Everything you think you know about
megalodon is wrong. New 2025 research
reveals it wasn't just a giant great
white. It was something far bigger.
For nearly 19 million years, this apex
predator ruled the oceans. The largest
shark to ever exist. Bigger even than a
T-Rex. With jaws so massive it could
crush a whale in a single bite.
And then one day it just vanished,
leaving behind only teeth the size of
your hands and questions big enough to
fill an ocean.
What happened to this nightmare of the
deep? Could it still be out there
lurking? Because more terrifying than
the idea of Megalodon surviving
somewhere in the abyss, is the
possibility that we never truly
understood it at all. But new evidence
is suggesting we were very, very wrong.
Could Megalodon not just have been
faster, but far bigger than we thought?
I'm James Stewart, and you're watching
Astram Earth. Join me on this journey
back to a time when Megalodon was at its
peak. We'll uncover the truth about this
colossal predator and find out how and
why scientists got things so wrong.
Imagining
our oceans patrolled by something three
times the size of a great white shark
with jaws easily big enough to swallow
two people side by side is irresistible.
But is it real? To find out, we need to
go back to a fateful day in 1666
when two fishermen caught a giant shark
off the coast of Levono in Italy.
The locals were so shocked by their
discovery that the Duke at the time
ordered that this curiosity be sent to
Neil's Steinson, better known as Stino,
a Danish anatomist working in Florence.
Curiously, it wasn't the size of the
shark that most interested Stino, but
rather its teeth. He was struck by how
much they resembled tongue stones,
triangular pieces of rock that since
ancient times, many thought to be
petrified snake or dragon tongues.
Instead, Steno postulated that they were
the remains of ancient sharks in rock.
He argued that rock layers formed slowly
over time and that an object like the
teeth could give us a snapshot of a
particular moment in history. The
significance of this observation would
change the course of paleontology
forever. He had discovered what fossils
really were. This was a revolutionary
idea. And whilst great for the future of
paleontology,
what's the link to megalodon?
Well, because sharks don't have bones,
their teeth are often the only part that
survives, making them our best clues.
And Megalodon had a lot of teeth, 276 to
be exact, some of which were up to 18 cm
long. Like modern sharks, Megalodon's
teeth were being constantly replaced.
They were arranged so that every time a
tooth fell out, one in the row behind
would push forward.
One megalodon could get through 40,000
teeth in its lifetime. In other words,
over Megalodon's 19 million-year
existence, the sea floor became
absolutely littered with old nashes. And
each one stood a chance of becoming a
fossil. And those fossilized teeth hold
the key to nearly everything we know
about this enormous shark. We even named
it for them. The word megalodon itself
simply means big tooth. So, in order to
determine what Megalodon was,
biologically speaking, paleontologists
have long tried to use these massive
teeth to identify its closest living
relatives. Megalodon was first formally
described in 1835 by Swissborn American
naturist, geologist, and teacher Louie
Agassiz, who named the species Cararadon
Megalodon.
It was placed here in the genus of
sharks within the lamniday family almost
entirely because its large triangular
serrated teeth were pretty similar to
that of modern-day great whites known as
carcarodon carcarius.
A skeletal reconstruction led by Mike
Godfrieded in 1996 backed this up. He
gave Megalodon the look of the stockier
great white we know and fear today.
extrapolating megalodon size from the
dimensions of its teeth.
Which is all pretty handy, isn't it?
Case closed. Giant great white shark
incoming. Jason Staithm's delighted and
the Megres wres havoc in Hollywood.
Well, not quite.
In the early 2000s, distinct differences
between the teeth and a closer look at
the fossil record suggested something a
bit more complicated.
So during the mid 2000s, Kevin Nyberg
and his colleagues conducted a series of
morphometric analysis between megalodon
and great white sharks. They found no
overlap in shape variants of the teeth,
nor in the shape of their roots. In
simple terms, the serrations of white
shark teeth were irregular and
triangular, whereas those of megalodon
were finer and rounder. Essentially, it
seemed very unlikely that the great
white evolved from Megalodon as
originally thought, but something else.
