Would you like to inspect the original subtitles? These are the user uploaded subtitles that are being translated:
1
00:00:09,460 --> 00:00:11,880
66 million years ago,
2
00:00:12,093 --> 00:00:15,120
Planet Earth was very different
from today.
3
00:00:21,219 --> 00:00:24,882
Back then, one of our closest
ancestors might have looked
4
00:00:24,918 --> 00:00:28,480
something like
this little furry creature.
5
00:00:40,600 --> 00:00:44,600
The rulers of the land
were giant reptiles.
6
00:01:06,880 --> 00:01:08,720
Dinosaurs.
7
00:01:08,720 --> 00:01:10,586
That's one of the most infamous,
8
00:01:10,619 --> 00:01:14,240
a carnivorous T-rex.
9
00:01:14,240 --> 00:01:17,200
And just behind are
the bison of their time,
10
00:01:17,200 --> 00:01:20,960
a common plant-eater,
Edmontosaurus.
11
00:01:20,960 --> 00:01:22,880
But what happened to them all?
12
00:01:24,640 --> 00:01:26,680
66 million years ago,
13
00:01:26,680 --> 00:01:29,000
an asteroid hit the Earth,
14
00:01:29,000 --> 00:01:32,200
and scientists think
that it was this collision
15
00:01:32,200 --> 00:01:35,320
that wiped out the dinosaurs.
16
00:01:35,320 --> 00:01:38,880
But no-one has ever found
direct evidence of that.
17
00:01:38,880 --> 00:01:43,200
In fact, no-one has ever found
the fossil of a dinosaur
18
00:01:43,200 --> 00:01:46,240
that died within
a thousand years of the impact.
19
00:01:49,160 --> 00:01:55,000
However, a remarkable dig site
promises to change that.
20
00:01:56,800 --> 00:01:59,600
It's in the Hell Creek formation
21
00:01:59,600 --> 00:02:02,000
in the American Midwest.
22
00:02:03,520 --> 00:02:08,840
These badlands are rich
in prehistoric remains...
23
00:02:08,840 --> 00:02:11,400
..from triceratops...
24
00:02:14,520 --> 00:02:17,320
..to pterosaurs.
25
00:02:18,760 --> 00:02:21,160
And here, one patch of land
26
00:02:21,160 --> 00:02:23,600
about the size of a football pitch
27
00:02:23,600 --> 00:02:27,680
is yielding a collection
of astonishing fossils.
28
00:02:30,000 --> 00:02:33,280
The precise location is
a closely guarded secret,
29
00:02:33,280 --> 00:02:36,480
because this place
may hold evidence...
30
00:02:38,600 --> 00:02:41,120
..of one of the most dramatic events
31
00:02:41,120 --> 00:02:44,200
in all the four-and-a-half-
billion-year history
32
00:02:44,200 --> 00:02:45,600
of our planet.
33
00:02:49,640 --> 00:02:52,040
Right, let me get down here
between you.
34
00:02:52,040 --> 00:02:55,640
For ten years,
a palaeontologist and his team
35
00:02:55,640 --> 00:02:58,800
have been trying to find out
exactly what happened here.
36
00:02:58,800 --> 00:03:01,280
You're at the edge
of your seat every moment,
37
00:03:01,280 --> 00:03:02,880
trying to dig this stuff up.
38
00:03:02,880 --> 00:03:04,840
It's like trying to defuse
a nuclear weapon
39
00:03:04,840 --> 00:03:07,000
while you're in a rainstorm.
40
00:03:07,000 --> 00:03:09,360
He's named the site Tanis,
41
00:03:09,360 --> 00:03:11,800
and believes it could be
a mass graveyard
42
00:03:11,800 --> 00:03:13,320
of creatures that were killed
43
00:03:13,320 --> 00:03:16,000
in the catastrophic asteroid strike.
44
00:03:20,960 --> 00:03:26,160
A site that could reveal not only
how the last dinosaurs lived,
45
00:03:26,160 --> 00:03:27,720
but how they died.
