Welcome back to the Deep Dive. Today we are clearing
the table. We are pushing aside the niche topics
and the obscure mysteries for a moment to tackle
the big one. And you really don't mean big. I
do mean the big one. The ultimate dinosaur. The
one that every single person listening from,
you know, toddlers to grandparents knows by name.
Or at least they know the abbreviation. Yeah.
It's the only dinosaur that has that kind of
celebrity status where you don't even need the
full name. T -Rex. Exactly. We are talking about
Tyrannosaurus Rex, the king. And honestly, I
think most of us carry around a very specific
mental model of this animal. Oh, for sure. It's
the movie monster. It's the thing rippling the
water in the plastic cup. It's the jeep chaser.
But looking through this massive stack of research
you've brought today. The reality is so much
stranger than the blockbuster version. It really
is. The popular image of T -Rex has been, well,
it's been frozen in time since the early 90s,
essentially. But the science, the science has
been moving at light speed. We aren't just looking
at a movie monster anymore. We are looking at
a biological marvel. We're going to be talking
about an animal that pushes the absolute limits
of what is physically possible for a bipedal
predator. And that's what I want to do today.
I want to peel back all those layers of pop culture.
We're going to reconstruct the real king. We're
going to talk about whether it had lips, the
raging debate over whether it had feathers, the
controversy over whether it's actually three
different species, and the absolute nightmare
mechanics of its bite. And we're going to do
this by looking at how paleontology actually
works, because we aren't just guessing anymore.
We're moving from looking at broken bones to
understanding life history, growth rates, cellular
biology. and even complex social behavior. It's
like a detective story. It is. It's a detective
story that's been running for over 100 years.
So let's set the stage. We all know the name,
Tyrannosaurus Rex. Tyrant Lizard King. It has
to be the coolest scientific name ever coined.
It is hard to beat, I have to admit. It was named
by Henry Fairfield Osborne way back in 1905.
And right from the start, there was this recognition
that this animal was the ruler of its domain.
Where was that domain exactly? It lived in western
North America on what was then a separate island
continent called Laramidia. This was right at
the very end of the age of dinosaurs, the Maastrichtian
age, so about 69 to 66 million years ago. So
it was there for the curtain call. Exactly. It
was one of the last non -avian dinosaurs to walk
the Earth before the asteroid hit. It saw the
end of the world. Wow. But before that, it was
the apex. And when I say apex, I don't just mean
it was at the top of the food chain. I mean,
it dominated the ecosystem in a way very few
predators ever have. Okay, let's unpack the sheer
scale of this beast, because I think sometimes
the numbers get lost. We hear big, but how big
are we talking? Well, let's look at the most
famous specimen, Sue, which is housed at the
Field Museum in Chicago. Sue has been the gold
standard for a long time. Right, everyone knows
Sue. And for good reason. We are talking about
a skeleton that is roughly 12 .3 to 12 .4 meters
long. Which is what? In feet? About 40? About
40 to 41 feet, yeah. That's a school bus. A living,
breathing school bus with teeth. A very heavy
school bus. Sue stands nearly 4 meters tall at
the hips. That's 13 feet. So its back is higher
than a basketball hoop. Unbelievable. But the
weight is where the modern science has really
changed our understanding. How so? Did we used
to think they were lighter? Oh, much. For a long
time, we thought of dinosaurs as these sluggish,
tail -dragging lizards. The models were, let's
say... A bit shrink -wrapped. Right. But modern
estimates, using 3D mathematical slicing and
volumetric displacement models, have bulked them
up significantly. We now put the mass of a mature
adult like Sue around 8 .8 to 9 .2 tons. Nine
tons. That is significant. That's two large African
elephants taped together. And balancing on two
legs. That's the key. And Sue isn't even the
biggest one we've found, right? Possibly not.
There is a specimen called Scotty. in Saskatchewan
that might be even heavier. Some estimates put
Scotty at nearly nine tons as well, maybe even
pushing the upper limit of 10. So this isn't
just big. This is pushing the biological limits
of walking on two legs, isn't it? It absolutely
is. When you get that heavy, gravity becomes
your biggest enemy. Every single step places
immense stress on the bones. And all that bulk
is centered around a massive torso and a tail
that has to balance, well, the business end.
The head. The skull. Let's talk about that skull.
