Welcome back to the Deep Dive. We're doing something
a little different today. Oh, yeah. Usually,
you know, we tackle a specific paper, a news
event, or maybe a complex historical figure.
Today, we are tackling a silhouette. A silhouette.
That sounds a little ominous. You know exactly
the one I mean. Yeah. If you grew up with a bucket
of plastic dinosaurs, and I think everyone listening
probably did, you had this one. It wasn't the
T -Rex and it wasn't the Triceratops. It was
the duck -billed one with that long curved tube
sticking out the back of its head. Ah, yeah.
The one that looks like it's wearing a giant
piece of macaroni on its head. A boomerang. Yeah.
Yeah, macaroni. That's a great way to put it.
The Parasaurovus. That is the one. And looking
at the stack of research we have today, and I
mean, it's... everything from the original field
notes in the 1920s to acoustic physics modeling
from Sandia National Labs, I realized something.
This dinosaur is probably one of the most recognized
yet least understood animals in the fossil record.
We all know the shape, but we kind of treat it
like a piece of clip art. It's just the one with
the weird head. I think that's a really fair
assessment. For a long time, even within paleontology,
Parasaurolophus was sort of... It was relegated
to being background scenery. It's the cow grazing
in the swamp while the T -Rex does all the cool
stuff in the foreground. It's the extra in the
movie of the Cretaceous. Exactly. So the mission
for this deep dive is to drag this animal out
of the background. I want to stop looking at
it as a plastic toy. And start understanding
it as a biological machine. Because when you
actually dig into the mechanics of this thing,
how it ate, how it moved, and specifically what
that crest was actually doing, it stops being
a generic duck bill and becomes something much,
much stranger. It really does. The engineering
involved in this animal's skull alone is enough
to keep us busy for the next hour. I mean, we
aren't just looking at bones today. We are looking
at... acoustics, thermodynamics, social behavior,
the whole package. Okay, before we get into the
really heavy engineering, let's just get the
taxonomy out of the way. Parasaurolophus. It's
a mouthful. I feel like I have to take a breath
before saying it. It is a bit of a tongue twister.
What are we actually saying when we say that
name? Well, it translates literally to beside
crested lizard. Beside crested lizard. That sounds
odd. It does, but you have to understand the
context of the discovery. We're going all the
way back to 1922. William Parks, the paleontologist
describing it, was looking at this new fossil
found in Alberta, and he's looking at the skull
and thinking, well, this looks a lot like another
dinosaur I know called Saurolophus. Saurolophus,
which means? crested lizard. Oh, okay. That makes
sense. Exactly. Saurolophus had a solid, much
smaller crest. So Parks, being a practical scientist,
basically names this new one near or beside Saurolophus.
It's not the most poetic name I'll grant you,
but it tells you exactly where it sits on the
family tree. So it's basically the crested lizard's
neighbor. Pretty much. And taxonomically, we
are placing this animal in the family Hedrosauridae.
These are the duck -billed dinosaurs. But within
that family, there's a crucial split you need
to know to understand the deep dive today. You
have the Hadrosaurines, which generally have
flat heads or solid crests. Think Edmontosaurus
or Myasaura. And then you have the Lambiosaurines.
And our guy is a Lambia serene. Exclusively.
The Lambia serenes are the hollow -crested duckbills.
And that word hollow, that is the key. That's
the big distinction. That is the distinction
that drives almost all the biology we're going
to talk about. If you don't have that hollow
space, you're just a flat -headed grazer. If
you do have it, well, you're capable of some
pretty incredible physics. Okay, hold that thought
on the physics. I want to ground this in physical
reality first. Because duckbill dinosaur sounds
cute. It sounds manageable. It does. Like a big
mallard that you could maybe feed bread to at
the park. Please do not try to feed bread to
a Parasaurolophus. Why not? Help us visualize
this scale here. If I'm standing next to a fully
grown Parasaurolophus walkery, that's the classic
species, right? That's the type Cepheusia. What
am I looking at? What am I feeling? You are looking
at a wall of muscle. You would feel incredibly
insignificant. We are talking about an animal
that is roughly 9 .45 meters long. That's 31
feet. 31 feet. So imagine a standard yellow school
bus parked in front of you. Now imagine that
school bus has legs and can run. That's substantial.
