1
00:00:35,274 --> 00:00:37,834
This little mammal is a scavenger.

2
00:00:37,914 --> 00:00:41,543
Called Didelphodon,
she is a marsupial

3
00:00:41,634 --> 00:00:45,752
and specialises in raiding
abandoned dinosaur nests.

4
00:00:46,834 --> 00:00:50,110
This evening, she could be in luck.

5
00:00:55,474 --> 00:01:00,502
Unfortunately, the smell of the nest
blinds her senses to danger.

6
00:01:07,954 --> 00:01:09,910
(Squeaking)

7
00:01:14,634 --> 00:01:16,590
(Huge roar)

8
00:01:25,154 --> 00:01:27,110
(Bellows )

9
00:01:41,995 --> 00:01:44,145
The end of the Cretaceous.

10
00:01:44,235 --> 00:01:47,386
The continents
are taking their modern forms.

11
00:01:47,475 --> 00:01:50,831
But this movement
of the Earth's crust

12
00:01:50,915 --> 00:01:54,660
has produced a surge
in volcanic activity.

13
00:02:00,596 --> 00:02:04,555
Massive eruptions
that have lasted for centuries

14
00:02:04,636 --> 00:02:06,945
have laid waste to landscapes,

15
00:02:07,036 --> 00:02:10,233
filling the atmosphere
with gases and debris.

16
00:02:10,316 --> 00:02:14,275
This desolate world
is still ruled by dinosaurs,

17
00:02:14,356 --> 00:02:17,871
as it has been
for 160 million years,

18
00:02:17,956 --> 00:02:21,153
but they are nearing the end
of their reign.

19
00:02:21,236 --> 00:02:24,194
Life on earth is choking to death.

20
00:02:33,168 --> 00:02:33,488
Yet in the last two million years,

21
00:02:33,488 --> 00:02:36,127
Yet in the last two million years,

22
00:02:36,208 --> 00:02:39,644
the dinosaurs'
most infamous predator has appeared.

23
00:02:39,728 --> 00:02:43,437
Tyrannosaurus, a five-tonne,
13-metre long carnivore,

24
00:02:43,528 --> 00:02:48,044
specifically evolved
to kill other giant dinosaurs.

25
00:02:49,808 --> 00:02:51,958
This is a male.

26
00:02:52,048 --> 00:02:57,441
He's been drawn to this volcano
by the smell of food.

27
00:02:58,528 --> 00:03:02,282
The area is full
of geothermal springs

28
00:03:02,368 --> 00:03:05,201
and the air thick
with sulphurous fumes.

29
00:03:05,288 --> 00:03:08,007
But there is another smell here.

30
00:03:08,088 --> 00:03:12,639
In one small valley,
there is the stench of death.

31
00:03:20,048 --> 00:03:24,678
Unwittingly, the Tyrannosaurus
has been drawn into a natural trap.

32
00:03:24,768 --> 00:03:28,204
Volcanic vents are producing
poisonous carbon monoxide,

33
00:03:28,288 --> 00:03:30,848
and because it is heavier than air,

34
00:03:30,928 --> 00:03:34,079
it has formed a suffocating layer
close to the ground.

35
00:03:38,688 --> 00:03:42,044
The giant predator
stands above the layer,

36
00:03:42,128 --> 00:03:46,167
but as he puts
his head down to feed

37
00:03:46,248 --> 00:03:48,842
he begins to feel the effects.

38
00:03:57,928 --> 00:04:02,877
If he topples over now,
he will never get up.

39
00:04:11,688 --> 00:04:15,158
Eventually,
his sheer size is his salvation.

40
00:04:15,248 --> 00:04:20,197
As he stands up with his prize,
his head just clears the gas layer.

41
00:04:31,848 --> 00:04:36,285
There are still islands of greenery
between the lava flows.

42
00:04:36,368 --> 00:04:40,486
In the warm, moist climate
of the late Cretaceous,

43
00:04:40,568 --> 00:04:42,604
the vegetation has transformed.

44
00:04:43,488 --> 00:04:45,444
Instead of conifers,

45
00:04:45,528 --> 00:04:49,680
broad-leaved trees
fill the forest canopy.