Because it's iconic, but it's also a piece of
engineering. It is massive. The largest skulls
are over 1 .5 meters. That's five feet long.
But it's the shape that's fascinating. If you
look at other large meat -eating dinosaurs, like
the Giganotosaurus from South America, or the
Spinosaurus. Right, they're kind of long and
narrow. Exactly. Their skulls are often narrow.
They look like knife blades from the front or
top. Thin and slicey. Exactly. But T -Rex, you
look at a T -Rex skull from the back, it is incredibly
wide. It's flared out. but the snout is narrow.
Okay, so wide at the back, narrow at the front.
Why does that shape matter? It's all about vision.
That shape allows the eyes to face forward, not
just to the sides. It grants T -Rex binocular
vision. Depth perception. Precisely. Most dinosaurs
had eyes on the sides of their heads. Great for
peripheral vision. You know, seeing a predator
coming from behind. But terrible for judging
distance. But the T -Rex is looking right at
you. Right at you. With overlapping visual fields.
And not just okay depth perception. There was
a landmark study by Ken Stevens at the University
of Oregon. He modeled the visual field of T.
rex using lasers and facial reconstruction. Lasers.
That sounds cool. Yeah, it was very cool. And
what did he find? He found it had a binocular
range of 55 degrees. 55 degrees. How does that
compare to, say, us or a bird of prey? It's better
than a modern hawk. Right. Better than a hawk?
In terms of the binocular overlap, yes. And it
gets crazier. Stevens estimated the T -Rex had
13 times the visual acuity of a human. 13 times?
Yes. And significantly better than an eagle.
He calculated that a T -Rex could distinguish
objects as separate from the horizon up to 6
kilometers away. 6 kilometers? That's almost
4 miles. Yep. It could see you long, long before
you could see it. Okay, so that scene in Jurassic
Park. Oh, you mean the don't move, its vision
is based on movement scene? Yeah. That's busted.
Completely and utterly busted. It is one of the
biggest myths in pop culture. If you stood still
in front of a T -Rex, it would see you comfortably
in high definition, and it would probably be
wondering why the snack is presenting itself
so politely. That is terrifying. It completely
changes the dynamic. It's not a clumsy monster
flailing around. It's a sniper. A sniper is a
good analogy. Yeah. And it's not just vision.
We have to talk about smell. I remember reading
about the brain casts. Right. We can use CT scans
on the inside of the skull to see the shape of
the brain or at least the cavity it sat in. The
endocast, right? The endocast, exactly. And the
olfactory bulbs, the part of the brain dedicated
to smell in T. rex. are huge. Relative to its
brain size, they are massive. In fact, research
showed that of 21 different dinosaur species
sampled, T. rex had the most highly developed
sense of smell. It's basically a bloodhound the
size of a bus. A bloodhound with eagle eyes.
It could likely smell a carcass or prey from
kilometers away. This combination of senses is
actually quite rare. Usually animals specialize.
They prioritize one or the other. T -Rex double
down on both. Okay, so it finds you. It sees
you from miles away. It smells you. Now we have
to talk about the lethal bananas. Ah, yes. The
teeth. I love that description. Lethal bananas
because they aren't flat, right? They're not
like knives. No. And this is a key distinction
from other predators. Many carnivorous dinosaurs
had teeth that were like steak knives, flat,
serrated, designed to slice through flesh. We
call those ziphodont teeth. T -Rex teeth are
different. They are encrasate. Encrasate. That's
a new one for me. It just means thickened. They
are D -shaped in cross -section. They are thick,
round, and reinforced with ridges on the back.
They look like railroad spikes. So they aren't
just for slicing. They are for crushing. That
shape. Prevents the tooth from snapping when
the animal bites down with tremendous force and
pulls. If you bite into bone with a flat, knife
-like tooth and the prey twists, your tooth snaps.
But if you use a railroad spike... The bone snaps.
That is a gruesome image. What's the biggest
tooth we've ever found? The largest one is over
30 centimeters. Yeah. That's 12 inches long.
But that includes the root. Oh. And the root
is actually two -thirds of the tooth. It's anchored
into the jaw like a pylon in concrete. This animal
wasn't just nipping at you. It was engaging in
osteophagy. Osteophagy? Bone eating. We find
coprolites, fossilized poop attributed to tyrannosaurs
that are just full of pulverized bone fragments.
