Original subtitles

I'M JEREMY WADE.

FOR MORE THAN 30 YEARS,

I'VE BEEN INVESTIGATING UNDERWATER MYSTERIES...

IT'S A FISH!

...AND UNCOVERING NIGHTMARISH BEASTS.

AAH!

BUT IF I THOUGHT I'D SEEN THE WORST,

I'D BE WRONG.

HALF A BILLION YEARS OF EVOLUTION

HAS SEEN MILLIONS OF FISH COME AND GO,

AMONG THE MONSTERS THAT WERE STRANGER, DEADLIER, AND BIGGER

THAN ANYTHING ALIVE TODAY.

BUT WITH THE EVIDENCE LOCKED IN STONE,

IT'S BEEN IMPOSSIBLE

FOR ME TO PURSUE THESE PREHISTORIC PREDATORS.

NOW, HOWEVER, BREAKTHROUGHS IN TECHNOLOGY

MEAN I'VE FOUND A WAY TO UNLOCK THEIR SECRETS.

IT'S AMAZINGLY CLEAR. YOU'VE GOT UPPER JAW, LOWER JAW.

AND NOW THAT THE DOOR TO THE PREHISTORIC PAST IS OPEN,

I HAVE TO GO THROUGH.

THIS IS THE FIRST TIME I'VE BEEN SO CLOSE

TO SUCH A LARGE PREDATOR.

I'M GOING ON AN EPIC JOURNEY

AROUND THE GLOBE AND BACK IN TIME

TO HUNT DOWN THE GREATEST RIVER MONSTER THAT EVER LIVED.

-- Captions by VITAC -- www.vitac.com

CAPTIONS PAID FOR BY DISCOVERY COMMUNICATIONS

IN 30 YEARS OF TRACKING DOWN MONSTERS,

I'VE ALWAYS RELIED ON A FISHING LINE TO GET RESULTS.

THEY DO EXIST. THEY DO EXIST.

BUT THIS MISSION IS DIFFERENT.

I NEED TO FIND A WAY TO CONNECT WITH ANOTHER TIME...

...BECAUSE THE MONSTERS I'M HUNTING NOW...

...LIVED MILLIONS --

EVEN HUNDREDS OF MILLIONS OF YEARS AGO.

I'M GOING TO HUNT THE SPECIAL LIVING RIVER MONSTERS

THAT STILL CARRY ECHOES OF THE DISTANT PAST.

THEY'RE GOING TO HELP ME FIND

THE BIGGEST, BADDEST RIVER MONSTER OF ALL TIME.

WHERE BETTER TO BEGIN

THAN WITH THE ULTIMATE INSTRUMENT

OF DEATH AND DESTRUCTION?

THIS IS A CAST OF A TOOTH THAT'S AROUND 260 MILLION YEARS OLD.

IT BELONGED TO THE VERY FIRST RIVER MONSTER.

ONE WAY TO HELP ME PICTURE MY PREHISTORIC CONTENDERS

IS TO DRAW THEM OUT IN SAND -- LIFE SIZE.

THIS 10-FOOT-LONG SERPENTINE SWAMP MONSTER

WAS A LETHAL AMBUSH PREDATOR KNOWN AS THE XENACANTH,

OR EEL SHARK.

THESE WERE THE FIRST PREHISTORIC PREDATORS

TO TAKE OVER FRESH WATER.

IN TEXAS, YOU STILL FIND THEIR FOSSILS

AND SIMILAR HABITAT TODAY.

SO THAT'S WHERE I'M STARTING MY INVESTIGATION.

THESE FRESHWATER SHARKS WERE HUNTING.

I WOULDN'T RECOGNIZE THE VEGETATION.

IT WOULD BE QUITE DIFFERENT TO WHAT WE'VE GOT HERE.

BUT THE GENERAL FEEL,

THE GENERAL HABITAT WOULD BE QUITE SIMILAR.

YOU HAVE THESE CHANNELS, BUT THEN OFF THESE CHANNELS,

YOU HAVE LOTS OF TREES STANDING VERY CLOSE TOGETHER.

EEL SHARKS WERE THE TOP PREDATOR

OF WARM SWAMPS AND RIVERS LIKE THESE IN THE PREHISTORIC PAST.

AND AMBUSH HUNTERS ARE DEFINED BY THEIR HABITAT.

IF I CAN FIND THE TOP PREDATOR HERE TODAY,

THEN MAYBE IT CAN SHED LIGHT

ON THE RISE OF THE VERY FIRST RIVER MONSTER.

NORMALLY, I TEND TO FISH WITH ONE ROD,

AND I TEND TO HOLD THAT ROD OR HAVE IT VERY CLOSE TO ME.

WITH MORE THAN ONE LINE, I CAN COVER A LOT MORE WATER.

I'VE JUST TAKEN 20 YARDS OR SO.

IT'S STILL GOING. IT'S MOVING RIGHT TO LEFT.

THERE.

IT'S STILL GOING. IT'S GOING ACROSS THE RIVER NOW.

GOT TO TIGHTEN UP AND GO, OKAY?

YEP, THIS IS A GOOD-SIZE FISH.

THERE IT IS. THERE IT IS. THERE IT IS.

Man: GOT HER, GUYS. FANTASTIC.

IT'S AN ALLIGATOR GAR, A LIVING FOSSIL

THAT'S BEEN UNCHANGED FOR MORE THAN 60 MILLION YEARS,

AND IT'S CLOSE TO THE SIZE OF THE PREHISTORIC EEL SHARK.

TAKE IT TO THE BEACH HERE,

WHERE WE CAN ACTUALLY JUST GENTLY SLIDE IT UP ON THE SAND.