That's a lot bigger than I pictured. It is. And
it's not just the length. It's the mass. The
weight estimates. Well, they vary a bit depending
on the method you use. How do they even figure
that out? Is it just a guess? It's more than
a guess. You can do volumetric models where you
sort of shrink wrap a digital skeleton with muscle
and calculate the volume. Or you can use the
circumference of the leg bones and compare it
to living animals. Okay. So what are those models
telling us? They're consistently landing us between
2 .5 and 5 metric tons. So that upper limit is
about 5 .5 short tons. So we're talking African
elephant territory. Easily. Maybe even heavier
than an average elephant. And unlike an elephant,
which is, you know, four on the floor stable,
this animal is built very differently. It's carrying
that mass in a completely different way. Right.
Which brings us to the locomotion question. Because
I've seen artwork of them walking on four legs,
looking all peaceful. And then I've seen artwork
of them running on two legs, looking absolutely
terrifying. Which one is it? They're both right.
We call this being a facultative biped. Okay,
define that for us. It essentially means the
animal has a choice. It's not locked into one
way of moving. Most of the time, when it's just
grazing, conserving energy, moving slowly through
the brush, it's a quadruped. It's on all fours.
That makes sense. It's the most efficient way
to support that five -ton gut. Exactly. It's
engaging the front drive, so to speak. But...
If a predator, say, a Gorgosaurus, appears on
the horizon or it needs to cover ground quickly,
it can shift its weight back, lift those front
arms up, and sprint on its hind legs. A five
-ton animal sprinting on two legs is... That's
a terrifying image. That's a lot of kinetic energy
moving very, very fast. It is. And the skeleton...
absolutely supports this power. If you look at
the femur, the thigh bone of Peawalkery, it's
over a meter long, about 103 centimeters. It
is an incredibly robust, thick piece of bone.
Wow. And the pelvis is just... massive, heavily
built to anchor these huge running muscles. But
then you look at the arms, the humerus, and they
are relatively short, especially for a hadrosaur
of that size. So they're a little bit T -Rex
-y in that way. Big legs, smaller arms. A little
bit, yeah. They're definitely not as comically
small as a T -Rex is, but the power is all in
the back. They wouldn't be winning marathons
on two legs, but for a short, powerful burst
of speed, they were built for it. And while we're
on the body, you mentioned something in the notes
about the spine. They had a weird back. Not weird,
so much as distinct. They had these very tall,
neural spines sticking up from the vertebrae,
especially over the hips and the back. So it
wasn't a flat back like a lizard? No, not at
all. It gave it a high -backed look, almost like
a ridge running down the spine. It created a
very distinct profile, even before you get to
the head crest. Okay, let's get to the head.
I want to circle back to the duck bill part.
You mentioned earlier that calling it a duck
is a problem. But, I mean, it has a bill. I'm
looking at the skull right now in the notes.
It has this... broad, flat beak. It has a beak,
yes. But the function is totally, totally different.
A duck uses its bill to, you know, dabble in
the water, filtering out soft algae and little
bugs. Right. It doesn't chew. It just sort of
slurps. Parasaurolophus was a shooing machine,
an industrial -grade shooing machine. But reptiles
don't chew. That's like the rule, right? They
rip and swallow. Crocodiles don't chew. Lizards
don't chew. Usually, yes, that is the rule. But
hadrosaurs, they invented a way to cheat the
system. They evolved something that we mammals
usually claim is our own special invention. Behind
that beak, they had what we call dental batteries.
Batteries, like are they energized? No, no, not
electric. Think more like an artillery battery.
Rows and rows of guns. Oh, I see. So imagine
a dense pavement of teeth. Hundreds of small
diamond -shaped teeth packed tightly together
in these columns. As the animal ground down tough
vegetation, we're talking pine needles, twigs,
abrasive ferns, the surface teeth would wear
away. And then they'd be toothless. Nope. Immediately
underneath, there was another tooth ready to
push up and replace it. It was a constant conveyor
belt of new grinding surfaces. Like a shark's
mouth, but for grinding. Similar concept, yeah,
but arranged for grinding, not for slicing. A
shark slices. A hadros... sore grinds. And the
mechanics of the jaw itself are just fascinating.
