[groaning]
T-Rex is not what we thought. Thanks to
the 1993 classic Jurassic Park, this
giant bulldozing, seemingly halfblind
wall of teeth has been seared into our
central consciousness. A tyrannosaurized
trope that's kept Jeff Goldblum running
across our screens ever since. Luckily,
none of us will have to contend with
this monster. Not just because dinosaur
deextinction is virtually impossible.
Sorry, Steven Spielberg, but because the
T-Rex was in fact nothing like this at
all. In fact, it was much, much worse.
From 2023 to 2026, a wave of
breakthrough discoveries transformed
this brute with a set of pretty serious
upgrades. T-Rex was more cunning, more
stealthy, and frankly more weird looking
than we'd thought.
So, how did we get T-Rex so wrong? What
new scientific approach changed it all?
And what does this new vision of T-Rex
tell us about just how effectively it
dominated its domain? I'm James Stewart,
and you're watching Astramm Earth. Join
me as we take a tour through 120 years
of our relationship with the coolest
creature in the Cretaceous. From the
bone collecting trailbases who
catapulted the T-Rex into the spotlight,
all the way to the latest remarkable
scientific techniques that have unlocked
this great beast's true nature.
Discoveries that paint an entirely new
picture of the dinosaur we love to fear.
To understand why these recent
discoveries are so earthshattering, we
first need to go back to the birth of
T-Rex. No, not 68 million years ago, but
to the dawn of the 20th century. The
year is 1905, and we're in Hell Creek,
Montana. The race for the world's
greatest fossil is very much on here. A
relentless young paleontologist, Barnum
Brown, is armed with several cases of
dynamite and determined to make the
discovery of a lifetime.
3 years earlier, Barnum had left Hell
Creek with little more than a pubic bone
and the feur of what seemed to be a
large carnivorous predator. Intriguing,
but nowhere near enough to make a
splash.
Now he was back baking in the same
merciless heat. And this time he had
something extra driving him. Jealousy.
Edward IIIth, King of England, had
recently paid a visit to the rival
Carnegie Museum in Pittsburgh to admire
their new shiny Diplodocus.
If Barnuman was going to put the
American Museum of Natural History back
in the spotlight, he needed something
even better. After three months of
blasting and digging, Barnum finally had
enough bones. But rumor had it the
Pittsburgh team were just about to name
their own large carnivore find. Back in
New York, Barnum's boss, Henry Fairfield
Osborne, wasn't waiting around.
Desperate to get there first, he began
writing up the discovery before a single
bone had even arrived. In late July, a
letter reached Barnum in the field. I
have just described the big dinosaur
under the name Tyrannosaurus Rex.
The king of the tyrant lizards was named
without Osborne ever laying eyes on it.
But when the grand reveal came, it was a
flop. With still only a handful of bones
and a whole lot of speculation, the
public preferred the more complete
dinosaur superstars of the time, such as
Diplodocus, Stegosaurus, and
Brontosaurus.
It wasn't until 10 years later in 1915,
that Barnum and his team finally had
enough bones to piece together a near
complete T-Rex skeleton. The American
Museum of Natural History mounted the
new finds. And this time, the public
lapped it up.
The T-Rex was a global sensation,
sparking newspaper and magazine articles
across the globe. And so, the king of
the beasts was born. Barnum himself
remarked, "T-Rex is my favorite child,
the most formidable fighting machine
ever devised by nature."
Barnum's vision was an imposing beast
standing upright like a kangaroo with a
terrifying set of teeth. This spawn the
archetype for Hollywood's vision of
terror and set the template for what we
thought the T-Rex looked like. A thought
that maintained for nearly a hundred
years.
But this creature was in many ways a
work of fiction. A terrifying beast
stitched together with incomplete
evidence and educated guesswork. A sort
of prehistoric Frankenstein's monster.
T-Rex was undoubtedly a supreme apex
predator. But this version was riddled
with errors. So where did they go wrong?
Well, firstly, T-Rex was put together
using a combination of finds. As
Professor Thomas Holtz from the
University of Maryland told News
Scientists in 2005,
"It was like placing Arnold
Schwarzenegger's legs on Brad Pitt's
body." Barnum's team also used
Allosaurus hands, which have three
fingers, not the two digits that T-Rex
was later found to have. It also
transpires that this version of the
T-Rex would have a pretty tough time
walking around with a long, heavy tail
dragging behind it like an anchor. not
very efficient for the greatest predator
to have ever stalked the earth. It
wasn't until the 1970s that T-Rex's
shape began to change from Barnum's
vision. Barney Newman from the British
Museum of Natural History in London
investigated where T-Rex's vertebrae
fused together and ligaments attached
and soon realized that its spine
couldn't have been upright without the
head being out of joint.