46
00:03:29,440 --> 00:03:33,400
If the dig team is right,
Tanis could be a place
47
00:03:33,400 --> 00:03:36,560
where the remains
of a long-lost world
48
00:03:36,560 --> 00:03:38,480
are frozen in time.
49
00:03:40,400 --> 00:03:43,200
A place that gives us,
for the first time,
50
00:03:43,200 --> 00:03:45,520
an unprecedented window...
51
00:03:48,520 --> 00:03:52,000
..into the lives
of the very last dinosaurs...
52
00:03:56,440 --> 00:03:59,200
..and a minute-by-minute
picture of what happened
53
00:03:59,200 --> 00:04:01,880
on the day the asteroid hit.
54
00:04:21,600 --> 00:04:24,960
This landscape is full of fossils
55
00:04:24,960 --> 00:04:27,320
dating from the Late Cretaceous,
56
00:04:27,320 --> 00:04:30,720
the period which began
around 100 million years ago
57
00:04:30,720 --> 00:04:34,320
and ended 66 million years ago,
58
00:04:34,320 --> 00:04:36,120
when the dinosaurs vanished.
59
00:04:37,800 --> 00:04:42,280
Palaeontologist Robert DePalma
wants to find out more.
60
00:04:42,280 --> 00:04:45,680
I think anybody
who's ever liked dinosaurs
61
00:04:45,680 --> 00:04:47,600
in the past, or still does,
62
00:04:47,600 --> 00:04:49,360
has thought at one point
or another,
63
00:04:49,360 --> 00:04:50,680
"Well, what happened to them?
64
00:04:50,680 --> 00:04:53,400
"Why are they not here
any more?"
65
00:04:53,400 --> 00:04:55,240
So many different theories
are out there,
66
00:04:55,240 --> 00:04:58,840
and nobody has a tight answer
to that question.
67
00:05:03,120 --> 00:05:05,200
Judging from fossil evidence,
68
00:05:05,200 --> 00:05:09,000
this is what Hell Creek looked
like in the Late Cretaceous.
69
00:05:14,880 --> 00:05:17,520
There were low-lying,
marshy flood plains,
70
00:05:17,520 --> 00:05:21,520
intercut by river channels
and covered with horsetails,
71
00:05:21,520 --> 00:05:23,920
ferns and trees.
72
00:05:23,920 --> 00:05:28,280
Back then, it was warm
and wet here all year round.
73
00:05:31,560 --> 00:05:34,720
Tanis lies
in the north-eastern corner
74
00:05:34,720 --> 00:05:37,160
of the Hell Creek formation.
75
00:05:38,800 --> 00:05:41,360
Instead of today's
dusty prairies,
76
00:05:41,360 --> 00:05:43,120
there were sandy river banks.
77
00:05:46,080 --> 00:05:49,640
Instead of rocky cliffs,
there were forests.
78
00:05:51,480 --> 00:05:53,840
And instead
of the life we know today...
79
00:05:59,600 --> 00:06:02,200
..well, Robert is hoping
to find out more
80
00:06:02,200 --> 00:06:03,920
about what that was like.
81
00:06:09,600 --> 00:06:13,680
A sandbank lying between
a river and a forest
82
00:06:13,680 --> 00:06:17,360
would one day become
what Robert now calls Tanis.
83
00:06:20,480 --> 00:06:25,840
He and his team have been
digging here since 2012.
84
00:06:25,840 --> 00:06:27,360
So somewhere from between there
85
00:06:27,360 --> 00:06:29,040
and down here
is where that came from.
86
00:06:29,040 --> 00:06:30,800
It's come from up above.
Hey, look at this.
87
00:06:30,800 --> 00:06:32,200
What? Look.
88
00:06:32,200 --> 00:06:33,720
Oh, yeah, yeah, yeah. OK.
89
00:06:33,720 --> 00:06:37,240
And what they found is unexpected.
90
00:06:37,240 --> 00:06:40,280
Here we've got
this freshwater environment
91
00:06:40,280 --> 00:06:41,600
of the Hell Creek formation,
92
00:06:41,600 --> 00:06:45,520
and these shocking
red, green colours
93
00:06:45,520 --> 00:06:48,200
coming from the shells of ammonites,
a marine organism,
94
00:06:48,200 --> 00:06:50,800
kind of like a coiled snail
in appearance.