We call it pleurokinesis. Pleurokinesis. Okay,
break that down for us. Pleuro meaning side,
kinesis meaning movement. So when a cow chews,
it moves its lower jaw side to side. You've seen
a cow chewing its cud. Sure. That round grinding
motion. Right. A Parasaurolophus couldn't move
its jaw side to side quite like that. Instead,
the upper jaw bones, the maxillae, could actually
flex and rotate slightly outwards against the
lower jaw. The skull itself was flexible. The
whole skull moved. Parts of it, yes. It created
this incredibly effective grinding surface that
could pulverize the toughest plants in the Cretaceous.
This wasn't passive eating. This was industrial
processing. That makes so much sense. You don't
get to be five tons by just nibbling on soft
algae. You need a massive calorie intake. You
need to unlock the nutrients in wood and tough
leaves. Exactly. They were effectively giant
biological wood chippers. We should mention the
skin, too. I saw a note that we actually have
impressions. We do. is incredibly rare. They
show these uniform tubercle -like scales, like
little bumps, but no larger distinct structures
like scutes or armor, just this pebbly texture
all over. Okay, so we have a five -ton bipedal
sprinting industrial chewing pebbly skin machine,
but we haven't talked about the elephant in the
room, or rather the trombone in the room. The
crest. The crest. This is what I was looking
forward to, the great crest debate. I was reading
through the history of how scientists have interpreted
this thing, and it feels like a comedy of errors.
It's like for 50 years, everyone has projected
their own weird theories onto this bone tube.
You have to be a little fair to the early paleontologists.
They were working without CT scanners, without
soft tissue evidence, and often with really incomplete
skeletons. They saw a shape and tried to find
an analogy in nature, and the biggest bias they
had was the habitat. The swamp bias. Right. The
prevailing dogma in the early 1900s was that
these big dinosaurs were just too heavy for land.
They thought their legs would snap under their
own weight. So they had to be aquatic. They had
to live in swamps to let the water support them.
their massive bulk. Which we now know is completely
wrong. Completely. But it colored every interpretation.
So when Alfred Sherwood Romer looks at Parasaurolophus
in that context, he sees a creature living in
the water. And what do you need if you're underwater?
A snorkel. A snorkel. So Romer proposes quite
seriously that the crest is literally a breathing
tube. I mean, visually, it works perfectly. You
can just picture the dinosaur submerged, just
the tip of that crest poking out of the water
like a periscope. This is a very... stealthy,
cool image. A great image. It would make a great
movie monster. But anatomically, it's a complete
and total disaster. Why? What's the fatal flaw?
Well, the fatal flaw is that there's no hole
at the end. It's solid bone at the tip. The airway
starts at the nose, goes all the way up the crest,
does a U -turn at the top, comes all the way
back down, and then goes into the throat. It's
a closed loop. It's a closed loop. If you used
it as a snorkel, you'd just be sticking a sealed
tube out of the water. You'd suffocate immediately.
It fails at the most basic level. Okay, so the
snorkel is dead on arrival. But they didn't give
up on the water angle, did they? The bias was
strong. No, it was very, very strong. So then
came the air trap theory. Charles Sternberg and
later Ned Colbert thought, okay, okay, maybe
it's not a snorkel. Maybe it's a scuba tank.
An air reservoir to hold their breath. Exactly.
The idea was they could fill this hollow crest
with air and use to hold their breath for long
periods underwater, like soaring extra oxygen
for a deep dive to escape a predator. That sounds
a little more plausible. I mean, whales hold
their breath. It sounds plausible until you do
the math. We're talking about a multi -ton animal
with lungs probably the size of a refrigerator.
The volume of air inside that crest is... maybe
at best a couple of liters. It's a tiny, tiny
fraction of their total lung capacity. So that's
like a human trying to survive underwater by
holding an extra mouthful of air in their cheeks.
That is a perfect analogy. It would buy them
maybe three seconds of extra dive time. From
an evolutionary standpoint, it is way too expensive
an investment. Growing this massive, complex
bone structure just for three extra seconds of
air. It doesn't pay off. So it fails the cost
-benefit analysis. Deserpsly. All right, so they're
out of the water. What happens next? We get into
the weapon theories, right? Athenio Abel suggested
it was a club. A battering ram, yeah. The idea
was that males would spar, head -butting each
other like bighorn sheep, either for mates or
for territory. But again, looking at the anatomy,
that just doesn't seem right. bone it's hollow
it's thin the walls the crest are actually quite
fragile if you took a five ton run and smashed
that crest into a rival's ribs you wouldn't break
their ribs you would shatter your own face it
would be a catastrophic self -injury the sinuses
would collapse it's just not built for impact
it's delicate my absolute favorite though has
to be the proboscis theory This one feels like
it came from a fever dream. Oh, Martin Woolforth.
