Original subtitles

[dramatic music]

- [Danny] Mysteries can be buried anywhere.

Under the earth.

[volcano exploding]

Beneath the sea.

[plane whooshing]

Or even right under our own feet.

And when we stumble upon them, sometimes

what we find can change history.

[upbeat music]

Tonight, beastly discoveries,

from mythical monsters.

- He realizes he may have the holy grail

of maritime mysteries in his hands.

- To scary barbarians.

- They're the original weapons of mass destruction.

They were like a mixture of a 19th century cavalry horse

mixed with a modern day tank.

- To one of the deadliest animals on the planet.

- Wild hippos only exist in Africa,

yet here there's a whole herd of them,

more than 5,000 miles across the ocean,

and they can't believe what they see.

[hippo roaring]

- Join us now, because nothing stays hidden forever.

[dramatic music]

When you think Arctic, you probably think freezing,

but one recent day, when the temperature hits 95,

something unexpected gets unleashed.

[tense music]

- In a small town in northwest Siberia,

a farmer is surprised to find the carcass

of one of his reindeer.

You know, it's not unusual.

Every now and then an animal will die

of some kind of natural causes,

but over the next month, other local farmers watch

as more and more reindeer, livestock get sick and die.

[intense music]

- In all, over 1,200 reindeer end up dying.

At first, the villagers chalk it up

to the stress the animals are undergoing

due to that summer's unusually high temperatures,

but then, suddenly, the villagers start getting sick.

- [Narrator] Locals develop high fevers and painful sores.

- 90 villagers fall critically ill and are hospitalized.

Tragically, one sick child dies.

- Doctors are completely baffled.

They're running blood tests and throat swabs,

but every test that they run ends up coming back negative.

- [Narrator] Then finally, one test comes back positive

and the result is shocking.

- It's bacillus and thoracis,

but we know it more commonly as anthrax.

[tense music]

- Most people think of anthrax as a biological weapon,

but it actually occurs naturally

in soils throughout the world.

When animals like reindeer graze,

they kick up the spores and form little dust clouds

and then the animals can inhale this and become infected.

- Once it's in the body, the bacteria grows quickly.

It causes fevers and difficulty breathing.

And after an infected animal dies,

its body decomposes, spilling even more

anthrax spores right back into the earth.

- The spores can sit there for decades,

like this ticking time bomb,

just waiting for its next unfortunate host.

Even with treatment, the fatality rate in humans

can be as high as around 80%.

- [Narrator] As government officials rush

to figure out the source,

they discover that in the early 1900s,

Siberia was ravaged by a series

of terrible anthrax outbreaks.

- More than a million reindeer died

with their infected carcasses sprawled out everywhere

across this tundra.

- Some of those remains were frozen in the permafrost,

essentially refrigerating the dead deer

and the bacteria inside of them.

- But then starting in the year 2011,

the area has five years of unusually warm summers.

- And the extreme heat begins to melt the permafrost,

exposing dormant anthrax spores.

- [Narrator] To contain the outbreak,

officials scour the tundra burning

thousands of infected reindeer carcasses

and vaccinating tens of thousands of living reindeer.

- Gradually, this works

and the number of new cases begins to slow

and then eventually completely stop.

- But it's very likely

that more pathogens lie frozen under the Arctic ice.

Researchers have found pieces of the 1918 Spanish flu virus

in bodies buried in mass graves in Alaska's tundra.

There's also likely smallpox

and bubonic plague trapped in the ice in Siberia.

- If rising temperatures continue to melt the permafrost,

it is very likely that animals and humans will be exposed

to these ancient pathogens which modern humans

have never had exposure to before.

As one researcher puts it, this is Pandora's box.

[tense music]

- While residents in the Arctic fear deadly outbreaks,

in Connecticut, it's the undead

that send locals into a panic.

- In 1990, a young boy is playing outside

with some friends in the rural Connecticut town of Griswold.

- As the boy slides down a hill,

he bumps into something sticking out of the rocks.

He moves the dirt to the side to look at what it is,

and suddenly, two human skulls are staring back at him.

[tense music]

- [Narrator] The boy heads home to tell his mother,

who calls the police.

- Investigators find more skeletons.

