How Did Tyrannosaurus rex Work?

The 'tryant king' of the dinosaurs has been inspiring science (and science fiction) since it was first discovered. Learn how Tyrannosaurus worked in this episode of BrainStuff, based on this article: https://animals.howstuffworks.com/dinosaurs/tyrannosaurus.htm

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Episode Transcript

Speaker 1 (00:01):
Welcome to Brainstuff, a production of iHeartRadio, Hey Brainstuff Lauren
Voleebaum here. The science fiction film Jurassic Park from nineteen
ninety three didn't just bring dinosaurs back to the forefront
of pop culture consciousness, It actually inspired some science of
its own. The film establishes early on that the Tyrannosaurus

(00:25):
rex's vision is based on movement, so the characters can
escape its notice if they can stand very still. That
got computer scientist Kent Stevens thinking. In two thousand and six,
he compared the eye socket orientation of several carnivorous dinos.
T Rex included. When you look straight ahead, the area

(00:46):
that both eyes can see simultaneously is called your binocular
field of view. The wider your binocular field of view,
the better your depth perception. So how did t Rex
measure up? According to Stephen's finding, these dinosaurs possessed an
impressive binocular field of view up to fifty five degrees wide.

(01:06):
Not even the hawks we have today can match this figure,
meaning Tyrannosaurus probably had great depth perception and division in general.
Of course, people were fascinated by the t rex long
before Jurassic Park came out. The paleontologist Henry Fairfield Osborne
coined the dinosaur's name in nineteen oh five, derived from

(01:27):
Latin and Greek Tyrannosaurus rex means tyrant lizard king. Osborne
named the species on the basis of an incomplete skeleton
found by the legendary fossil hunter Barnum Brown at a
Montana dig site in nineteen oh two. Two years before that,
Brown had discovered another carnivorous dinosaurs remains in eastern Wyoming.

(01:50):
A close inspection would prove it belonged to the same species,
although Osborne didn't recognize that at first. Osbourne's workplace, the
American Museum of now History in New York City, eventually
mounted one of Brown's t Rex specimens in nineteen fifteen.
Then the film industry stepped in. A stop motion animator

(02:10):
Willis O'Brien brought the beast to life for nineteen eighteen's
The Ghost of Slumber Mountain and Early Dinosaur Flick. And
t Rex has stayed in the public eye ever since.
As science historian Jane Davidson once noted, it's the animal
that probably springs to mind when most of us hear
the word dinosaur. Remains of around fifty individual Tyrannosaurus have

(02:36):
been found in western North America. These range from isolated
backbones to almost full skeletons claws down. The most complete
t Rex yet discovered is Sue, a beautiful find from
South Dakota. This celebrity skeleton is now on display at
the Chicago Field Museum. A Scientists have identified three hundred

(02:59):
and eighty bones that full grown Tyrannosaurus would have possessed.
Siou contains two hundred and fifty of these and is
about ninety percent complete by bulk of bones. Sue is
also one of the bigger skeletons on record. A t
Rex could grow to a hip height of roughly twelve
feet that's three point six meters, and could be forty

(03:19):
feet in length that's twelve meters. The skull alone is
over four feet long in large adults that's about one
point two meters. Only a couple known species of dinosaurs
may have been bigger. Gigantosaurus, a predatory dinosaur native to
what's now South America, might have been a midge longer
than t Rex, a couple extra feet from nose to tail,

(03:41):
and the fin backed Spinosaurus from what's now Africa could
have been over fifty two feet or sixteen meters long.
Guessing any dinosaur's weight is not an easy task because
generally speaking, their fossilized bones are what we have to
go on, and that doesn't tell us very much about
how filled out they might have been. I mean, if

(04:03):
you had to guess that what a penguin looked like
based just on bones, you might never make the jump
to the plump, well insulated bird. But by one calculation,
a full grown t Rex would have pushed some seventeen
thousand pounds that's about seven thousand, seven hundred kilos. At
that size, Tyrannosaurus may have been heavier than Gigantosaurus or Spinosaurus.

(04:28):
All three of these creatures actually belonged to the same group,
a huge and diverse array of dinosaurs known as the theropods.
Tyrannosaurus was part of a subgroup known as the tyrannosauroids.
T Rex was the largest and one of the last.
This subgroup first appeared in what's now Eurasia one hundred
and seventy million years ago during Earth's Jurassic Period. These

(04:53):
critters started small. An early species was only about the
size of an adult human being. Geologically speaking, t Rex
had a brief rain. The fossils this giant left behind
range from sixty eight to sixty five and a half
million years of age, so Tyrannosaurus was around to see
the last days of the Cretaceous period, which ended with

(05:14):
a mass extinction event. Birds, which are modern therapods, were
the only dinosaurs to survive this ordeal. At some point,
the tyrannosaurids entered what's now North America. No t Rex
remains have ever been found outside of this continent, but
a twenty sixteen paper speculates that the species could have

(05:36):
originated in Asia and later spread to the Americas. In
other words, perhaps Tyrannosaurus rex was an invasive species A
Judging by the bone microstructure evidence, it would have taken
to Tyrannosaurus twenty years or so to attain its maximum size.
Maturity came with some lifestyle changes. Adult t Rex had thick,

(05:59):
bananas shaped teeth, rigid skulls, and seriously powerful jaw muscles.
Those attributes gave the dinosaurs a punishing bite force of
around seven tons a, meaning that like hyenas, mature Trannosaurus
or consummate bone crushers. On the other hand, juvenile t
rex had narrow blade like teeth and weaker jaws, so

(06:23):
instead of ripping prey apart and eating them pretty much whole,
the youngsters probably specialized in slicing meat off of prey. Proportionally,
adolescent t rex had longer arms and legs than their
parents did. The forelimbs on an adult trannosaurus were only
about three feet long that's around a meter, which looked

(06:44):
kind of puny when you take their total body size
into account. Nobody knows what the function of these forelimbs was.
Maybe the pendages were hooks used to grasp struggling prey,
or maybe they helped the dinosaurs hang on to their
partners during intercourse. Their hind limbs were huge and powerful,

(07:04):
but according to biomechanical research published in twenty seventeen, t
rex legs weren't built for running. Instead, the dinosaur was
more of a speed walker, astriding across the prehistoric countryside
up to around twelve miles an hour that's nineteen kilometers
an hour. They were not picky about their meals, though

(07:26):
bitemarks attributed to this carnivore have been found on the
bones of triceratops on duck billed plant eaters called pattersaurids,
and even other Tyrannosaurus skeletons. Yes, friends, the tyrant lizard
king probably ate its own kind. Also, on top of
being a sharp eyed predator, Tyrannosaurus had a keen sense

(07:48):
of smell, as is evidenced by the contours of its
brain cavity. Today's episode is based on the article Tyrannosaurus
Rex was the Tyrant Lizard King on housdifforks dot com,
written by Mark Mancini. The brain Stuff is production of
iHeartRadio in partnership with houstfforks dot Com and is produced
by Tyler Kuang. Four more podcasts my heart Radio, visit

(08:11):
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