46
00:04:51,448 --> 00:04:56,044
Driving this quiet revolution
among the plants

47
00:04:56,128 --> 00:04:58,961
is the remarkable
evolution of flowers.

48
00:04:59,048 --> 00:05:02,927
Their secret lies in their
intimate relationship with insects,

49
00:05:03,008 --> 00:05:07,559
so close that some flowers
can only be pollinated by insects

50
00:05:07,648 --> 00:05:12,039
and some insects, like butterflies,
can only feed on flowers.

51
00:05:17,528 --> 00:05:21,077
Among these new plants,
the birds are flourishing,

52
00:05:21,168 --> 00:05:23,204
and their calls form
an ever-present chorus.

53
00:05:30,985 --> 00:05:33,374
Millions of years of evolution

54
00:05:33,465 --> 00:05:37,344
have also created
intimate relationships

55
00:05:37,425 --> 00:05:40,383
among different types of dinosaurs.

56
00:05:40,465 --> 00:05:45,061
Especially the delicate balance
between predator and prey.

57
00:06:08,105 --> 00:06:10,061
(Terrifying squawk)

58
00:06:15,585 --> 00:06:17,576
(Hissing roar)

59
00:06:21,305 --> 00:06:24,422
0ne dinosaur
that specialises in defence

60
00:06:24,505 --> 00:06:27,463
is the extraordinary Ankylosaurus.

61
00:06:27,545 --> 00:06:32,255
They are evolved to withstand attack
even from giant predators

62
00:06:32,345 --> 00:06:34,905
like Tyrannosaurus.

63
00:06:34,985 --> 00:06:38,978
At seven tonnes, Ankylosaurus
are so heavily armoured

64
00:06:39,065 --> 00:06:42,023
that even their eyelids
are hardened.

65
00:06:44,225 --> 00:06:48,980
And if that wasn't enough,
they have a formidable club

66
00:06:49,065 --> 00:06:52,023
on the end of their tails.

67
00:06:54,785 --> 00:06:59,336
Sadly, not even these magnificent
creatures have any defence

68
00:06:59,425 --> 00:07:03,976
against the natural forces
that are suffocating their world.

69
00:07:13,425 --> 00:07:15,814
Nearby lies the Tyrannosaurus nest.

70
00:07:15,905 --> 00:07:19,784
These are usually
closely guarded by the mother,

71
00:07:19,865 --> 00:07:22,220
but this nest has been abandoned,

72
00:07:22,305 --> 00:07:25,342
and a Didelphodon
has burrowed into the side.

73
00:07:29,625 --> 00:07:34,540
Dinosaurs are vulnerable because
they lay their eggs on the ground.

74
00:07:36,389 --> 00:07:36,949
But size helps,

75
00:07:36,949 --> 00:07:38,268
But size helps,

76
00:07:38,349 --> 00:07:41,307
and the egg is a challenge
for this marsupial.

77
00:07:41,389 --> 00:07:44,506
Soon the age of the mammals
will dawn,

78
00:07:44,589 --> 00:07:46,944
and they will grow massive,

79
00:07:47,029 --> 00:07:49,827
but this is as big
as Cretaceous mammals get.

80
00:07:53,777 --> 00:07:59,249
The Tyrannosaurus embryo inside
the abandoned egg is already dead.

81
00:08:01,897 --> 00:08:05,446
The scent is a lure
to another Didelphodon.

82
00:08:08,697 --> 00:08:11,450
(Snarls and growls)

83
00:08:12,577 --> 00:08:14,613
(Growling)

84
00:08:22,883 --> 00:08:25,443
(Loud shrieks )

85
00:08:30,667 --> 00:08:31,227
Many dinosaur embryos cannot
survive in this volcanic environment

86
00:08:31,227 --> 00:08:34,264
Many dinosaur embryos cannot
survive in this volcanic environment

87
00:08:34,347 --> 00:08:36,303
because acidic pollution

88
00:08:36,387 --> 00:08:40,300
prevents their eggshells
from forming properly.

89
00:08:42,507 --> 00:08:44,941
(Bellowing)

90
00:08:49,787 --> 00:08:53,985
The mother is calling
for a new mate.

91
00:08:54,067 --> 00:08:58,504
Tyrannosaurus have huge territories
of hundreds of square kilometres.

92
00:08:58,587 --> 00:09:02,023
Her challenge is to attract
a wandering male.