Some of them laying in the remnants of wooden boxes.

They can tell that these bones are old.

This isn't a job for a coroner.

They need to call in an archeaologist.

- [Narrator] Connecticut state archeaologist,

Nick Bellantoni, comes to the site to investigate

and determines that they've stumbled upon

a forgotten graveyard from the early 1800s.

- Bellantoni and his team discovered 29 graves in total,

but one of those graves is distinctly different.

It's covered with heavy rocks

as if they didn't want anyone to dig there.

- When the team lifts the heavy stones,

they find a coffin with brass tacks nailed into it

that spell out JB 55.

- They find that the skeleton inside

has been totally rearranged.

The rib cage has been crushed, the skull's been removed

and then turned around facing downward.

The thigh bones are crisscrossed

with the skull in the symbol of the Jolly Roger.

The old pirate flag.

- The condition of the grave reminds one of the researchers

of scary stories he heard as a child.

Campfire tales about a wave of terror

that overtook Connecticut in the early 1800s.

It was known as the Great New England Vampire Panic.

- Back then when healthy people

would find themselves becoming ill,

turning gaunt and pale and even coughing up blood,

it was speculated that their blood

was being drained at night by vampires

that rose from the dead.

- Villagers would go out

and dig up the grave of the suspected vampire,

and rearrange the bones to guarantee

that the vampire could not crawl out.

- [Narrator] When investigators take a closer look

at JB's body, they get more insight into why

his neighbors suspected he could have been a vampire.

- One answer might be the coral-like lesions

discovered on his rib bones.

These are the telltale signs of tuberculosis,

a disease that causes ulcers in the lungs.

- You cough up blood, you waste away,

you become pale and gaunt.

Your gums recede,

so your teeth might actually look like fangs.

- [Narrator] In 2019, almost 30 years

after JB's body is found,

DNA and genealogical analysis

finally reveal his true identity.

- JB was a man named John Barber

who died in his mid 50s,

which probably explains the 55

that was spelled out in tacks on his grave.

- Signs of stress on his bones indicate

that he worked in manual labor, probably as a farmer.

- Ironically, his top front teeth were missing,

so he really couldn't bite anyone.

To this day,

the discovery of John Barber's grave is considered

compelling proof that vampires,

or at least vampire hunters,

really did lurk in the cemeteries of New England.

- Back in 1938,

a fishing boat captain in South Africa invites a friend

to check out his catch.

What she finds ends up shocking scientists everywhere.

- It's just before Christmas in 1938

in East London, South Africa,

and a woman named Marjorie Courtnay-Latimer

is the curator of a small natural history museum.

She is with a friend of hers that is a commercial fisherman

and she often will go through his hall to find cool

and unique animal specimens to display in her museum.

- She sticks her hands in these layers

of these slimy sea creatures

and she starts to dig around when something catches her eye.

It's this five-foot long bright blue fish

with these four fins that kind of look like arms.

- The fishermen with 30 years

of professional fishing experience

cannot identify this fish.

- [Narrator] Marjorie is also baffled,

but determined to figure out

what type of species this unusual creature is.

- She wants to show this specimen to a fish expert

that she knows.

However, he is gone for the holiday

and won't return for weeks.

- Exposure to the sun is already starting to change

the color of the fish from blue to gray,

and she's becoming really eager to preserve it,

so she calls a local taxidermist.

This is the only way to save it.

- [Narrator] Eight weeks later, the fish expert returns

and is shocked by what he sees.

- That fish actually turns out to be a known species.

It's called a coelacanth,

and it was thought that this particular species had died out

around 65 million years ago,

right alongside the dinosaurs.

- [Narrator] While this coelacanth is the first found,

it's far from the last.

Over the next several decades,

experts uncover and study more than 300 in the wild,

and they learn something remarkable.

- Scientists eventually realized that they had a unique way

of locomoting in the ocean.

Instead of swimming with primarily tail motion,

as most bony fish do today,

the coelacanths swims using some paddling

of its front and back legs,

almost as though it's sort of wading

or walking through the water.

- Some scientists speculate that coelacanth is the ancestor

to the first vertebrates to crawl out of the water.

Thus the ancestors of modern land animals.

- And actually, coelacanths are genetically linked

with all other tetrapods.

