Dinosaurs ruled the planet
for over 150 million years.
They occupied almost every corner of the globe
and came in almost every shape and size imaginable.
Some were truly extraordinary.
[grunts]
We now know that T. rex was a powerful swimmer...
Velociraptors were cunning, feathered hunters,
and that some dinosaurs had the most bizarre behavior.
But new discoveries are being made almost every day
that tell us more about life on this planet 66 million years ago.
[bellowing, rumbling]
[David Attenborough] This time on Prehistoric Planet,
- we reveal new animals... - [roars]
...and new insight into their quest to find a partner...
[chirps]
...the challenges faced by raising a family...
[bellows]
...and their titanic battles.
[rumbling]
[bellows]
[roars]
- [roars] - [squawking]
Journey to a time when nature put on its greatest show.
This is Prehistoric Planet 2.
[Attenborough] The vast swamplands of northeast Asia.
Within this low-lying flooded territory, there are countless islands.
Each of them is surrounded by slow-moving waters...
and that makes them potential sanctuaries for new life.
[squawking]
A young pterosaur, an azhdarchid. Just a few hours old.
Being on an island
means that she's able to take her first tentative steps in safety.
[squawking]
Having found her feet, it's time to try out her wings.
[squawks]
Getting them to work properly will take some practice.
Although she's only 1-foot tall,
she will grow into a giant with a 30-foot wingspan.
And to do that will require plenty of food...
something this tiny island can't provide.
She will have to leave
to feed in the swampy forests that surround her island.
Maiden flights are always tricky, especially when they're over open water.
Today there is a light breeze.
That will help by giving some extra lift.
But this youngster is not yet strong enough.
[squawks]
[roaring]
Shamosuchus. Fifteen-feet-long predators.
This island might offer safety,
but the surrounding waters certainly do not.
If the takeoff isn't perfect, it's difficult to gain height.
And this is not high enough.
[chirps]
Some of the stronger flyers
have almost reached the safety of the forest.
Others have still to make their attempt.
[squawking]
[chirps]
A near-miraculous escape.
And now the chance to collect her rewards.
In these rich swamp forests, there's all the food she needs.
Here in the wetlands of South America,
long summer days are fueling a greater feast.
These swamps are teeming with animals of all kinds.
And hunters are gathering.
The ferocious three-foot-long garfish.
Lunch for a giant Austroraptor.
They are relatives of Velociraptors but much, much bigger.
Twenty feet from head to tail and weighing over 800 pounds.
[bellows]
And with teeth not unlike those of a crocodile,
these dinosaurs are very skilled at catching fish.
For most of the year, they're solitary hunters.
But as the number of fish increases during summer,
so does the number of Austroraptors.
The biggest try to keep the best fishing spots for themselves.
They won't tolerate rivals.
[bellowing]
[hissing, roaring]
For those not yet in their prime, it's a challenging time of year.
This young male, still in his juvenile colors,
has little hope of securing a good place to fish.
However, there are other ways of getting a meal here.
With so much food around, the adults are very wasteful feeders.
They often eat only the choicest parts of the fish.
And for a youngster, any leftovers will do very nicely.
But it's risky.
To succeed, he will have to be sneaky.
- [bellowing] - [whines]
[roaring]
Bruised and empty-handed.
But with the adults still feasting around him,
there might be another opportunity.
[roaring]
[bellowing]
Two adults fighting over the best fishing spot.
[grunting, growling]
[roaring]
Time for the youngster to make a move...
[predator roaring]
...and time to leave.
[bellowing]
Success.
And more than just scraps.
A lesson learnt.
And when the good conditions return next year,
perhaps he'll be able to challenge for a fishing spot of his own.
[thunder rumbling]
In northern Madagascar, conditions are already changing.
The first rain in months is reviving the parched land.
As pools and channels refill, the animals return.
And they're not all dinosaurs.
Lurking in these muddy pools...
is a monster.
[rumbling]
[squawking]
[croaks]
- Beelzebufo, the devil toad. - [croaks]
It's so big it can swallow a small dinosaur whole.
But this male isn't here to hunt.
He is looking for a mate.
Female devil toads are fussy, so he needs to find a good spot.
Only then will he be able to entice them in.
[croaking]
[croaking continues]
His deep croaks travel far and wide.
[predators roaring]
[roaring continues]
This isn't quite what he was hoping for.
Fifty-foot-long rapetosaurs.
They have been attracted here by the promise of a mud bath.
For Beelzebufo, their timing couldn't be much worse.
His pools now lie beneath 70 tons of sauropod.
Time is short.
Female devil toads will only mate at the start of the rainy season.
He needs a new pool.
There's one.
Reaching it will be dangerous.
[bellowing, grunting]
Finally he's got there...
but he's been noticed.
[croaks]
He's not known as a devil toad for nothing.
[croaking]
Time to try more singing...
- [croaking] - [bellowing, grunting]
...but he can't make himself heard above the sound of satisfied sauropods.
[sauropods bellowing]
Luckily for him,
there's one thing that rapetosaurs enjoy even more than wallowing in mud...
and that is food.
