♪♪ Attenborough: I'm on
the south coast of England in what is known
as the Jurassic Coast. 150 million years ago, the land was ruled by dinosaurs. But the oceans were dominated
by a mysterious sea monster known as a pliosaur. Its remains are very rare, but some have just
been discovered in the cliffs behind me. This could be
one of the largest, best-preserved pliosaur skulls
ever found. And now working with scientists,
we can uncover more about this prehistoric giant
than ever before. What an extraordinary,
terrifying thing. Could this be the greatest
Jurassic predator... ...that ever lived? ♪♪ [ Seabirds calling ] ♪♪ Attenborough: Britain has
a wealth of fossil science, but perhaps none are quite
so famous as this, the Jurassic Coast. I've been collecting fossils
since I was a boy, and I haven't yet
got tired of it. These days, you're supposed
to wear glasses for safety. And if you would know
a locality, you would begin to recognize the sort of block
that might contain a fossil. And this rock was split earlier
to make it easier to show you. And if I can hit it quite hard
about there... What about that? Is anything more beautiful
than that? Fantastic. Finding even the smallest
fossils is a thrill, but discovering
something much larger can be an unforgettable moment. And that is exactly what
happened to a fossil enthusiast who was walking along a beach
near Kimmeridge Bay in Southwest England
one morning. Man: I just found something
quite extraordinary. It's the jaw
of a massive pliosaur. It's enormous. It's a massive pliosaur; it's
the best fossil I've ever found. It must have just come out of
the cliffs up there somewhere. Attenborough:
Renowned fossil expert Dr. Steve Etches
is called in, and he knows immediately
that it is hugely significant. Etches:
Look, look at those teeth. That's a tooth there, look. Let's have a look at the front. You can walk along here
for hundred of times and not find anything and then occasionally,
you'll hit the jackpot. Attenborough: And this certainly
is the jackpot. It's the snout of
an enormous pliosaur skull. And Steve suspects that
the rest of the head might still be imbedded
in the cliff above. But he needs to work fast
before the whole thing tumbles into the sea
and is lost forever. So he quickly gathers a team
of experts, including fellow fossil hunter
Chris Moore. Moore:
It's day one of the dig. Steve and team and diggers
are up on the cliffs, and they're putting a net down
to stop any loose rock rolling down and hitting us. And then we'll go down
and expose the skull. [ Drill pounding ] Attenborough:
Steve and Chris have worked together
for decades, but this is the biggest
challenge they have ever faced. The skull is nearly 40 feet up
from the base of the cliff... ...and lying upside down
in a horizontal position. Its full length
is not yet known, but Steve believes
it could be over 6 feet long. But how did the fossil
end up here? Well, these rocks were once mud
on the seafloor... ...in which the remains
of prehistoric marine creatures were buried. Over millions of years,
the continents shifted... the seas receded... and today, as these
cliffs erode, fossilized skeletons
are revealed. Etches:
The jaw is there and the idea is to actually cut
this down vertically and then we form a platform
where the fossil is. ♪♪ Attenborough: I've known Chris
and Steve for many years, and I can't wait to join them and find out
how they're getting on. ♪♪ Moore:
Here we've got a live feed, actually digging halfway up
the cliff face. What's happened so far --
the tip of the snout has already come out
and been recovered, so the rest of it
is going into the cliff. Attenborough: What exactly
are they doing there? Moore: At the moment, they are
using tinfoil to try and protect
the exposed piece of jaw... Attenborough: In case something
falls on it and breaks it. Moore: Yeah, yeah,
and then they're also using Superglue to consolidate
the crumbly teeth and parts that have
been weathered over millenniums. Attenborough: And they are
hanging by the ropes there. Moore: Yes. Pretty much
in the center of the cliff. Attenborough: Dear me.
Pretty dangerous stuff, this. Moore:
Yeah, yeah, it really is. After you've worked there
for a few hours, it becomes a bit more natural and you concentrate
on the actual digging. Attenborough:
You must be pretty sure that there is something there to put this amount of effort
into it, really. Moore: Oh, positive
there is something there. It's beautiful.
It's a beautiful specimen. -Attenborough: Is it?