They were eating the marrow, the rich nutrients
inside the bone that other predators couldn't
access. It's a whole other level of predation.
It's total consumption. Okay, speaking of the
mouth, we have to address a recent controversy.
The lips. Oh, the great lip debate. This has
really heated up in the last few years. It's
one of those things that seems small, but it
totally changes how you picture the animal. Because
in movies, the teeth are always hanging out,
right? Like a crocodile. They look snaddle -toothed
and scary. It's part of the monster aesthetic.
But there's been a pushback on that. There has.
For a long time, the assumption was that, like
crocodiles, T -Rex didn't have lips. But there's
a problem with that model. What's that? Crocodiles
are aquatic. They spend most of their time in
the water, so they don't need to worry about
their enamel drying out. But T. rex was terrestrial.
And if your teeth dry out, they get brittle.
Exactly. Enamel needs hydration to stay strong
and not crack. A study came out in 2023 by Thomas
Cullen and his colleagues that looked at this
specifically. They compared the wear patterns
on tyrannosaur teeth to crocodiles and monitor
lizards. What did the forensic evidence show?
They found that the enamel on T -Rex teeth didn't
show the kind of wear you see in crocodiles.
Croc teeth get eroded on the outside because
they are constantly exposed to the elements.
Tyrannosaur teeth look pristine, much more like
a monitor lizard, which has lips covering its
teeth when the mouth is closed. So T -Rex likely
had lips. It's the leading theory right now based
on that study. Now, it wouldn't have looked like
a human mouth with big fleshy kissing lips. Right,
right. Think more like a Komodo dragon. A thin,
scaly covering. The teeth would be hidden when
the mouth was closed. That actually makes it
scarier to me. It looks more calculating. Less
like a mindless monster with teeth sticking out
everywhere and more like a giant focused reptile.
It cleans up the lines of the face. It changes
the profile completely. It makes it look less
like a fantasy dragon and more like a real plausible
animal. So we have this massive, keen -eyed,
lip -having, bone -crushing beast. The big question
is, can I outrun it? The age -old question. The
one everyone asks. The movie scene. The jeep
chase. Must go faster. Could a T -Rex actually
chase down a jeep doing 30 or 40 miles per hour?
In a word, no. Really? You're crushing dreams
here. I'm saving lives. Or, well, ruining the
movie at least. The jeep chase is pure Hollywood.
When we look at the biomechanics of an animal
that weighs eight or nine tons, running in the
strictly biomechanical sense of having both feet
off the ground at the same time becomes nearly
impossible. Why? Is it just too heavy? It's the
skeletal load. A 2017 study modeled this using
stress analysis on the bones. If a T -Rex tried
to run at, say, 70 kilometers per hour, which
is about 45 miles per hour. Yeah. The forces
generated when its foot hit the ground would
likely shatter its leg bones. Oh, so it would
literally break its own legs if it tried to sprint.
Likely, yes. The impact force would exceed the
sheer strength of the bone. It's a physics problem.
And that's not even getting into the muscles.
What about the muscles? The muscle mass required
to move that fast would be impossible. Some studies
calculated it would need to be something like
86 % of its body weight just in its legs. Which
is not feasible. Not even close. There'd be no
room for organs. So what is the speed limit?
What's the real number? Most modern studies put
the top speed around 27 kilometers per hour.
That's about 17 miles per hour. 17 miles per
hour. That's attainable. A good human sprinter
can do that. Usain Bolt can do 27 -kilometer
error. A reasonably fit human might hit 15 or
16 -mile error in a panic sprint. So it's going
to be close. But here's the thing. T -Rex wasn't
built for sprinting. It was built for efficiency.
What do you mean by that? There was a study in
2020 that looked at the leg proportions. T -Rex
has relatively long legs, but not for speed.
It's for energy -efficient walking. They are
power walkers. Power walkers? I'm picturing a
T -Rex in a mall walking club with light weights.
It's funny, but it's biomechanically accurate.
They could cover huge distances with very little
energy expenditure. They were the marathon walkers
of the Cretaceous. So they were stalkers. Exactly.
They could stalk prey for days, just keeping
pace, waiting for an opening. While you were
sprinting and getting tired, it is just walking
tirelessly. And there was something about the
tail, right? Helping them walk. That seems counterintuitive.
