Original subtitles

[dramatic music]

[dramatic music]

- [Danny] Mysteries can be buried anywhere,

under the earth,

[explosion rumbles]

[airplane engine humms]

beneath the sea,

or even right under our own feet.

And when we stumble upon them

sometimes what we find can change history.

[dramatic music]

Tonight, discoveries that prove monsters

aren't just make-believe.

From a mythical creature-

- [Sami] It's incredibly well-preserved

and it has an unmistakable base of a giant horn.

- [Andrew] This is not the unicorns of make-believe,

this unicorn was built like a tank.

- [Danny] To a prehistoric predator-

- [Kavitha] They could hit running speeds up to 60 miles

per hour. This bird was truly a monstrous killer.

- [Danny] To a terrifying beast lurking in the deep.

- [Sami] Nobody has ever seen anything like it.

- [Austin] It has massive eyes, a gaping mouth,

and its body looks like some kind of deep-sea mutant.

- [Danny] Join us now because nothing stays hidden forever.

[dramatic music]

- [Danny] For one family, a simple summer hike

is nothing out of the ordinary,

until they spot something strange in the dirt

that ends up being the find of a lifetime.

[dramatic music] [letters clacking]

- [Don] In July 2022,

Sam Fisher is hiking with his preteen sons, Jessin and Liam,

and their cousin Kaiden,

in a rocky and rugged area of the North Dakota Badlands.

- [Hugo] The kids are running and playing,

and then suddenly

they see something sticking out of a rock.

It looks like long, pale bones.

[dramatic music]

- [Ashley] The father snaps a picture of Liam lying

next to the bone, which is pretty much

the size of his entire body.

- [Don] He sends it to an old high school friend,

Tyler Lyson,

who is a paleontologist

at the Denver Museum of Nature and Science.

Lyson takes a look at the picture

and a chill goes down his spine.

It sure looks like a leg bone of a dinosaur.

- [Hugo] He thinks that it might belong to a duck-billed species.

- [Danny] Duck-billed dinosaurs, also known as hadrosaurs,

were giant plant eaters that roamed the earth

almost 100 million years ago.

- [Hugo] Hadrosaurs evolved these grooved, shovel-shaped

beaks that were perfect for chewing, kind of like a duck.

- [Dan] Their fossils turn up fairly regularly

in North America, China, and Europe.

But any discovery that's over 65 million years old

is a big deal.

So Lyson can't wait to get boots on the ground

and take a look at this thing.

- [Kenneth] Tyler gets a permit

and he brings his team to North Dakota to start digging.

They're joined by a few extra hands,

Sam, his sons, and their sister, Emalynn.

- [Hugo] On the first day of the dig,

the team finds three giant serrated teeth.

[dramatic music]

They carefully excavate the area

and they find the entire lower jaw of a dinosaur.

Lyson gets goosebumps.

Now it's clear, this is no duck-billed plant eater.

- [Danny] To Lyson's surprise,

the Fisher family has actually uncovered

a tyrannosaurus rex.

- [Dan] Everyone knows T. rex is the king of the dinosaurs.

These apex predators grew up to 40 feet long

and weighed up to 10 tons.

This one though seems much smaller.

- [Kenneth] Lyson takes a closer look at the size of the jaw

and the length of the tibia

and realizes this is even more rare than he suspected.

- [Dan] It's a juvenile between 12 and 14 years old.

- [Hugo] Adult T. rex specimens are incredibly rare.

There's only a few dozen

that have ever been found in good condition.

But finding a T. rex that was still growing,

that's almost unheard of.

Only a handful of juvenile specimens

have ever been discovered.

- [Dan] The specimen offers a missing link

in the understanding of the growth cycle

of the king of the dinosaurs.

Scientists gain insight into T. rex puberty,

a rapid adolescent growth spurt similar to human teenagers.

- [Ashley] The specimen also has tiny maxillary teeth,

highlighting the process of losing and regrowing teeth

the T. rex goes through throughout its entire life.

- [Dan] This is an absolutely mind-boggling discovery,

and it's made by a few kids under the age of 10.