So anything in the horse family,

anything in the feline family,

and yes, even us.

- [Narrator] To this day,

Marjorie Courtnay-Latimer's discovery

is known as the zoological find of the century.

- And what's even more amazing is

that had it not been for Marjorie's determination

to preserve and to save this fish,

it is possible that it could have ended up

on somebody's table for Christmas dinner in 1938.

- Rediscovering an ancient species is truly incredible,

but what if you found a sea monster

that's not supposed to exist, and is actually real?

- As dawn breaks on a small Danish village,

down the beach, a crowd has gathered around something

that has been washed up overnight.

A strange creature lies dead on the sand.

- It's massive.

It has sort of an amorphous blob of a body,

two giant cloudy eyes, a bony beak that resembles

that of a bird, and it has 10 long arms with openings

that resemble mouths with hooked sharp teeth.

- To the villagers, this looks like a sea monster,

and to some, it looks like a specific monster,

the mythical kraken.

[dramatic music]

- [Narrator] According to legend,

the kraken is an enormous multi-armed beast

that has terrorized the ocean for centuries.

It was infamous for smashing boats to pieces

and dragging sailors to a watery grave.

- Kraken or not, the villagers know

that this massive carcass is stinking up the beach.

A few fishermen cut off some pieces to use as bait

and they bury the rest.

- But someone in the village takes a souvenir, its beak.

- Three years later, the beak is gifted

to a Norwegian scientist, Japetus Steenstrup.

He is fully aware

of the stories about the bloodthirsty kraken.

- So when Steenstrup gets his hands

on what may be a piece of an actual kraken,

he realizes he may have the holy grail

of maritime mysteries in his hands.

- He immediately notices the similarity

between the beak he's received

and the beak of another animal, a squid.

Squids use their beaks to pulverize their prey

before they eat them.

- The description of the sea monster

from the beach also reminds Steenstrup of squids.

Both have unusually large eyes and 10 limbs in total.

- And in certain species,

the suckers have small tooth-like hooks inside of them

to create a better grip.

- Steenstrup declares the world that he's discovered

a new genus of squid,

architeuthis, the giant squid.

This takes the myth of the kraken

and it moves it into the reality of science.

- [Narrator] But does one beak and a secondhand story

really prove the existence of a giant killer squid?

Debate in the scientific community continues until 1873.

- In Portugal Bay, Newfoundland,

two men and a boy are out in a fishing boat

when they spy something floating in the water,

this sort of large unidentifiable mass.

So they use a pole with a hook on it

to pull the objects closer.

- As the point of the hook pierces the creature,

it roars to life, charges the boat,

and slings a massive tentacle over the side.

- The young member of the fishing crew

grabs their tackle axe

and cuts off part of the tentacle.

After which the creature pulls back into the sea.

- The men then bring this 19-foot long tentacle

back to the mainland and they give it to a local reverend

who has an interest in biology.

- [Narrator] Then one month later,

another local fishing boat finds an entire giant squid

tangled in its nets.

The reverend buys the squid for $10

and documents the discovery in a photograph.

- This is the first ever complete specimen

of the giant squid recovered from nature.

It's evidence that

the mythical kraken may indeed be real.

- And it makes you wonder,

what other mythical creatures actually exist

in the depths of the briny deep?

[water bubbling]

- Picture this, it's 2007 in rural Colombia

and you're fishing on a river with friends.

When you cast your line, you hear a roar

and see a huge beast swimming right at you.

- This beast is nothing short of terrifying

and they've never seen anything like it.

It's huge, big, bulbous body, massive head,

beady eyes, and massive, sharp tusks.

- The villagers report the incident

to the Ministry of Environment,

and within weeks, the ministry is flooded

with more calls of sightings of these beasts.

- [Narrator] The government sends a wildlife expert

to investigate the area

and he's shocked at what he sees.

- He identifies it immediately.

It's a hippopotamus.

[dramatic music] [hippo growling]

- Wild hippos only exist in Africa,

or at least that's supposed to be true.

Yet here, there's a whole herd of them

more than 5,000 miles across the ocean

in South America.

- Hippos are mostly gentle herbivores.

Unless they feel threatened,

that's when they become

one of the most dangerous animals to humans.