Instead, a horizontal posture was much
more likely with the tail lifted off the
ground like a counterweight. He also
shortened the tail by about 3.7 m. The
old version was longer because it was
thought to act like a third leg to
balance, as well as being based on the
Allosaurus.
The real T-Rex was slowly coming to
light, but rearranging bones can only
get you so far. What scientists needed
to know now was not necessarily how
these bone fragments sat together, but
what the individual bone fragments
themselves could tell us. This new
thinking was the driver behind what
paleontologist Gregory Ericson dubbed
the microscopic revolution, transforming
how scientists integrated dinosaur
fragments. And what it revealed was a
T-Rex that went from dangerous to
profoundly terrifying.
Let's stop at the sharp end of the
T-Rex's bone crushing bite. T-Rex's
teeth are massive, the largest of any
carnivorous dinosaur found so far,
reaching up to 30 cm in length. And in
2015, a study led by Kirsten Brink at
the University Toronto Missy Saga showed
T-Rex teeth are far more formidable than
we thought. No filler or killer. Under
the microscope, each tooth has serrated
edges like a steak knife, designed to
slice through meat and reinforced with
extra dentine to absorb tremendous bite
force. Since these nashes were so large
and sharp, it was thought they sat on
the outside of the mouth, much like the
crocodile, an animal whose lipless mouth
scientists had long used as a reference
point for T-Rex.
But in 2023, Thomas Cullen at Auburn
University led a study that changed all
of that. Cullen's team ran three
separate tests. First, they measured
skull length against tooth height across
a range of two-legged dinosaurs and
modern lizards. They found the T-Rex
ratio most closely match modern lipped
lizards like monitors and iguanas.
Next, they took a thin slice of T-Rex
tooth and looked at the enamel. Now,
crocodile teeth are permanently exposed
to the air. So, over time, their enamel
is worn thin on the outside and thick on
the inside. However, the T-Rex had even
thickness of enamel on both sides and
hardly any wear.
Finally, they looked at the small holes
in the jawbones called foramina. These
carry nerves and blood vessels to the
soft tissue of the face. Crocodiles have
foramina scattered all over their snouts
in a distinctive pattern. Lipped
reptiles like lizards and iguanas have
them arranged in a single line along the
jaw margin. Again, T-Rex matched the
lipped group. Three lines of evidence,
all pointing to the same remarkable
conclusion. T-Rex's teeth sat behind
scaly lips like a giant terrifying
Komodo dragon. So why does this matter?
Well, keeping the teeth continuously
bathed in saliva behind lips would have
prevented their tooth enamel from
becoming brittle and prone to fracture.
So T-Rex teeth were always in peak
killing condition. Yeah, basically moist
teeth are also the secret behind T-Rex's
greatest weapon, its bite. With the most
powerful bite of any known land animal,
up to three times more powerful than
today's record holder, by the way, the
Nile crocodile. Even microscopic
brittleleness in a tooth could cause
catastrophic chipping at the moment of
impact, damaging T-Rex's primary weapon.
And a T-Rex unable to use its teeth is
no T-Rex at all. Cullen's team sectioned
a tooth from a closely related
tyrannosaurid under a microscope to
count their daily growth layers called
von Ebnner lines and they found well
over 500. The same would have almost
certainly applied to a T-Rex too,
meaning a single tooth took over a year
to grow. So putting its teeth behind the
lips to protect them from wear and
erosion was doubly important. as they
took such a long time to replace. A bone
crushing jaw with a set of giant flesh
ripping teeth kept in perfect condition.
Well, T-Rex truly earned the deadliest
bite on Earth. But things get even
crazier when you look at the rest of the
body. T-Rex is often portrayed as a
scaly beast. There are hints of a rather
more feathery past. Feathered dinosaurs
became a point of renewed scientific
interest after the discovery of
feathered sinosaur opterex in the 1990s.
The first dinosaur to be found preserved
with filaments of proto feathers and
bolstered by a wave of other discoveries
such as Dylong paradoxus
cordipix
and bay piosaurus.
So when a T-Rex relative UTranis Harley
was found by Shuing and colleagues
covered in proto feathers, the question
became impossible to ignore. Did T-Rex
have feathers too? Well, it's an
intriguing idea and quite a comical
vision. But let's look at the evidence.
Exhibit A. T-Rex skin. In very rare
instances, dinosaur skin presses into
the sediment before decaying, leaving a
perfect imprint of what that animal
actually looked like on the outside.