Yes, the trunk. Tell us about the trunk. It's
just so wonderfully bizarre. So Woolforth looked
at the crest and thought, what if this isn't
just a crest? What if it's an attachment point
for big muscles? And he proposed that a mobile
trunk, like an elephant's, dangled off the end
of the crest to grab leaves and pull them to
the mouth. I am trying so hard to picture a duck
-billed dinosaur with an elephant trunk coming
out of its forehead. It's a nightmare. It looks
like something from a bad 1950s sci -fi movie.
It's strictly impossible. Elephants have these
massive, rough scars on their skulls where those
powerful trunk muscles attach. You can see exactly
where the anchor points are. And Parasaurolophus.
Nothing. The bone is smooth. There are no muscle
scars. Plus, as we just established, it has a
hyper -efficient beak and grinding teeth. Why
would you evolve a cropping beak and a trunk
to do the exact same job? It's redundant. Completely.
Nature almost never keeps two expensive tools
that do the same thing. Okay, there's one more
that was kind of funny. The foliage deflector.
Andrew Milner's idea. Right. That it worked like
a helmet or the cask on a cassowary, you know,
pushing branches and leaves out of the way as
it ran through the forest. Which makes sense
for the shape, right? It sweeps back. It looks
like it could part the bushes. The shape works.
Sure, I'll give him that. But it doesn't explain
the inside. If it's just a branch of asher, why
is it hollow? Why does it have all these complex
internal tubes and chambers? You could just have
a solid ridge of bone. The complexity. The complexity
implies a more sophisticated function. It's over
-engineered for just pushing leaves. So we've
ruled out snorkel, scuba tank, club, trunk, and
helmet. Which is a pretty good list of what it
wasn't. Yeah. That leaves us with the theory
that actually stuck. And this is where the story
gets really, really cool because we stop guessing
and start using physics. The idea that the crest
is fundamentally a musical instrument. A biological
resonator. This is the leading theory today,
by a wide margin. And we have hard data on this.
In 1997, a team at Sandia National Laboratories,
and you have to keep in mind, these are people
who usually model shockwaves for nuclear explosions
or high -speed aerodynamics for jets. Right,
they're not paleontologists. Not at all. They
got involved in this project. That's a crossover
I did not expect. They got their hands on a CT
scan of a Parasaurolophus tubicin skull. Tubicin?
That's the one with the most complex crest. Correct.
Tubicin literally means trumpeter. Its crest
is longer and has a more intricate internal structure
than the other species. So they took that digital
model and they simulated airflow through it.
They basically played the dinosaur like a virtual
instrument to see what sound it would make. And
what happened? What did it sound like? The crest
acted as a perfect resonance chamber. The air
travels from the nostrils up the long tubes,
vibrates, and produces a sound. But not just
any sound. Because the tube is so long, over
two meters in some adults, it resonates at incredibly
low frequencies. How low are we talking? The
fundamental frequency that's the lowest note
it could produce was about 30 hertz. 30 hertz.
For context, the lowest note on a standard 88
key piano is about 27 hertz. So this is deep.
This is bass. It's right at the bottom edge of
human hearing. We can generally hear down to
about 20 hertz. So if you were standing there
on the Cretaceous, you wouldn't just hear this
sound, you would feel it. Like when a subwoofer
hits in a movie theater. That rumble in your
chest. Exactly that. A visceral thrumming that
you feel in your bones. The modeling suggested
they could produce a whole range of sounds from
about 55 to 720 hertz. But that low end rumble
is the key. Why is the low end the key? Why not
just chirp like a bird? Why invest so much bone
and energy in being a biological subwoofer? Physics
again. High -frequency sounds, chirps, squeaks,
whistles, they scatter easily. Leaves, trees,
even fog, they all block and absorb high -frequency
sound waves. If you yell in a dense forest, your
voice doesn't travel very far. Right. But low
-frequency infrasound, it cuts through everything,
it travels for miles, barely losing any energy.