BUT I'M WARY

OF ANY PREDATOR THAT WEIGHS IN AT OVER 120 POUNDS.

THIS FISH'S BODY IS PACKED WITH MUSCLE

TO LAUNCH SURPRISE ATTACKS,

JUST AS I IMAGINE THE EEL SHARK'S WAS.

ALL RIGHT, THIS CREATURE IS VERY MUCH

THE TOP PREDATOR IN THE WATER THESE DAYS.

AND THAT'S A DOUBLE ROW OF TEETH IT'S GOT ON THE UPPER JAW.

BUT THE EEL SHARK TOOK ITS HARDWARE

TO AN EVEN MORE DEVASTATING LEVEL.

IF YOU CAN IMAGINE SOMETHING

WHERE EVERY TOOTH HAS TWO PRONGS...

THEN ANY ATTEMPT TO WRIGGLE FREE

WOULD SHRED THE PREY ALIVE.

THIS 10-FOOT-LONG PREHISTORIC PREDATOR

WAS THE LARGEST FRESHWATER FISH OF ITS TIME

AND GREW BIGGER THAN ANY FISH IN THESE WATERS TODAY.

THE XENACANTH, AN EEL-LIKE SHARK,

WOULD HAVE BEEN 3 1/2-FOOT LONGER THAN THIS.

EEL SHARKS DOMINATED THE WORLD'S SWAMPS AND RIVERS

FOR MORE THAN 100 MILLION YEARS,

HUNTING THE SAME WATERS AS THE ANCESTORS OF THE GAR.

EEL SHARKS WERE THE KINGS OF STEALTH,

FRESHWATER SWAMP MONSTERS

THAT AMBUSHED THEIR VICTIMS AT CLOSE RANGE.

BUT MANY FACTORS MAKE FOR A SUCCESSFUL PREDATOR,

LIKE STRENGTH, SIZE, AND SPEED.

EVIDENCE IS EMERGING

OF A FAST-SWIMMING, OPEN-WATER PREDATOR

WHICH DEFINITELY TICKS ALL THESE BOXES,

AND IT'S BEING EXCAVATED FROM LANDLOCKED KANSAS.

I'M ON AN EXCAVATION SITE

WHERE THIS LIGHTNING-FAST PREDATOR HAS BEEN FOUND,

BUT ITS EXACT LOCATION IS SECRET

SO THAT THE SITE'S NOT LOOTED.

BUT I CAN TELL YOU IT LIES I N THE SMOKEY HILLS OF KANSAS

IN THE HEART OF TORNADO ALLEY.

NORMALLY, WE CAN'T SEE WHAT'S BENEATH THE SURFACE OF THE EARTH

WITHOUT DIGGING A HOLE,

BUT WHAT'S HAPPENED HERE

IS THAT NATURE, IN THE FORM OF WIND AND WATER,

HAS DONE THE EXCAVATION FOR US.

AND AS I WALK DOWN INTO THESE CHALK DEPOSITS, LAYER BY LAYER,

IT'S LITERALLY LIKE TRAVELING BACK IN TIME.

AND JUST ABOUT EVERYWHERE YOU LOOK,

EMERGING INTO THE LIGHT FOR THE FIRST TIME IN 85 MILLION YEARS,

ARE THE REMAINS OF EXTINCT CREATURES.

AND THEY'RE MOSTLY THINGS LIKE THESE CLAMS THAT YOU CAN SEE HERE.

BUT THERE WERE ALSO PREDATORS.

THIS TOOTH BELONGED TO A LIGHTNING-FAST RIVER MONSTER

CALLED XIPHACTINUS.

SOME OF THE BODIES EXHUMED FROM THIS ANCIENT SEA BED

HAVE REACHED MORE THAN 17 FEET LONG.

TO GET MY FIRST GLIMPSE OF THIS DEADLY SPEED MERCHANT,

I'M GOING TO THE ROCKY MOUNTAIN DINOSAUR RESOURCE CENTER,

WHERE ITS FOSSILS ARE CLEANED, CAST,

AND THEN RECONSTRUCTED INTO THREE-DIMENSIONAL SKELETONS.

NOW THAT I CAN SEE THE WHOLE THING IN THREE DIMENSIONS,

THERE ARE PARTS OF IT THAT REALLY DO REMIND ME

OF FISH THAT I'VE SEEN IN THE FLESH.

THE WAY THE JAWS OPERATE

IS UNCANNILY LIKE THE GOLIATH TIGERFISH.

AND THE SHAPE OF THE BODY IS SOMEWHAT LIKE A GIANT TARPON.

THE TARPON USES THIS STREAMLINED BODY DESIGN

TO CUT THROUGH THE WATER WITH MINIMAL DRAG.

IT'S EXPLOSIVE ON THE LINE

AND REACHES WEIGHTS OF 350 POUNDS.

YEAH, YEAH, YEAH, YEAH.

BUT XIPHACTINUS COULD TOP A TON.

THIS IS THE BIGGEST COMPLETE SPECIMEN OF XIPHACTINUS

THAT'S EVER BEEN FOUND.

HERE'S THE TAIL, DORSAL FIN, AND ALL THE WAY DOWN HERE,

GIVING A TOTAL LENGTH OF 18 1/2 FOOT, THE HEAD.

AND THERE ARE BONES FROM OTHER INDIVIDUALS

THAT SUGGEST THEY COULD HAVE GROWN EVEN BIGGER.