The hungry herd moves on...
although, not without leaving something useful behind.
Dozens of giant footprints, full of water.
Perfect for a Beelzebufo to continue his quest for a mate.
[croaking]
A devil toad can only survive here
because every year the land is flooded by seasonal rains.
However, there are places where changing climate
means the rains are less certain.
This inland basin in North America was, in the past, several feet deep in water.
But after a decade of drought, it's now bone dry.
Nonetheless, some dinosaurs still linger here.
A herd of pachycephalosaurs,
bizarre creatures with thick, dome-shaped skulls.
[roars]
They prefer to feed on fruit and leaves...
but now they are forced to make do with roots and insects.
The herd is led by a large male.
[bellowing]
He keeps order, so everyone is able to search for food in peace.
But trouble is brewing within the herd.
The young male is throwing his weight around.
[bellowing]
It's time for the dominant male to put him in his place or kick him out.
He flaunts his colorful headgear...
trying to intimidate the youngster.
But he's not going to back down that easily.
[bellowing]
[bellowing, grunting]
Ten-inch-thick skulls enable them to survive powerful, head-on collisions.
The older male is heavier,
but the younger is more agile and has more stamina,
and that tips the balance in his favor.
A bellow of victory.
[bellowing]
[whines]
But too soon.
The loser has to pay a heavy price.
Exile.
Alone, it will be a struggle to fend for himself.
But life here will not be easy for the winner either
unless the water returns to this land and soon.
Across this vast continent,
there are over 100,000 square miles of swamplands...
and most of them remain flooded all year round.
Here in spring,
new plant growth creates excellent feeding grounds for the gathering herds.
[roars]
But where there are large numbers of plant eaters...
there are great hunters.
T. Rex...
the most powerful land predators on the planet.
They usually ambush their prey...
but with so many watching eyes...
this is not the right time to attack.
As darkness falls,
some of the herds that had been grazing out in the open
retreat into the forest for shelter.
Now the odds switch in favor of the predators.
Tyrannosaurs have the largest eyes of any dinosaur,
which gives them superb low-light vision.
[bellowing]
And they're able to move through the forest in near silence,
thanks to cushioned pads on their feet.
A group of edmontosaurs.
They lack armor,
but they're as big as T. rex and twice as fast.
To catch one needs cunning.
Each of the hunters carefully moves into position.
Then one deliberately makes a noise.
[branches cracking]
[rumbling]
The edmontosaurs are alarmed.
They now know hunters are close,
but they don't know exactly where they are.
Time to spring the trap.
One T. Rex rushes out.
[roaring]
[roars]
The herd panics and bolts to where the other T. rex is waiting in ambush.
[roaring]
[bellowing]
A perfectly executed plan...
by one of the greatest land predators that have ever lived...
in the swamps of our prehistoric planet.
This is the skull of a pachycephalosaur,
a 16-foot-long plant eater.
Despite years of research,
we're still trying to understand why it had this bizarre-shaped head.
The most distinctive feature about the pachycephalosaurs, of course,
is this really weird dome that they have on their head.
All around it is a series of very odd tubercles and nobbles and bobbles.
They look quite dragonlike.
When they first saw these very thick, domed skulls,
and these domes could be up to 30 centimeters in thickness,
they were thought to be very strong.
It was thought that maybe they were using them for headbutting each other
in contests over social hierarchy.
[Attenborough] Today, animals like bighorn sheep butt heads in this way.
A thickened skull helps protect their brain from impact.
But does this fully explain pachycephalosaur's domed head?
[squawks]
[grunts]
A number of paleontologists thought that they should look inside the skulls.
They sliced up a number of pachycephalosaur domes,
and when they did that, they found out that maybe it wasn't strong enough
to withstand these direct head-on impacts.
[Attenborough] However, they did discover something else,
suggesting the dome had a different use.
The surface was marked with a mesh of tiny fibers.
Perhaps they supported brightly colored skin,
used to attract a mate.
This new theory seemed to be accepted until 2013,
when a new discovery was made.
A pachycephalosaur was found,
with marks showing it had survived multiple injuries to the top of its head,
and it wasn't a one-off.
They went back and looked through historic museum collections
and discovered that actually there was quite a lot of evidence for these lesions
in a similar place across a whole bunch of different pachycephalosaurs.
This is good evidence that they probably were headbutting.
[Attenborough] So, were the skulls strong enough
to protect pachycephalosaur's brain after all?
[grunting]
To find out, scientists turned to the latest scanning technology.
We can use CT scans to build virtual models of the bones,
and then we can subject those to various engineering tests
in the same way that we'd do with an aeroplane part or an artificial hip.
[Attenborough] This provided the final piece of evidence.
[Maidment] What they've shown is that pachycephalosaur domes
could actually have withstood an enormous amount of force.
It's the sort of force that goes through American footballers
when they hit each other.
[Attenborough] We now believe pachycephalosaurs used their head
both as a formidable weapon...
[roaring]
...and as a colorful display.
Two ways to demonstrate who was boss in their prehistoric world.