Now, in 2017, Phil Bell and his team
from the University of New England in
Australia, examined a T-Rex specimen
from Texas, nicknamed Yrex, with skin
preserved from the neck, hip, and tail,
and they showed no evidence of feathers.
So, had we all been tricked by this
feather fad? Well, hang on a sec. Not so
fast. Because the same 2017 study by
Belle and colleagues looked at the whole
Thoropod family tree, the clay that
includes T-Rex, and found that while
some therapods develop feathers, large
Tyrannosaurids like T-Rex subsequently
lost them. Why? Well, it comes down to
heat and a question that's been debated
for decades. Was T-Rex warm-blooded?
private as we head back to everyone's favorite monster.
For most of its existence, T-Rex was
imagined as a sluggish, cold-blooded
brute. But in 2022, a remarkable paper
by Yasmina Weimman at Yale rewrote that
entire picture. Her team used twin
techniques called Ramen and Faria
transform infrared spectroscopy.
FTIR measures which specific frequencies
of infrared light a sample absorbs while
Rama measures how a laser's light
scatters off the sample at different
frequencies.
This provides a complete and unique
chemical footprint to identify the
substances present. In this case,
scientists are on the hunt for advanced
lipoxidation end products or ALES,
tiny molecular scars left behind by an
animal's metabolism. The faster your
metabolism runs, the more of these scars
acrew in your bones during life. And
crucially, they survive fossilization.
Weman's team analyzed 30 dinosaur bones
for ALES and they found that every
theropod they tested, T-Rex included,
plotted right alongside modern birds and
mammals on the metabolic chart, meaning
they were warmblooded. Yes, T-Rex
generated its own heat. This is so
important because for warm-blooded
animals, the larger you are, the more
heat you generate and retain. So, if
you're a small young T-Rex, you might
need feathers to keep warm, but once you
get big enough, you retain heat so well
that the extra insulation actually risks
overheating you. This led scientists to
suggest that baby T-Rex may have had
feathers, but shed them as it got older.
It's possible some feathering persisted
in places we haven't yet found
impressions for, but the picture we have
right now for T-Rex is of a largecale
predator with pristine teeth built for
explosive bursts of energy to take down
its prey. A deadly killing machine with
or without feathers. But the most
shocking revelation was yet to come, its
size.
The biggest T-Rex we've found so far is
a specimen called Scotty, discovered in
Saskatchewan, Canada. It was first
spotted by a school teacher, Robert
Ghart, in 1991, but took over a decade
of painstaking excavation before
scientists could study the complete
animal. This whopper of a T-Rex was
estimated to be 13 m long and using the
circumference of its massive thigh bone
estimated to weigh over 8,800
kg.
As one of the largest terrestrial
predators we've ever found, it was
rightly crowned the Rex of Rexes. But
these impressive numbers don't actually
tell us what T-Rex looked like. And for
decades, that's been a surprisingly
difficult question to answer.
For a long time, scientists trying to
work out the size of dinosaurs like the
T-Rex stuck with the convex hole
expansion method. This is when you take
the 3D skeleton of a T-Rex and surround
it in a skin wrapper as tightly as
possible. This is the convex hole. Then
you expand the hole, the skin outward
after you've estimated where the soft
tissue, muscles, organs, fat, etc. would
be. Now, the problem is this led artists
and scientists to come up with some
wildly diverse size estimates for T-Rex.
But two new studies, one by Sophie
McCauley at the University of Liverpool
and her colleagues in 2023, and another
by Matt Dempsey at the University of
Liverpool and his colleagues in 2025,
have removed that guesswork.
Instead, they use CT scans of living
birds and reptiles, T-Rex's closest
living relatives, to define how much
soft tissue each segment of the body
should have. They essentially created a
series of ratios showing how big a body
part should be compared to the
underlying bones for every part of the
animal. They then used those ratios as a
recipe to flesh out 52 dinosaur
skeletons, including the T-Rex.
They found that many of the old
reconstructions for non-avian dinosaurs
were too slim. The real animals were
more muscular, heavier than previous
artistic depictions suggested. For
T-Rex, the weight was roughly in keeping
with previous estimates, but the old
visuals were underselling how heavily
muscled it really was because the truth
is T-Rex was stacked.
And this fits in with what
paleontologists already knew about T-Rex
anatomy. It had longer distal limb
bones, larger muscle attachment surfaces
on the hips, and more rigid tails than
any other large theropod. This all
points to an animal that was capable of
more vigorous and more powerful physical
movement than any predator its size.
