CAPTIONING MADE POSSIBLE BY BBC WORLDWIDE AMERICAS
Narrator:THE BALLAD OF BIG AL WAS A HUGE TECHNICAL CHALLENGE,
TAKING OVER A YEAR TO MAKE.
BUT THIS WAS NOTHING
COMPARED TO THE ENORMOUS AMOUNT OF SCIENTIFIC RESEARCH
THAT INSPIRED THE FILM.
THIS IS THE STORY OF HOW SO MUCH IS KNOWN
ABOUT ONE VERY DEAD DINOSAUR.
Reporter: SCIENTISTS ARE UNCOVERING
THE REMAINS OF AN ALLOSAURUS, A DINOSAUR THAT...
THE EXCAVATING TEAM HOPES
TO HAVE BIG AL OUT OF THE GROUND BY WEEK'S END...
HAVE TO VERY CAREFULLY CHIP AWAY THE ROCK,
TRY TO PUT TOGETHER THE WHOLE STORY OF THIS ANIMAL.
Narrator: IN 1991, OUT OF THE ROCK
CAME A PALEONTOLOGICAL STAR--
ONE OF THE MOST COMPLETE DINOSAUR SKELETONS EVER FOUND.
HE WAS NICKNAMED "BIG AL."
AND HERE WE HAVE WHAT A CLAW FROM AN ALLOSAURUS
WOULD LOOK LIKE.
AFTER 145 MILLION YEARS, AL'S BACK ON HIS FEET AGAIN
AT THE UNIVERSITY OF WYOMING GEOLOGICAL MUSEUM.
BUT SCIENTISTS HAVE BEEN ABLE TO DO MORE
THAN JUST REBUILD HIS BODY.
AFTER EXTENSIVE FORENSIC ANALYSIS OF HIS BONES,
RESEARCH INTO OTHER FOSSILS,
AND THE BEHAVIOR OF HIS MODERN RELATIVES,
THEY KNOW MORE ABOUT BIG AL
THAN ALMOST ANY OTHER DINOSAUR.
IT ALL ADDS UP
TO A GREAT PALEONTOLOGICAL DETECTIVE STORY.
LIKE ALL GOOD THRILLERS,
THE FIRST CLUES HAD TO BE GATHERED
AT THE SCENE OF THE CRIME.
Woman: THIS IS THE SITE IN WYOMING
WHERE BIG AL WAS DISCOVERED IN 1991.
AND BIG AL DIED 145 MILLION YEARS AGO
DURING THE LATE JURASSIC PERIOD
AND WAS BURIED IN A RIVER CHANNEL DEPOSIT
THAT'S NOW PART OF THE MORRISON FORMATION.
THINGS WOULD HAVE LOOKED A LOT DIFFERENT
AT THAT TIME.
IT WOULD HAVE BEEN MUCH FLATTER.
WE WOULDN'T HAVE HAD ANY FLOWERING PLANTS.
AND IN THEIR PLACE, WE WOULD HAVE HAD
FERNS, CYCADS, EVEN CONIFERS.
Narrator: AT THAT TIME, WYOMING WAS FULL OF DINOSAURS.
MOST WERE THE LUMBERING PLANT EATERS LIKE DIPLODOCUS
AND THE ARMORED STEGOSAURUS.
FAR LESS COMMON WERE THE CARNIVORES,
BUT THIS HASN'T STOPPED THEM BECOMING INFAMOUS,
LIKE THE ALLOSAURUS.
THESE FEARSOME PREDATORS WERE THE T-REX OF THEIR DAY,
AND AL WAS ONE OF THEM.
BUT LIKE EVERY LIVING THING,
THESE MONSTERS STARTED OFF SMALL AND DELICATE.
DESPITE THIS, SCIENCE CAN STILL TELL US SOMETHING
ABOUT HOW AL PROBABLY STARTED LIFE.
HELLO. HELLO, DARLING.
WE'RE VERY FAMILIAR WITH HOW LIFE BEGINS FOR HUMANS,
BUT YOU MIGHT BE SURPRISED TO LEARN
HOW A JURASSIC CARNIVORE RAISES ITS BABY.
EVIDENCE FOR THIS COMES FROM REMARKABLE FOSSILS
FOUND ON THE ATLANTIC COAST OF PORTUGAL.