Like elephants. I know they use infrasound. Exactly
like elephants. Elephants use infrasound to coordinate
herd movements over vast distances. You might
not be able to hear an elephant calling from
two miles away, but another elephant certainly
does. Parasaurolophus was likely doing the exact
same thing. They were broadcasting. What were
they saying? I'm here. Predator approaching.
Where is the herd? This is good feeding ground.
Long -distance communication to keep a potentially
huge scattered group cohesive. And the biology
backs this up, right? It's not just the crest.
You need the right hardware to hear what you're
shouting. Right. It's pointless to make a specific
sound if no one can hear it. And when we've looked
at the brain cases of hadrosaurs, we find that
they had very delicate stapes, those little ear
bones, and an elongated cochlear duct, which
is very similar to what you see in a modern crocodile.
And that means... That setup is specifically
tuned to be highly sensitive to low frequencies.
So they had the transmitter, the crest, and they
had the receiver, the ears. It's a complete system.
That completely recontextualizes the whole animal.
It's not a silent, peaceful grazer. It's a node
in a communication network. A very loud one.
Imagine a whole herd of these things. It wouldn't
have been a quiet, peaceful swamp. It would have
been a constant thrumming conversation happening
all around you. But the crest wasn't just for
sound, surely. If you stick a six -foot tube
on your head, people are going to look at it.
There has to be a visual component. Oh, absolutely.
We can't ignore the visual aspect. Dinosaurs
were highly visual animals. We know from their
skulls that they had large optic lobes in their
brains and large sclerotic rings in their eyes.
Sclerotic rings. They're rings of bone that support
the eyeball. Their size tells us about the size
of the eye and likely their reliance on vision.
Everything points to them having excellent daytime
vision, probably in color. So the crest is a
flag, a billboard. It's a species ID card. You
have to remember Parasaurolophus didn't live
alone. It lived alongside other Lambiosaurians
like Korthosaurus and Lambiosaurus, which also
had these big hollow crests, but they were shaped
differently, like helmets or hatchets. If you're
a Parasaurolophus looking for a mate from a mile
away, you need to be able to spot that unique,
long, curved profile instantly. You don't want
to waste time and energy courting a Korthosaurus.
And presumably, the bigger the crest, the better
the mate. The classic sexual selection. argument
that's the standard theory and it holds up well
here a big elaborate crest is expensive to grow
it takes a lot of calcium a lot of energy and
a lot of time if you have a massive perfect crest
you are advertising to the opposite sex look
at my good genes i am so healthy and successful
that i can waste energy on this giant ridiculous
hat meet with me so it's a dual purpose signal
the shape tells you the species and the size
and quality tell you about the fitness of the
individual exactly And the sound would have been
part of that, too. A bigger crest would produce
a deeper, more resonant call. So you could see
and hear the quality of a potential mate from
a long way off. Before we move on, I want to
touch on one other functional theory that seems
to have some merit, even if it's not the primary
one. The air conditioning theory. Ah, yes. Wheeler's
theory from 1978. This one is really interesting
because it deals with thermodynamics. The idea
is that because the crest has so much surface
area and the bone is vascularized, which means
it had lots of blood vessels, it worked like
a radiator to cool the brain. Right. The basic
concept is you pump hot blood from the body up
into the crest. At the same time, you're breathing
in cooler air through your nose. That air moves
through all those internal tubes and passages,
cooling the blood through convection. And then
that newly cooled blood flows back down and circulates
around the brain, keeping it from overheating.
It's a biological brain cooler. Does that hold
up? It's very likely a secondary benefit. I don't
think most paleontologists think the crest evolved
for that purpose. Why not? Well... You could
cool down with much simpler structures like the
big ears on an elephant or the frill on a triceratops.
You don't need to evolve a complex, sound -producing
trombone just to cool your brain. The acoustics
seem to be the primary driver. But if you're
a five -ton animal living in the hot, humid Cretaceous
summer, having a built -in radiator on your head
is definitely a fantastic bonus. Because it's
a multi -purpose tool. Nature loves efficiency.
If you're going to build a big, expensive structure,
you might as well use it for everything you can.
So yeah, it's a boombox, it's a billboard, and
it's an AC unit, all in one. A boombox, a billboard,
and an AC unit. I love that. Now, we've been
talking about the Parasaurolophus as if it's
just one thing, but the notes highlight that
there are three distinct, recognized species,
and the differences between them actually caused
a massive fight in the scientific community.