-Moore: Yeah, amazing. Attenborough: But what can
this spectacular find reveal about the lives of these
mysterious sea creatures and the world they inhabited? In the late Jurassic, Europe was
an archipelago of islands, much closer to the equator
than it is today. Its seas were warm,
shallow and teeming with life. And in these waters
underneath my feet lurked the ultimate marine
predator, the pliosaur. ♪♪ ♪♪ Unlike dinosaurs
that lived on land, these colossal marine reptiles spent their whole lives
in the ocean. Thought to have been
over 30 feet in length, similar to a double-decker bus. They had long, broad flippers, short, strong necks, huge heads... and enormous jaws. But there's still a lot
we don't know about these great sea monsters, which is why this new discovery
is so important. Steve believes
that the entire pliosaur may still be inside the cliff, but it's the skull on which
he is concentrating. A skull can reveal more
about an animal than any other part
of its skeleton. ♪♪ Finding a complete specimen
is rare, but it can tell us a great deal
about how the animal lived. ♪♪ [ Drill pounding ] Moore:
It's quite hot and thirsty work. Attenborough: Steve and Chris think they will
have about three weeks to dig the fossil out before
the storms of late summer come. Etches:
This is a learning curve. I thought, stupidly,
that it wouldn't be quite as hard as this. We're probably over a meter in. There's the skull
there just behind me. It's up to us now to get it out
without any damage. Attenborough: If the skull is
successfully extracted, it will be taken to the Etches Collection Museum
in Kimmeridge, which was founded by Steve
in 2016 and now contains
nearly 3,000 fossils from the Jurassic period. This was where
the pliosaur snout was brought to be assessed. And I've come here to learn
what Steve has found out so far. What an extraordinary,
terrifying thing. Huge teeth. Etches: They are.
They're massive. These big, fang-like teeth
that come up. Attenborough:
And they interlock. Etches: Yes, they do. Attenborough: So how far
do these teeth extend? Etches:
They come right up here. Attenborough: Is that
characteristic of this? Etches: Yes, typical pliosaur. Trihedral teeth,
they're sort of... They got two sharp,
cutting edges and then a flat face
on the inside. Attenborough:
And they must have used that to rip apart ichthyosaurs. Etches: Ichthyosaurs,
plesiosaurus as well. We've got evidence in the museum
because they've got sub-triangular teeth,
when they bite in the bone, they leave
a very distinctive tooth hole. Attenborough:
Steve's collection contains a limb bone of a plesiosaur, another large marine reptile,
which has bite marks on it that exactly match the size
and shape of pliosaur teeth. What a godsend it is that
the teeth are triangular so that you are able
to then identify prey... -Etches: Oh, yeah.
-Attenborough: ...just as much as you can identify
the predator. Etches: That's right. Attenborough:
That's pretty unusual to find teeth in position.
-Etches: It is. This is the first pliosaur
I've ever seen with actually closed jaws. Attenborough:
It is extraordinary. It is quite extraordinary. And there is another
unusual feature on this snout. Etches: So let me show you
the other side. I'll spin it 'round. Attenborough: Oh, gosh,
there's a lot of stuff here. Etches: Oh, yeah. Attenborough: And these,
these holes here... Etches: Why I think
these are sensory pits, they're all on the snout. If you look at them, they go... See, they strike back in
at an angle, you know? They're sensory pits
for picking up his prey, I'm pretty sure. Pretty impressive beast. Attenborough: Astonishing. But exactly how did
these sensory pits help our pliosaur to hunt? These days, we have equipment that can help us answer
such a question. We take the snout to
the University of Southampton, which has some of the most
powerful CT scanners in the UK. Once the snout has been scanned, paleobiologist
Dr. Neil Gostling looks for clues
about the sensory abilities of our pliosaur. So what does this scan tell us? Gostling:
I've taken the CT data, and we can rack our way
through this stack of images and we can see
all of those internal structures which otherwise wouldn't have
been revealed to us. And there were some things,
which are, I think, quite exciting. We've got these little
structures in red and I had to do these each one,
slice by slice, dot by dot, because there's lots of
imperfections and holes in it, but these are continuous. And I think these are
blood vessels, little branching blood vessels. Attenborough: Oh, come on. You're really telling me
this block of stone can show blood vessels? Gostling: Yes, and what I think
we've got here are actually branches