WAS IN THIS PLACE THAT WE FOUND IN 1993
A SMALL EGGSHELL LIKE THIS
THAT WE FIGURED OUT WAS FROM A DINOSAUR.
FURTHER YEARS, WE'VE DUG IT
AND FOUND MORE THAN 100 EGGS.
THAT MAKES ONE OF THE BIGGEST NESTS
IN THE WORLD.
Narrator: BUT MORE SIGNIFICANTLY,
THEY FOUND SOMETHING
WHICH COULD TELL THEM WHO THESE EGGS BELONGED TO.
THE MOST RARE AND SOUGHT-AFTER FOSSILS OF ALL--
TINY PRESERVED BONES OF BABY DINOSAURS
STILL CURLED UP INSIDE THEIR SHELL.
WE'VE FOUND MORE THAN 200 EMBRYONIC BONES.
WITH THEM, WE CAN SAY EXACTLY
WHICH KIND OF DINOSAUR WE HAVE.
IN THIS CASE,
IT'S A MEAT-EATER DINOSAUR, A CARNIVORE,
AND WE HAVE ALMOST ALL SKELETON HERE.
Narrator: AND IF THERE WERE EGGS,
THERE MUST HAVE BEEN A NEST.
BIZARRELY, THERE IS INFORMATION ABOUT THIS
IN THE FOSSILIZED EGGSHELLS THEMSELVES.
UNDER THE MICROSCOPE,
SCIENTISTS CAN IDENTIFY HOLES IN THE SHELL.
THEIR LARGE SIZE ALLOWS MAXIMUM AIR FOR THE EMBRYO TO BREATHE,
WHICH TELLS THEM THAT THESE EGGS
WERE BURIED AND PACKED TOGETHER
IN AN UNDERGROUND NEST.
SCIENTISTS KNOW THIS
BECAUSE THERE ARE ANIMALS ALIVE TODAY THAT DO THE SAME THING...
THE CROCODILES.
THIS IS NOT SURPRISING,
BECAUSE CROCODILES AND ALLIGATORS
ARE ONE OF THE DINOSAURS' CLOSEST LIVING RELATIVES,
AND WITH SCALY SKIN AND A MOUTH FULL OF TEETH,
IT'S EASY TO SEE THE FAMILY RESEMBLANCE.
BUT CARNIVOROUS DINOSAURS HAVE
AN EVEN CLOSER GROUP OF RELATIVES
WHO SHARE SOME OF THEIR OTHER TRAITS.
THEY ARE THE BIRDS.
STANDING ON 2 LEGS, BIG AL'S SKELETON
WAS ACTUALLY MORE LIKE A BIRD THAN A CROCODILE,
BUT IN PRACTICE, HE WAS A STRANGE MIX OF THE TWO.
SO AFTER AL HATCHED, DID HE FEED HIMSELF LIKE A CROCODILE
OR WAIT TO BE FED LIKE MOST BIRDS?
EVIDENCE FOUND AT THE SITE IN PORTUGAL PROVIDED A CLUE.
INSIDE THE EGGS WERE FOUND SEVERAL TEETH
THAT ARE QUITE RARE.
AND WITH THESE TEETH,
WE CAN TELL A LOT OF THINGS.
FOR INSTANCE, THEY ARE BORN WITH TEETH.
SINCE THEY WERE BORN, THEY WERE ABLE TO CHEW
AND TO EAT SOFT MEAT, FOR INSTANCE.
Narrator: BEING BORN WITH TEETH
WOULD HAVE MADE ALL THE DIFFERENCE.
ALTHOUGH THEY WERE TOO SMALL
TO TEAR UP CHUNKS OFF HIS MOTHER'S DINNER PLATE,
THEY WERE PROBABLY PERFECT FOR CAPTURING INSECTS.
JUST LIKE BABY CROCODILES,
IT SEEMS AL WAS ABLE TO FEND FOR HIMSELF
FROM AN EARLY AGE.
BUT AL'S BIGGEST PROBLEM AT THIS STAGE IN HIS LIFE
WAS BEING EATEN BY A BIGGER DINOSAUR.
HIS ONLY DEFENSE WAS TO GROW UP FAST.
AND AN AMAZING COLLECTION OF ALLOSAURUS BONES
SHOWS JUST HOW QUICKLY A BABY DINOSAUR COULD GROW.