- [Danny] Dinosaurs aren't the only predators

that haunt our imagination.

Nearly 2,000 miles away,

friends on a beach stumble upon something far weirder

but just as terrifying.

[dramatic music] [letters clacking]

- [Andrew] On July 12th, 2008,

Jenna Hewitt and two friends are taking a stroll

along Ditch Plains Beach,

a well-known surfing spot on the Montauk Peninsula.

They're looking for a good place to stop and relax

when they notice something in the sand.

- [Adam] They get a little bit closer

and they realize it's some kind of a carcass,

but not anything that they can identify.

- [Kavitha] This creature is bizarre.

It's completely hairless, its skin is shiny and leathery,

its limbs are oddly misshapen

and it's got a beak-like snout.

- [Andrew] Jenna snaps a photo of this creepy, bruised animal,

and then she and her friends go on their way.

- [Danny] Later, Jenna posts her picture online,

and almost instantly, it goes viral.

- [Micah] On July 23rd,

the East Hampton Independent publishes a story

about Jenna's very bizarre discovery titled,

The Hound of Bonacville.

- [Adam] Once online news site, Gawker, picks up the story

and publishes the picture, it goes crazy

and mainstream news outlets like NBC News,

Fox News, Huffington Post begin covering the story.

And of course they give it an even catchier nickname,

the Montauk Monster.

- [Andrew] Some think it's a sea creature that washed up dead.

Others think it's a land animal

that walked out on the beach and died.

- [Kavitha] Some say it's a pit bull, it's a turtle without its

shell, it's a chupacabra.

The New York City Parks Department even claims

that it's a pig leftover from a cookout.

- [Kenneth] Most people agree it's an animal of some kind.

Problem is nobody can really agree

on what specifically the animal is.

- [Adam] Naturalists and animal experts begin to weigh in

on what this animal could possibly be.

The sharp teeth on the bottom jaw

indicate that it's a carnivore,

but that strange curved beak-like top jaw

confuses people.

The color, it's hairless nature, the beak, everything,

the thing is just freaking weird.

- [Danny] As the mystery grows,

the story takes a strange turn

when the creature suddenly disappears.

- [Kenneth] Locals tell the media that the carcass

was allegedly

moved to somebody's house, but nobody knows exactly where.

- [Andrew] Others aren't buying it and proposed theories

that are straight out of science fiction.

Now, there is a notorious animal research facility nearby

on Plum Island.

So some speculate that this Montauk Monster

is in fact some kind of genetically engineered animal

that escaped from the lab

and then whose carcass was secretly reclaimed

by these mad scientists.

- [Danny] Then in 2009,

a headline-grabbing revelation surfaces

that's a little harder to swallow.

- [Adam] Fox News reports that one man claims responsibility

for the creature.

- [Andrew] He says it's a dead raccoon.

He and some friends discovered it

the weekend before the 4th of July holiday in 2008.

- [Adam] Because they were young and stupid

and more than a little drunk,

they decide that they're going to give this raccoon

a Viking burial.

[dramatic music]

- [Andrew] They put the raccoon on an inflatable swim float,

set it on fire, and push it out to sea.

Two weeks later, the Montauk Monster is discovered.

So they think that the monster

is really their dead Viking raccoon

that has drifted to the other side

of Long Island South Fork.

Many remain skeptical.

But with the creature gone, there's no way to know for sure.

- [Danny] To this day, there's no real consensus

on the strange monster found by Jenna and her friends.

- [Kavitha] Was it a normal animal that just decayed in a

creepy way? Was it a cryptid?

Or was it a monstrous lab experiment gone awry?

[dramatic music]

- [Danny] In Colombia, ranchers are used to facing predators

like wolves and coyotes.

But for one man,

a routine day's work turns into a brush

with something straight out of a nightmare.

[dramatic music] [letters clacking]

- [Kavitha] In 2008, longtime rancher, Cesar Perdomo,

is repairing a fence on his ranch

in Colombia's Tatacoa desert

when he spots something on the ground.