- Hippos kill hundreds of people in Africa

every single year,

far more than shark attacks.

These beasts can run at least 20 miles per hour,

and hippos have a bite that can tear a human body in half.

- [Narrator] So how exactly did a herd of hippos

end up swimming in a Colombian river?

- Turns out that their origins can be traced

to hippos owned by the notorious drug lord,

Pablo Escobar.

The Colombian cocaine kingpin amassed a huge fortune

that he used to build himself a fortified compound,

including a full zoo.

He had zebras, rhinos, kangaroos, ostriches,

and four hippos.

- [Narrator] After his death in a police shootout in 1993,

the Colombian government seizes Escobar's property

and ships most of his animals

to local zoos, but not the hippos.

- It was believed that the hippos

were far too dangerous to release,

so they figured they would just leave the hippos

inside the high walls of the compound.

- But the hippos escape and wander 65 miles down river.

[dramatic music] [hippo roaring]

With no natural predators, the hippo population explodes.

- In the last 30 years, those four hippos multiply

to a herd of around 200.

- Hippos are an invasive species.

They eat up loads of vegetation that's normally reserved

for the indigenous species there,

and they drastically drop the oxygen levels in the river

with their waste.

- [Narrator] But recent research suggests their impact

might not be all bad.

- [Adam] Thousands of years ago,

animals like the large armored armadillo

or the large headed llama would graze in those areas.

- This kept the ecosystem in balance

but ended with the end of the ice age

and human intervention.

- Some researchers suggest

that these hippos fill the niche once held

by those native species,

so it turns out their presence

could actually restore the landscape

to what it was like thousands of years ago.

- It's one thing to see a huge beast

hunting someplace unusual, but how about finding one

that died out 10,000 years ago?

[pensive music] [wolf howling]

- Pavel Efimov is trudging along the banks

of an icy river in Yakutia, Siberia

scouring for mammoth ivory.

He's waited until midsummer to begin his search

because it's a little bit easier to dig into the ground.

- It's hard work in a harsh environment,

but it's got its rewards.

A single tusk can fetch up to $20,000,

so just a couple can have Efimov set up for years.

- On this day, he's not having any luck, so he decides,

"Okay, I'm gonna abort and go home."

But as he decides to leave, he sees what looks like a clump

of fur sticking up out of the ice.

- Efimov freezes over and starts digging.

It's definitely not a tusk.

It seems to be some sort of animal jaw,

but its teeth are much smaller than a mammoth's.

- He chips away at the ice

and he discovers it's a giant severed head.

[dramatic music]

- At first, it looks like a dog,

but upon closer inspection he realizes

that it's a wolf's head.

This head is incredibly well preserved and it is gigantic.

- [Narrator] The find reminds Efimov of a fearsome beast

that when extinct 10,000 years ago.

[wolf howling] The direwolf.

- At six feet long and 175 pounds,

the direwolf was approximately the size of a man,

but much more powerful.

Its bite alone was strong enough to take down prey

many times its size, like mastodons and bison.

- So Efimov takes the head home with him

and he gets in contact with the Republic of Sakha,

Academy of Sciences.

- [Narrator] Efimov hands over the head

to a biologist who's stunned by what he sees.

- When he measures the skull, it's 16 inches long,

much bigger than any modern wolf head.

- The fur is so well preserved that the scientist thinks

that there is no way this thing is 10,000 years old,

and so they send some samples away for carbon dating.

It turns out, he was right.

It's not 10,000 years old.

It's 40,000 years old.

- [Narrator] While the time period still lines up

with when direwolves roam the Earth,

none have ever been found in this area.

- After a lot of testing,

it turns out that this isn't the head of a direwolf,

but it's a similar species of Pleistocene wolf

that preyed on large animals.

It's the first remains found of a well-preserved,

fully grown wolf from the Pleistocene era,

and this ancient find shows us

that this wolf was much bigger

and much deadlier than previously thought.

[wolf growling]

- In July of 1979, Walter and Ruth Roman

are searching for gold on their mining claim

outside of Fairbanks, Alaska.

In an effort to cut through the permafrost,

they use a high-pressure hydraulic hose

that acts like a blade to cut through the frozen earth.