THE SHAPE OF ITS SKELETON,

ESPECIALLY THE DESIGN OF ITS PECTORAL FINS AND TAIL,

IS VERY CLOSE

TO ANOTHER OPEN-WATER PREDATOR LIVING TODAY.

I'M HEADING SOUTH OF THE EQUATOR TO THE INDIAN OCEAN

TO TRY TO CATCH A SAILFISH, THE FASTEST FISH ON THE PLANET,

WHICH IN TERMS OF SHEER SPEED,

COULD BE A VERY CLOSE MATCH FOR THE TORPEDO-LIKE XIPHACTINUS.

THE LARGE EYE SOCKETS ON THE XIPHACTINUS SKULL

SUGGEST TO ME THAT IT WAS A SIGHT PREDATOR,

JUST LIKE THE SAILFISH.

WE HAVE SOME TEASERS OFF THE BACK,

IN ADDITION TO THE WAKE OF THE BOAT.

AND THERE ARE BAITS SWIMMING FAST ACROSS THE SURFACE.

I'M WAITING FOR SOMETHING TO HIT ONE OF THOSE.

OH, HERE.

I THINK IT'S OFF.

NO.

OH.

I'M ON A MISSION

TO HUNT DOWN THE BIGGEST, MOST TERRIFYING RIVER MONSTER

THAT EVER LIVED.

MY LATEST CONTENDER IS THE XIPHACTINUS,

WHOSE GIANT, STREAMLINED FOSSILS

SUGGEST A PREDATOR ENGINEERED FOR SPEED.

TO HELP ME CONSTRUCT A MENTAL PICTURE OF A LIVE XIPHACTINUS,

I'M AFTER THE FASTEST FISH ALIVE TODAY -- THE SAILFISH.

OH, YES.

THE ONLY PROBLEM IS,

I'VE NEVER TRIED TO BRING IN A FISH THAT CAN SWIM THIS FAST.

THAT'LL HAPPEN VERY, VERY QUICKLY.

IT'S JUST JUMPING THERE IN THE DISTANCE.

I'M GONNA COME TO THAT SIDE.

HERE WE GO.

THIS FISH CAN STRIP LINE IN EXPLOSIVE BURSTS,

APPROACHING 70 MILES PER HOUR.

ALL RIGHT, WE'LL GET SOME LINE BACK IN.

JUMPS. JUMP, JUMP, JUMP, JUMP, JUMP.

AND AGAIN.

I'M GONNA GO RUN TO THE FRONT, RUN TO THE FRONT, RUN TO THE FRONT.

IF I CAN KEEP IT ON THE HOOK,

IT SHOULD TIRE ENOUGH FOR ME TO BRING IT IN.

SLOWLY GAINING LINE.

SAILFISH HAVE BEEN KNOWN TO IMPALE FISHERMEN

DURING THE STRUGGLE TO BRING THEM ONBOARD.

THIS IS A REAL FIRST FOR ME.

SAILFISH.

THAT'S THE REASON IT'S CALLED THAT.

THIS FISH IS SAID TO BE

THE FASTEST FISH ON THE PLANET TODAY.

CLOCKED AT NEARLY 70 MILES AN HOUR.

THE SAIL IS A BIT OF A MYSTERY.

SOME SAY IT'S USED TO CORRAL SMALLER FISH.

OTHERS, THAT IT IMPROVES MANEUVERABILITY.

BUT WHEN IT'S DOWN, I CAN SEE HOW CLOSELY

THIS FISH SHARES A BODY PLAN WITH XIPHACTINUS.

IT'S JUST THIS STREAMLINED, TUBULAR SHAPE BUILT FOR SPEED.

VERY CHARACTERISTIC-SHAPED TAIL,

LIKE A BIT OF AERONAUTICAL ENGINEERING.

IT'S ALMOST IDENTICAL TO THE GIANT FOSSIL TAIL.

SO, TOO, ARE THE PECTORAL FINS.

BUT THAT'S WHERE THE SIMILARITIES END.

XIPHACTINUS HAD JAWS THAT COULD BITE FISH LIKE THIS IN HALF.

THE XIPHACTINUS WAS THE BIGGEST FISH OF THIS GENERAL BODY DESIGN

THAT'S EVER LIVED.

IT GREW UP TO ABOUT 20 FEET LONG.

85 MILLION YEARS AGO, XIPHACTINUS HUNTED OPEN WATERS

FOR FAST-SWIMMING FISH AS BIG AS I AM.

AND THOSE PREY FISH HAD TO BE FAST

BECAUSE IN THE OPEN OCEAN, THERE'S NOWHERE TO HIDE.

IN TERMS OF SPEED, SIZE, AND HARDWARE,

XIPHACTINUS HAS TO BE UP THERE

AS ONE OF THE GREATEST RIVER MONSTERS

THAT'S EVER LIVED.

BUT ONE PREHISTORIC LEVIATHAN GREW TO THREE TIMES ITS LENGTH.

AND WITH MONSTERS, SIZE COUNTS FOR A LOT.

AND THERE'S ONE MODERN-DAY BEHEMOTH

SHARING THESE WATERS WITH THE SAILFISH,

WHICH CAN GIVE ME A SENSE OF THAT SCALE.

I'VE NEVER TRIED TO GO AFTER A FISH THIS BIG,

AND I'M STARTING TO WONDER IF I SHOULD.

A DARK SHADOW BETRAYS A GIANT BENEATH THE SURFACE.

EMERGING FROM THE GLOOM IS NOT A WHALE BUT A WHALE SHARK,

THE LARGEST FISH ON THE PLANET TODAY.

THAT THING IS JUST MASSIVE.

IT'S A GOOD 20-FOOT LONG.