They did. It's easy to lump them together, but
the differences are crucial and tell us a lot.
So the three main players on the field are, first,
Parasaurolophus walkeri. That's the classic one,
the type species from Alberta that William Parks
found. Straight crest. Mostly straight with a
slight graceful curve. And its internal tubes
are relatively simple. Then you have Parasaurolophus
tubicin, the giant trumpeter from New Mexico.
The loud one, the one they CT scanned. The loud
one. It's the biggest of the three, and its crest
is longer and much more complex inside. It has
more chambers, more loops. It was probably capable
of a greater range of sounds. And then we have
the troublemaker. Parasaurolophus sardicrystatus.
Sardicrystatus. Why is he the troublemaker? Because
he just looks wrong. Walkery and Tubison have
these long, backward -sweeping tubes. They look
elegant. Sardicrystatus is smaller, and its crest
is short and curves down sharply, almost tucking
in against the back of the skull. It looks unfinished.
That's a great way to put it. It looks like a
Parasaurolophus that gave up halfway through
growing its crest. And that appearance led to
the female hypothesis, right? Exactly. In biology,
when you see two animals in the same place that
look similar, but one is big and robust with
a fancy ornament, and the other is smaller and
more gressle, your first instinct is sexual dimorphism.
Males versus females. Sure. So the paleontologist
James Hobson suggested that maybe Serticostatus
wasn't a different species at all. Maybe it was
just the female form of one of the other species,
like Tubicin. Which happens all the time in nature.
Male deer have antlers, females don't. Male peacocks
have the giant tail. Females don't. It was a
very solid, very elegant theory. It tidied everything
up nicely. Oh, the short curved crests are the
girls and the long straight crests are the boys.
Simple. But then stratigraphy, the study of rock
layers, kind of ruined the party. How so? What
did the rocks say? While P. sardicristatus is
found in different rock layers than P. tubuson
is, especially in New Mexico, they are separated
by time and geography. You usually don't find
the males of a species living a million years
apart from the females. Yeah, that makes mating
very, very difficult. The long -distance relationship
from hell. Exactly. So the consensus now is that
Cerda crustatus is a valid, distinct species,
perhaps a more primitive or basal form. Or maybe
it just occupied a different ecological niche
where a shorter crest was more advantageous for
some reason. But speaking of crest shape and
how they grow, we have to talk about Joe. Everyone
loves Joe. Joe is a rock star. Who is Joe? Joe
is the nickname for specimen ram 14 ,000. It
was found in Utah in the Kuyperowitz Formation
back in 2009 and was found by a high school student,
actually, a kid named Kevin Terrace. He was volunteering
on a dig and saw a little bit of bone sticking
out of a rock that seasoned professional paleontologists
had walked right past for years. Good eye on
that kid. An incredible eye. And it turned out
to be the most complete and by far the youngest
paras... saurolophus we have ever found. How
young are we talking? A baby. Based on bone histology,
it was less than a year old. It was only about
2 .5 meters long, so about eight feet. An eight
foot long baby? Yeah. That's still bigger than
a human? They grew fast. Insanely fast. These
animals were putting on mass at an incredible
rate to get out of that bite size for predator
stage as quickly as possible. But the real shocker
was the head. Based on the adult skulls, you'd
expect maybe a tiny little tube starting to form.
A little snorkel. Joe didn't have a tube. So
what did he have? He had a bump. A little low
hemispherical nub right on his forehead. It looked
more like a pimple than a crest. So they aren't
born with a trombone. It has to grow. No. And
that tells us something really crucial about
their life history. The crest starts growing
very early, and it grows very, very fast. In
other related crested dinosaurs, like Corythosaurus,
the crest doesn't really pop up until they are
about half grown. They look like generic flat
-headed duck bills for a long time. But not Parasaurolophus.
No, Parasaurolophus kids were pushing that bone
up almost immediately. It was a priority. Which
implies that even for the juveniles, that signal,
or maybe the beginnings of that sound, was vital.
Maybe for staying in touch with the parents.
That's one possibility. Or it could be that the
final adult structure was so massive and complex
that they simply had to start growing it early
just to get it finished in time for adulthood.
Either way, it implies a life that was strictly
governed by that crest. It was the center of
their entire existence. I want to pivot now to
something that makes these animals feel real.