Man: WHAT WE HAVE HERE ARE ALLOSAURUS THIGH BONES,
AND WHAT'S UNIQUE IS THE FACT THAT THEY ARE GOING
FROM VERY, VERY SMALL TO VERY, VERY LARGE.
IF WE TAKE THIS SMALLEST BONE HERE,
WE CAN SEE THAT IT'S ABOUT 18 CENTIMETERS IN LENGTH
AND WOULD PROBABLY BELONG TO A DINOSAUR
THAT WAS MAYBE A METER AND A HALF IN LENGTH
AND POSSIBLY STOOD OFF THE GROUND
ABOUT A METER OR SO.
IF WE LOOK AT THIS LARGER BONE OVER HERE, THIS SUB-ADULT,
WE PROBABLY WILL HAVE AN ANIMAL
CLOSE TO 8 METERS IN LENGTH--
THIS BONE ITSELF BEING ABOUT A METER IN LENGTH--
AND PROBABLY STOOD OFF THE GROUND ABOUT 2 1/2 METERS.
AS WE LOOK AT THE ALLOSAURUS BONE,
WE CAN MAKE THIN SECTIONS OF IT,
AND THEN WE CAN COMPARE IT TO CROCODILES AND TO BIRDS.
AS WE COMPARE IT TO BIRDS,
WE SEE THAT THERE IS SO MUCH SIMILARITY, THAT WE KNOW
THAT ALLOSAURUS PROBABLY GREW VERY RAPIDLY LIKE A BIRD WOULD.
Narrator: SO AL WAS BORN LIKE A CROCODILE
BUT GREW LIKE A BIRD,
PROBABLY REACHING FULL SIZE IN JUST 6 TO 8 YEARS.
AND BY THE TIME A CHILD IS JUST STARTING SCHOOL,
AL WOULD ALREADY HAVE BEEN A FINE PHYSICAL SPECIMEN.
Boy: HEY, TOSS IT TO ME! I'M OVER HERE! PLEASE!
[AIR ESCAPING]
THAT'S THE LAST TIME I PLAY WITH A DINOSAUR.
DINOSAURS.
Narrator: SO HOW DID HE FEED THIS FANTASTIC GROWTH?
AGAIN, HIS 2 LIVING RELATIVES MIGHT PROVIDE A CLUE,
BUT THEY HAVE VERY DIFFERENT APPROACHES TO EATING.
THEIR STRATEGY IN FEEDING IS PLENTY OF TIME.
THAT'S ALL THEY'VE GOT IS A LOT OF TIME TO WAIT
FOR SOMETHING TO MAKE A MISTAKE,
A PERSON OR ANOTHER ANIMAL.
IT'S BITE FIRST AND THEN ASK QUESTIONS LATER.
THAT'S WHAT THEY DO. THEY GRAB SOMETHING
WHEN IT OFFERS THE OPPORTUNITY FOR IT.
SUCH AS MY LEG RIGHT NOW.
LET ME MOVE THIS ANIMAL.
SHE'S GONNA BE REAL TESTY HERE.
THIS IS A LITTLE FEMALE.
MOVE, GIRL.
THANK YOU.
Man: OH, NOW HERE'S A GREAT OPPORTUNITY
TO SEE A BASIC DIFFERENCE
BETWEEN A BIRD AND AN ALLIGATOR.
WHAT WE SEE IS HOW A BIRD IS CHOOSING TO FEED.
THE GREAT PART IS IS ANY TIME YOU SEE
A BIRD LIKE THIS FEEDING,
IS IT CAN ACTUALLY TAKE AND PICK OUT ITS FOOD
AMONGST THE TWIGS AND STICKS
AND OTHER PEBBLES AND THINGS HERE.
IT SELECTIVELY PICKS THEM UP AND SWALLOWS THEM.
AN ALLIGATOR, ON THE OTHER HAND, WILL STRIKE AT ANYTHING IT SEES.
WHAT WE'RE GOING TO TRY TO DO HERE
IS TRICK THESE ALLIGATORS
INTO COMING AFTER THE DINOSAUR DOWN HERE.
SEE, THEY DON'T REALLY CARE
WHAT IT IS THEY'RE GRABBING.
THEY'RE OPPORTUNIC EATERS.