of the trigeminal nerve and these are the sensory
nerves in your face that allow you to feel fingers dancing over your cheeks
and what have you. But if you're in water and
you've got these sensory pits, you can detect changes
in pressure. That's going to give you
an advantage in what might be murky water where your eyes
aren't working so well, so you can always be sure that you're going to
catch your next meal. Attenborough: Fantastic. Knowing how these senses worked,
we can start to build up a picture
of how our pliosaur hunted. Its prey... ichthyosaurs --
reptiles much the same shape as a modern dolphin
and similarly fast and agile. The sensory pits found
on our pliosaur's snout may have acted
like miniature pressure pads, detecting the turbulence
produced by ichthyosaurs as they swam through deep water. In effect, our pliosaur was able
to stalk its prey even in the darkest depths
just by using its skin. ♪♪ There are animals today that
have similar sensory systems. Crocodiles have over
9,000 pressure receptors, which are concentrated
on their snouts, each one of which is thought
to be 10 times more sensitive
than a human's fingertip. Two weeks into the dig
and the work is proving to be even harder
than anyone was expecting. ♪♪ Moore: Let me throw
this big chunk away. Attenborough: But at last,
there's a breakthrough. Moore: There is something
under there, which is huge. Here you've got the jaw showing and this one
is heading back this way. It's gonna be
the underneath of the skull. Etches:
There's a vertebrae there; there's another vertebrae there. Attenborough:
Finding these bones confirms that the entire skull
really is inside the cliff. Moore: It's nice to actually
see something. You feel like you've been
rewarded a bit. Etches: What Alex is doing here
is chipping out a loose tooth. Hang on, that's a crown.
-Alex: Yeah. Etches: Oh, that's interesting. Yeah, keep going. This is part of the root and there is
a pulp cavity there. That tooth would be probably
about 10 inches long. [ Thunder rumbling ] Moore: Oh, the thunder is
coming. Oh, look at that. Attenborough: Just as the dig is revealing
further exciting finds... -Man: Come on, guys.
-Etches: Yeah, come on. Man:
Because we've got a lot to do. We've got to get you all up. Attenborough: ...conditions
become treacherous and the rope safety team
decides that it's too dangerous
to continue. Etches: Now it's rained,
this lithified mudstone has turned to like a slippery
clay; it's lethal. There's certainly no way now,
with us stopping now, that we're gonna get it done
in those days left. Attenborough:
The weather may be against them, but finding a pliosaur tooth
is a real stroke of luck. It could also help us understand more about the type of prey
our sea monster could eat. The teeth of marine
predators vary according to their function. Some are used to shred
and slice. Others to grasp or crush. So what do we know about
the teeth of our pliosaur? [ Machine beeping ] Back in Southampton,
the investigation of the pliosaur snout has revealed something
even more intriguing. These teeth are extraordinarily
well preserved, aren't they? Is there new information
that we can get from this? Gostling:
Well, from the CT scan, if we take it back again
so we can expose the teeth, these are large pointed teeth and these are really
well adapted for grasping slippery fish, but this is on an order
of magnitude larger, which would have allowed it
to eat all sorts of prey that are swimming around in the ancient
Kimmeridge Bay of the time. Attenborough: Were the teeth
permanent or were they replaced? Gostling:
As we move it back through, we can see that we've got
individual teeth almost all the way along. However, in one place,
we've got this little tooth here and this is a replacement tooth. The thing that most animals
die of is that their teeth
have worn out and they can't feed anymore. And if you are a large predator,
and you are catching large prey, you might lose teeth
relatively frequently. Well, this isn't such an issue
if you can replace your teeth multiple times
throughout your life. Attenborough: Not only
were its teeth replaceable, but they were also
shaped differently -- long and sharp
towards the front of its jaws, more hook-like at the back. This deadly combination
meant that pliosaurs could feed
in a variety of ways, from grabbing large sharks
and squid to gripping smaller,
slippery fish. ♪♪ Three weeks into the dig,
the weather is holding. And now the biggest question
for Steve and Chris is how to lift
the skull off the cliff. Etches:
I reckon we take out a big slab. -Moore: One piece?
-Etches: Cut it underneath. -Moore: What, cut it underneath?
-Etches: Yeah. -Moore: All the way through.
