontology since the first dinosaur fossils were identified almost 200 years ago it's been science that's fueled science fiction the evidence unearthed by paleontology the study of fossils and ancient life-forms has given new life to the dinosaur and set them roaming across the landscapes of our imagination [Music] and with the new fossil being discovered about every seven weeks our knowledge of dinosaurs is growing by leaps and bounds where did the name dinosaur come from Sir Richard Owen rode into history when he declared that the fossils of giant animals being discovered in England in the early 1800s should be called Dinosauria meaning terrible lizards why lizards we know dinosaurs were similar to reptiles because fossils have revealed that they had scaly skin and laid eggs it's the dinosaur body plan which sets them apart from the reptiles 250 million years ago the reptile design of the day incorporated the short sprawling legs of the lizard and the short bent-kneed legs of ancient crocodiles dinosaurs evolved because of a breakthrough in leg design dinosaur legs were longer and tucked under the body and this breakthrough came in both 4 & 2 legged models dinosaurs could not only stand up they could run faster than anything else around this ability to pursue or escape pursuit was a major factor in the dinosaurs success t-rex enjoyed its success by eating its own weight in meat every week that 7 tonnes or the equivalent of 12 cows the first t-rex found wasn't called to rhinosaurus Rex when Barnum brown known as mr. bones because he found so many dinosaurs dug up the first t-rex in 1900 he identified it as a large meat-eater and called it dynamo soros imperio psious but venema soros imperio psious an overnight sensation in the world of paleontology would soon change its name to something more befitting the largest meat-eater ever to kill for a living Tyrannosaurus Rex literally tyrant Lizard King people have been finding dinosaur bones all over the world for 2,000 years people like the Chinese have always called them dragons the first known dinosaur extinction theory is attributed to the third century writer Chang Chu who explained the mystery of dinosaur bones by writing a dragon ascended a mountain and went directly to the gate of heaven the gate being locked the dragon fell back to earth and died at this spot later it sank into the earth [Music] although we may never be able to completely answer the why of dinosaur extinction we do know the wind [Music] 225 million years ago when dinosaurs first appeared the earth was a very different place all the land was joined together in one supercontinent called Pangea for the next 160 million years dinosaurs dominated the earth to get an idea of this immense time scale imagine a book 225 pages long each page equal to 1 million years dinosaurs would be the main characters for the first 160 pages mammals would take over for the last third of the book humans wouldn't appear until the top of the last page 1 million years ago and it wouldn't have been until the bottom of the last page that we even knew dinosaurs existed when the second t-rex was found in 1902 a large four leg found nearby was believed to belong to it it wasn't until 88 years later in 1990 when the 10th t-rex was excavated that paleontologists realized mr. bones got it wrong it wasn't the first mistake made in piecing together a dinosaur and it won't be the last when the freshest evidence to be found has been dead for 65 million years it's no wonder paleontology has a long tradition of getting things wrong one of the first bloopers occurred in England in 1820 dr. Gideon Mantell found some fossilized teeth and excavated Iguanodon named after the modern day iguana Iguanodon might be considered the beginning of Dino mania it was such a hit with the English public that a full scale model was built in Crystal Palace Park before the model was finished a dinner party was held inside it for 20 people the diners are long gone but the Iguanodon model is still there a monument to the pitfalls of paleontology what Mantell assumed to be a nose horn turned out to be a thumb spike on the iguanodons multi-purpose and what still remains a mystery is we're broken and buried under New York's Central Park are two similar statues maybe someday they'll be found by an urban paleontologist but man tells Iguanodon is just one example from over 1,000 dinosaur finds scattered across all the continents a tiny fraction of the billions of dinosaurs that must have lived during the 160 million year period known as the Mesozoic era what was it like then at the beginning of the Mesozoic era called the Triassic period when dinosaurs first evolved low shrubbery fern like plants dominated the landscape next came the Jurassic period when huge coniferous forests and groves of cycads supported the heyday of the plant eating dinosaurs then came the cretaceous period when the western part of North America was covered with extensive rivers deltas swamps and marshes when large herds of grazing dinosaurs were hunted by a smaller number of meat-eaters flowering plants had just begun to appear and the air was thick with t-rex breath although no one claims that t-rex could kill with its breath some believe the bacteria level was so high in its mouth that t-rex had only to deliver one septic bite then wait until its prey was brought down by the ensuing infection not so far-fetched when you consider the Komodo dragon the largest living lizard which uses such a septic bite when hunting in 1907 Barnum brown found the third t-rex with 8-inch teeth in a four foot long skull it was the most complete t-rex to date and would remain the largest found for the next sixty years even with the help of dynamite it took three summers to dig it out today excavation is a much more painstaking and