THEY SEE SOMETHING, THEY PERCEIVE IT AS A FOOD ITEM,
AND THEY GO FOR IT.
Narrator: THE ALLIGATORS USE THEIR EXCELLENT SENSE OF SMELL
TO TRACK DOWN THEIR PREY.
AND DIPPED IN FISH OIL,
EVEN THE INEDIBLE TOY SEEMS TEMPTING.
IN FACT, THE DIFFERENCES
BETWEEN THE BIRD AND THE ALLIGATOR'S BEHAVIOR
IS REFLECTED IN THE SHAPE OF THEIR BRAIN.
A LOOK INSIDE AL'S HEAD
COULD PROVIDE DIRECT EVIDENCE OF HIS BEHAVIOR,
AND ALTHOUGH ALLOSAURUS ARE LONG DEAD,
A REMARKABLE FOSSIL HAS LET SCIENTISTS DO JUST THAT.
IT'S A BRAIN
CAST FROM THE INSIDE OF AN ALLOSAURUS SKULL.
HOW DOES THIS COMPARE WITH HIS RELATIVES?
WELL, LET'S START WITH A BIRD.
HERE'S A MODEL OF A BIRD.
IF WE LOOK AT THE WAY THE BIRD IS,
WE FIND OUT THAT A BIRD HAS A VERY LARGE REGION
THAT'S DEDICATED TO PROCESSING INFORMATION
AND A VERY SMALL REGION DEDICATED TO SENSORY INPUT,
SUCH AS SMELLING SOMETHING.
WHAT ABOUT AN ALLIGATOR?
IF WE TAKE THE ALLIGATOR BRAIN AND COMPARE THAT TO ALLOSAURUS,
WE SEE SOMETHING THAT LOOKS VERY, VERY SIMILAR.
THIS IS SENSORY INFORMATION THAT COMES IN HERE
AND THEN GOES TO A REGION THAT'S ACTUALLY RATHER SMALL
FOR PROCESSING THAT INFORMATION,
AND IT SNAPS AT IT,
SO IT JUST STRIKES AND HITS WHATEVER SMELLS RIGHT.
THAT COMPARES EXTREMELY WELL WITH ALLOSAURUS.
THEREFORE, THESE FEATURES TELL US THAT IF WE WANT
TO COMPARE ALLOSAURUS TO A MODERN-DAY ANIMAL,
THAT WOULD BE AN ALLIGATOR,
BECAUSE THEIR BRAINS RESEMBLE EACH OTHER VERY, VERY MUCH.
CONSEQUENTLY, THEIR BEHAVIORS MUST HAVE BEEN VERY SIMILAR.
Narrator: THERE IS AN EXTRAORDINARY
AND BAFFLING SITE IN UTAH
THAT MIGHT JUST BEAR WITNESS
TO THIS SORT OF FEEDING BEHAVIOR.
CLEVELAND LLOYD DINOSAUR QUARRY.
OVER 10,000 DINOSAUR BONES
HAVE BEEN FOUND JUMBLED TOGETHER AT THIS ONE SITE,
BUT AS THE DIFFERENT BONES WERE IDENTIFIED,
SOMETHING STRANGE EMERGED.
THEY FOUND HUNDREDS AND HUNDREDS OF ALLOSAURUS BONES
AND JUST A FEW OF THE PLANT-EATING DINOSAURS--
THE TOTAL OPPOSITE OF WHAT YOU WOULD EXPECT.
IT WAS A MYSTERY
WHY THE PREDATORS OUTNUMBERED THEIR PREY.
WHAT MIGHT HAVE HAPPENED HERE IS THE FACT THAT WE HAVE A BOG AREA
THAT COLLECTS SMALL POOLS OF WATER
THAT WOULD ATTRACT STEGOSAURUS AND SOME OTHER ANIMALS
THAT WOULD BE PREY FOR THE ALLOSAURUS,
AND THEY WOULD GET STUCK IN THE MUD
AND MIGHT BE THERE FOR DAYS.
THEY MIGHT STINK.
THEY MIGHT BE VERY ATTRACTIVE TO AN ALLOSAURUS
THAT WOULD BE GLAD TO JUMP IN THERE,
NOT REALIZING THAT THEY WOULD BECOME ENTOMBED THEMSELVES
JUST LIKE THEIR PREY.