BUT THAT'S A SMALL ONE. THEY GROW TO ABOUT TWICE THAT LENGTH.

THAT IS THE SIZE AND WEIGHT OF A SCHOOL BUS.

BUT COMPARED WITH WHAT CAME BEFORE,

THE WHALE SHARK IS SMALL FRY.

INCREDIBLE.

HUGE AS THESE THINGS ARE, EVEN A FULLY GROWN ONE

IS SMALLER THAN THE BIGGEST FISH THAT EVER LIVED.

THAT WAS ABOUT THE SIZE OF A TRAIN CAR.

THIS PREHISTORIC, SHADOWY BEAST

HAS TO BE A CONTENDER

FOR THE GREATEST RIVER MONSTER EVER.

IT PATROLLED OUR PLANET'S WATERS

LONG BEFORE GIANTS LIKE WHALE SHARKS OR WHALES

CAME ON THE SCENE.

THE SHEER SCALE OF THE BIGGEST-EVER RIVER MONSTER

IS SOMETHING THAT CAN ONLY BE APPRECIATED OUTDOORS.

NORMALLY, WHEN I GO TO THE BEACH,

I'M THERE TO BRING IN A MONSTER.

I NEVER GET TO PLAY IN THE SAND.

TODAY I'M GOING TO CREATE MY OWN LIFE-SIZE IMAGE

OF THIS CONTENDER FOR THE ULTIMATE RIVER MONSTER.

FROM THE TIP OF THE SNOUT TO THE END OF ITS TAIL,

WE'RE TALKING MORE THAN 50 FEET.

SO, YOU COULD LINE ME UP EIGHT TIMES ALONG ITS LENGTH.

AND AT UP TO 12 FEET LONG,

YOU COULD LINE UP TWO OF ME ALONG EACH FIN.

THIS FISH WAS LIKE A GIANT OCEAN GLIDER.

THEN, THERE'S ITS ENORMOUS MOUTH.

IT HAD A HUGE GAPE.

I COULD PRETTY MUCH WALK INTO ITS MOUTH.

BUT I WOULDN'T FIND ANY SAVAGE FANGS IN THERE.

THIS GIANT ATE PLANKTON, LIKE THE LARGEST WHALES DO TODAY.

LONG BEFORE WHALES CAME ON THE SCENE,

LEEDSICHTHYS WAS THE FIRST PLANKTON-EATING LEVIATHAN.

NO BONY-SKELETONED FISH

HAS EVER GROWN NEAR THIS SIZE AGAIN.

IT MAY HAVE TOPPED 20 TONS,

YET IT FLEW THROUGH PREHISTORIC OCEANS LIKE A GREAT GLIDER.

AND ONCE LEEDSICHTHYS VANISHED,

IT WOULD BE MANY MILLIONS OF YEARS

BEFORE ANY OTHER PLANKTON FEEDER

APPROACHED ITS PHENOMENAL SIZE.

THERE'S NO DENYING

THAT THE LEEDSICHTHYS IS AN UNSURPASSED GIANT,

BUT DESPITE ITS MONSTROUS SIZE,

I THINK THE ULTIMATE RIVER MONSTER

HAS TO BE A PREDATOR, A DEADLY HUNTER.

THAT STILL LEAVES XIPHACTINUS

AS THE STRONGEST CONTENDER SO FAR.

BUT I'VE JUST FOUND OUT

THAT ONE OF THE MOST FEARED FRESHWATER FISH ALIVE TODAY,

THE PIRANHA...

[ MAN SCREAMS ]

...HAD A GIANT, EVEN MORE HORRIFIC

PREHISTORIC RELATIVE.

ENTER MEGA PIRANHA.

MY HUNT FOR THE GREATEST RIVER MONSTER THAT EVER LIVED

HAS UNEARTHED A SINISTER AMBUSH PREDATOR, AN AQUATIC LEVIATHAN,

AND A FANGED TORPEDO.

NOW I'VE DISCOVERED EVIDENCE FOR WHAT MIGHT BE

MY MOST BLOODTHIRSTY CONTENDER SO FAR.

THESE PHOTOGRAPHS SHOW A UNIQUE AND VERY DISTURBING FOSSIL

FROM THE BANKS OF THE RIO PARANá IN ARGENTINA.

IT'S PART OF A FISH'S JAW WITH THREE TEETH.

BASED ON THE SIZE AND CURVATURE OF THIS JAW FRAGMENT,

ITS OWNER WAS A GIANT PIRANHA THREE FEET LONG.

IF IT WAS SWIMMING ALONGSIDE ME,

IT WOULD EXTEND FROM MY HEAD TO MY WAIST.

AND IF THE MEGA PIRANHA SHARED

THE AGGRESSIVE PACK-HUNTING BEHAVIOR OF THESE GUYS...

[ MAN SCREAMS ]

...THEN THE MEGA PIRANHA IS A TRULY TERRIFYING CANDIDATE

FOR THE BADDEST RIVER MONSTER OF ALL TIME.

BUT WITH NOTHING ELSE TO GO ON,

HOW CAN I BRING THIS BEAST TO LIFE?

I'M GOING TO SCALE UP THE PIRANHA'S BODY

TO MATCH SCIENTISTS' ESTIMATES OF MEGA PIRANHA.

I'VE ALSO HAD THE PIRANHA'S SKULL LASER-SCANNED,

THEN SCALED UP AND 3-D-PRINTED.

THE BIGGEST PIRANHA THAT'S EVER LIVED,

WITH THE DEADLIEST SMILE I'VE EVER SEEN.

