WEBVTT - How Did Tyrannosaurus rex Work?

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<v Speaker 1>Welcome to Brainstuff, a production of iHeartRadio, Hey Brainstuff Lauren

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<v Speaker 1>Voleebaum here. The science fiction film Jurassic Park from nineteen

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<v Speaker 1>ninety three didn't just bring dinosaurs back to the forefront

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<v Speaker 1>of pop culture consciousness, It actually inspired some science of

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<v Speaker 1>its own. The film establishes early on that the Tyrannosaurus

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<v Speaker 1>rex's vision is based on movement, so the characters can

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<v Speaker 1>escape its notice if they can stand very still. That

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<v Speaker 1>got computer scientist Kent Stevens thinking. In two thousand and six,

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<v Speaker 1>he compared the eye socket orientation of several carnivorous dinos.

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<v Speaker 1>T Rex included. When you look straight ahead, the area

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<v Speaker 1>that both eyes can see simultaneously is called your binocular

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<v Speaker 1>field of view. The wider your binocular field of view,

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<v Speaker 1>the better your depth perception. So how did t Rex

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<v Speaker 1>measure up? According to Stephen's finding, these dinosaurs possessed an

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<v Speaker 1>impressive binocular field of view up to fifty five degrees wide.

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<v Speaker 1>Not even the hawks we have today can match this figure,

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<v Speaker 1>meaning Tyrannosaurus probably had great depth perception and division in general.

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<v Speaker 1>Of course, people were fascinated by the t rex long

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<v Speaker 1>before Jurassic Park came out. The paleontologist Henry Fairfield Osborne

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<v Speaker 1>coined the dinosaur's name in nineteen oh five, derived from

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<v Speaker 1>Latin and Greek Tyrannosaurus rex means tyrant lizard king. Osborne

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<v Speaker 1>named the species on the basis of an incomplete skeleton

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<v Speaker 1>found by the legendary fossil hunter Barnum Brown at a

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<v Speaker 1>Montana dig site in nineteen oh two. Two years before that,

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<v Speaker 1>Brown had discovered another carnivorous dinosaurs remains in eastern Wyoming.

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<v Speaker 1>A close inspection would prove it belonged to the same species,

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<v Speaker 1>although Osborne didn't recognize that at first. Osbourne's workplace, the

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<v Speaker 1>American Museum of now History in New York City, eventually

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<v Speaker 1>mounted one of Brown's t Rex specimens in nineteen fifteen.

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<v Speaker 1>Then the film industry stepped in. A stop motion animator

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<v Speaker 1>Willis O'Brien brought the beast to life for nineteen eighteen's

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<v Speaker 1>The Ghost of Slumber Mountain and Early Dinosaur Flick. And

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<v Speaker 1>t Rex has stayed in the public eye ever since.

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<v Speaker 1>As science historian Jane Davidson once noted, it's the animal

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<v Speaker 1>that probably springs to mind when most of us hear

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<v Speaker 1>the word dinosaur. Remains of around fifty individual Tyrannosaurus have

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<v Speaker 1>been found in western North America. These range from isolated

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<v Speaker 1>backbones to almost full skeletons claws down. The most complete

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<v Speaker 1>t Rex yet discovered is Sue, a beautiful find from

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<v Speaker 1>South Dakota. This celebrity skeleton is now on display at

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<v Speaker 1>the Chicago Field Museum. A Scientists have identified three hundred

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<v Speaker 1>and eighty bones that full grown Tyrannosaurus would have possessed.

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<v Speaker 1>Siou contains two hundred and fifty of these and is

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<v Speaker 1>about ninety percent complete by bulk of bones. Sue is

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<v Speaker 1>also one of the bigger skeletons on record. A t

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<v Speaker 1>Rex could grow to a hip height of roughly twelve

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<v Speaker 1>feet that's three point six meters, and could be forty

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<v Speaker 1>feet in length that's twelve meters. The skull alone is

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<v Speaker 1>over four feet long in large adults that's about one

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<v Speaker 1>point two meters. Only a couple known species of dinosaurs

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<v Speaker 1>may have been bigger. Gigantosaurus, a predatory dinosaur native to

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<v Speaker 1>what's now South America, might have been a midge longer

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<v Speaker 1>than t Rex, a couple extra feet from nose to tail,

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<v Speaker 1>and the fin backed Spinosaurus from what's now Africa could

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<v Speaker 1>have been over fifty two feet or sixteen meters long.