exact science although plaster jackets are still used to protect the fossils during transport the use of modern heavy equipment has greatly sped up excavation and transfer to the lab a big help when the block of stone containing a perfectly preserved hadrosaur tale can be 2 yards of solid rock ironically much of the heavy equipment we use today could be considered the descendants of the very first heavy equipment dinosaurs for many dinosaurs were massively powerful creatures the first front loaders were the theropods big meat-eating dinosaurs who used their powerful necks and huge jaws to rip giant chunks of meat off a kill modern machinery has similar claws to rip through the earth the first cranes were the sauropods big plant eating dinosaurs that used their long necks to go where no herbivore had ever gone to the tops of trees although the bus-sized Stegosaurus was a gentle vegetarian few meat-eaters wanted to tangle with its spiked tail [Music] [Music] tails were used for much more than defense longneck dinosaurs were counterbalance like today's suspension bridges with long tails balancing their equally long necks the longest dinosaur neck found to date measures 33 feet even in two-legged dinosaurs the tail served as a balancing mechanism to counterweight various body builds and head designs from the smallest baby hadrosaur less than a yard in length to the 10 foot long meat-eating albertasaurus balance was crucial when several tons of dinosaur decided to run imagine a multi-ton ostrich and you begin to get an idea of how the swiftness of dinosaur predators might have moved but how fast were they paleontologists can calculate the answers from fossilized footprints called trace fossils the race to clock T Rex's top speed remains the subject of great debate opinions range from his slow as 15 miles an hour to his fast as 40 miles an hour it's certainly safe to say that a man would be lucky to finish the race fortunately for humans the only dinosaur bite will ever deal with is its overbite the largest on record belongs to t-rex number 4 found in 1966 the study of dentition or the shape size and wear of teeth tells us more about feeding habits than anything else and dinosaurs have left us great dental records most plant eating or habilis dinosaurs such as this Triceratops had cheek teeth for breaking down coarse vegetation before it was swallowed the record for the most teeth to Edmontosaurus also known as the tooth fairy's nightmare over 1,000 teeth acted like self sharpening vegetable graders the largest herbivores such as Diplodocus and Brachiosaurus had peg shaped teeth much like a horse which they used like race to strip leaves and needles off trees many of them didn't chew their food they swallowed it whole and what about the meat-eaters who fed on these herbivores from the Albertosaurus to the crocodile like Baryonyx most meat eaters or carnivores had dagger-like teeth and many such as t-rex had teeth with serrations like those on a steak knife to help rip meat off the bone [Music] [Music] [Applause] [Music] but t-rexes bark might have been worse than his bite were the biggest carnivores to walk the earth killers or just scavengers the best evidence that they hunted live prey is in fossilized footprints of one large theropod stalking a sauropod heard this kind of evidence also supports the theory that large herds of grazing dinosaurs were hunted by a smaller number of predators making the Mesozoic seem not unlike the African savanna of today [Music] with sickle like claws on its hind legs Deinonychus or terrible claw was the dinosaur equivalent of pack hunting wild dogs or wolves from a find in Montana we know that the 150 pound Deinonychus hunted down live prey the scene was reconstructed using hard evidence from the site a Deinonychus pack brought down a Tanana Saurus but not without paying a price before succumbing the Tanana Soros killed four of its attackers similar finds have revealed pack hunting Raptors at the site of other kills the carnivorous dinosaur is no longer hunt but are now hunted themselves by a human pack of fossil hounds in 1981 three Canadian high school students found the next t-rex black beauty named after the color of its fossilized bone only after it was cleaned in the lab did anyone realize how complete this 5 foot long skull was when a fossil is brought to the lab first the plaster casing is removed then it's often given an acid bath to remove the last of the stone covering the fossilized bone this process can take months or even years but not all dinosaurs were as big as t-rex many of them were in fact quite small as small as a bird and they came in all shapes and sizes with the heavyweight title going to Brachiosaurus tipping the scales at 77 tons that's heavier than two Boeing 737s although the largest dinosaurs have traditionally played the leading roles in popular entertainment it's the smaller dinosaurs that have starred in the debate over dinosaur descendants Compsognathus and seal offices have similar skeletons to Archaeopteryx the first bird this missing link supports the theory that modern birds are the nearest living relatives of small meat-eating dinosaurs and the nearest relatives of large dinosaurs like Baryonyx are crocodiles the ninth t-rex was found in 1987 and provided the first known tip of the tail vertebrae all the bones of t-rex had now been found except for those of its mysteriously shriveled four limbs the same area in North America that produced eight of the ten known t-rex's to date produced a find that would radically change our view of dinosaur family life a massive bone bed was discovered spread over several miles an estimated to contain the remains of a dinosaur herd 10,000 strong proof that dinosaur herds once roamed the American West like the Buffalo of a more recent era