THIS COULD TAKE A HAND OFF, AND THAT'S JUST FOR STARTERS.

I CAN SCARCELY BEGIN TO IMAGINE

WHAT A PACK OF HUNGRY MEGA PIRANHAS MIGHT BE CAPABLE OF.

EVEN A SCHOOL OF RED-BELLIED PIRANHAS,

THE MOST FEARED FISH IN THE AMAZON TODAY,

WOULDN'T STAND A CHANCE AGAINST MEGA PIRANHA.

BUT WE ONLY HAVE A SINGLE, SOLITARY FOSSIL

FOR THIS ENTIRE SPECIES.

WE DON'T REALLY KNOW ANYTHING ABOUT ITS BEHAVIOR.

IF IT WAS A PACK HUNTER,

THEN I PITY ANYTHING ELSE IN THE WATER.

BUT NOT ALL PIRANHAS HUNT IN PACKS.

SO, DESPITE ITS HORRIFIC TEETH,

I'M GONNA PARK THIS ONE UNTIL MORE EVIDENCE TURNS UP.

WHICH IS EXACTLY WHAT HAS HAPPENED

WITH ANOTHER FIERCELY ARMED PREHISTORIC PREDATOR.

I'VE HEARD FROM A SCIENTIST

WHO'S JUST SOLVED A FIENDISH, CENTURY-OLD PUZZLE

ABOUT A MUCH BIGGER, STRANGER,

AND POSSIBLY MORE DEADLY CONTENDER.

THIS IS AN ANNOUNCEMENT FROM MORE THAN 100 YEARS AGO

OF A GREAT DISCOVERY BY A RUSSIAN SCIENTIST --

ALEXANDER KARPINSKY.

AND THIS IS THE STRANGE FOSSIL AT THE HEART OF THE PUZZLE.

AT FIRST SIGHT,

THIS FOSSIL LOOKS LIKE THE FAMILIAR AMMONITE,

BUT IN KARPINSKY'S FOSSIL, THESE ARE TEETH.

KARPINSKY NAMED THE MYSTERY FISH HELICOPRION,

WHICH MEANS "SPIRAL SAW."

TO PUT THAT INTO MORE MODERN LANGUAGE,

LET'S CALL IT THE BUZZ SAW KILLER.

TO BUILD A BETTER PICTURE OF THIS KILLER CONTENDER,

I'M HEADING TO IDAHO,

WHERE THESE WEIRD WEAPONS KEEP TURNING UP.

THE SITE OF THIS PHOSPHATE MINE

IS NOW MORE THAN 600 MILES FROM THE COAST,

BUT ONCE, IT WAS AT THE BOTTOM OF THE SEA OF PHOSPHORIA,

A SHALLOW, VIRTUALLY LANDLOCKED SEA,

WHICH WAS HOME TO A POPULATION OF HELICOPRION.

AND LAST YEAR,

DR. LEIF TAPANILA FROM IDAHO STATE UNIVERSITY,

SOLVED THE CENTURY-OLD MYSTERY

OF HOW THESE LETHAL BLADE SPIRALS WERE USED

BY ANALYZING A UNIQUE AND NOW-PRICELESS SPECIMEN.

SO, THAT IS IT. THAT IS THE FOSSIL.

LOOKING AT THIS, THE FIRST THING I THINK YOU THINK OF IS,

"IT LOOKS LIKE A SAW BLADE."

BUT THIS FOSSIL ISN'T UNIQUE FOR WHAT'S ON THE SURFACE,

BUT FOR WHAT LIES BENEATH.

DR. TAPANILA USED C.T. X-RAYS TO SCAN THE FOSSIL

AND REVEALED, FOR THE VERY FIRST TIME,

THE CARTILAGE JAWS THAT HELD THE BIZARRE TOOTH WHIRL.

THE NEXT STEP

WAS TO BRING THESE JAWS TO LIFE WITH 3-D PRINTING.

AND THIS IS THE RESULT.

THIS IS AN EXACT ONE-TO-ONE REPLICATION

OF WHAT'S IN THE ROCK, TO SCALE.

LIFE SIZE. LIFE SIZE.

YOU'RE HOLDING A HELICOPRION THAT NO ONE EVER HAS TOUCHED.

THE ONLY THING THAT'S MISSING FROM THIS NOW IS THE TOOTH WHIRL.

THIS ANIMAL IS MEANT TO EAT MEAT.

BUT NOT BONE.

VERY LITTLE WEAR HAS BEEN FOUND ON ANY TEETH,

SUGGESTING THESE TOOTH WHIRLS

WERE DESIGNED TO EAT BONELESS PREY, LIKE SQUID OR SHARKS.

THIS WHIRL BELONGED TO A BUZZ SAW KILLER

THE SIZE OF A GREAT WHITE,

BUT THEY GOT A LOT BIGGER THAN THAT.

WE HAVE SPIRALS THAT GO UP OVER 2 1/2 FEET IN DIAMETER,

WHICH MEANS THE SKULL IS NOW PUSHING US UP TO FOUR FEET

AND GIVES US AN ANIMAL THAT REACHES WELL PAST 20, 25,

MAYBE EVEN UP TO 30 FEET FOR THE LARGEST HELICOPRIONS.

WITH THIS KNOWLEDGE,

I'M ABLE TO IMAGINE SUCH A BEAST IN ACTION,

PERHAPS ON A MOONLIT NIGHT,

WHEN ANCIENT SQUID, CALLED BELEMNITES,

GATHER NEAR THE SEA BED TO MATE.

ANY FISH ARMED WITH A WEAPON LIKE THIS

HAS TO RANK VERY HIGHLY

ON THE LIST OF THE DEADLIEST RIVER MONSTERS EVER.