As he clears away some dirt surrounding the object,

he sees what appears to be a five-inch-long fossil.

- [Adam] He carefully cleans it off and he takes it home

and he adds it to the collection

of interesting finds and fossils

that he's collected through the years.

- [Kavitha] Eventually, Perdomo decides to share his discoveries

with the public and opens a small museum

where he can display his most curious finds.

- [Danny] In 2023,

paleontologist Rodolfo Salas-Gismondi

comes to the museum to see the collection.

- [Adam] Gismondi is going through the little museum,

checking out Perdomo's various bones and fossils.

One in particular really grabs his attention.

It's that five-inch fossil

that Perdomo pulled up near the fence.

Salas Gismondi can tell that it's from a bird.

- [Danny] But not just any bird.

This is a giant flesh-ripping predator

that ruled the Americas millions of years ago,

the terror bird.

[dramatic music]

- [Kavitha] Terror birds were apex predators

that could weigh up to 330 pounds.

They had massive beaks

which they could use to crack open skulls,

but surprisingly, they were flightless.

They inflicted their terror entirely on the ground,

where they could hit running speeds up to 60 miles per hour.

- [Kenneth] This fast-running monstrous bird

was absolutely terrifying, an ostrich from hell.

- [Adam] About 20 terror bird species are known to

researchers. And while there have been terror birds found

in Florida and Texas,

almost all terror bird fossils have been recovered

from Argentina.

And until Perdomo found this bone in Colombia,

nothing was found in between.

- [Kavitha] This particular fossil comes from

the terror bird's left lower leg bone.

It's similar to a human's tibia or shin bone.

When the bone is analyzed,

they realize that this might be a new species

even more terrifying than the rest.

Perdomo's fossil is estimated to be up to 20% bigger

than any previously found terror bird.

At over eight feet tall and 350 pounds,

Perdomo's terror bird was truly a monstrous killer.

- [Danny] Even more astonishing than its size is its age.

- [Adam] It turns out this fossil is almost 13 million

years old, from the Middle Miocene Epoch.

- [Kavitha] This is a wild time in history.

All of the non-flying dinosaurs are long extinct

from the asteroid event that wiped out 75% of life

on the planet.

In this time period,

South America is crawling with crazy huge animals

like giant sloths, 30-foot crocodiles,

and armored creatures called Glyptodonts

that can reach the size of cars.

And right there with them were the aptly named terror birds.

- [Danny] Unfortunately,

this particular bird's final hunt didn't end well.

- [Adam] On the leg bone are these massive puncture marks,

teeth marks from a Purussaurus,

essentially an ancient 30-foot crocodile.

[dramatic music]

- [Kavitha] In a way, the terror birds survives to this day.

Their closest living descendants,

the red-legged seriema,

are still used by Brazilian ranchers to guard livestock.

- [Adam] Much like their fearsome ancestors,

these birds still eat meat.

But don't worry, they don't present nearly as much danger,

they're only three feet tall.

[dramatic music]

- [Danny] Discovering a monster that died out millions of years

ago is one thing,

but finding one that's still alive,

that's a whole different kind of shock.

- [Sami] On November 15th, 1976,

the crew of a US Navy vessel is conducting research

in the deep waters off the coast of Oahu, Hawaii.

While they're doing their work,

the team has deployed anchors

to help keep the ship in place.

But when it's time to retrieve the anchors,

one of them just doesn't want to come back up.

- [Dr. Hakeem] The crew tugs the cable strain.

It feels like something is pulling back

in the other direction.

But whatever's down there is not letting go.

- [Austin] Eventually, slowly they are able to haul it up.

And when they do, they discover a terrifying creature.

[dramatic music]

Staring back at them is a set of massive eyes

and a gigantic mouth,

and its body looks like some kind of deep-sea mutant.

- [Sami] It is big.

It has an enormous bulbous head around its snout,

and a 14-and-a-half-foot body.

It weighs about the same amount as a car.

And that enormous mouth is about three feet wide

and contains hundreds of teeth.

Nobody onboard has ever seen anything like it.