Narrator: THE ALLOSAURUS WERE PROBABLY
LED TO THEIR DEATH BY THEIR NOSES.
THEY COULDN'T IGNORE
THE STINKING ATTRACTION OF A CARCASS.
Dr. Bybee: WHAT PROBABLY HAPPENED IS
WHEN THE DINOSAURS GOT INTO THE BOG,
THERE WAS A LOT OF DINOSAUR BIOTURBATION,
OR A LOT OF DINOSAURS MIXING UP A LOT OF THE MUD.
HENCE WE HAVE A HUGE, HUGE COLUMN OF BONES
THAT GOES QUITE DEEP,
AND THEY'RE ALL MIXED UP.
Narrator: THE REMAINS OF AT LEAST 44 ALLOSAURUS
WERE FOUND AT THIS ONE SITE.
IT LOOKS LIKE THIS WAS A NATURAL PREDATOR TRAP.
SO AL'S BRAIN WAS PROBABLY SOMETHING LIKE AN ALLIGATOR'S.
THEY LIE IN WAIT FOR A MEAL TO COME TO THEM.
BUT AL'S BODY WAS BUILT DIFFERENTLY.
HE LOOKED MORE LIKE A BIRD,
AND THEY DON'T HANG AROUND FOR FOOD TO WANDER BY.
JUST LIKE THE BRAIN,
THESE 2 DIFFERENT LIFESTYLES
LEAVE THEIR MARK NOT ONLY ON THE SKELETON,
BUT ON THE BODY'S INTERNAL ORGANS.
OSTRICH TEND TO BE ABLE TO RUN GREAT DISTANCES
AND KEEP SPEED AND ACTIVITY UP ALL DAY LONG,
AND THEY HAVE TO DO THAT
SO THAT THEY CAN GATHER THEIR FOOD.
TO HELP THEM DO THAT, THEY HAVE A HEART
THAT DELIVERS OXYGEN VERY EFFICIENTLY
TO ALL THE TISSUES OF THE BODY
AFTER IT'S GONE TO THE LUNGS.
CROCODILES, ON THE OTHER HAND,
REALLY SIT AND SNEAK
AND KIND OF WAIT FOR PREY TO COME UP TO THEM.
THEY CAN MOVE VERY QUICKLY FOR A SHORT TIME,
BUT THEIR HEART AND THE WAY THEIR BLOOD WORKS
AND THEIR TISSUES WORK
DON'T ALLOW THEM TO SUSTAIN ENERGY
FOR A LONG PERIOD OF TIME.
Narrator: NOWADAYS, TO FIND OUT HOW A HEART WORKS,
MEDICINE HAS INVENTED MACHINES
FOR SCIENTISTS TO SEE INSIDE THE BODY.
AT THE NORTH CAROLINA COLLEGE OF VETERINARY MEDICINE,
AN ALLIGATOR IS DUE FOR A C.T. SCAN.
TO PREVENT HIM INJURING HIMSELF OR THE TEAM,
HIS EYES ARE TAPED OVER
AND HIS ARMS AND LEGS RESTRAINED.
Stoskopf: THIS IS AN ALLIGATOR STRAITJACKET.
THAT'D BE GOOD.
Narrator: TO HELP RELAX THE ALLIGATOR,
A BIZARRE FORM OF HYPNOSIS IS USED.
WE'RE JUST PUTTING HIM TO SLEEP
BY STROKING HIS BELLY.
IT HELPS AN AWFUL LOT
THAT HE HAS ALL THE TAPE ON
SO THAT WE CAN GET TO HIS BELLY,
BUT THIS ACTUALLY WORKS.
GO TO SLEEP.
NOTHING HAPPENING.
OKAY, PAUL, TURN THE LIGHTS OUT
SO WE CAN SEE THE GUIDELINES,
AND LET'S GET HIM SET UP.
START THERE.
Narrator: THE IMAGES ON THE SCREEN
SHOW A CROSS SECTION THROUGH THE ALLIGATOR'S CHEST,
AND WITH EACH NEW SCAN, THEY ARE BUILDING UP
A PICTURE OF THE STRUCTURE OF THE HEART.
HOWEVER, UNTIL RECENTLY,
THERE WAS LITTLE POINT IN DOING THIS TO A FOSSIL,
BECAUSE SOFT TISSUES DON'T NORMALLY FOSSILIZE.