FOR ME, SHEER SIZE AND INCREDIBLE WEAPONRY

PUSH THE BUZZ SAW KILLER WAY AHEAD OF THE XIPHACTINUS.

BUT NOW MY CHALLENGE IS TO FIND OUT

IF THERE'S ANYTHING BIGGER, BADDER, OR EVEN MORE TERRIFYING

THAT CAN POSSIBLY RIVAL IT.

I'M ON AN EPIC MISSION AROUND THE WORLD

TO HUNT DOWN THE GREATEST RIVER MONSTER THAT EVER LIVED.

LET ME TAKE YOU ON A JOURNEY BACK THROUGH TIME.

IF THIS LINE HERE REPRESENTS TODAY

AND THIS LINE HERE REPRESENTS 400 MILLION YEARS AGO,

THEN ALL THE MONSTERS THAT I'M HUNTING

ARE SOMEWHERE IN THIS SPACE.

NOW, THE VAST MAJORITY OF FISH ALIVE TODAY

ARE THE SO-CALLED RAY-FINNED FISH.

THEY'VE GOT VERY OBVIOUS BONY RAYS IN THEIR FINS.

THERE ARE TENS OF THOUSANDS OF THESE SPECIES,

INCLUDING PIRANHAS, TIGERFISH, AND CATFISH.

THIS GROUP IS ALSO HOME TO XIPHACTINUS, THE LEEDSICHTHYS,

AND MEGA PIRANHA.

BUT WHEN YOU DIG BACK INTO THE FOSSIL RECORD,

THE NUMBER OF RAY-FINNED FISH STEADILY DIMINISHES

UNTIL THERE ARE NONE AROUND.

THE OTHER SIGNIFICANT GROUP OF FISH AROUND TODAY

ARE THE SHARKS AND THEIR RELATIVES.

SHARKS ORIGINATED SIGNIFICANTLY FURTHER BACK

THAN THE RAY-FINNED FISH.

THIS WAS THE ERA OF THE EEL SHARK

AND THE BUZZ SAW KILLER.

BUT THERE WAS ANOTHER GROUP OF FISH.

THEY WERE ON THE SCENE FOR MORE THAN 50 MILLION YEARS,

BUT THEN THEY ALL BECAME EXTINCT.

THERE ARE NO DESCENDANTS ALIVE TODAY.

THESE WERE THE PLACODERMS, OR PLATE SKINS,

ANCIENT ARMORED FISH THAT STARTED A MONUMENTAL ARMS RACE.

NOT ONLY WERE THEIR HEADS ENCASED IN BONY ARMOR,

BUT THESE WERE ALSO THE PREHISTORIC FISH

THAT PIONEERED AND PERFECTED BITING JAWS.

AND ONE ARMORED FISH

GREW INTO A GARGANTUAN BONE-CRUNCHING GIANT...

...THE DUNKLEOSTEUS.

AND THIS IS HOW BIG ITS HEAD ARMOR WAS.

SOMEHOW, I HAVE TO FIGURE OUT WHETHER THIS LONG-EXTINCT BEAST

IS THE GREATEST RIVER MONSTER THAT EVER LIVED.

THERE'S ONLY ONE LIVING FISH I KNOW THAT EVEN APPROACHES

THE ANCIENT ANCESTRY, GIANT SIZE, AND ARMOR PLATING

OF THE DUNKLEOSTEUS.

IT LURKS IN THE DRAMATIC LANDSCAPE

OF CANADA'S FRASER CANYON IN THE WILDS OF BRITISH COLUMBIA.

BUT FISHING HERE IS EXTREMELY CHALLENGING.

THIS IS TREMENDOUSLY DEEP, POWERFUL, TURBULENT WATER.

AND EVEN THOUGH I'VE BEEN FISHING A LONG TIME,

I HAVE TO REMIND MYSELF THAT IT'S POSSIBLE

FOR CREATURES TO LIVE AND HUNT IN WATER LIKE THIS.

WHO KNOWS WHAT COULD BE DOWN AT THE BOTTOM OF THIS WATER?

YEAH, SO, WE'RE ALL SET. BAITS ARE DOWN.

JUST WAITING NOW.

BELOW ME, THESE CHURNING WATERS

PLUNGE IN TO MORE THAN 150 FOOT OF DARKNESS.

BECAUSE OF THE CURRENT,

THERE'S A CERTAIN AMOUNT OF LINE MOVEMENT AND ROD MOVEMENT.

BUT WHEN A FISH TAKES ONE OF THOSE BAITS,

IT SHOULD BE FAIRLY UNMISTAKABLE.

HERE.

THAT'S A GOOD SIZE, I THINK.

LET'S DO THAT ONE.

I'M GOING BACK MILLIONS OF YEARS

TO UNEARTH THE GREATEST RIVER MONSTER OF ALL TIME.

IN CANADA'S FRASER CANYON,

I'M SEARCHING FOR THE ONLY ARMORED GIANT ALIVE TODAY

THAT CAN SHED LIGHT

ON WHAT COULD BE MY STRONGEST CONTENDER SO FAR --

...THE DUNKLEOSTEUS, OR BONE CRUSHER.

[ REEL CLICKING ]

Wade: HERE WE GO, A CHANCE TO GET A LITTLE BIT OF LINE BACK.

[ GRUNTS ]

I THINK IT MIGHT BE APPROACHING THE SURFACE.

HERE WE GO. HERE WE GO. HERE WE GO. HERE WE GO.

YEP, HERE WE GO.

AHH!