It does. But a 2021 study by Pasha van Beelert
in the Netherlands changed how we see it. They
modeled the tail not just as a dead weight for
balance, but as a resonating ligament. Like a
spring. Almost exactly. Imagine a giant rubber
band running down the tail. As the animal walks,
the tail sways up and down naturally. The ligaments
store energy on the upswing and release it on
the downswing, helping to propel the animal forward.
It acts like a suspension system. That is incredible
engineering, so it made walking... cheaper energetically.
It is. And their model found a preferred walking
speed, a resonant frequency. It's roughly 4 .6
kilometers per hour, which is almost exactly
the preferred walking speed of a human. That
is creepy. So if you were walking through the
Cretaceous forest, a T -Rex could just silently
pace you step for step without getting tired.
Precisely. It's the persistence hunter model.
And while they weren't fast in a straight line,
they might have been surprisingly agile. Agile.
A nine -ton animal. How? Relative to other giants,
of course, they have a specific foot structure
called the arctometatarsus. Break that down for
me. The middle foot bone, the metatarsal, is
pinched at the top between the other two bones.
This locks the foot bones together into a single
stable unit, making them very good at transmitting
force without twisting. A more efficient foot.
A much more efficient foot. Combined with massive
leg muscles and low rotational inertia because
the weight is centered near the hips, some studies
suggest they could pirouette. Pirouette? Like
a ballerina? A horrifying nine -ton ballerina.
They could pivot on one foot very quickly to
turn and face a threat or prey. So you might
outrun it in a long straight line if you're fast,
but don't try to outmaneuver it in close quarters.
It can spin faster than you think. Okay, noted.
Don't play tag with a T -Rex. Now we have to
talk about the arms. We can't avoid them. The
elephant in the room. Or the tiny arm theropod
in the room. It is the joke of the paleontology
world. The tiny arms, they're only about a meter
long. About the size of a human arm, really.
Which sounds big, but not on that body. But attached
to a building -sized animal, are they vestigial?
Like, were they just on their way out evolutionarily?
That's been the assumption for a long time. But
vestigial implies useless. And when you look
at the bones, they aren't useless at all. What
do you see? The areas where the muscles attach,
the insertion points, are huge. The cortical
bone, the outer layer, is extremely thick. These
were not flimsy, weak little arms. So they were
strong. Very strong. Estimates suggest the bicep
alone could lift nearly 199 kilograms. That's
over 400 pounds. Wait, each arm? Yes. So this
animal could curl a motorcycle. That doesn't
sound vestigial. If they were useless, evolution
would have withered the muscles away. But they're
so short, they can't even reach the mouth. What
were they doing with them? That is the million
-dollar question. There have been so many theories
over the decades. Back in 1906, Osborne suggested
they were for grasping mates. The romantic hug
theory. A very strong, potentially painful hug.
Then there was the push -up theory from Newman.
The push -up theory. The idea that if a T -Rex
was sleeping on its belly, it needed those strong
little arms to push its front end up enough to
get the legs under it to stand up. That makes
some sense. It's a lot of weight to lift off
the ground. It does. Then there's the weapon
theory. Steve and Stanley suggested they were
used for slashing. The claws were sharp. If it
got close to prey, it could inflict deep gashes.
But the reach is so short, you'd have to be basically
chest -bumping the prey to use them. True. The
range of motion is really limited, which brings
us to a really interesting recent theory by Kevin
Padian in 2022. He flipped the script completely.
Oh, okay. He suggested the arms didn't get small
for a function. They got small for safety. Safety?
How is having smaller arms safer? Imagine a group
of T -Rex feeding on a carcass. It's a frenzy.
Giant jaws snapping, teeth crushing bone, heads
thrashing around. If you have long, waving arms
in that mix. Chop. Exactly. You get them bitten
off. accidental amputation by a feeding partner.
Padian argued that shrinking the arms got them
out of the way of the jaws of other T. rex. It's
adaptation by reduction. That is fascinating.
So it's not, what are these for? It's, let's
tuck these away so I don't lose them. It's a
compelling hypothesis. It reminds us that evolution
isn't always about building bigger weapons. Sometimes
it's about damage control. Speaking of damage
control, let's talk about growing up. Because
a T -Rex doesn't start out nine tons. They hatch
from an egg. No, and the growth curve is terrifying.