Not just biological machines, but individuals.
Because we have a specific and kind of sad story
about the very first Parasaurolophus ever found.
The holotype. The paleopathology, yes. This is
one of my favorite details in this whole story
because it was misunderstood for almost a century.
Right. So when William Parks found this skeleton
back in the 1920s, he noticed this strange notch
in the spine. Right where the neck meets the
back, the vertebrae are kind of crunched down
in a V shape. And Parks, working with what he
knew, thought it was a natural feature. He actually
proposed that a huge ligament ran from the tip
of the crest all the way back to the notch in
the spine. Like a suspension bridge cable. Exactly.
He thought, wow, that head and crest are so huge
and heavy, the neck muscles can't possibly hold
it up alone. So he imagined this thick ligament
acting as a tether. holding the head up which
we now know is completely wrong completely wrong
there's no anatomical precedent for that in any
animal we know of the main neutral ligament which
supports the head attaches to the base of the
skull not to the tip of a fancy hollow crest
so if it's not a ligament anchor what is it it's
a broken back a healed but severe injury That's
a lot more dramatic. A study in 2020 by a paleontologist
named Pertotso really took a close look at this
with modern technology. The bones are clearly
deformed. They were crushed by some kind of massive
blunt force trauma. And the leading theory is
the falling tree hypothesis. OK, paint the picture
for us. Imagine the late Cretaceous of Alberta.
It's a storm. The weather patterns were much
more intense back then. You have high winds,
maybe a hurricane -like storm coming off that
big interior seaway. And this animal is hiding.
Settling in the forest, maybe with its herd,
trying to stay low and ride it out. It's loud.
It's wet. It's terrifying. In a massive tree
trunk, maybe a redwood relative, something huge
snaps in the wind and crashes down. It strikes
the animal right across the shoulders, just behind
the neck. A direct hit. A direct hit from a tree.
It would have been crushing. It smashed the tall
neural spines of the vertebrae, compressed the
vertebral column itself, and likely broke several
ribs. It would have been an agonizing, crippling
injury. And usually in the wild, a broken back
like that means death. You can't move, you starve,
or a predator finds you and eats you. That's
the miracle of the specimen. The bone shows extensive
signs of healing. There's a lot of remodeled
bone, calluses where the fractures were. This
wasn't a death blow. It survived. It survived.
It lived for months, maybe even years after this
injury. The bone grew back together, but it healed
in that deformed V -shaped notch that Parks saw.
That is just incredible. It tells us two amazing
things. One, Parasaurolophus was tough as nails.
This animal walked around, ate, and interacted
with its herd while recovering from a major spinal
fracture. It must have been in constant pain,
but it kept going. And the second thing? It implies
a level of social support. You think the herd
protected it? It's certainly possible. An animal
that injured would have been slower, more vulnerable
to predators. If it survived for years, it suggests
it wasn't immediately picked off or left behind.
It stayed with the group, and the group provided
some measure of safety. It adds this whole layer
of biography to the bones. This wasn't just a
generic specimen number. It was a survivor. It
had a really, really bad day, and it lived to
tell the tale. Let's widen the lens a bit. We've
looked at the animal in detail. Let's look at
the world it survived in. Where are we geographically
when we talk about Parasaurovus? We are in a
place called Laramidia. During the late Cretaceous,
North America was split in half by a giant inland
sea. the Western Interior Seaway. It ran all
the way from the Arctic Ocean down to the Gulf
of Mexico. The landmass to the east is called
Appalachia. The long, thin landmass to the west,
stretching from Alaska down to Mexico, is Laramidia.
This is where all the famous dinosaurs like T
-Rex, Triceratops, and Parasaurolophus lived.
But it wasn't just one big uniform forest, right?
The environments were different. No, it was highly
regional, which is why we see different species
in different places. In the north, in Alberta,
where our survivor with the broken back lived,
you had the dinosaur park formation. This place
was crowded. Crowded with what? Herds of Centrosaurus,
Styracosaurus, lots of other kinds of dovetails
like Corithosaurus. It was like the Serengeti
of the Cretaceous. But strangely, Parasaurolophus
walkeri was actually pretty rare there. Just
passing through. Maybe. Or maybe it preferred
the uplands away from the crowded floodplains.