- The water cuts through layer after layer of icy mud,

but then suddenly they see something shining

in the sunlight.

- This isn't gold, it looks like a pair of hooves.

And then they see these two huge legs.

It appears to be some type of massive animal.

- But the strangest thing is its skin.

It has a blue hue, like sort of like the color

of the chalk that you use at the head of a pool cue.

- [Narrator] The Romans call a local university

and they send paleontologist Dale Guthrie to the site.

- He realizes he is looking at a fully intact steppe bison.

A species of bison that is thought to have gone extinct

tens of thousands of years prior.

- And it's so perfectly preserved by the permafrost

that its skin and muscle are still intact.

- From the blue coloring of the skin,

it reminds him of the blue ox

from the old Paul Bunyan folklore.

So they decide to nickname it "Blue Babe".

- It's an extraordinary find,

but they still have to figure out how to get it

out of the permafrost.

- Ultimately, they decide to let the summer thaw

do the work for them.

- Except there's one problem.

The sun is thawing the carcass and this can cause it to rot,

but the head is still stuck in the ice.

- The team has no choice

but to decapitate the bison, refreeze its body,

and come back later to retrieve the head.

- [Narrator] Eventually, the ice releases

the head and neck with all the pieces in place.

Guthrie and his team take a closer look

at the blue bison in his lab.

- It's an adult male

and it's even more intact than they thought.

It actually still has blood in its veins

and marrow in its bones.

- [Narrator] Even more incredible,

carbon dating reveals the beast is over 50,000 years old.

But why is its skin blue?

- It turns out that the bison skin

naturally sheds a phosphate,

and when it reacts with the iron in the soil around it,

it creates a mineral called vivianite.

- When vivianite is exposed to oxygen,

it turns somewhat bluish

and the crystals within it give it a bit of a shine.

- After it completely defrosts,

the bison's muscles are still pliable

with a texture and color of a kind of beef jerky.

Seeing that gives Guthrie an idea.

- They decide to slice up some of the bison muscle

and make it into a stew and serve it

at a small dinner party.

- The meat is said to be tough, it tastes earthy, gamey,

but it's also surprisingly delicious.

No guests get sick for the meal,

but I'm also guessing no one asks for seconds either.

- Finding and eating an ancient blue beast

is definitely strange,

but so is what one construction worker digs up in Canada.

[tense music]

- It's just another day at work for Sean Funk,

who's an excavator operator at an oil sand mine

in Alberta, Canada.

[excavator rumbling]

- So Sean is operating his excavator in this pit

and he's scooping out this material called bitumen.

- Bitumen is essentially the remains

of plants and animals from millions of years ago

that, over time, have been transformed into petroleum.

- He raises his bucket to get another scoop of this material

and he hears the bucket hit something hard.

[excavator thudding]

- He switches off his machine and jumps out to take a look,

and what he sees are some small brown rocks

begin to fall outta the wall.

He calls over some other members of his crew to take a look,

and when they look closer, they see more

of these strangely textured brown stones

still embedded in the wall.

- [Narrator] For more insight, Funk's supervisor

calls in experts from Canada's Royal Tyrrell Museum

to check out the find.

- Paleontologist Don Henderson arrives

and he finds that these strange discs in the stone

are fossils.

- So they carve a huge block out of the side of this mine

in order to preserve whatever is inside

without cutting into it.

- [Narrator] After plastering that section,

they carefully strap it to a crane and begin removing it.

- But as they're lifting with the crane, they hear a crack.

The plaster splits in half,

the dirt and rock tumble to the ground in a big pile.

- It's a terrible moment, to put it lightly, for Henderson,

because he and his team

might have just pulverized this fossil.

- [Narrator] The team gathers up the fragments

hoping they can salvage at least some of the fossil.

- Paleontologists spend the next six years

painstakingly working, piecing them back together bit by bit

as if they're working on this giant, prehistoric

jigsaw puzzle.

- Once the fossil is fully assembled, Henderson realizes

he has something extraordinary on his hands.

- This is a 110 million year old dinosaur called a nodosaur,

which is this giant spiked herbivore

that walked around on four legs.

- It is a perfect, full-sized fossil

of the entire body of the animal.