WITH SKELETONS LIKE BIG AL,
SCIENTISTS COULD ONLY SPECULATE
ON WHAT WAS INSIDE A DINOSAUR'S CHEST.
BUT THIS YEAR, A HIGHLY CONTROVERSIAL FIND
MAY HAVE CHANGED ALL THAT.
THIS IS AN ABSOLUTELY SUPERB SPECIMEN
OF A SMALL PLANT-EATING DINOSAUR.
WE CALL IT THESCELOSAURUS IN PALEONTOLOGY,
BUT HERE AT THE MUSEUM WE LIKE TO CALL IT "WILLO,
THE LITTLE DINOSAUR WITH A HEART."
AND IN THIS REGION IS THE ACTUAL PRESERVATION OF STRUCTURES
WHICH DEMONSTRATE THE PRESENCE OF A HEART.
THIS STRUCTURE WAS SO PECULIAR
THAT MY COLLEAGUES DECIDED TO PROBE IT WITH AN X-RAY SCAN.
Narrator: TO HELP READ WILLO'S SCAN
THE IMAGES INSIDE THE ALLIGATOR'S CHEST
PROVIDE A GUIDE.
AS WE MOVE THROUGH THE THORAX, WE'RE GONNA SEE THE LUNG FIELDS,
AND THEN COMING UP BETWEEN THE 2 LUNG FIELDS,
WE'LL START TO SEE A SOLID MASS,
AND THAT'S THE HEART.
Narrator: SHOWN ON THE ALLIGATOR SCAN AS A GRAPHIC,
THE 2 AORTAS, OR TUBES WHICH CARRY BLOOD AROUND THE BODY,
ARE HIGHLIGHTED.
THEY LEAD FROM THE 2 VENTRICLES OF THE HEART.
THIS PLUMBING, ALTHOUGH PERFECT FOR AN ALLIGATOR,
ONLY ALLOWS IT SHORT BURSTS OF ACTIVITY.
INSIDE WILLO, THE PICTURE APPEARS TO BE DIFFERENT.
IF YOU LOOK AT THIS THREE-DIMENSIONAL RECONSTRUCTION
OF WILLO'S C.T. SCAN,
WE CAN SEE RIGHT HERE
THAT THE 2 VENTRICLES ARE EASY TO IDENTIFY.
Narrator: HIGHLIGHTED AT THE BOTTOM OF THE PICTURE.
THEN LOOK UP ABOVE THE HEART BASE.
WE SEE THIS CORRUGATED STRUCTURE.
THAT'S THE SINGLE AORTA.
Narrator: IF THIS A SINGLE AORTA,
IT WOULD BE REMARKABLE
BECAUSE IT WOULD SHOW THAT THIS DINOSAUR'S HEART
HAD THE POTENTIAL TO POWER IT FOR THE MARATHON
AS WELL AS THE SPRINT, UNLIKE THE CROCODILES.
APPARENTLY THIS LITTLE DINOSAUR HAD A HEART
THAT WAS MORE LIKE A BIRD OR A MAMMAL
THAN LIKE A CROCODILE.
Narrator: THIS INTRIGUING FOSSIL IS STILL UNDER SCRUTINY,
BUT IF CONFIRMED, WILLO'S HEART
WILL GIVE A NEW, MORE ENERGETIC LOOK TO THE DINOSAURS.
IF THIS DINOSAUR HAD A HEART THAT LOOKS ADVANCED,
THEN THAT IMPLIES THAT IT ALSO HAD A HIGH METABOLIC RATE,
AND NOW INSTEAD THERE IS AMPLE REASON TO THINK OF THESE
AS RATHER HIGH-ENERGY, ACTIVE ANIMALS.
Narrator: WITH THE BODY OF A BIRD,
BUT BEING 10 METERS LONG,
AL COULD HAVE RUN AT SPEEDS OF UP TO 30 KILOMETERS PER HOUR.
IF THERE WAS ANY DOUBT WHETHER AL LED AN ACTIVE LIFE,
THERE IS CONCLUSIVE EVIDENCE WRITTEN IN HIS VERY BONES.
REBECCA HANNA KNOWS BIG AL BETTER THAN ANYONE.