In 2019, Donna J. used this new evidence
to officially allocate megalodon within
the extinct Otodontday family, aka the
megatthed sharks. Other sharks in this
family include Ottous obliquequis
megalodon's earliest ancestor that lived
during the eosene times about 60 to 37
12 million years ago. So today we arrive
at the middle ground of ootus megalodon
the scientific name megalodon now
generally goes by although it should be
noted not everyone agrees with this and
some still prefer to use cararacles.
There's a bit more dental drama in
amongst all of that to be honest. But I
think that gives us a good overview of
Megalodon's lineage. But that's not the
only thing scientists were mistaken
about though. And something even more
sinister was about to come to light.
Every depiction of this prehistoric
shark you've seen in theaters, online,
and in your nightmares is very likely
wrong.
Because the largest shark to have ever
lived was actually bigger than we first
thought. Much bigger. For a long time,
the estimates for how long Megalodon was
were based purely on lots of fossilized
teeth and the occasional very rare
fossilized vertebrae. No complete
skeleton has ever been found. Now, from
that evidence we had, we thought its
body was between about 15 and 18 m in
length at most until now. Because this
year in 2025, a group of 28
international scientists led by
paleobiologist Dr. Kenshu Shimada
reshaped how the world thinks about this
prehistoric giant.
Central to this reimagining is one
particularly rare set of vertebrae
discovered in Belgium and now safely
cataloged in the Royal Belgian Institute
of Natural Sciences Conservatories in
Brussels. It measures a whopping 11 m in
length, but that only represents the
trunk of the shark. Its head and tail
are still missing.
So to try and fill in the gaps,
Shimada's team compared it to the bodies
of 165 other living and extinct shark
species. This enabled them to
extrapolate the animal's true size, and
they found that Megalodon's head likely
made up about 16.6% of it, while its
tail accounted for around 32.6%.
Applying this to the Belgian vertebrae
specimen, the shark's total length would
have been roughly 16.4 4 m with a 1.8 m
head and a 3.6 m tail, which was pretty
much in line with what the current
estimates were. But here's where things
get really interesting because there's
another even larger fossilized vertebrae
from Denmark, 23 cm wide. Now, that
suggests that some individuals may have
been even larger than that 16.4 4 m.
Perhaps even reaching an astonishing
24.3
m, nearly 10 m larger than we previously
thought, rivaling the size of a blue
whale and weighing in at a mindblowing
94 tons. But the revelations don't stop
there. Not only were megalodons bigger
than we previously thought, they also
looked vastly different, too.
Whilst reviewing a paper from August
2022 in which scientists built a digital
3D model of Megalodon, Shimada and his
team realized that some of the maths
behind the sharks proportions didn't
seem to add up. Using the same 145
species of living sharks and 20 ext,
they built a database logging the
proportions of their heads, bodies, and
tails. The researchers then compared
them to the parts of Megalodon's body
that have been found, and what they
found changed everything. Megalodon was
not a stout tankike great white shark at
all, but rather a more streamlined fish
with a much shorter nose when compared
with the great white. It had a flatter,
almost squashed jaw equipped with
extra-l long pectoral fins to support
its weight and size. It was more like a
lemon shock. The same study also
revealed something deeply disturbing.
Fossilized vertebrae suggested that baby
megalodons were born huge, measuring
between 3.6 and 3.9 m long. But that's
not the gross part because like
modern-day great whites, they also
likely practiced a form of inutro
cannibalism where embryos ate
unfertilized eggs to fuel their early
development. Survival of the fit is
personified.