We can determine their age by looking at the
rings in their bones, like tree rings. It's called
skeletochronology. And what does the life of
a T -Rex look like based on those rings? It's
an S -shaped curve. For the first decade or so,
they grow relatively slowly. A teenage T -Rex,
say... 13 or 14 years old. It's still a large
animal, but it's lanky. It's built for speed.
It doesn't have the massive bulk yet. It's the
gazelle phase. Maybe the cheetah phase. They
were likely chasing smaller, faster prey. But
then around age 14, something happens. They hit
a physiological growth spurt that is hard to
comprehend. How fast are we talking? They start
putting on about 600 kilograms a year. That's
1 ,600 pounds every single year for four years
straight. That is, they are gaining a cow and
a half every year. Basically, they bulk up massively.
The skull deepens, the bite force increases exponentially,
they slow down, and they become the bruisers
we know. It's one of the most extreme growth
rates in the animal kingdom. This brings us to
a huge controversy in the field. The dwarf tyrant.
Nanotyrannus. Oh boy. This is one of the biggest
fights in dinosaur paleontology. It gets heated
at conferences. People have very strong feelings
about this. So explain this to me. For years,
we've found these smaller, sleeker tyrannosaur
skulls. And some people say, that's a different
species, Nanotyrannus. And others say, no, that's
just a teenage T -Rex. That's the debate in a
nutshell. The most famous specimens are Jane
and the Bloody Mary specimen found in the Dueling
Dinosaurs fossil. They have more teeth than adult
T -Rex. Their skulls are flatter. They just,
they look different. So who is winning this fight?
Where does the science stand now? It swings back
and forth like a pendulum. For a while, the teenage
T -Rex theory was winning. A study by Holly Woodward
in 2020 analyzed the bone rings of Jane and another
specimen. They found that these animals were
young, 13 to 15 years old, and were actively
growing. So the bone ring said, I'm a kid. Right.
Woodward argued that Nanotyrannus is just what
a T -Rex looks like before that massive growth
spurt. It filled that mid -sized predator niche
while it was a juvenile. Case closed. You'd think
so. But recently, in 2024, the separate species
camp came back swinging. Researchers like Nick
Longridge and Evan Sayeta put out a new paper
arguing the growth curves just don't match up.
How so? They argue the bone rings in the nanotyrannus
specimens are getting close together, suggesting
it was nearing its full size, a much smaller
size than T. rex. And they identified distinct
anatomical features that shouldn't change just
because you grow up. So there might have been
a mid -sized tyrannosaur running around alongside
the giant T. rex. That's their argument. that
there was another more grassy tyrannosaur in
the ecosystem. It's an ongoing debate, science
in action. We are watching the consensus form
and break in real time. It's incredible that
we're still arguing about the identity of these
bones. It is, and it connects to life expectancy.
Sue, the oldest T. rex we know of was only about
28, maybe 33 years old. when she died that seems
young for such a huge animal elephants live way
longer it's the live fast die young strategy
they grew explosively reach sexual maturity and
then they died the fossil record suggests high
mortality right around the time they become adults
right what was killing them each other mostly
Fighting for mates, reproductive stress, defending
territory. The life of a T -Rex was violent.
Almost every adult specimen we find has healed
fractures, bite marks, or infections. They beat
each other up constantly. Scotty had a broken
rib, an infected jaw, and a bite mark on his
tail from another Tyrannosaur. Which actually
leads us to a specific discovery that changed
everything. Not about bones, but what's inside
the bones, the soft tissue. This is the Jurassic
Park moment, for real. In 2005, Mary Schweitzer.
Her work turned paleontology on its head. Tell
us that story. I've heard it, but it's always
amazing. She was studying a T. rex femur specimen,
MOR1125. They had to break the bone to ship it
via helicopter, which is usually a no -no, but
it was a happy accident. It allowed her to look
deep inside the marrow cavity. And she didn't
just find rock? No. She dissolved the mineral
part of the bone away using a weak acid, a process
called demineralization, and she was left with
flexible, stretchy tissue. She found transparent
structures that looked like blood vessels. She
found small red round things that looked like
red blood cells. In a 68 million year old bone,
that shouldn't be possible. Everyone thought
it was impossible. Fossilization is supposed
to replace everything with mineral. But she found
collagen protein. It caused a massive storm in
the scientific community. People said it was
biofilm bacteria contamination. But it held up.