SHE SPENT MUCH OF THE LAST 8 YEARS
EXAMINING EVERY INCH OF HIS SKELETON,
AND HER SEARCH HAS REVEALED THAT HE HAD
OVER 19 ABNORMAL OR INJURED BONES IN HIS BODY.
IT SEEMS THAT THIS IS AN UNUSUALLY HIGH NUMBER
FOR AN ALLOSAUR TO HAVE, IN COMPARISON
TO OTHER ALLOSAURS THAT I'VE LOOKED AT.
NOW, WHAT THIS MAY MEAN OR SUGGEST
IS THAT BIG AL MAY HAVE BEEN
MORE AGGRESSIVE THAN OTHER ALLOSAURS,
OR HE MAY HAVE ACTUALLY
BEEN JUST SORT OF CLUMSY.
Narrator: CLUMSY OR BRAVE, AL'S BONES REVEAL
A CHRONOLOGY OF ACCIDENTS IN THE LATTER YEARS OF HIS LIFE
THAT MADE HIM FAMOUS
AS THE DINOSAUR WHO LIVED FAST AND DIED YOUNG.
Hanna: BIG AL RECEIVED AN INJURY
TO THIS SECTION OF HIS TAIL
PROBABLY 1 TO 2 YEARS BEFORE HE DIED,
AND THE WAY WE CAN TELL THAT
IS THE AMOUNT OF REHEALING ON THE BONE.
THIS BONE WAS BROKEN IN HALF
AND THEN HEALED BACK TOGETHER,
SO THERE IS A LITTLE BIT OF A BULGE THERE
WHERE YOU CAN SEE WHERE IT WAS BROKEN
AND HEALED BACK TOGETHER.
BUT FOR THE MOST PART,
IT'S LOOKING MORE LIKE THE ORIGINAL BONE.
Narrator: IT LOOKS LIKE AL TOOK A NASTY KNOCK.
BUT IT OBVIOUSLY DIDN'T SLOW HIM DOWN,
BECAUSE REBECCA HANNA FOUND OUT
THAT HE WAS SHORTLY IN TROUBLE AGAIN.
WHEN I WAS FIRST STUDYING THIS BONE
FROM THE RIGHT HAND OF BIG AL,
IT WAS UNCLEAR
WHAT HAD CAUSED IT TO LOOK THIS WAY.
I KNEW IT WAS ABNORMAL FOR SOME REASON.
SO WHAT I DECIDED TO DO
WAS TO CUT A VERY THIN SECTION
TO LOOK AT THE ACTUAL BONE MICROSTRUCTURES.
WHAT I DISCOVERED
WAS THAT THIS BONE WAS ACTUALLY FRACTURED
RIGHT ALONG ITS LENGTH,
CALLED A LONGITUDINAL FRACTURE,
AND WE CAN SEE THAT UNDER THE MICROSCOPE.
Narrator: THE BREAK RUNS DIAGONALLY
THROUGH THIS CROSS SECTION.
BELOW IT, ROWS OF NORMAL BONE LIE TIGHTLY PACKED TOGETHER,
BUT ABOVE IT, THE BONE IS MORE LOOSELY WOVEN--
A SURE SIGN IT'S TRYING TO MEND.
THE BONE WAS BROKEN BY SOME SORT OF TWISTING FORCE,
AND THIS BONE WAS BROKEN
AFTER THE TAILBONE INJURY EVENT,
AND WE KNOW THAT BASED ON BONE MICROSTRUCTURE
AND ALSO JUST THE LOOK OF THE BONE.
Narrator: IT DIDN'T STOP THERE.
AL WENT ON TO BREAK 4 RIBS
AND HURT HIS BACKBONE, SHOULDER, AND PELVIS.
EVEN WITH ALL THESE INJURIES,
AL HAD TO KEEP GOING.
BUT EVENTUALLY SOMETHING HAPPENED TO HIM
THAT WOULD THREATEN HIS LIFE ALTOGETHER.
IT COULD HAVE BEEN JUST A CARELESS TRIP,
BUT IT COST HIM DEARLY
AND PROBABLY SPELLED THE BEGINNING OF THE END.
AL'S LEFT FOOT LOOKS NORMAL,
BUT THERE IS A HUGE AMOUNT
OF ABNORMAL BONE GROWTH IN THE RIGHT FOOT.