We've seen what happens when we lose
large predators. The damage to ocean
ecosystems is catastrophic. And sadly,
human activity today doesn't help that
with things like over fishing and bottom
trolling. But that's where our friends
and see the results in less than 30 days. As we head back to the video,
all of those revelations about
Megalodon's shape also led to Shimada's
team stumbling upon a larger pattern in
marine biology. This new, more
streamline, more menacing shape makes
sense as to why Megalodon was able to
grow to the whopping 24.3 m his team had
estimated.
Stocky bodies like that of the previous
iterations of megalodon create far more
drag, making it much harder to move
efficiently through the water. These
constraints are why our current
modern-day great white sharks tend to
cap out at around 7 m. Any bigger and
they would lose the speed that makes
them such dominant predators.
The same logic applies to other animals
such as blue whales. They can grow up to
30 meters long, owing to their sleeker,
more hydrodnamic shape, allowing them to
traverse hundreds of thousands of miles
of ocean. Megalodon's new lightweight
frame may also go some way to explain
why it was able to pop up all around the
globe, too. The species was so
widespread that megalodon teeth have
been found on every continent except
Antarctica.
Based on what we've just discussed, it
seems very much like Megalodon was
superior to the great white shark in
every single way. Not only unrelated,
but more refined, fitter, bigger,
better. It makes the fearsome great
whites we have today feel pretty feeble.
But don't write off the great white
shark just yet, because it has one last
card up its sleeve. One that's about to
deal a fatal blow.
So, now we finally know what this
creature was. How did something so
dominant, so powerful, just disappear?
What went wrong for Megalodon? How did
the ocean's most fearsome predator just
vanish from history?
We know when Megalodon went extinct
because we've only ever found teeth that
are roughly between 20 million and 3.6
million years old. But why Megalodon
went extinct is not as straightforward.
It had spent millions of years
flourishing in the nutrient-rich waters
of the Meioene epoch, and it certainly
had a good run. But all good things come
to an end.
One theory that has popped up time and
time again is that as the planet got
closer to the ice age, it brought about
colder water temperatures and it simply
became too cold for the giant shark to
cope. However, data from scientists
Catalina Pimeento and Hberto G. Feron
seem to suggest otherwise. When
analyzing Megalodon's global
distribution through time, Pimento found
that Megalodon was capable of inhabiting
colder latitudes and its distribution
through time did not correlate with any
warming or cooling temperature trends we
know of. These findings fit nicely into
the work of Ference, who has theorized
that Megalodon was likely a mistherm, a
type of warm-blooded animal that keeps
its body temperature somewhat warmer
than the surrounding water and therefore
able to cope quite well with a wide
range of temperatures. So, if the planet
itself couldn't see Megalodon off, then
what did?
Pimeento's research showed that
Megalodon's global abundance and
distribution peaked in the middle
meioene roughly 11.6 to 16 million years
ago before going into decline. Now,
interestingly, this correlates with a
huge loss of whales, dolphins, and
porpuses, i.e. megalodon's favorite
foods. Extinction rates of marine
megapora, the largest genus or species
of a particular group of animals, were
incredibly high in the pioene.
Among those lost included 55% of large
marine mammals, 43% of sea turtles, and
9% of sharks with a total of 36% of
large marine species going extinct.
Changes in sea level may have also
impacted megalodon indirectly.
Fluctuations were common during the
plyio scene and could have spelt bad
news for a giant shark if coastal
habitats where there's a lot of food
available were impacted.
As all of that occurred, Megalodon was
likely forced to compete harder for what
remained with guess who? Jaws himself,
the great white shark. After all that,
Megalodon's size could well have been
its undoing. The evolution of the great
white, a smaller creature that needed
less to eat, meant megalodon never
really stood a chance, a deep sea
version of David versus Goliath. So, how
is it that 3.6 million years after it
went extinct, there are numerous
eyewitness accounts and documentaries
suggesting it's still out there? Could
Megalodon really be seeking refuge in
the dark depths of the ocean? Is it
possible even that it's hiding in the
Mariana Trench, waiting for the perfect
time to reveal itself to the world
again? Well, for a brief moment, they
almost had us. One of the best known
fuelers of the Megalodon Alive Fire was
a 2013 documentary which revolved around
an investigation into the huge shark's
continued existence. Watched by
millions, it was, I must admit, quite
compelling. It showed a blue whale
carcass beed off the coast of Hawaii
that looked to have been brutally
attacked. A scientist in the program
explained that the culprit had to be the
size of a megalodon. And other scenes
claim to show 6-ft tall fins poking out
of the ocean near similar blue whale
attacks. Unfortunately, or fortunately,
depending on your view, many people
missed the disclaimer at the start of
the show, which stated the potential
return of the species was not based on
fact.