T-Rex wasn't just the biggest. It was
also the most powerfully built land
predator that ever lived. For years,
scientists thought Scotty at just under
9 tons was the upper biological limit of
T-Rex. But in 2024,
new research suggested something far
more menacing. T-Rex may have been much,
much bigger. The study was based on the
idea that of the estimated 2.5 billion
T-Rex to have ever lived, we only have
84 reasonably complete skeletons. And
that means the chances that we've
already found the maximumsized T-Rex are
basically zilch. And that inspired
analysis by Jordan Malin from Canadian
Museum of Nature and David Hone from
Queen Mary University in London who
built a statistical model of the full
range of T-Rex sizes.
Staggeringly, their results show that in
fact the absolute maximum body of T-Rex
could have actually been more like 15
tons. That is 70% heavier than Scotty,
the largest specimen we've ever found.
They also calculate that a full-size
T-Rex would have exceeded 15 m in
length.
That was a lot to digest. And I don't
know about you, but if I were a
paleontologist discovering that T-Rex
was actually almost twice the size we
thought, well, that would make my entire
career. I mean, this is the stuff of
dreams for paleontologists and for many
of us, the stuff of nightmares.
This new vision of the T-Rex blows
everything else out the water. This
beast was likely bigger, stronger, and
more terrifying than we could ever have
imagined.
But we're not done yet, because the
Dempsey study also reveals something
about how T-Rex carried all of that
mass. Compared to other giant theropods
of similar size, T-Rex's center of mass
sat further toward its head, implying a
more crouched, actively balanced posture
than its rivals. And that leads to one
big question. How did it actually move?
Hot off the press just this year in
2026, Adrien Boai at the College of the
Atlantic and his colleagues turned their
attention to the T-Rex foot. Combining
trackway evidence with biomechanical
analysis, they found that T-Rex almost
certainly hit the ground toe first like
a bird with shorter, faster shries than
its size would suggest. Yeah, that
probably means no thundering water in
glass shaking steps that we see in
movies, but something much closer to a
giant power walking ostrich.
This style of movement means T-Rex was
much more stable on its feet and could
move its head sharply for more precise
hunting. It also means the T-Rex was
quieter and more agile than Jurassic
Park suggests. Based on analysis,
depending on their mass, T-Rex could run
between 18 and 40 km per hour with
heavier adults at the slower end. So,
Usain Bolt might be okay running away
from one of these things at 44.72 km/h,
but it's not good news for the rest of
us or any other large Cretaceous
herbivore for that matter. Boi and
colleagues also looked at juvenile T-Rex
speeds and found that these younger,
lighter T-Rex were significantly faster.
fast enough to chase down different
kinds of prey to their parents.
This opened up the possibility that
young T-Rex could have lived a totally
different kind of life before it was
fully grown. So, what were the T-Rex's
wonder years like? We used to think that
T-Rex reached adulthood quickly,
reaching 8 tons, wrong, within 20 years.
But more rigorous testing by Holly
Woodward at Oklahoma State University
and her team counting growth rings in
bone cross-sections under polarized
light microscopy showed that T-Rex
reached full size around 35 to 40 years
old, a whole 15 years later than
previously thought. This meant T-Rex
grew rapidly from early juvenile to late
sub adult stages over a period of 30
plus years. So, it must have had massive
energy demands for most of its life. If
you ever saw a T-Rex, it was almost
certainly hungry. There were some
alarming behavioral conclusions that
came out of this, too. We know from
predators today that sub adults are
often the most active, bold, and
aggressive hunters. Now, seeing as T-Rex
was in this phase for something like two
decades, that was very bad news for its
prey. And once a T-Rex was fully grown,
it already had 35 years of accumulated
hunting experience. Its strategies, to
put it lightly, were pretty finely
tuned.
This slower sustained growth also meant
T-Rex terrorized ecosystems for longer
and with potentially more aggression
than we previously thought.
But Woodward's growth modeling came with
another surprising twist. Two of the 17
used T-Rex specimens didn't quite fit
the growth curve. Enter Jane, BMRP
2002.4.1,
and PY, BMRP 2006.4.4,
who would turn the T-Rex kingdom upside
down again. At the same time, Woodward's
team were scratching their heads over
Jane and Pety strange number of growth
rings. Another group led by Lindseay
Zano from the North Carolina Museum of
Natural Sciences and James Napoli at
Stonybrook University were looking at
the spaces between growth rings. They
knew that as an animal matures, the gaps
between each growth ring shrink and then
stack together, indicating a full grown
animal that's reached adulthood. Their
star specimen was NCSM40000,
a teen rex nicknamed Mantio from the
famous jeweling dinosaurs discovery
where a triceratops and a smaller body
tyrannosaur were discovered locked in
ancient combat. The result, this tiny
T-Rex was actually fully grown.