-Etches: Yeah. I can't see any other way
of doing it. If we do it any other way,
it's gonna just crumble up. What do you think? Moore: I think I'm going home
and not coming back. [ Laughs ] Attenborough:
Luckily for Steve and Chris, friend and local farmer
Robert Vernicom has been devising a solution. He's building a crate which will be lowered
down the cliff into which the skull
will be maneuvered and then hauled up to the top. Vernicom: The theory is that
whatever angle the skids are as it comes up the cliff, the box stays level
to protect the fossil because we're trying to keep
the fossil as level as possible. Attenborough: The big day
finally arrives, and a local army of helpers
is assembled for this crucial stage
of the operation. And Steve is feeling
the pressure. Etches: Well,
the best in the world, it looks like
it's all gonna function, but the risk is immense. You know,
what happens if it just actually turned
on its side? There's a lot of things
that could go wrong, so it's a risky sort of time. Attenborough:
This is one of the largest and best-preserved
pliosaur skulls ever found. So the stakes are
very high indeed. [ Indistinct conversations ] ♪♪ Etches: When it comes down,
we've got to get that aligned and we got to get that jaw,
that skull, inside that box. Moore: And we've got to be
really careful. That sled has got a metal bar and as it comes down,
it doesn't hit the nose. Etches: No one has ever done
this before, ever. Moore:
Extracting a giant skull halfway down a cliff face? Attenborough: The crate
must be lowered into position with great precision if the
skull is not to be damaged. Moore: The position
it's coming down in, it's almost -- it's gonna
glance the side of the skull. Woman: Stop! -Man on radio:<i> Stop!</i>
-Woman: Stop. Moore: So somehow we've got
to manually try and move the whole sled over. Etches:<i> I think
we can afford to do</i> <i> 30 centimeters lower
and no more.</i> Attenborough: After weeks
of backbreaking work, emotions are running high. -Etches: Down!
-Moore: Quick, quicker! This moment is really fraught. We've got one skid just about
glancing side of the skull and we've got to try
and pull it out now to get it over the edge. Vernicom: Very slowly. 6 inches. Attenborough:
One clumsy move and the skull could be smashed. ♪♪ Etches: Oh, my... Moore: Pull, pull again. Missed it.
We've done it. Vernicom: Stop, stop! Etches:
It's all pretty stressful. Every part of this is really,
really stressful. Moore: After quite a few hours,
we have got it into position. We haven't knocked the end
of the snout off, so far, and it's all ready to go. Attenborough: But the next stage
looks even more risky. Man:
Just retreat from the edge, and we're going
up the ropes now. Moore: Al and Steve are gonna
go up to the hole and attach the winch
and then start the process of slowly dragging it
into the box. Attenborough: Shifting a fossil
that weighs over half a ton is really dangerous. Moore: Move in. Very nervous
and it's very tense, so let's see how it goes. ♪♪ Etches: Ooh. Go on. That's better. Man: Whoa! Right, I think slide
it straight in. Moore: Steve, is it okay?
Has it come off okay? Etches:
Well, we're losing a bit of it, but we can't help it, mate. Go on. Go on. Now it's on it.
There you go. Alex: Good, that will do. That's well in. Etches:<i>
It's right in the case now.</i> Vernicom: Yay, the fossil's in. Woman: Brilliant. Brilliant.
We're all cheering here. Well done, well done. Vernicom: Well done, everybody. Moore: Right. Well done.
Brilliant. We've overcome a lot of problems
to get this far and we've done it
by the skin of our teeth. Attenborough: The skull
at last is in the crate. Etches:<i>
Take up the slack again.</i> Attenborough:
But shifting it carelessly, let alone dropping it,
could be disastrous. Vernicom: Come over a bit. So there will be
six ropes coming up to be able to lift it
and hold it steady... hopefully. With the tide coming in
and the sun setting, we could cut at any point. Okay, right. Whoa! Whoa, whoa, whoa. Attenborough:
Finally, the skull is safe. -Moore: Brilliant, Rob.
-Vernicom: Well done. Moore: Well done. It's amazing. Etches: It's a dream come true
and I tell you what, I don't think anyone
in their right would ever believe
we could have ever done it. Three weeks ago, it was buried
in a cliff face. Found a top 13 predator and now we're bringing it back
to life and this will be one of the best
that's ever been found. Moore: Good on you. Etches: Oh, none of that. Get off, you little devils. God, dear, oh, dear! It's out.