- [Danny] The team transports the creature to a Navy lab

where marine biologists examine the mysterious specimen.

- [Dr. Hakeem] Scientists try to make sense of the animal,

but even they come up empty.

They think it's some kind of shark,

but they can't find any records or references

that are anything close to this sort of thing.

- [Sami] The mystery makes headlines all around the world.

And the find is so bizarre

that scientists have to create an entirely new genus,

family, and species just to classify it.

- [Dr. Hakeem] They name it Megachasma Pelagios,

which means the giant yawner of the open sea.

But the press comes up with a catchier name,

the megamouth shark.

- [Danny] And just like its name suggests,

this mysterious shark's feeding style

is all about that enormous mouth.

- [Austin] Interestingly though,

they discover the megamouth shark has a different approach

from some of its shark brethren.

It swallows its prey whole.

- [Sami] It glides through the water, opens its huge mouth,

and just engulfs about 150 gallons of water

at a single time.

That's basically the equivalent to two bathtubs of water

and anything else that flows in with it.

So essentially it's a filter feeder vacuuming up plankton.

- [Dr. Hakeem] What's crazy is that

even though it's one of the biggest sharks on the planet,

before this, no one even knew it existed.

And even after its discovery,

the megamouth shark still remains elusive.

- [Austin] Despite being discovered almost 50 years ago,

there's still been fewer than 300 specimens observed.

- [Sami] Researchers believe that it lives so deep

among the darkest shadows in the ocean,

it actively avoids light so that it can hide.

The only time it would come up near the surface of the water

would probably be at night.

- [Dr. Hakeem] Scientists continue to study the behavior

and the ecology of this elusive creature.

Where it goes, how it hunts,

and what other secrets it may be keeping.

- [Sami] But here's the thing,

if something this big can stay hidden for this long,

who knows what other massive monsters

could be lurking down there?

- [Danny] Siberia's frozen tundra hides many treasures,

some worth a lot of money.

But in 2020,

hunters unearthed something surprising and priceless.

[dramatic music] [letters clacking]

- [Dan] A group of hunters are searching the melting permafrost

of Yakutia, Russia for mammoth tusks,

or as they call it, ice ivory.

- [Ashley] This material is highly valued in China

where it's used for carvings seen as a status symbol,

with each one potentially fetching up to $10,000.

The discovery of even one tusk

can make or break an expedition.

- [Andrew] As the hunters search near the Badyarikha River,

they spot something, but it's not ivory.

It looks like a small fur-covered bundle

protruding from the ice.

So they carefully begin to pry it out of the ice.

What they see is astonishing.

It's a perfectly-preserved cat.

- [Don] It's small enough to fit in one hand,

with dark golden fur, baby teeth,

and eyelids that seem frozen mid-blink.

- [Andrew] It looks like it could have died yesterday,

but it doesn't look like any cat species

that these hunters have seen.

- [Danny] The hunters bring it to experts

from the Russian Academy of Sciences for more insight.

- [Dan] Using CT scans and DNA analysis,

the scientists realize that this is a saber-toothed kitten.

This is a species

that went extinct around 12,000 years ago.

- [Andrew] Carbon dating reveals that the kitten

is approximately 37,000 years old,

dating it to the Late Pleistocene Era.

- [Danny] This isn't just rare, it's unprecedented,

and it opens a window into a long-lost world.

- [Andrew] Finding fossils from saber-toothed cats

is a significant discovery under any circumstances.

But before this,

only skeletal remains of the species have been found.

This is the first time that a complete specimen

with fur and soft tissue on it has been found.

- [Dan] Since the specimen is so well-preserved,

scientists get their first clear picture

of what the living animal actually looked like.

They can tell the young saber-toothed tiger's fur

was thick and brown.

- [Andrew] Researchers are also able to study the other features

of the kitten like its whiskers, even its paws.

- [Ashley] By comparing the growth of its incisors to the

lions of today,

scientists were able to determine

that this baby cub died at only about three weeks of age.

- [Andrew] When fully grown,

this saber-toothed cat would've been about the size

of a modern-day lion with large serrated saber-like teeth.