It held up. Study after study has supported the
idea that some original organic material can
survive under the right conditions. That is mind
-blowing. And it helped confirm the connection
to birds, right? It did. The proteins they sequenced
matched most closely with chickens and ostriches.
But there was another clue in that femur. She
found medullary bone. What is that? It's a special
type of bone tissue that only female birds produce
when they are pregnant, or rather, when they
are ovulating, to create eggshells. It acts as
a calcium reservoir. Finding it in a T -Rex proved
this specimen was a female and she was pregnant
when she died. That is incredible. We can actually
sex the dinosaur from its bone tissue. Now, speaking
of birds, feathers. The other big controversy.
The one everyone wants to know about. Did T.
rex look like a giant chicken? Because I've seen
the art. Sometimes it's fluffy. Sometimes it's
scaly. What's the verdict? It's complicated.
We know for a fact that early Tyrannosauroids,
the ancestors, had feathers. A fossil from China
called Dilong had them. And Eudoranus. And the
large Eudoranus, which also lived in China, was
covered in shaggy filamentous feathers. And it
was big, about nine meters long. So big Tyrannosaurs
can have feathers. It's possible. Yes. It's definitely
possible. However, for T. rex specifically, we
have skin impressions. We have patches of skin
from the neck, the tail, the hip, from a specimen
nicknamed Y. rex. And what do they show? Scales.
Tiny, bumpy, mosaic scales. No sign of feathers
in those preserved patches. So, no feathers.
Likely not a full coat. Think about it like an
elephant. Elephants are mammals. Their ancestors
were hairy. But elephants are huge and live in
warm climates. If they were covered in thick
fur, they'd overheat. Gigantothermy. They're
so big, they generate their own heat. Exactly.
Large animals retain heat well. A fully feathered
adult T. rex might have cooked itself from the
inside out. So the current thinking is that if
they had feathers, they were sparse, maybe just
along the back like elephant hair, or maybe they
were born with downy feathers and lost them as
they grew up. So less giant chicken and more
scaly monster with maybe a feathery mullet. That's
a fair visual. A very intimidating mullet. Okay,
let's get into the behavior. The diet. Predator
or scavenger? This was a huge debate in the 90s,
thanks largely to Jack Horner. Right. Jack Horner.
The famous paleontologist who advised on the
Jurassic Park films, ironically, really pushed
the pure scavenger hypothesis. And his argument
was what? He looked at the tiny arms, useless
for grappling, the relatively slow speed we just
talked about, and that incredible sense of smell,
and said, this thing is a glorified vulture.
It walks around sniffing out dead things. It
makes sense on paper. Why risk fighting a triceratops
if you can just eat a dead one? It does make
sense energetically. And to be clear, T -Rex
absolutely scavenged. If it found a free meal,
it would take it. Almost all large predators
do. Lions scavenge. Wolves scavenge. But was
it only a scavenger? That's where the theory
falls apart. We have the smoking guns. Healed
wounds. Yes. We have fossil evidence of failed
predation. There is an Edmontosaurus, a duck
-billed dinosaur with a tail vertebrae that has
a chunk missing. And nestled in that wound...
is a T -Rex tooth. And the key part. The bone
has grown back over the wound and around the
tooth. Which means? It means a T -Rex bit it
and the Edmontosaurus got away and lived long
enough for its bone to heal. You can't bite a
dead animal and have it heal. Evidence of active
hunting. The ultimate proof. There's also a Triceratops
horn that was bitten off and the stump healed
over. Oh. So T -Rex was actively hunting live,
dangerous prey. And when it bit? The hardest.
The bite force estimates are, frankly, astronomical.
They're between 35 ,000 and 57 ,000 newtons.
Put that in perspective for me. What's a human
bite? A human is maybe 800 newtons on a good
day. A lion is maybe 4 ,000 newtons. A saltwater
crocodile, the living champion, is around 16
,000. T -Rex is more than double that, maybe
triple. It's just off the charts. It's hydraulic
press levels of force. You can simply crush the
neck or back of its prey instantly. It didn't
need to be surgical. It was overwhelming force.