93
00:09:02,107 --> 00:09:06,066
She may have to call
like this for weeks.

94
00:09:21,307 --> 00:09:25,619
0ne of the Tyrannosaurus's
principal sources of prey

95
00:09:25,707 --> 00:09:28,426
are these bulky Torosaurus.

96
00:09:28,507 --> 00:09:33,217
In the late Cretaceous, herds of
horned herbivores are very common

97
00:09:33,307 --> 00:09:35,867
and attract many predators.

98
00:09:39,427 --> 00:09:44,182
It is rutting season. To display,
males flush blood into their crests,

99
00:09:44,267 --> 00:09:46,701
creating vivid patterns.

100
00:09:51,267 --> 00:09:54,862
These displays help
to avoid physical contact.

101
00:09:54,947 --> 00:09:57,177
With one-metre-long horns,

102
00:09:57,267 --> 00:10:00,703
fighting can easily result
in bad injuries.

103
00:10:00,787 --> 00:10:03,142
The best and the brightest crest

104
00:10:03,227 --> 00:10:06,742
is all that is needed
to settle arguments.

105
00:10:15,587 --> 00:10:18,897
0ccasionally,
showing off is not enough

106
00:10:18,987 --> 00:10:20,898
and males resort to brute force.

107
00:10:48,172 --> 00:10:52,688
For this old Torosaurus,
this was one fight too many.

108
00:10:54,172 --> 00:10:57,369
He will never again
challenge for the right to mate.

109
00:10:57,452 --> 00:10:59,408
(Gruff mooing)

110
00:11:06,511 --> 00:11:09,742
The mating call
of the Tyrannosaurus

111
00:11:09,831 --> 00:11:13,301
continues to echo
across the volcanic slopes.

112
00:11:13,391 --> 00:11:15,268
And it has been heard.

113
00:11:15,351 --> 00:11:19,625
A male has killed
a young Triceratops.

114
00:11:19,800 --> 00:11:24,580
It's not just to satisfy his hunger.
It is a gift.

115
00:11:24,924 --> 00:11:28,553
Female Tyrannosaurus
are larger and more aggressive,

116
00:11:29,004 --> 00:11:30,500
and he courts her with food

117
00:11:30,502 --> 00:11:32,999
to stop her attacking him on sight.

118
00:11:44,884 --> 00:11:47,193
(Growls)

119
00:11:48,244 --> 00:11:50,439
(Growls)

120
00:11:51,524 --> 00:11:54,482
The female arrives.

121
00:11:57,644 --> 00:12:00,875
(Short roars )

122
00:12:00,964 --> 00:12:03,432
She is wary.

123
00:12:07,328 --> 00:12:07,888
The primary weapon
of a Tyrannosaurus is its mouth.

124
00:12:07,888 --> 00:12:12,200
The primary weapon
of a Tyrannosaurus is its mouth.

125
00:12:12,288 --> 00:12:15,837
Its arms are tiny
so it can carry a massive jaw

126
00:12:15,928 --> 00:12:18,203
and remain balanced.

127
00:12:21,168 --> 00:12:26,117
This jaw can crush bone
and tear off up to 70 kg of meat

128
00:12:26,208 --> 00:12:28,164
with one bite.

129
00:12:28,248 --> 00:12:30,808
The male keeps his distance.

130
00:12:45,568 --> 00:12:48,241
Later that evening, they mate.

131
00:12:48,328 --> 00:12:51,001
This is the first of many couplings

132
00:12:51,088 --> 00:12:54,543
as the male stays by the female
while she is receptive -

133
00:12:54,546 --> 00:12:58,840
ready to see off any other males.

134
00:13:14,368 --> 00:13:18,361
0n the lava flows,
a group of Anatotitan

135
00:13:18,448 --> 00:13:21,520
wanders between islands of greenery.

136
00:13:25,648 --> 00:13:30,278
These animals are members
of the hadrosaur family,

137
00:13:30,368 --> 00:13:34,646
the most common group of dinosaurs
in the Late Cretaceous.

138
00:13:34,728 --> 00:13:37,288
But their kind has evolved

139
00:13:37,368 --> 00:13:42,078
to thrive in lush lowland swamps,
not in an ash wilderness.