THERE IT IS. THERE IT IS.

IT'S A 140-POUND WHITE STURGEON,

THE LARGEST FISH IN NORTH AMERICAN RIVERS.

STURGEON BELONG TO THE MOST ANCIENT GROUP

OF RAY-FINNED FISH AROUND TODAY.

AND THEY'RE INCREDIBLY LONG-LIVED.

184 1/2.

THAT'S JUST OVER SIX FOOT, ISN'T IT?

HEAVY FISH. TWO OF US STRUGGLING TO HOLD THIS UP BRIEFLY.

BUT BY STURGEON STANDARDS, THIS ISN'T BIG.

THEY GROW UP TO THREE TIMES THE LENGTH OF THIS --

HARD TO BELIEVE.

THAT'S AROUND THE SAME SIZE RANGE AS THE BONE CRUSHER.

THE STURGEON'S BONY PLATES ARE UNUSUAL IN LIVING FISH,

AND ITS BODY HELPS ME IMAGINE

THE STRENGTH AND POWER OF THE BONE CRUSHER'S BODY.

IT REALLY IS A STRANGE-LOOKING BEAST,

BUT BACK WHEN THESE STARTED TO EMERGE,

THIS LOOK WAS ACTUALLY VERY COMMON -- ARMOR PLATING.

AND THIS IS ONE OF THE FEW REMNANTS OF THAT AGE

THAT SURVIVES TO THIS DAY.

THIS STURGEON HAS GIVEN ME LIVING CLUES

TO A LOST ARMORED PREDATOR.

IT'S GOING. IT'S GOING.

BUT TO FIND THE LAST PIECE OF THE PUZZLE,

I'M HEADING BACK TO THE U.S.,

TO THE CLEVELAND MUSEUM OF NATURAL HISTORY,

TO COME FACE-TO-FACE WITH THE VERY FIRST

OCEAN-GOING APEX PREDATOR -- THE DUNKLEOSTEUS.

AND THIS IS IT. THIS IS DUNKLEOSTEUS.

AND I HAVE TO SAY, I'M HAVING A BIT OF TROUBLE

BELIEVING THAT THIS WAS ACTUALLY A FISH.

IT'S UNLIKE ANYTHING I'VE CAUGHT OR SEEN

OR ANYTHING THAT'S ALIVE ON THE PLANET TODAY.

BASED ON THE REMAINS OF CLOSE RELATIVES,

EXPERTS HERE THINK THE BONE CRUSHER

REACHED LENGTHS OF AROUND 20 FEET.

AND YOU JUST CAN'T FAIL TO NOTICE THESE HUGE FANGS.

THEY'RE NOT ACTUALLY TEETH, BUT SHARPENED, BARE JAWBONES.

IT'S ESTIMATED THAT THE BONE CRUSHER

COULD SLAM ITS JAWS SHUT

WITH A FORCE OF AROUND 8,000 POUNDS PER SQUARE INCH

INSIDE 5/100ths OF A SECOND --

POSSIBLY THE STRONGEST FISH BITE EVER

AND HORRIFICALLY MORE POWERFUL THAN ANY CREATURE ALIVE TODAY.

AND WHAT ALL OF THIS TELLS US

IS THAT THIS WASN'T A FISH THAT MERELY GRABBED PREY,

WHICH HAD TO BE SMALL ENOUGH TO SWALLOW WHOLE.

THIS COULD SLICE THROUGH FLESH AND BONE,

WHICH MEANT IT COULD GO AFTER MUCH LARGER PREY

AND BITE CLEAN MOUTHFULS OUT OF THEM.

AND THIS TOOK PREDATION TO A WHOLE NEW LEVEL.

AS A CONTENDER FOR THE ULTIMATE PREHISTORIC RIVER MONSTER,

THE BONE CRUSHER IS HITTING HARD.

BUT THERE'S ONE MORE GROUP OF FISH

WITH EVEN MORE FORMIDABLE ROOTS.

THE ARMORED FISH WEREN'T THE ONLY OTHER GROUP OF ANCIENT FISH

THRIVING BACK HERE IN PREHISTORY.

THERE WERE ALSO THE LOBE FINS.

THEY ARE STILL HANGING ON BY A THREAD.

THERE'S ONLY A HANDFUL LEFT,

AND THE MOST FAMOUS IS THE COELACANTH.

IT WAS THOUGHT TO BE EXTINCT

UNTIL ONE WAS FOUND IN THE INDIAN OCEAN IN THE 1930s.

WHEN IT WAS FIRST FOUND,

THE COELACANTH WAS NICKNAMED "OLD FOUR LEGS"

BECAUSE OF ITS STRANGE, FLESHY, PAIRED FINS,

WHICH LOOKED LIKE SIMPLE LIMBS.

IT'S A NICKNAME THAT'S VERY APT BECAUSE WAY BACK IN PREHISTORY,

SOME LOBE FINS BRANCHED OFF TO EVENTUALLY BECOME

ALL MODERN-DAY FOUR-LIMBED VERTEBRATES,

INCLUDING US.

AND ONE PREHISTORIC LOBE-FINNED COUSIN

WAS A GARGANTUAN HEAVYWEIGHT, A 23-FOOT, 4-TON RIVER MONSTER.

THE RHIZODONT --

...A PREDATORY FRESHWATER FISH

THE SIZE AND WEIGHT OF A KILLER WHALE.

330 MILLION YEARS AGO,

THEY HUNTED LAKES AND RIVERS IN SCOTLAND.