Hanna: THIS IS THE MOST SERIOUS PROBLEM
BIG AL HAD.
IT'S IN THE RIGHT FOOT, THE THIRD TOE.
THE INFECTION IN THIS TOE BONE
WAS VERY LONG-LIVED,
AND SO IT'S PROBABLY NOT SOMETHING THAT HAPPENED
RIGHT AT THE TIME OF DEATH.
BIG AL PROBABLY WOULD HAVE HAD TO HAVE BEEN ALIVE
WITH THIS INFECTION IN THE BONE
FOR AT LEAST 6 MONTHS TO A YEAR.
AND IT PROBABLY WOULD HAVE CAUSED THIS ANIMAL
A GREAT DEAL OF PAIN AND CAUSED IT TO LIMP,
BECAUSE YOU CAN IMAGINE WITH THIS TYPE OF INFLAMMATION
WHEN THE BONE IS USUALLY ABOUT THAT WIDE,
IT WOULD HAVE ACTUALLY BEEN RUBBING
AGAINST THESE OTHER 2 TOES.
Narrator: ALTHOUGH AL'S INJURIES DIDN'T KILL HIM INSTANTLY,
THEY STOPPED HIM HUNTING
AND LEFT HIM STRUGGLING TO FIND FOOD AND WATER.
IF AT THIS POINT, A DROUGHT HIT,
IT WOULD HAVE BEEN ENOUGH TO TIP HIM OVER THE EDGE.
145 MILLION YEARS LATER,
IT SEEMS ENOUGH CLUES WERE LEFT
TO PIECE TOGETHER THE LAST FEW HOURS OF AL'S LIFE.
BIG AL WAS FOUND WHEN THE TAILBONES HERE
WERE ON THE EDGE OF THE HILLSIDE.
AND AS THEY EXCAVATED FURTHER INTO THE HILL,
THEY FOUND MORE TAILBONES
WHICH CONTINUED ON AND CONNECTED WITH THE HIPS,
THE REST OF THE BACKBONE, AND EVEN THE SKULL.
SO THIS IS A DECAY POSTURE
THAT OCCURS WHEN THE LIGAMENTS
THAT RUN ALONG THE SPINE
DRY OUT AND DECAY,
ARCHING THE HEAD AND TAIL BACK OVER THE LEGS
TOWARDS EACH OTHER.
WHAT THIS TELLS US
IS THAT THE ANIMAL DIED
AND LAID OUT FOR SOME PERIOD OF TIME,
AND WE'VE ESTIMATED
THAT BIG AL LAID OUT ON THIS SURFACE
FOR A PERIOD OF A COUPLE OF MONTHS.
IT'S POSSIBLE THAT BIG AL
CAME TO THIS RIVER CHANNEL IN SEARCH OF WATER
AND USUALLY IT HAD WATER IN IT
AND WAS A DRINKING SOURCE FOR HIM,
BUT AT THIS POINT IN HIS LIFE, IT WAS DRY,
HE WAS AFRAID TO LEAVE IT.
MAYBE HE WAS SO INJURED,
HE COULDN'T GO GREAT DISTANCES FOR WATER
AND WAS HOPING THAT EVENTUALLY
WATER WOULD FLOW DOWN HERE.
AND HE MAY HAVE ACTUALLY DIED OF THIRST.
[THUNDER RUMBLING]
Narrator: WHEN WATER FINALLY CAME, IT WAS TOO LATE FOR AL.
BUT IRONICALLY THE FLOOD SEDIMENTS
THAT GENTLY BURIED HIM
INSURED THAT HIS BONES WERE BEAUTIFULLY PRESERVED
SO THAT 145 MILLION YEARS LATER,
NO ONE WOULD FORGET HIM.
CAPTIONING MADE POSSIBLE BY BBC WORLDWIDE AMERICAS
CAPTIONED BY THE NATIONAL CAPTIONING INSTITUTE --www.ncicap.org--
Man: ?? OH, HOW I'VE LOVED YOU ??
?? SINCE THE DAY YOU FIRST TOLD ME YOUR NAME ??
?? YES ??
?? I HAVE LOVED YOU ??
?? THINKING YOU ??
?? ALL THE WHILE ??
?? FELT THE SAME ??
?? OH, HOW I'VE LOVED YOU ??
[WOMAN SCREAMS]
[BIG AL ROARS]