140
00:13:53,408 --> 00:13:55,717
Three days have passed.

141
00:13:55,808 --> 00:13:59,960
The Triceratops carcass
has been stripped

142
00:14:00,048 --> 00:14:04,599
and the female Tyrannosaurus
is beginning to tire of her mate.

143
00:14:05,688 --> 00:14:07,644
(Roars )

144
00:14:12,409 --> 00:14:14,365
(Hisses )

145
00:14:27,897 --> 00:14:31,207
The male knows better than to stay.

146
00:14:46,236 --> 00:14:48,796
Gliding in from the coast,

147
00:14:48,876 --> 00:14:53,825
a magnificent pterosaur,
Quetzalcoatlus, is hunting for food.

148
00:14:53,916 --> 00:14:56,476
This is now a rare sight.

149
00:15:08,676 --> 00:15:13,431
For 20 million years, these flying
reptiles have been in decline.

150
00:15:13,516 --> 00:15:17,589
These 13-metre giants
are the only ones left.

151
00:15:17,676 --> 00:15:19,792
And this is a dangerous place to be.

152
00:15:22,487 --> 00:15:26,162
0ne-tonne crocodiles
live in the lake,

153
00:15:26,247 --> 00:15:29,284
and could easily drag
the delicate glider to his death.

154
00:15:47,035 --> 00:15:49,595
Driven on to extinction.

155
00:15:49,675 --> 00:15:53,634
The skies of the future
belong to the birds

156
00:15:53,715 --> 00:15:56,275
that already flourish around him.

157
00:15:59,835 --> 00:16:03,714
Months have passed,
and the female Tyrannosaurus

158
00:16:03,795 --> 00:16:07,184
has built a new nest,
camouflaged in the forest.

159
00:16:09,636 --> 00:16:11,592
Mother keeps watch.

160
00:16:11,676 --> 00:16:15,555
For the full two months
of the eggs' incubation,

161
00:16:15,636 --> 00:16:18,025
she will not leave or even eat.

162
00:16:18,116 --> 00:16:21,825
She knows her nest
is a magnet to scavengers.

163
00:16:23,116 --> 00:16:25,676
Like this Dromaeosaur.

164
00:16:33,324 --> 00:16:37,761
His cautious approach
is watched by the Tyrannosaurus.

165
00:16:39,244 --> 00:16:43,795
She judges exactly
when he has got too close.

166
00:16:44,964 --> 00:16:46,920
(Roars )

167
00:16:47,004 --> 00:16:49,154
(Squeals)

168
00:16:55,044 --> 00:16:59,993
As the sun sets, another threat
comes out to haunt the mother.

169
00:17:00,084 --> 00:17:02,075
(Chirps and yowls)

170
00:17:04,044 --> 00:17:06,000
(Growls)

171
00:17:15,204 --> 00:17:18,355
(Bellowing roar)

172
00:17:18,444 --> 00:17:22,995
With food becoming scarce,
the mammals are getting bolder.

173
00:17:24,724 --> 00:17:29,195
She checks to make sure
more have not burrowed in,

174
00:17:29,284 --> 00:17:31,673
then returns to her vigil.

175
00:17:37,924 --> 00:17:42,475
The weeks pass, and above
the brilliant volcanic sunsets,

176
00:17:42,564 --> 00:17:47,115
there are signs of an even more
destructive natural disaster.

177
00:17:50,417 --> 00:17:55,047
Showers of shooting stars
herald the approach of a giant comet

178
00:17:55,137 --> 00:17:58,095
on a collision course
with the Earth.

179
00:18:02,817 --> 00:18:05,933
Far below,
the dinosaurs are oblivious.

180
00:18:06,893 --> 00:18:07,293
The Torosaurus herd
continues to feed.

181
00:18:07,293 --> 00:18:10,444
The Torosaurus herd
continues to feed.

182
00:18:10,533 --> 00:18:12,489
Nervous of moonlight predators,

183
00:18:12,573 --> 00:18:16,691
younger animals seek protection
among the larger adults.

184
00:18:16,773 --> 00:18:18,889
(Restless mooing)

185
00:18:18,973 --> 00:18:23,649
Using the darkness, a pair
of Dromaeosaurs unsettle the herd

186
00:18:23,733 --> 00:18:26,645
and isolate one of the youngsters.