The next stage starts. ♪♪ Attenborough: The skull is
transported to Steve's workshop. Man: Ready, go. Right up. Moore: Oh, my God. Etches: The mudstone has cracked
and dried. Of course what it's done is just
cracked the bone as well. Jeepers creepers. Moore: You'll be fine. Etches: Oh, yeah. Attenborough:
The painstaking task of removing the stone
from around the skull so that it can be examined
in detail... ...can at last begin. After the heavy work of the dig, this stage requires
a delicate touch. First, Steve removes the rocks
around in the fossil so that the fragile areas
of the skull can be strengthened. Then, using
an air-abrasion tool, he starts work to reveal
the more intricate details about the anatomy
of this extraordinary animal. This giant sea monster,
after 150 million years, finally begins to emerge
from the rock. And I have the privilege
of coming to see this whole skull
for the first time. So here it is. And it's enormous. I am meeting
Dr. Judyth Sassoon, a paleontologist who has
studied pliosaur specimens for decades. Does it still take your breath
away as it takes mine? Sassoon: It is the most
astonishing specimen, David. I'm very pleased to be part
of the work on it. Attenborough: What insights can
Judyth give us into the life of this ancient monster? How's it coming along? What sort of detail you can get
from this, which you never knew before? Sassoon: Steve Etches
has been working on it now for several months and has made
some fabulous progress. We're seeing,
as it's being prepared, gradually more and more detail
being revealed. So far we have some information
about its senses. Attenborough: Really?
Was their eyesight good? Sassoon:
There are indications that, in fact,
it could have been. The eyes themselves were
quite important for this animal. One of the reasons
is the position itself. The eyes are on the side
of the head, more or less in the middle,
so not too high and not too low. Attenborough: This important
feature of the skull may suggest how our pliosaur
hunted in the open ocean. The position of the eyes
in living animals varies according to the way
in which they hunt. Dolphins are pursuit hunters. Their eyes are placed
on the side of their heads giving them panoramic vision... ...helping them to attack
their prey more accurately. Ambush predators,
such as crocodiles, have eyes higher up
on their heads. So they can remain
just below the surface with only their eyes above water
and judge when to attack. ♪♪ Our pliosaur seems to have
had something in between... ...with an eye position
that not only enabled it to pursue prey through water
with accuracy but alternatively surprise it
by attacking from below. And there is another
remarkable feature, which could tell us more about where our sea monster
may have hunted. Sassoon: We talked about eyes, there is also another
interesting structure, which is the parietal eye. In many reptiles,
this still exists. When it is present
in terrestrial animals, it has a full eye structure
like the lateral eyes and is light-sensitive. Attenborough: The parietal eye
on the top of the head is something of a puzzle. It's known as a third eye and is still found
in a few living species. It apparently helps an animal
to regulate its body clock. ♪♪ The pliosaur's parietal eye
is thought to have had a lens, a cornea and a retina. Although its exact function
is unclear, it may have enabled
our sea monster to gauge which way was up
when swimming at depth and potentially navigate
deeper hunting grounds. What other questions would
you have wished the skull to provide answers for? Sassoon: I've already made some
measurements on this animal and the proportions do seem
to be different from other pliosaurs
that we know. The skull is quite long-snouted, but the position of the nose
and the eye and also of the crest suggest that it is something else,
something new. Attenborough:
A new species of pliosaur? Sassoon: Of pliosaur. -Attenborough: A new species?
-Sassoon: Yes. Attenborough: Really? Sassoon: I think it could be.