The research team is still hard at work

studying this extinct species.

But the cub opens up new realms of exploration,

a variety of fields including Ice Age ecosystems,

the development of large prehistoric felines,

and even the climate conditions

that preserved this kitten so hauntingly well.

- [Danny] Digging up a saber-toothed kitten

is more than a little surprising,

so is a find made by a young boy in China.

[dramatic music] [letters clacking]

- [Sami] It's July 23rd, 2019,

and nine-year-old Zhang Yangzhe

is out exploring with his mother

near the Dongjiang River in China.

- [Kavitha] Eventually he works up an appetite

and stops to have a snack.

His mom gives him some walnuts

and he looks for a rock to crack them open over.

And that's when something catches his eye.

It's a weird-looking rock sitting on the bluff

with strange swirling patterns on it.

- [Danny] Overcome with excitement,

the boy calls his mother over to look at what he found.

- [Sami] Zhang tells his mom that what he's found

isn't just a rock, it's a dinosaur egg.

[dramatic music]

Now of course, he's nine.

You have a very vivid imagination when you're a child

so everything probably looks like a dinosaur egg

to this kid.

- [Kavitha] Here's the thing, Zhang is obsessed with dinosaurs

and he recently saw an exhibit at a museum

with fossils that looked exactly like this.

His mom believes him and she calls the police.

And she and Zhang stay

with this potentially priceless discovery, guarding the egg.

- [Ashley] The police arrive,

bringing with them scientists

from the Heyuan Dinosaur Museum,

and they're excited too

because when they get a chance to see the strange rock,

they realize Zhang nailed it.

It actually is a dinosaur egg.

[rock clatters]

- [Kenneth] The pros start to excavate,

and soon find 10 eggs in a dinosaur nest.

- [Kavitha] All the eggs are embedded in rough red sandstone,

so the museum workers have to very carefully drill them out

in large chunks,

and then they haul them back to their lab.

- [Danny] At the museum,

researchers begin the slow process of freeing the eggs

from the sandstone and restoring them.

- [Sami] It takes over three years,

but the team eventually carves, polishes,

and restores all of the eggs and puts them on display.

- [Kenneth] When their analysis is complete,

the experts can see that these three-and-a-half-inch eggs

are remarkably preserved,

and they date back to the last moments of the dinosaurs.

They're 66 million years old.

- [Kavitha] Dinosaur eggs aren't just cool,

they're like scientific gold

because unlike footprints or bones,

they give scientists reproductive information.

- [Kenneth] What we see is that certain species of dinosaurs

seem to have preferred nesting grounds,

and we see this today with birds and reptiles.

They find areas that they know from experience

are more safe from predators,

are more safe from the elements.

- [Kavitha] Beyond the eggs,

this region of China turns out to be a goldmine

for paleontologists.

It's one of the few places on earth

where the trifecta of dinosaur eggs, bones, and footprints

have all been discovered.

As for young Zhang's discovery,

somehow despite being buried for so long,

they're in incredible shape.

[gentle music]

- [Kenneth] The ancient embryos inside those eggs never got to

hatch, but 66 million years later,

they would hatch a spark of curiosity in this young boy.

- [Danny] Say you are a student at a typical public high school

in Los Angeles.

Everything seems normal until one day construction workers

uncover something remarkable and terrifying.

[dramatic music] [letters clacking]

- [Hugo] It's June 2022,

and construction workers

are renovating San Pedro High School

some 20 miles south of Los Angeles.

While digging a trench, they find something unexpected,

a dense layer of shells.

- [Austin] This isn't just like a bunch of shells

you'd find on the beach,

the school is about two miles inland

and 800 feet above sea level

so shells really shouldn't be here.

- [Kenneth] Thinking that something might be unusual,

construction stops

and they call in a team of consultants to investigate.

- [Austin] When the scientists arrive,

they're excited at what they see.

The deposit is unlike anything ever before found

in California.

This shell bank is incredibly dense,

and they estimate that it's probably 120,000 years old.