Its skin, its soft tissue, even its eyeballs.

It is an incredible, rare view

of what an actual living dinosaur

would've looked like in the flesh.

- The fossil turns out to be distinctive enough

from every other nodosaur

that it actually is given a new genus.

- What's even more amazing about this find

is that it turns out to be

the most well-preserved dinosaur ever found.

- Imagine you're a soldier way back in the first century BC.

You hear a loud roar,

and what you see isn't part of a movie,

it's terrifying and real.

- A hospital in Cordoba, Spain

is thrilled by the acquisition of three new

high-tech x-ray machines, but there's a problem.

Concrete bunkers have to be built

to shield the rest of the facility from the radiation.

- The hospital is situated on a hill that once served

as an important economic hub for the ancient Romans,

Moors, and Spanish.

So before any construction can truly begin,

archeologists are brought into survey the ground.

- Digging begins and the team comes across something

completely unexpected.

An ancient arsenal.

- They find 17 huge stone boulders shaped to be ammunition

for catapult launching.

Among the stones are spearheads and other weapons.

- [Narrator] Then they find something

that you might not expect to see in an arsenal.

- They find a bone that measures three inches by six inches

and it's a carpal bone,

basically the equivalent of like a hand bone.

- [Narrator] But this bone isn't from a human,

or even an animal local to the region.

It's from a much more surprising beast.

- This bone actually comes from an elephant.

Many researchers believe

that these are the first physical remains

of a war elephant ever uncovered in Europe.

[elephant trumpeting]

- The use of elephants in ancient warfare

is thought to have begun between two and 3,000 years ago

in ancient India.

- After that, the use of elephants in war spread

to places like Southeast Asia, Persia, Northern Africa,

and the Roman and Greek empires.

Elephants were the original weapons of mass destruction.

They were like a mixture of a 19th century cavalry horse

mixed with a modern day tank.

- They could scatter enemy formations, crush chariots,

trample foot soldiers,

and their riders enjoyed a distinct height advantage

slinging their weapons down at enemies.

[elephant trumpeting]

- The elephants wore armor with these terrifying designs

and razor-sharp blades were tied to their tusks

to increase both the damage and fear factor.

- [Narrator] But who did this particular elephant fight for?

- Based on the date range

for other artifacts found at the site,

experts narrow down the elephant

to the two likeliest armies.

- [Narrator] The first is regarded

as one of the greatest military leaders of all time,

Hannibal.

- From 218 to 201 BC, General Hannibal led the empire

of Carthage in the second Punic war against the Romans.

We know that Hannibal deployed elephants as part of his army

and fighting was featured in places like Portugal,

Spain, and Italy.

- [Narrator] Some experts think

the war elephant could have belonged

to an even more infamous leader,

Julius Caesar.

- In 45 BC, Caesar leads a siege on the city of Cordoba,

killing 20,000 men.

It's believed that his forces included

a battalion of war elephants.

- Currently, there's no definitive evidence

linking this elephant bone to the siege at Cordoba.

But researchers are working to find more evidence

to figure out whose army this elephant hand belonged to.

[elephant trumpeting]

- Not all shocking beasts are the size of an elephant.

Take our next story about a find

in a Midwest backyard in 2017.

[ominous music]

- One spring night,

the wife of Jonathan Martin asks her husband

to take out the trash.

He doesn't want to, so he tells a little white lie.

- Martin is a forestry professor

who specializes in studying trees, so he says he can't

because he has to collect some specimens for his class.

- He walks into a forest area behind his yard

and pulls a small handheld black light out of his pocket.

Lichen and fungi glow and black light,

so he uses it to help him find samples.

- He stops to examine a specimen on a tree,

but then suddenly, the quiet of the forest is pierced

by a shrill shrieking noise.

[animal shrieking]

- The black light catches a creature that is moving fast

and shaking the branches.

Instinctively, Martin ducks

and a glowing, bright pink beast is jumping

right over his head.

- His mind and his heart are racing.

He's like, "What did I just see?"

- He flashes the black light at it,

he sees these two blue beady eyes staring back at him.

[dramatic music]

- It looks like a flying squirrel, but it's glowing pink.

The animal gives him a look and then quickly darts away.

- Martin is dumbfound.