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<v Speaker 1>Guessing any dinosaur's weight is not an easy task because

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<v Speaker 1>generally speaking, their fossilized bones are what we have to

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<v Speaker 1>go on, and that doesn't tell us very much about

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<v Speaker 1>how filled out they might have been. I mean, if

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<v Speaker 1>you had to guess that what a penguin looked like

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<v Speaker 1>based just on bones, you might never make the jump

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<v Speaker 1>to the plump, well insulated bird. But by one calculation,

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<v Speaker 1>a full grown t Rex would have pushed some seventeen

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<v Speaker 1>thousand pounds that's about seven thousand, seven hundred kilos. At

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<v Speaker 1>that size, Tyrannosaurus may have been heavier than Gigantosaurus or Spinosaurus.

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<v Speaker 1>All three of these creatures actually belonged to the same group,

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<v Speaker 1>a huge and diverse array of dinosaurs known as the theropods.

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<v Speaker 1>Tyrannosaurus was part of a subgroup known as the tyrannosauroids.

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<v Speaker 1>T Rex was the largest and one of the last.

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<v Speaker 1>This subgroup first appeared in what's now Eurasia one hundred

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<v Speaker 1>and seventy million years ago during Earth's Jurassic Period. These

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<v Speaker 1>critters started small. An early species was only about the

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<v Speaker 1>size of an adult human being. Geologically speaking, t Rex

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<v Speaker 1>had a brief rain. The fossils this giant left behind

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<v Speaker 1>range from sixty eight to sixty five and a half

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<v Speaker 1>million years of age, so Tyrannosaurus was around to see

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<v Speaker 1>the last days of the Cretaceous period, which ended with

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<v Speaker 1>a mass extinction event. Birds, which are modern therapods, were

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<v Speaker 1>the only dinosaurs to survive this ordeal. At some point,

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<v Speaker 1>the tyrannosaurids entered what's now North America. No t Rex

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<v Speaker 1>remains have ever been found outside of this continent, but

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<v Speaker 1>a twenty sixteen paper speculates that the species could have

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<v Speaker 1>originated in Asia and later spread to the Americas. In

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<v Speaker 1>other words, perhaps Tyrannosaurus rex was an invasive species A

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<v Speaker 1>Judging by the bone microstructure evidence, it would have taken

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<v Speaker 1>to Tyrannosaurus twenty years or so to attain its maximum size.

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<v Speaker 1>Maturity came with some lifestyle changes. Adult t Rex had thick,

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<v Speaker 1>bananas shaped teeth, rigid skulls, and seriously powerful jaw muscles.

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<v Speaker 1>Those attributes gave the dinosaurs a punishing bite force of

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<v Speaker 1>around seven tons a, meaning that like hyenas, mature Trannosaurus

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<v Speaker 1>or consummate bone crushers. On the other hand, juvenile t

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<v Speaker 1>rex had narrow blade like teeth and weaker jaws, so

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<v Speaker 1>instead of ripping prey apart and eating them pretty much whole,

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<v Speaker 1>the youngsters probably specialized in slicing meat off of prey. Proportionally,

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<v Speaker 1>adolescent t rex had longer arms and legs than their

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<v Speaker 1>parents did. The forelimbs on an adult trannosaurus were only

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<v Speaker 1>about three feet long that's around a meter, which looked

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<v Speaker 1>kind of puny when you take their total body size

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<v Speaker 1>into account. Nobody knows what the function of these forelimbs was.

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<v Speaker 1>Maybe the pendages were hooks used to grasp struggling prey,

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<v Speaker 1>or maybe they helped the dinosaurs hang on to their

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<v Speaker 1>partners during intercourse. Their hind limbs were huge and powerful,

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<v Speaker 1>but according to biomechanical research published in twenty seventeen, t

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<v Speaker 1>rex legs weren't built for running. Instead, the dinosaur was

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<v Speaker 1>more of a speed walker, astriding across the prehistoric countryside

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<v Speaker 1>up to around twelve miles an hour that's nineteen kilometers

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<v Speaker 1>an hour. They were not picky about their meals, though

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<v Speaker 1>bitemarks attributed to this carnivore have been found on the

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<v Speaker 1>bones of triceratops on duck billed plant eaters called pattersaurids,

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<v Speaker 1>and even other Tyrannosaurus skeletons. Yes, friends, the tyrant lizard

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<v Speaker 1>king probably ate its own kind. Also, on top of

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<v Speaker 1>being a sharp eyed predator, Tyrannosaurus had a keen sense

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<v Speaker 1>of smell, as is evidenced by the contours of its

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<v Speaker 1>brain cavity. Today's episode is based on the article Tyrannosaurus

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<v Speaker 1>Rex was the Tyrant Lizard King on housdifforks dot com,

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<v Speaker 1>written by Mark Mancini. The brain Stuff is production of

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<v Speaker 1>iHeartRadio in partnership with houstfforks dot Com and is produced

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<v Speaker 1>by Tyler Kuang. Four more podcasts my heart Radio, visit

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