- [Hugo] As the researchers excavate around the shells,

they begin to find fossilized animal bones,

lots of them.

Massive piles of fish and mammal bones.

It appears to be an enormous marine graveyard

packed with millions of fossils.

And this collection is much older than the shells.

Scientists estimate that it's 9 million years old.

- [Austin] One of the most amazing discoveries

is a saber-toothed salmon.

This isn't like the salmon you'll find in your sushi roll,

this is a massive fish.

It's eight feet long and nearly 400 pounds,

making it the largest salmon to ever exist.

They had razor-sharp spikes

which they used to defend their territory

in prehistoric waters.

- [Hugo] Nearby researchers also find vertebrae

of a colossal baleen whale, a behemoth 100 feet long.

Alongside it, they come across remains of sea turtles,

ancient clams and birds.

And then probably the most fearsome discovery of them all,

the megalodon.

[dramatic music]

- [Austin] This is an ancient shark over 80 feet in length

that's three times larger than a modern-day great white.

It's believed to be one of the largest

and most fearsome marine predators of all time.

- [Hugo] It consumed 2,500 pounds of prey every day,

including whales and other sharks.

[dramatic music]

- [Austin] This shark had a massive mouth packed with 276

teeth, each of which is the size of your hand.

And they discovered many of them at the dig.

- [Danny] Long before it was a high school campus,

this ground was part of the ocean floor,

an ancient marine graveyard teeming with giants.

- [Hugo] Based on fossil evidence,

San Pedro might have been near

a now lost prehistoric island.

Scientists think that millions of years ago,

heavy storms might have swept marine life from this island

into a canyon burying them under layers of sediment

where San Pedro High School is standing today.

- Then around 9 million years ago,

local volcanic eruptions

helped to seal these fossils in place,

preserving them for all time.

- [Danny] In total, the team uncovers remains

from more than 200 different species,

with some like the saber-toothed salmon

having never been found before in Southern California.

- [Hugo] Scientists have now moved from cataloging bones

to reconstructing

how this lost prehistoric ecosystem functioned,

how it changed,

and how it shapes the world we live in today.

- [Ashley] For students, the discovery of this marine

graveyard turns their campus into a prehistoric wonderland.

Many take active roles

in excavating and cataloging the specimens,

giving them opportunities

that most students can only dream of.

- [Kenneth] The scientific team and students

excavate fossils side by side for more than two years.

- [Hugo] For them, history isn't in a textbook or in a museum,

it's here right beneath their feet.

[dramatic music]

- [Danny] We usually think of monsters as creatures

that are huge and clearly visible.

But one Australian woman and her doctor

had a very different monstrous experience.

[dramatic music] [letters clacking]

- [Dan] In 2021, a 64-year-old woman

in New South Wales, Australia, arrives at the hospital.

For three weeks, she suffered from abdominal pain,

a dry cough, and night sweats.

Tests reveal lesions

in the woman's lungs, liver, and spleen,

and a very high white blood cell count,

suggesting that her body's fighting off an infection.

- [Andrew] But the search for a cause comes up empty.

Doctors can't find any sign of an infection,

bacterial, viral, or fungal.

Eventually the woman's conditions begin to improve,

but then they take a nose dive.

- [Micah] She's experiencing symptoms that include

forgetfulness, difficulty processing thoughts,

and she's even experiencing pretty severe depression.

When an MRI is performed, it shows something concerning.

There appears to be a lesion

in the woman's right frontal lobe.

- [Danny] To figure out what it is,

surgeons perform a biopsy and what they find is astonishing.

- [Dr. Hakeem] When Dr. Hari Priya Bandi

removes part of the patient's skull to access the brain,

she sees something strange.

- [Dan] She describes it as a string-like structure

embedded in the patient's brain.

It's red, but too pale to be a blood vessel.

She grabs it with her surgical tools and she starts to pull.

And then it starts to move.

[dramatic music] [monitors beeping]

- [Dr. Hakeem] Dr. Bandi can't believe her eyes.

There's a worm in her patient's brain and it's still alive.