They also noted that despite weighing
less than a tenth the size of an adult,
its arms were already longer than a
fully grown T-Rex's, and it had fewer
vertebrae in its tail.
The final nail in the coffin was when
Zano and Napoli looked at specific
features of skull and skeletal anatomy
that are locked in and don't change as
an animal develops and grows. For
instance, the pattern of sinuses inside
the stout, specific bone projections on
the upper arm and pelvis. Again, they
were different from T-Rex. And that's
because Teen Rex was not a T-Rex at all.
A few weeks later, a separate team,
Christopher Griffin at Princeton and
Caitlyn Kiri at the Cleveland Museum,
re-examined a juvenile T-Rex fossil
called the Cleveland Skull. This skull
had a history. Back in the 1980s, a
researcher named Robert Backer made a
controversial suggestion that it didn't
belong to a younger T-Rex at all, but to
an entirely different, smaller
tyrannosaur, a nanotyrannus lancensis or
pygmy tyrant. Since skulls are
notoriously hard to age, discussions
over its identity were abandoned, the
scientific community largely dismissed
the idea. But Collier spotted something
researchers had overlooked. A tiny
throat bone called the hyoid.
Tube-shaped like a limbbone and
therefore capable of holding growth
rings. When they sliced it open, the
answer was clear. Like our Jane and Pey,
the Cleveland skull was not a young
T-Rex, but an adult of a new and
different species, the Pygmy tyrant,
Nano Tyrannis.
This rewrites the life story of T-Rex.
For decades, paleontologists had used
fossils like Jane, Petey, and the
Cleveland skull as their reference point
for what a teenage Rex looked like. How
it hunted, how it grew, how it fit into
its ecosystem. But this new work reveals
all those comparisons were built on the
wrong animal. In one fell swoop, it was
back to the drawing board for Teenage
T-Rex. What we now do know instead is
that a young T-Rex shared its ecosystem
with other predators, which means it
needed to be utterly laser focused on
its niche. And that's where there's some
good news, because clues are now
emerging that shed light on how it did
just that.
T-Rex had a giant alactory bulb, the
part of the brain that deciphers
messages from the nose. So, it's
obviously devoted a lot of brain power
to smell, but receptor genes within the
olfactory bulbs can tell scientists how
many different channels the brain can
tune into. In other words, it can tell
scientists how good T-Rex was at
discriminating between different types
of smell. So a group from University
College in Dublin led by Graeme Hughes
had the idea that rather than just
looking at the size of the oldactory
bulbs in skull casts, they should
combine that physical data with genomic
information from living birds and
reptiles to estimate how many actual
smell receptor genes T-Rex probably had.
The more genes, the richer and more
detailed the T-Rex's allactory world
would be. They discovered that its
olfactory system was exceptional,
suggesting upwards of 600 receptor
genes, on par with a domestic cat, the
highest of any theropod ever studied.
The UCD group also postulated that T-Rex
had the ability to smell blood from far
away, allowing it to track prey over
large distances like modern wolves or
scavenge carrying like today's vulture.
So, in reality, it probably sniffed out
its prey long before it ever saw it. So,
once the T-Rex had prey in its sights,
what did it actually see? We can infer a
few things. First, both crocodiles and
birds had the retinal capacity to see
color. So, it stands to reason that
T-Rex had it, too. T-Rex's eye
positioning gave it stereoscopic vision,
so it would see well in three dimension,
with some suggesting it had a binocular
field of vision of 55°,
on par with Modern Hawks, which means
even if you stood still, T-Rex would
still spot you, which would have made
Jurassic Park a much shorter and much
bloodier film.
What started off as a handful of bones
blasted out of a Montana hillside has
become 120 years later something
completely different to what Barnum
Brown imagined. T-Rex was bigger,
sharper sensed, and more cunning than
the monster we thought we knew. And yet,
for all the breakthroughs, we're still
only working from fragments. To remind
you of the estimated 2.5 billion T-Rex
that ever lived, we found the remains of
fewer than a hundred. But the tools and
techniques of today still continue to
squeeze remarkable new insights from
these fragments. A generation of
scientists armed with technology Barn
and Brown could have only dreamed of are
slowly, painstakingly bringing this
animal into focus. And the clearer the
picture gets, the more terrifying it
becomes. The king, tyrant, lizard we
knew is dead. Long live the king. Let me
know in the comments what you think
about these new discoveries and
revelations and whether it's changed
your view on the T-Rex and whether
that's a good thing or a bad thing the
next time you watch Jurassic Park. And
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