So a terrifying predator. But did it hunt alone?
Or are we talking about the dino gang's hypothesis?
This is fascinating. The idea of pack hunting
tyrannosaurs was really pushed by Philip Curry.
He based this on bone beds places where multiple
tyrannosaurs of different ages died together.
Like the dry island bone bed in Alberta. Exactly.
For the related tyrannosaur Albertosaurus, you
have two dozen individuals, from young juveniles
to old adults, all dead in the same place. And
Curry's idea was that this was a pack. His idea
is that they had a division of labor. The fast,
lanky teenagers, the nanotyrannostypes, would
act as the drivers, flushing out the prey. And
the massive, bone -crushing adults would be the
anvil that the prey ran into. That is a terrifying
coordinated strategy. Is it accepted? It's debated.
Some argue that the bone beds could just be predator
traps. Maybe they all got stuck in mud over time
or gathered at a drying waterhole. But then there
are the trackways. In Canada, we found tracks
of three tyrannosaurs moving together in the
same direction at the same speed. That sounds
like a group to me. It definitely suggests some
level of social behavior. They weren't just solitary
loners. They tolerated each other, at least sometimes.
Tolerated being the key word, because there is
a darker side to their social life. Cannibalism.
We have proof of this. We do. We have T -Rex
bones with T -Rex tooth marks on them. And given
the spacing and shape of the gouges, it can only
be another T -Rex. So if it's a buddy died. Lunch
is served. Or maybe they thought to the death
and the winner ate the loser. It's a dog -eat
-dog world. Rex eat Rex world. Brutal. Now, before
we wrap up, we have to touch on the taxonomy
wars. We mentioned Nanotyrannus, but there was
that study in 2022 that tried to split T -Rex
into three species. Oh, the king, queen, and
emperor study. Like Gregory Paul and his colleagues.
Right. They argued that the variation we see
in skeletons, some are robust with two pairs
of incisors, some are slender with one worn in
three names. Tyrannosaurus Rex, the king. Tyrannosaurus
Imperator. the emperor, and Tyrannosaurus Regina,
the queen. Did that stick? Not really. The paleontological
community largely rejected it. The consensus
is that the differences are just natural variation
within a single species. Just like humans vary
in height and build, T. rex did too. Or maybe
males and females were different sizes. Exactly.
Sexual dimorphism could account for it. The boundaries
between the proposed species were just too fuzzy
to be taxonomically valid for most people. So
for now, T. rex stands alone as the one king.
Mostly. But there is a new twist from just this
year, 2024. Tyrannosaurus micreansus. The New
Mexico find? Yes. A partial skull found in the
Hall Lake Formation. It looks incredibly similar
to T. rex, but the dating suggests it might be
6 to 7 million years older. Whoa. So the grandfather
of T. rex. Or a very close cousin. A direct ancestor,
perhaps? It suggests that the Tyrannosaurus lineage
might have originated in southern Laramidia,
what is now the southern U .S., rather than being
an immigrant from Asia, which was a leading theory.
So the king might be a native son after all.
It rewrites the map of where the tyrant king
came from. So let's bring it all together. The
real T -Rex. It's not the movie monster. No,
it's a smart, social, potentially lipped, power
walking, bone crushing, attentive parent that
grew from a lanky teen into a massive bulk. It's
an animal that lived a violent life, grew faster
than almost anything else, and died young. It's
scarier than the movies because it's a real biological
animal that was Perfectly adapted to its world.
Exactly. The why it matters is that Tyrannosaurus
is the standard bearer for paleontology. Every
new technology, CT scans, molecular analysis,
biomechanical modeling is tested on T. rex first.
Understanding it helps us understand the limits
of life itself. And that leads me to my final
thought. The soft tissue. The collagen. If we
can find proteins in a 68 million year old bone,
what does that mean for the future of genetic
research? We're not talking about cloning, but
could we one day know the color of its eyes from
melanosomes or the actual sound of its call from
the structure of its inner ear and syrinx? We're
opening doors we didn't even know existed. We
may never resurrect them, but we might know them
more intimately than we ever thought possible.
Next time you see a pigeon on the street, just
remember that's the distant fluttering cousin
of the tyrant king. Thanks for diving deep with
us. Always a pleasure.