[dramatic music]

- [Andrew] The medical team removes a three-inch-long worm,

and sends it to a parasite specialist.

It turns out to be an ophidascarus robertsi,

a species of roundworm commonly found in pythons.

- [Danny] So just how did a python parasite

end up inside this woman's brain?

- [Dr. Hakeem] An investigation reveals

that the patient lives next to a lake

that is inhabited by carpet pythons.

- [Micah] Now, the patient had never had any direct contact

with pythons,

but she did collect spinach that grew around the lake

which she used in her cooking.

- [Andrew] Doctors and scientists believe

that a python may have shed the parasite into the grass

through its feces,

and then eggs of the parasite

could have been transferred from the grass

into the woman's home

where it could have infected food or been on kitchen tools.

- [Dan] Once ingested, the roundworm eggs hatched larvae

that burrowed into the host's stomach wall.

The larvae would usually stay near the stomach,

but this roundworm may have burrowed

to other organs in confusion,

causing the lesions in her liver.

From there, it migrated up to the head.

- [Dr. Hakeem] It turns out roundworms are incredibly

resilient and they're able to survive in a wide range of

environments. And apparently, including a human brain.

- [Micah] The patient is immediately treated

and her symptoms finally begin to subside,

and she makes a full recovery.

- [Dan] Thankfully, this kind of infection

can't be transmitted between people,

so there won't be a roundworm pandemic anytime soon.

But it's a cautionary tale for all of us

to carefully watch and wash what you eat.

[dramatic music]

- [Danny] Something taking over your brain is a nightmare,

but what if it took over your whole body?

[dramatic music] [letters clacking]

- [Andrew] In 2021, a film crew is making a nature documentary

about the harsh conditions British wildlife face

in the winter.

They're shooting around the grounds of Castle Espie

in Northern Ireland in an old abandoned gunpowder shed.

And as they're looking around,

they see a dead spider hanging from the ceiling.

- [Micah] Now, it's not particularly unusual to find a

dead spiders, but this documentary crew are keen

observers of wildlife.

- [Austin] Volunteers from a local wetlands conservation

group are assisting the filmmakers,

and they notice something strange about this dead spider.

First, it's an orb-weaver spider.

These are usually found in deep dark caves,

not in man made spaces.

- [Dr. Hakeem] Even weirder,

the spider has a lacy white fungus erupting out of its body.

[dramatic music]

- [Danny] Intrigued,

the team sends a photo to fungus expert, Dr. Harry Evans.

- [Andrew] When he looks closely at the spider, Evans is

surprised. It looks like the fungus has infested the spider,

eating it from the inside out.

- [Micah] This isn't just an infection, it's a hostile

takeover. And he believes it's never been seen before.

- [Andrew] After the film project is over,

Evans requests a sample of the dead spider.

And he then puts together a team to look for more of them.

[dramatic music]

- [Dr. Hakeem] They hunt for evidence near caves,

and sure enough, they find more of these orb-weaver spiders

that have crawled out of the darkness.

- [Austin] Though orb-weavers

naturally prefer dark, dank, tight spaces,

something in the fungus is compelling them

to go towards the light before they die.

- [Danny] What the crew has stumbled upon

is no ordinary fungus.

It's something much more diabolical.

- [Micah] The fungus doesn't just destroy its host,

it manipulates it.

It works by flooding the spider's system

with mind-altering chemicals like dopamine,

which can control its movement

and also helps create a false sense of feeling good.

- [Dr. Hakeem] The hijacked spiders leave their layer

and fulfill the parasites' wishes

by moving closer to the mouth of the cave before dying.

This is so the air currents can better disperse the spores

to find new victims.

- [Andrew] It's like the

fungus is turning the spiders into zombies.

[dramatic music]

- [Austin] Similar parasitic fungi

have been found to attack wasps and ants,

but this is the first time it's ever been found

in a stronger, more resilient animal.

- [Andrew] The research team has continued to examine the fungus,

trying to understand its origin

and whether it might have beneficial applications

in agriculture or medicine.