He's never heard of any mammal glowing like that.

When he brings the story of his encounter

to the university, his colleagues are skeptical,

to put it mildly.

- But a graduate student named Allison Kohler decides

that she wants to investigate.

So she takes a black light with her

to a local natural history museum

that has hundreds of these flying squirrel skins.

- She opens the drawer full of specimens,

shines the black light on it,

and it begins to emit this blinding pink glow.

- [Narrator] Kohler's curious,

so she launches a study with a group

of researchers from Northland College

to figure out why flying squirrels glow.

- They think it's due to a pigment in the squirrels' fur

that's known as porphyrin.

Flying squirrels have a lot of porphyrin in their stomach

as well as that stretchy piece of skin

that appears between their legs

that they use like wings when they're gliding.

- Scientists around the world are amazed by this discovery

and they quickly start shining their own UV lights

onto a range of animals.

- It turns out it's not just flying squirrels

that emit a glow, but possums, polar bears,

zebras, bats, even some kinds of leopard.

- So far, scientists have identified

125 species of mammal that glow in the dark.

There is a whole new field

of research investigating this strange phenomenon,

and it is all thanks to a husband

who didn't want to take out the trash.

- Know the old saying,

"Every family has skeletons in their closet"?

One Chinese family finds out that saying is true.

- In 2018, the family of an elderly man

gathers around his deathbed.

He beckons his grandson to come closer

and in a weak voice tells him to go into the abandoned well

behind his house to go looking

for something hidden there.

- It's a strange and cryptic request,

but the grandson does it.

He lowers himself into the dark well

and finds something buried in the bottom, wrapped in cloth.

He tears away the fabric and sees inside a human skull.

- When the grandson shows the skull to the rest of the family,

they're shocked, they're bewildered

because not only has their grandfather

been hiding a human skull, but it looks different, right?

It's not like your typical human skull.

- It's longer than normal, with prominent brow ridges,

eye sockets that are very large,

almost square, and a wide mouth.

- [Narrator] Horrified,

the young man asks his grandfather for the story

behind the strange skull.

[ominous music]

- Back in 1933, he was a construction worker

on a bridge over the Songhua River,

which translates into English as the Black Dragon River.

It was wartime

and the bridge was being built under the direction

of the occupying Japanese forces.

- One day as he was digging in the mud along the riverbank,

his shovel hits what he thinks is a stone.

So he reaches down and he grabs it

and is about to toss it off to the side.

But when he looks at his hand, he realizes it's not a stone.

It's in fact, a skull.

- He realized that the skull looked kind of odd and very old.

He flashes back to a newspaper story

from a few years earlier

about the discovery in China of a skull.

It was known as the Peking man.

- But he's terrified.

If his Japanese overseers find out about it,

they might claim it, and who knows what they might do

to keep him quiet.

- So he smuggled the skull back to his house

and hid it in the bottom of the old well.

He's worried about

what people might think if they learn

he worked for the enemy during wartime,

so he doesn't tell anybody about it

for over eight decades.

- [Narrator] Eventually,

news of the skull reaches a paleontologist

named Chengzhi at a local university.

- Once Chengzhi sees the skull, he immediately recognizes

that it's prehistoric.

So the family decides yes, they will hand it over

to researchers under the condition

that their grandfather's name is never revealed.

- When scientists analyze the skull,

they discover that it's about 146,000 years old.

But what's most remarkable is

that it's not a homosapien's skull.

They suspect it's a new distinct human species,

an extinct relative of homo sapiens,

even more closely related to us than the Neanderthals.

- The skull itself is from a mature male,

most likely in its 50s,

and the size of the brain within the skull

is the same size as ours,

but the size of the actual skull itself

is much longer than any human skull ever recorded.

- Experts know very little about how this early human lived.

So far we haven't found any other fossilized remains

or any tools, weapons, or any items

that might reveal more of the hominid's lifestyle.

- Researchers call this new species Homo longi,

but it's more popularly known as Dragon Man,

after the Black Dragon River

where that one unnamed worker

made his astonishing discovery back in 1933.

[pensive music]

- We never know when, where, or who

will unleash the next beastly discovery.

I'm Danny Trejo.

Thanks for watching Mysteries Unearthed.