Yes. Attenborough: The revelation
that our pliosaur could be a new species
is truly exciting. ♪♪ There are only eight recognized
species of pliosaur and this skull is certain
to provide new scientific data on the evolution of these
mysterious marine reptiles. I have to say,
you take my breath away. The detail
which you can deduce, it is mind-blowing, I think. I mean, that's
what paleontology is about. I used to think it was just
a question of finding a fossil and digging it out
and saying how nice it was. You've made it sound
rather different. ♪♪ In recent decades,
huge advances have been made in our ability
to study prehistoric animals. And we can now investigate the
predator power of our pliosaur in more detail than ever before. Paleobiologist Dr. Andre Rowe
is a world-leading expert in 3D visualization of fossils. Rowe: The first thoughts -- this thing
is absolutely massive. And I will also add that the level
of preservation is amazing. This is actually
a one in a million, maybe one in a billion
type specimen here. Attenborough:
Using the latest technology, Andre is carrying out the world's first surface scan
of a pliosaur skull. Rowe: So right now, we're
capturing basically hundreds of thousands of images
all at once. The end result is a really
nice-looking 3D model. I think we'll be able to unlock
a lot of mysteries about what these sea monsters
were doing and I'm really excited
to see where it takes us. Attenborough: Once the scan
has been finalized, I meet Andre at the University
of Bristol to discuss his findings. Has he seen anything
at the skull structure that shows our sea monster had the power of
a truly deadly predator? Rowe: There are some massive
openings back here, along the jaw line, and that's good for muscles
to attach and bulge out. Attenborough:
There would have been a muscle running through there. Rowe: Yes, we have the pterygoid
muscle group, which is in a lot
of big dinosaurs. That's integral to having
a really strong bite. We've hypothesized that
this particular pliosaur is kind of the apex predator in the Jurassic ecosystems
it was living in. Attenborough: Now, this is,
of course, not a dinosaur, but neither is it
a modern reptile, but it does look a lot
like a crocodile, doesn't it? Rowe: Yes, well,
we have this process called convergent evolution, where a lot of animals will
adapt a similar-shaped skull or similar trends throughout
their evolutionary history even if they're not
closely related. That's because having
those similarities can give you a lot
of advantages, but in terms of this pliosaur, it's got that kind of
streamlined skull that's kind of broad
on the back. It's very triangular-shaped. I think that it's good
for swimming quickly and ambushing prey. Attenborough: Does the skull
give you any information about what animal of prey
might have been? Rowe: The animal would have been
so massive that I think it would have
been able to prey effectively on anything that was unfortunate
enough to be in its space. A popular hypothesis
is that these animals were actually ripping off
the limbs of other animals and disabled them
from swimming away and then kind of going in
for the kill. Attenborough:
So this is a top predator? Rowe: Yes, I have very little
doubt just judging from how massive that skull is. I don't see what could have
possibly hurt it. Attenborough:
What size is that actually? Rowe: So the actual skull itself
comes in at about 6.5 feet,
about 6'6". Attenborough:
So it's longer than I am tall? Rowe: Yes, it's quite a big boy
and that's just the skull. Attenborough: The dimensions
of a fossilized skull enable us to estimate the overall size of an animal
when it was alive. And based on Andre's
measurements, our pliosaur could have been up
to an astounding 40 feet long. Rowe:
Just on the sheer size of it, just from looking at this animal and how big those
pterygoid muscles would have been at the back
of the jaw, the animal would have delivered
a devastating bite, no doubt. Attenborough:
A powerful bite is vital to the success
of any marine predator. Scientists are able to estimate how much force an animal can
exert when biting into its prey. And great white sharks have one
of the strongest bites... at around 10,000 newtons. But how do you work out
the bite force of a creature that became extinct
millions of years ago? Professor Emily Rayfield is
a world-renowned paleontologist who specializes
in skeletal mechanics. Using the model created
by Andre, Emily has assessed
the bite force of our pliosaur. Rayfield:
So this is a 3D print, a model, it's not full size,
though it's just over a third of the size
of the actual animal. These large openings
are the spaces in the skull, which would have been filled
with jaw-closing muscles. Attenborough: So you can
estimate the force of the bite from the size of those muscles?