187
00:18:26,733 --> 00:18:29,691
(Hoarse shrieks )

188
00:18:29,773 --> 00:18:32,287
(Lowing noises )

189
00:18:42,773 --> 00:18:44,729
(Shrieking)

190
00:19:03,093 --> 00:19:08,008
Safe. But the predators have tasted
blood and will not give up easily.

191
00:19:25,373 --> 00:19:29,571
Morning reveals
the results of last night's tussle.

192
00:19:29,653 --> 00:19:33,885
The little Torosaurus lost his fight
with the predators.

193
00:19:33,973 --> 00:19:38,842
For the herd, it is a blow.
Too few young are being born

194
00:19:38,933 --> 00:19:41,367
in this polluted environment.

195
00:19:46,933 --> 00:19:51,131
A Didelphodon
is already at the carcass.

196
00:19:51,213 --> 00:19:56,162
These little opportunists are about
the only animals that are thriving.

197
00:19:59,933 --> 00:20:04,290
During their reign, dinosaurs
have adapted to huge changes

198
00:20:04,373 --> 00:20:08,207
but now they face
a combination of events

199
00:20:08,293 --> 00:20:10,807
that will spell their doom.

200
00:20:13,776 --> 00:20:16,336
After trekking
across the ash fields,

201
00:20:16,416 --> 00:20:21,500
Anatotitans gather round
a stagnant pool to drink and feed.

202
00:20:22,076 --> 00:20:24,465
Huge batteries of chewing teeth

203
00:20:24,556 --> 00:20:28,310
make short work of the vegetation.

204
00:20:34,356 --> 00:20:39,111
0nce again, the predators make
the water's edge a dangerous place.

205
00:20:43,716 --> 00:20:47,186
The group senses danger
and starts to break up.

206
00:21:14,821 --> 00:21:18,211
The mother Tyrannosaurus
has broken her fast

207
00:21:18,301 --> 00:21:20,337
and is back with a vengeance.

208
00:21:26,101 --> 00:21:30,777
Nearby is the reason for her hunger.
Three Tyrannosaurus chicks.

209
00:21:30,861 --> 00:21:34,695
The only survivors
from a clutch of twelve.

210
00:21:34,781 --> 00:21:37,773
The moment they hear the kill,

211
00:21:37,861 --> 00:21:40,056
they start calling for food.

212
00:21:40,141 --> 00:21:42,291
(Mewling and yelping)

213
00:21:45,261 --> 00:21:50,460
The mother delivers
a slab of Anatotitan meat.

214
00:21:55,301 --> 00:21:57,769
0nly four weeks old
and less than a metre high,

215
00:21:57,861 --> 00:22:00,329
competition is intense between them.

216
00:22:00,421 --> 00:22:03,777
0ne is already picked on
by the others.

217
00:22:05,901 --> 00:22:07,732
(Faint mews )

218
00:22:21,021 --> 00:22:26,379
They'll remain under their mother's
protection for another two months.

219
00:22:26,461 --> 00:22:29,658
Soon after that,
she will abandon them,

220
00:22:29,741 --> 00:22:32,414
or worse, view them as food.

221
00:22:35,661 --> 00:22:39,540
It is unlikely
the outcast will last that long.

222
00:22:53,501 --> 00:22:56,857
A few days later
and the mother rests

223
00:22:56,941 --> 00:22:59,739
in the warm afternoon sun.

224
00:22:59,821 --> 00:23:03,291
There is no sign
of the smaller runt.

225
00:23:03,381 --> 00:23:06,896
He may have been killed
by his siblings.

226
00:23:11,701 --> 00:23:16,456
Increasingly, the bickering pair are
happy to wander from their mother

227
00:23:16,541 --> 00:23:19,374
to explore their surroundings.

228
00:23:19,461 --> 00:23:22,339
(Squawks )

229
00:23:27,981 --> 00:23:30,449
From the undergrowth,
a snake watches.

230
00:23:30,541 --> 00:23:33,692
These reptiles
have only recently evolved

231
00:23:33,781 --> 00:23:36,295
from the same family as lizards,

232
00:23:36,381 --> 00:23:41,136
but they specialise in hunting
warm-blooded creatures like mammals.