It's actually one of the rarer hadrosaurs in
that particular fauna. But as you go south into
New Mexico and Utah, the picture changes completely.
Utah was the jungle, right? The Kuiperowitz formation.
That's right. That was the home of Joe the Baby.
It was a hot, humid, swampy jungle. Very wet.
Lots of rivers and floodplains. And the predators
were different. In the north, in Alberta, you
had to worry about Gorgosaurus. In Utah, you
had Teratophonius, another Tyrannosaur, but you
also had something much, much worse in the water.
Deinosuchus. The Terror Crocodile. How big are
we talking when we say Terror Crocodile? We are
talking about an alligatoroid that grew up to
12 meters long. That's 40 feet. It weighed more
than the T -Rex of its time. Its bite force was
strong enough to crush giant sea turtle shells
and dinosaur bones like they were popcorn. So
if our parasaurolophus goes down to the river
to get a drink. It is entering the kill zone.
We actually have had parasaur bones from that
formation with Deimosuchus bite marks on them.
This was a world where the water could and dead
eat you. And yet the southern species P. tubicin
and Serticristatus seem to be more common in
these swampy wet areas. They were living right
next to the danger. Which means. Maybe that's
why they needed such a sophisticated long distance
communication system. You need to be able to
warn the rest of the herd about the 40 foot crocodile
lurking in the river. It makes a lot of sense.
A low frequency rumble. That means watch the
water. I have to ask about one last physical
detail because it ties into how a lot of people
first saw this dinosaur, especially if they're
of a certain age. If you watch Disney's Fantasia.
Oh, the Rite of Spring sequence, a classic. For
all its inaccuracies, it was beautiful. It was.
And in the movie, the Parasaurolophus has this
sail, a flap of skin connecting the crest to
the back of the neck. It looks kind of like a
basilisk lizard. It looks very, very cool. It
does look cool. I'll admit that. Is there any
truth to that? Or is that just Disney magic?
That idea actually goes way back to Barnum Brown,
a very famous fossil hunter around 1912. He was
describing a related animal and saw some texture
on the back of a crest and hypothesized there
might have been a skin flap. And because of that
notch in the spine of the Parasaurolophus holotype
we talked about earlier, artists just, they connected
the dots. They thought the sail attached to the
broken back. Exactly. They thought, oh, that
notch must be the anchor point where the skin
flap attaches. So it became a popular look. But
now that we know the notch is an injury, the
anchor point is gone. And there's no other soft
tissue evidence to support a big sail like that.
So most modern paleo artists have ditched it.
The crest stands free. I think it looks better
that way, honestly. It highlights the instrument
itself. I agree. It's striking enough on its
own. It doesn't need any accessories. So let's
wrap this all up. We started this deep dive with
a silhouette. A plastic toy that basically every
kid knows. And we've ended up with this highly
complex, socially sophisticated biological entity.
Yeah, we've gone from a snorkel -using water
beast to a land -dwelling five -ton athlete that
could run on two legs. We've realized the crest
wasn't a weapon or a snorkel, but a high -fidelity
subwoofer capable of broadcasting messages for
miles. We've learned they grew up incredibly
fast, starting with just a little bump on their
heads that blossomed into this incredible structure.
And that they were resilient enough as individuals
to survive broken backs and tough enough as a
species to live in crocodile infested swamps.
It really, really changes the way you look at
a museum skeleton. It's not just a collection
of bones anymore. That's the goal. When you look
at that skull now, don't just see a bone. Try
to hear the sound. Imagine a foggy morning in
the Cretaceous and that low vibrating hum rolling
across the landscape. That is the reality of
Parasaurolophus. So here is a final thought for
you to chew on. If they had this hardware, this
incredible ability to send specific, complex,
low frequency signals, what were they really
saying? We assume simple things, you know, food
here, danger there. But animals with complex
communication often have complex social structures.
Were they calling to specific individuals? Did
they have unique voices that their herd mates
could recognize? Were they identifying their
own offspring in the creche of thousands by their
specific call? The hardware suggests a level
of communicative complexity that we usually reserve
for animals like whales or primates. It's very
possible there was a lot more going on inside
that crested head than we give them credit for.
So next time you see that dinosaur, don't just
ask what the creche was for. Ask yourself, what
was it saying? Always ask the next question.
Thanks for listening to The Deep Dive. We'll
catch you on the next one.