-Rayfield: Exactly, yeah. We can get an estimate of that
from here. We know that muscles
of a certain -- a certain size, a certain area, are capable of generating
a certain amount of force. Saltwater crocodiles have got the largest-ever
bite force measured, and they're up
to about 16,000 newtons. Attenborough: And these? Rayfield: So our pliosaur here, from the estimations
that we've made, has a bit force that's about
twice the size of that -- the larger saltwater crocodile
that's ever been measured. And it's in the region
of around 32,000 newtons. Attenborough: So this is the
most powerful biter in the sea that ever has been
or that we know of. Rayfield: That we know of,
absolutely, yes, definitely. If you're looking at
kind of statistics in terms of car-biting metrics, I'm pretty sure it could
probably bite through a car. -Attenborough:
So it's a monster. Rayfield: Absolutely. [ Both laughing ] ♪♪ Attenborough: The evidence
gathered from the skull so far suggests that this pliosaur
had the jaws, teeth and senses
of a highly successful hunter. Its long stout, short neck
and streamlined skull enable it to move easily
through the water. But what else helped
our enormous sea monster to power through
the Jurassic seas fast enough to catch its prey? Pliosaurs were unique
in the natural world as they had four almost
identical wing-like flippers. How pliosaurs used their
flippers has been debated by paleontologists for decades. Some believe that they moved
using a sort of rowing stroke, like oars in a boat. While others argued they used
a flight stroke, seen in animals
such as sea turtles. But in recent years,
scientists have been able to use computer modelling to finally
solve this mystery. And it appears that these
giant sea monsters swam in a way that is surprisingly similar to
a very different type of animal, one that is alive today. ♪♪ Whoa. Penguins may appear
somewhat clumsy as they waddle around on land. But once they're in the water,
they move very differently. These are Humboldt penguins
and they're excellent swimmers. Their streamlined body shape
and their oily feathers enable them to reach
astonishing speeds of up to 30 miles an hour. But a key factor
behind penguins' speed are their flippers, which underwater, act like
propellers driving them forward and increasing their speed
dramatically. In slow motion, you can see
that the penguins are using a lift-based
underwater flight movement, twisting their wings
as they flap and propelling
themselves forward on the upstroke as well
as the downstroke. As strange as it may seem,
it's thought that pliosaurs would have moved
in a very similar way. But, of course, pliosaurs
were enormous and most large animals
are relatively slow-moving. So as an apex predator, how could this huge creature
maneuver itself fast enough to catch its prey? To find out, I've come to
the hydrodynamic laboratory at Imperial College London
where Dr. Luke Muscutt is studying
the locomotion of pliosaurs using a rather unusual
research tool. How did you first
become interested in the way that pliosaurs swam? Muscutt: The only animal
that we know of that has four large flippers. So the question is,
how did they use them? The fossils of the pliosaur show that the flippers were
very much like wings. So what I found was that
the hind flipper can actually operate at a much higher thrust
and a much higher efficiency because it's utilizing the wake
of the flipper in front of it. We can see a similar effect
in the flight of migrating birds,
such as geese. Attenborough: When geese are
flying in formation, each bird benefits
from the uplift created
by the one in front of it so that they fly
in a very energy-efficient way. Muscutt: So you can think
of the pliosaur as almost two birds,
one flying behind the other, and the back one is benefiting
from the one in front. Attenborough: That's
an extraordinary parallel, yes. Muscutt: The hind flipper has increases in thrust
and efficiency of up to 40%.
-Attenborough: Ahh. Muscutt: So this would have
increased the swimming speed that pliosaurs would have been
able to achieve and increase the number of
different things it could eat. Attenborough: To take
his research to the next level, Luke has built a robot to study the swimming pattern
of pliosaurs more accurately
than ever before. So what more information
do you think you can get from this model? Muscutt: This robot enables me
to test the complete animal. How fast something can move
is an absolutely critical part of what that animal is and it tells us what animals
it could have eaten, how far it might have
been able to travel, all sorts of questions come back
down to its locomotion ability. Attenborough:
Have you estimated a speed that this might produce? Muscutt: Well, I've only
finished building this yesterday so...
-Attenborough: Oh, really? Muscutt: So far,
I haven't actually ran the experiments yet. If you would like to have a go,
you're more than welcome to... Attenborough: Yes.