As it transpired, the entire documentary
was full of faked photos, footage, and
even actors hired to portray scientists.
There have, of course, been other
unconfirmed sightings of living
megalodons. In 1918, a fisherman off the
eastern coast of Australia claimed to
have seen a shark 31 to 95 meters long
making off with some lobster pots. And
as recently as 2022, NBC Boston led with
the headline, "Two megalodon sightings
off New England." Spoiler alert, it was
a basking shark. Another common argument
for megalodon being out there somewhere
points to the fact that some large
animals such as the giant squid took a
while to be discovered by scientists.
However, their remains have been washing
up on shore and caught by fishermen for
decades if not longer, giving us real
hard evidence that they existed before
we had ever seen or recorded a full
specimen. By far and away the most
common argument you'll see for megalodon
survival is we've only explored 5% of
the oceans. Whilst that may be true
thanks to science, we don't really need
to explore all that much to know that a
giant whale killing shark isn't in
there. Megalodon was an apex predator
and if they were still out there, orcas
and great white sharks would never have
taken up their mantle. It's also no
coincidence that from around the same
time megalodon went extinct, the size of
whales exploded.
In the absence of large predators like
megalodon, whales in the plea scene were
twice the size of those in the plyene.
Hence the appearance of the blue whale.
But I've saved the best theory for last.
Don't you worry, I hadn't forgotten.
What if the megalodon is just hiding in
the Mariana Trench? Love this. A theory
popularized of course by Jason Staithm's
film The Meg. That story was actually
based on the fact that Megalodon teeth
were discovered near the trench by the
HMS Challenger in 1873 and were
considered new because they were
unusually white, dated to between 24,000
and 11,000 years old. The reality though
is much different. Instead, it's likely
the fresh pearly whites were just
uniquely well preserved by a thick
mineral crust of manganese dioxide that
significantly reduced the decomposition
rate. Megalodon teeth absolutely recent.
No way.
There are other issues, too. If we've
learned nothing else from this video,
it's that Megalodon likes to eat and eat
a lot. We made a video on the Mariana
Trench. Please do check it out on the
channel. and we showed exactly what is
there. And the reality is there's not
loads.
Certainly not enough food to
sufficiently feed a 24 m mega shark.
Incidentally, snail fishes are the
deepest dwelling fishes, but we don't
find them until much deeper than 8,000
m. Quite possibly for the same reason.
They're just isn't enough to eat, and
they're only 20 cm long.
So, there we have it. Our journey back
in time to the true land of the giants
and one of the most gloriously monstrous
beings ever to exist comes to an almost
anticlimactic end. Something so
mysterious and so powerful feels like it
deserves to bow out amongst fireworks
and explosions.
But instead, the reality is rather meek.
Despite that, it doesn't make the
megalodon any less intriguing. It seems
fitting that something so elusive was
able to keep a 19 millionyear-old
secret. And that leaves me feeling very
satisfied indeed. Actually, yes,
Megalodon is most definitely extinct.
But it's mystery still lives on. There's
just one way to know for certain what
Megalodon was. And like any good murder
mystery cliffhanger, they've still never
found a body. So until then, giant lemon
shark it is.
Let me know you've got this far in the
video by leaving a lemon emoji in the
comments as a tribute to Megalodon's
lemon shark makeover. And I'll see you
in the next one.