- [Dr. Hakeem] After all, whatever the fungus is doing

to control the spider's brain, it's extraordinary.

There's even speculation

that it could potentially provide new treatments

for diseases like Alzheimer's.

- [Austin] While it's nice to look on the bright side

of finding a zombie spider fungus,

one unsettling fact remains.

95% of the fungus species on the planet

have yet to be discovered.

- [Andrew] So if nature has already created a zombie spider

fungus, who's to say there isn't out there somewhere

a zombie human fungus just waiting to be found.

[dramatic music]

- [Danny] People think unicorns are magical,

but what villagers find in Siberia

is far from a fairy tale.

[dramatic music] [letters clacking]

- [Andrew] In the 1980s, locals in the Pavlodar region of

Kazakhstan begin stumbling upon fragments of bone and fossils

along the Irtysh River.

[dramatic music]

Most residents don't pay much attention to these,

but a few curious collectors hold onto their finds.

- [Austin] 30 years go by before one collector brings his stash

to the Museum of Nature.

They investigate the samples

and find it's a hodgepodge of different animals

from different times.

- [Andrew] It's interesting, certainly,

but not necessarily anything important.

So they accept the donation and store it away.

- [Sami] In 2016, researchers from Tomsk State University

in Russia take another look.

They're examining fossils from the area

in the hopes of putting together a complete specimen.

In the mess of all the jumbled up bones,

one of the researchers finds a piece

that definitely shouldn't have been overlooked.

It's a skull, it's massive, it's incredibly well-preserved,

and it has a giant base for where a horn once was.

- [Andrew] Officially, this specimen is a Elasmotherium

sibericum, otherwise known as the Siberian unicorn.

Before you start picturing a magical white creature

prancing through a fairytale forest,

this is not the unicorns of make-believe,

this unicorn was built like a tank.

- [Austin] It was 15 feet lon, six to seven feet in height,

and weighed a whopping eight to 10,000 pounds.

And of course, on top of its skull, a three-foot horn.

[dramatic music]

- [Sami] Despite its massive size and girth,

the Siberian unicorn had relatively slender limbs,

which suggested that it was a pretty fast runner.

It was also covered in a lot of shaggy hair.

Basically, it was a cross between a rhinoceros

and a wooly mammoth, but with the gait of a horse.

- [Danny] When the skull is sent to experts

in Northern Ireland for carbon dating,

the results are shocking.

- Up until this discovery,

scientists believed that the Siberian unicorn

went extinct 350,000 years ago.

But this specimen is actually only 29,000 years old,

which means unicorns coexisted with humans.

- [Andrew] This discovery rewrites the timeline

of the Siberian unicorn's extinction to the last Ice Age,

which reshaped the Earth's ecosystem,

wiping out other ancient megafauna

like the wooly mammoth,

the Irish elk, and the saber-toothed cat.

- [Danny] But why did this giant beast disappear?

- [Sami] By studying isotopes in the specimen's teeth,

researchers came to the conclusion

that it primarily fed on tough grasses.

- [Austin] When the last Ice Age took hold 40,000 years ago,

the temperature changed, the ground froze over,

vegetation disappeared,

and the Siberian unicorn just couldn't adapt.

- [Danny] It may be extinct,

but researchers find a surprising trace

of the unicorn's legacy still intact.

- [Ashley] Scientists were able to isolate DNA from this

specimen for the first time,

demonstrating that this Siberian unicorn

is a distant relative of today's rhinoceros.

It isn't totally surprising

'cause there is some resemblance,

but it's a very distant cousin.

Those lineages may have split off

more than 40 million years ago.

- [Danny] The Siberian unicorn's skull now resides

at the Natural History Museum in London

where it amazes visitors from all over the world.

- [Andrew] Legends of unicorns have been told for millennia,

but now we know the truth.

Unicorns were real,

and once upon a time, we walked the earth with them.

- [Danny] From the bottom of the sea to the back of your brain,

monsters are out there.

And sometimes they're closer than you think.

I'm Danny Trejo,

thanks for watching Mysteries Unearthed.