THE FIRST TIME I CAME TO THE HUNTERIAN MUSEUM IN GLASGOW,

IT WAS TO SEE THE PLESIOSAUR, THE REPTILE SOME BELIEVE

IS BEHIND THE BIGGEST AQUATIC MONSTER MYTH OF ALL TIME --

LOCH NESS.

BUT I'VE HEARD THAT MASSIVE RHIZODONT TEETH FOUND NEAR HERE

LEAVE THE PLESIOSAUR'S DEADLY HARDWARE IN THE DUST.

RHIZODONT MEANS "ROOTED TOOTH,"

AND YOU CAN CLEARLY SEE FROM WHERE THE ENAMEL ENDS

THAT FULLY HALF OF THIS WEAPON WAS BURIED IN THE JAWBONE.

THIS TUSK WAS CLEARLY DESIGNED

TO DRIVE INTO FLESH AND BONE AND RIP PREY APART.

NOW, THE SIZE OF THE TEETH SUGGESTS LARGE PREY.

AND AT 23 FEET LONG, THIS FISH HAD MORE THAN ENOUGH MUSCLE

TO TAKE ON ANYTHING ELSE IN THE WATER.

BUT APART FROM ITS HUGE TUSKS AND FANGS, MOST OF ITS REMAINS

ARE THE BONY SCALES THAT MADE UP A SUIT OF FULL-BODY ARMOR.

THERE'S NO FISH ALIVE TODAY THAT COMES ANYWHERE NEAR

THE RHIZODONT'S SIZE, APPEARANCE, AND AGGRESSION.

BUT IN AUSTRALIA, THERE IS A RIVER MONSTER THAT DOES --

...THE ESTUARINE CROCODILE.

TO COMPLETE THIS NIGHTMARISH PICTURE,

I'LL STARE INTO THE JAWS OF DEATH

TO BRING THE GARGANTUAN RHIZODONT TO LIFE.

MY WORLDWIDE HUNT

FOR THE BIGGEST, BADDEST RIVER MONSTER OF ALL TIME

HAS FINALLY BROUGHT ME TO THE RHIZODONT.

THE SIZE OF A KILLER WHALE AND ARMED WITH 10-INCH TUSKS,

NO FRESHWATER FISH COMES CLOSE

TO THE RHIZODONT'S SCALE AND POWER.

BUT THE WORLD'S LARGEST REPTILE DOES.

HIS MISSING LIMBS

ARE THE PRICE A TOP PREDATOR PAYS TO STAY AT THE TOP.

AT 18 FEET LONG, CHOPPER IS THREE TIMES MY LENGTH,

BUT THE GIANT RHIZODONT

COULD HAVE BEEN ANOTHER FIVE FEET LONGER.

WELL, I'M JUST TRYING TO SORT OF CALM MYSELF DOWN A LITTLE BIT

AND GET INTO PROPER OBSERVATION MODE.

THIS GIANT AQUATIC PREDATOR

DEPLOYS THE SAME AMBUSH STRATEGY AS THE RHIZODONT,

AND THE POWER OF THAT STRIKE IS ROOTED IN THE TAIL.

IT'S HALF THE BODY LENGTH, SO ON AN 18-FOOT ANIMAL LIKE THIS,

YOU'VE GOT A 9-FOOT TAIL.

AND THAT'S JUST SOLID MUSCLE.

IT WORKS IN THE SAME WAY AS A FISH'S TALE,

AND IT'S ALL ABOUT PROPULSION.

JUDGING BY SIZE ALONE, THE RHIZODONT'S MASSIVE TAIL

MUST HAVE PACKED MORE THAN TWICE THE CROC'S MUSCLE POWER.

IT'S AN UNCOMFORTABLY CLOSE VIEW I'M GETTING

OF THE TEETH AND JAW OF THIS ANIMAL.

THESE CROCS HAVE THE STRONGEST RECORDED BITE

OF ANY ANIMAL ALIVE TODAY --

CLOSE TO 4,000 POUNDS PER SQUARE INCH

FOR A BEAST THIS SIZE.

A 23-FOOT, 4-TON RHIZODONT

MIGHT PACK MORE THAN DOUBLE THAT.

CHOPPER HAS GIVEN ME A VISCERAL INSIGHT

INTO THE AWESOME KILLER POTENTIAL

OF THIS PREHISTORIC FISH.

I'M STARTING TO THINK

THE RHIZODONT COULD EVEN OUT-BITE THE BONE CRUSHER.

IT'S TIME TO PUT THIS GARGANTUAN FISH

IN CONTEXT IN SCOTLAND,

WHERE IT TERRORIZED LAKES AND RIVERS

330 MILLION YEARS AGO.

MY JOURNEY HALFWAY AROUND THE WORLD

HAS GIVEN ME THE FINAL INFORMATION I NEEDED

TO PICTURE THIS RIVER MONSTER'S GENERAL BODY PLAN AND SIZE.

NOW I'M TRYING TO IMAGINE THE WORLD THAT THAT BEAST LIVED IN.

MILLIONS OF YEARS BEFORE SOLID ICE CARVED OUT THE LOCHS,

RHIZODONT STALKED PREY AS BIG AS A MAN

IN MURKY, SLOW-FLOWING WATERS.

AT THE END OF MY SEARCH

FOR THE GREATEST RIVER MONSTER OF ALL TIME,

IT'S A VERY CLOSE CONTEST

BETWEEN THE BONE CRUSHER...

...AND THE RHIZODONT.

BUT I NOW KNOW WHERE I'D PLACE MY BET.

SO, FOR ME, THERE'S NO QUESTION --

THE RHIZODONT IS THE ULTIMATE PREHISTORIC RIVER MONSTER.