Oh, show me. Muscutt: So if you just move
this joystick sort of upwards further... So this is how the pliosaur
would have swam. The flippers move
primarily up and down. It's much more like
a bird flies. Attenborough: Luke and his team
set up the robot for a test swim, and they entrust me
with its maiden voyage. Muscutt: If you would like
to take the control... There we are. It's off. Attenborough: I suppose --
actually that's only a model -- but if it was full size,
it would be going quite fast. Muscutt: Indeed. You can just imagine it chasing
after a smaller ichthyosaur. Attenborough:
Luke's research is so new, it's yet to be published. But it's helping to provide
a new perspective on these extraordinary animals. ♪♪ Large marine predators
like minke whales and orcas can swim at great speed
through the ocean. What speed might our pliosaur,
with its four flippers, have been capable of? Estimates suggest that they
could have accelerated up to 30 miles an hour, making them one of the fastest
animals in the Jurassic seas. ♪♪ This skull is not only
helping us to understand more about the lives
of these giant sea monsters but also allows scientists
like Dr. Andre Rowe to visualize the Jurassic world
as never before. So often, I've been involved
in looking at fossil studies and the skull, unless the skull
is there, you are really missing an awful lot of information. We are lucky to find this
as a first thing. Rowe: Yes. I'm very biased
since I study feeding and teeth, but I think the majority
of information about an animal, you can get from its skull. The brain, the teeth,
what it was feeding on, its maximum body size,
if you have the whole skull. It's just a treasure trove
of information and we're very fortunate
to have the whole thing. One of the reasons
why I love the UK is because it's got
such a great collection of marine reptiles. Attenborough:
[ Laughs ] Delighted to hear it. Rowe: I mean, in America, we've
got our big tyrannosaurus and our triceratops, but UK is great
for marine reptiles. Attenborough: But we did
discover the dinosaurs. Rowe: Yes, the science of
paleontology did originate here. Attenborough: How would it
compare with T-rex? Rowe: I imagine it would be
pretty comparable and they were kind of both
the respective apex predators in their ecosystems. So I have no doubt that this is sort of like
an underwater T-rex if you will. Attenborough:
Okay, let me ask you the million-dollar question. In a battle between T-rex
and our pliosaur, who's gonna win? Rowe:
As much as it pains me and brings a tear
to my eye to admit it, I think my T-rex
is going to lose this fight. Millions of years later,
an American paleontologist will envision the scene
and break down into tears. Attenborough: [ Laughs ] Bringing an enormous predator
back to life after 150 million years
is no easy task. But restoring this giant skull
is a labor of love for Steve and his team. Almost a year after the skull
was discovered, I return to Kimmeridge
to see how they're getting on. My goodness. It is absolutely magnificent. It's astonishing. Moore:
It's bigger than a T-rex. -Attenborough: Is it?
-Moore: Yeah, yeah. -Attenborough: What, the skull?
-Moore: Yup. Bigger than any T-rex
ever found. Etches:
David, now what we've done, since you've come here last,
is we've -- I've air-penned off
all the mudstone and then air-brated it. Now, the air-abrasive machine cleans out
all these little voids and you see every little detail,
every suture where the bone joined together,
you can see every detail, that's what we really wanted. Moore:
So the teeth here have been basically tumbled
on the beach and the shingle has worn away
all the crowns so we can do a bit
of dentistry on them. So we've got this tooth,
which has been scanned, and then we're gonna
increase or decrease it, and then add all the teeth
back in position. Show people what it actually
looked like. Attenborough: You must feel,
looking at this -- I mean, I know it was a huge
amount of work to get it out. Etches: We never thought
we'd get it, to be honest. I'll be honest with you. Attenborough:
Well, it's certainly a triumph. Etches: Yeah, quite an emotional
moment for everyone. Attenborough:
Yeah, I'm sure. It's sensational. ♪♪ Once the pliosaur's dagger-like
teeth are added, the picture is finally complete. ♪♪ Our journey of discovery
has shown that this sea monster was one
of the greatest predators the world has ever seen. And we can now visualize,
more accurately than ever, how it may have hunted
in the Jurassic seas. ♪♪ Ichthyosaurs... swimming in groups
along the coast... concentrating on hunting
their prey, unaware that they themselves
are being stalked. On their trail, our pliosaur
uses its highly tuned senses to launch an attack. ♪♪ In the chase, its four flippers,
each measuring over 6 feet long, drive it through the water
at great speed. ♪♪ Splitting the shoal,
it isolates its target. Our sea monster's
primary weapons are its 90 razor-sharp teeth... ...with which it slices
through its victims' flesh. The impact alone
may have been enough to kill. But with a bite force twice
the strength of any animal living today, its prey
had little chance of survival. ♪♪ ♪♪ ♪♪ From a chance discovery
on a beach one morning to the painstaking restoration
of such a rare and impressive specimen, the story of this fossil
is one of skill, dedication and of fascinating scientific
discoveries made along the way. We've been given
a unique insight into the life of our pliosaur that swam in the Jurassic seas
150 million years ago... but we're also reminded that
there is still so much to learn about these extraordinary
prehistoric animals. And I, for one, will never tire
of discovering more. ♪♪ ♪♪ ♪♪ ♪♪ ♪♪ <i> To learn more about
what you've seen</i> <i> on this "Nature" program,
visit pbs.org.</i> ♪♪