233
00:23:41,221 --> 00:23:44,258
They use sensory pits
on their snouts

234
00:23:44,341 --> 00:23:49,096
as a way of detecting the heat
signatures of other animals.

235
00:23:50,341 --> 00:23:52,809
It doesn't like what it sees.

236
00:23:58,661 --> 00:24:00,617
(Hissing)

237
00:24:05,941 --> 00:24:10,810
While the chicks play, they are
oblivious to approaching danger.

238
00:24:10,901 --> 00:24:13,256
(Hoarse grunting)

239
00:24:21,741 --> 00:24:26,019
The mother is caught
completely by surprise.

240
00:24:26,101 --> 00:24:30,891
The Ankylosaurus has very little
brain inside its reinforced skull,

241
00:24:30,981 --> 00:24:36,499
so when faced with danger, it reacts
automatically and aggressively.

242
00:24:44,421 --> 00:24:47,299
Normally,
Tyrannosaurus would retreat,

243
00:24:47,381 --> 00:24:49,770
but she will not abandon her young.

244
00:24:56,261 --> 00:24:58,695
(Low grunting)

245
00:24:58,781 --> 00:25:00,737
(Roar)

246
00:25:10,261 --> 00:25:13,776
The blow has cracked
the mother's femur

247
00:25:13,861 --> 00:25:16,011
and ruptured internal organs.

248
00:25:16,101 --> 00:25:18,456
She limps away in agony.

249
00:25:18,541 --> 00:25:20,497
(Chicks squawk)

250
00:25:25,928 --> 00:25:28,522
That night, the usual evening chorus

251
00:25:28,608 --> 00:25:32,647
is joined by the whimper
of a dying giant.

252
00:25:37,568 --> 00:25:42,596
By morning, she lies lifeless
on the baking ash fields.

253
00:25:42,688 --> 00:25:47,637
The chicks stand expectantly by
the colossal corpse of their mother.

254
00:25:53,208 --> 00:25:55,961
Hours pass, and still they wait.

255
00:25:58,608 --> 00:26:02,157
But their fate will now be settled,

256
00:26:02,248 --> 00:26:07,163
along with all the other
giant dinosaurs of the Cretaceous.

257
00:26:15,048 --> 00:26:19,803
3,000 km to the south, the massive
comet crashes into Earth.

258
00:26:20,888 --> 00:26:23,243
(Dinosaurs squawking)

259
00:26:31,528 --> 00:26:35,965
The light from the impact
fades in silence.

260
00:26:37,048 --> 00:26:39,801
Then the shock waves arrive.

261
00:26:40,408 --> 00:26:43,923
(Rumbling)

262
00:26:45,168 --> 00:26:47,124
Next comes the blast front.

263
00:26:56,849 --> 00:26:59,124
(Winds howl)

264
00:27:01,009 --> 00:27:02,920
(Tearing and crashing)

265
00:27:16,333 --> 00:27:16,893
Finally a rain of molten rock starts
to fall out of the darkening sky -

266
00:27:16,893 --> 00:27:21,648
Finally a rain of molten rock starts
to fall out of the darkening sky -

267
00:27:21,733 --> 00:27:26,568
this is the end
of the age of the dinosaurs.

268
00:27:34,213 --> 00:27:36,807
The comet struck the Gulf of Mexico

269
00:27:36,893 --> 00:27:40,442
with the force of 10 billion
Hiroshima bombs.

270
00:27:40,533 --> 00:27:43,730
In the catastrophic climate changes
that followed,

271
00:27:43,813 --> 00:27:47,044
65% of life died out.

272
00:27:47,133 --> 00:27:50,887
It took millions of years
for Earth to recover,

273
00:27:50,973 --> 00:27:55,091
and when it did,
the giant dinosaurs were gone,

274
00:27:55,173 --> 00:27:57,289
never to return.

275
00:28:02,213 --> 00:28:07,367
In their place have emerged other
powerful and beautiful creatures.

276
00:28:10,773 --> 00:28:13,731
We now know one small group
of dinosaurs

277
00:28:13,813 --> 00:28:16,202
did survive the extinction -

278
00:28:16,293 --> 00:28:19,490
and they are all around us today -

279
00:28:19,573 --> 00:28:21,404
the birds.