the most significant fine was the nesting grounds much like present-day sea birds which nest in colonies these dinosaurs called Maiasaura also nested in groups the eggs were laid in circular nests six feet across containing 20 to 25 seven-inch eggs they belong to several Maiasaura or good mother lizards who shared nesting feeding and babysitting duties once the young were hatched we know the hatchlings stayed in the nest and were fed by their parents because the nest were filled with trample shells you [Music] sometimes dinosaur eggs provided food for others / Raptors literally egg thieves were bird like dinosaurs that like their eggs raw like many modern-day birds and reptiles hadrosaurs had to guard their nests against predators dinosaurs probably also shared another trait with today's birds and reptiles they used sound to communicate with their young and some dinosaurs were louder than others Edmontosaurus had an inflatable nasal sack which amplified its call much like many animals living today dinosaur head gear was also used for a less harmonious activity head butting was probably the most popular way of resolving differences over territory or potential mates this tradition is still alive and well in many animals today in fact it's now believed that Triceratops with its three horns and massive frill saw more action going head-to-head with other Triceratops than it did in the popular image of a one-on-one with t-rex another long-held belief was shattered when the 10th t-rex was excavated by John Horner in 1990 his fossil 90% complete was the first to produce a complete forelimb the notion that t-rex had three fingers accepted since 1902 was false t-rex only had two but in the serious game of paleontology much larger mysteries still remain and opposing theories vie for the answers were dinosaurs cold-blooded like reptiles or warm-blooded like birds it's the kind of question paleontologists love to argue long into the night those who contend dinosaurs were warm-blooded point2 fossils found as far north as Alaska and northern Canada they say dinosaurs must have been warm-blooded because cold-blooded animals at the mercy of external temperatures couldn't have lived in such cold warm blooded theorists also contend that dinosaurs must have had the four chambered double pumped heart of today's mammals to supply them with enough blood pressure to pump blood up their long necks to their heads the heart of a cold-blooded animal couldn't have pumped enough blood to their brains and they would have been constantly fainting but the strongest evidence for dinosaurs being warm-blooded is that their bones are honeycombed with holes proof of a network of blood vessels as complex if not more complex than living mammals those who contend that dinosaurs were cold-blooded say all this evidence is full of holes they claim dinosaurs living in the cold north were mobile enough to head south for the winter and they gleefully point to the crocodile which has a four chambered heart yet is still cold-blooded they also suggest that the dinosaurs large size would have allowed it to store a great amount of heat warm-blooded cold-blooded given the lack of evidence the real answer may never come to light one thing paleontologists have few arguments about is how dinosaur muscle lay on the bone they can read the bones by looking at the ridges of smooth patches and grooves and determine how muscle tendons nerves and blood vessels were arranged however laying skin over the muscle is more a matter of guesswork from fossilized skin impressions we know that dinosaur skin was much like that of modern reptiles scaly tough and waterproof and probably came in the same variety of colors to break up the outline of the body some may have had stripes since blending in was important polka dots were unlikely but Armour was very popular the toughest armor belonged to ankylosaurus and yet even armor couldn't protect the ankylosaurus or any of the dinosaurs from extinction the greatest mystery of the dinosaurs is the what dunnit of their extinction there are many theories one holds that a huge increase in ultraviolet rays gave dinosaurs cataracts and they stumbled blindly into extinction it was once believed they became so huge in lethargy they died of boredom one of the more widely held theories is supported by the fact that about the time the dinosaurs disappeared a meteor 5 to 10 miles wide hit the earth throwing up a crater 93 miles wide and surrounding the earth in a huge cloud of dust and steam which blocked out the Sun for months possibly years the only problem with this theory is that fossil teeth have been found from dinosaurs that lived long after this cataclysmic event it's just such evidence that makes some scientists believe that the dinosaurs declined was more gradual and might have been because they couldn't keep their bodies cool enough in the increasingly hot summers falling sea levels possibly turned dinosaur habitats into deserts or the opposite may have been the case rising sea levels might have flooded lowlands where most dinosaurs lived of one thing we are certain after 160 million years of dominating the earth the dinosaurs did die out but life on earth continued to evolve until humans came along to ponder these fossilized remains and indulge in their fantastic reality some would say all over the world dinosaurs have made quite a comeback and there are more today than ever before although they are far from real perhaps they are the children born of our fertile imaginations and the hard evidence of dinosaurs mere shadows in the Stone [Music] [Applause] [Music] certainly there are many more dinosaurs waiting to be discovered many new mysteries waiting to be pondered and if it's true that life imitates art maybe someday we'll even bring them back to life [Music] you