95
00:06:50,800 --> 00:06:53,480
So we've got this marine organism
that's been thrown up
96
00:06:53,480 --> 00:06:56,000
into this freshwater environment,
97
00:06:56,000 --> 00:06:57,920
and they do not belong here.
98
00:06:58,960 --> 00:07:01,440
How they got here is a mystery.
99
00:07:01,440 --> 00:07:02,480
OK...
100
00:07:02,480 --> 00:07:04,600
And there's more.
101
00:07:04,600 --> 00:07:08,120
I'm just going to go ahead and
plane down some of this rock.
102
00:07:08,120 --> 00:07:10,320
Sitting just above the ammonites
103
00:07:10,320 --> 00:07:13,040
is something that
many dinosaur hunters
104
00:07:13,040 --> 00:07:15,080
are desperate to find.
105
00:07:15,080 --> 00:07:20,120
So this orange layer right here
is composed 100%
106
00:07:20,120 --> 00:07:24,280
of impact-related debris
that is enriched in iridium.
107
00:07:24,280 --> 00:07:28,080
Iridium is an element that's rare
in the Earth's crust,
108
00:07:28,080 --> 00:07:31,200
but it's common in asteroids.
109
00:07:31,200 --> 00:07:35,800
The layer it's in is called
the K-Pg boundary.
110
00:07:36,920 --> 00:07:38,200
Dear Momma...
111
00:07:39,560 --> 00:07:41,640
Oh, dear. Really?
Yeah.
112
00:07:41,640 --> 00:07:46,200
It's made up of dust and debris
from a huge asteroid impact.
113
00:07:48,360 --> 00:07:49,800
Look at that. That's amazing.
114
00:07:49,800 --> 00:07:51,880
Yeah, yeah, yeah, yeah, yeah.
That's what we want.
115
00:07:51,880 --> 00:07:53,560
OK. So it's coming
from this area here.
116
00:07:53,560 --> 00:07:56,480
So somewhere within that region is
where these pieces are coming from.
117
00:07:56,480 --> 00:07:59,320
The boundary separates
the age of the dinosaurs
118
00:07:59,320 --> 00:08:01,280
from the age of mammals,
119
00:08:01,280 --> 00:08:04,120
so the rocks here
come from about the time
120
00:08:04,120 --> 00:08:06,560
that the dinosaurs became extinct.
121
00:08:06,560 --> 00:08:08,520
No rattlesnakes.
122
00:08:08,520 --> 00:08:11,360
What makes the site even
more exciting
123
00:08:11,360 --> 00:08:14,360
is the rock layer
right beneath the boundary
124
00:08:14,360 --> 00:08:16,160
where Robert found the ammonites.
125
00:08:16,160 --> 00:08:18,840
The rock here
is really not quite rocky,
126
00:08:18,840 --> 00:08:21,480
as you would expect dinosaur bones
and things to be encased -
127
00:08:21,480 --> 00:08:24,000
you expect really, really hard
rocks and jackhammers
128
00:08:24,000 --> 00:08:26,640
and things like this,
but it's very, very crumbly
129
00:08:26,640 --> 00:08:30,280
and it just falls apart
in your hands.
130
00:08:30,280 --> 00:08:32,760
As well as being crumbly
throughout,
131
00:08:32,760 --> 00:08:36,480
this layer of rock is also
around a metre thick,
132
00:08:36,480 --> 00:08:39,760
which, along with
other unusual features, makes
133
00:08:39,760 --> 00:08:44,880
Robert think that something very
strange must have happened here.
134
00:08:48,280 --> 00:08:51,400
Maybe a flood or a mud flow,
135
00:08:51,400 --> 00:08:54,880
burying anything within it
in an instant.
136
00:08:54,880 --> 00:08:58,160
Oh, there's a beautiful...
Look at that one - beautiful.
137
00:08:58,160 --> 00:09:01,240
This could mean that anything
he finds in this layer
138
00:09:01,240 --> 00:09:03,960
would have been quickly entombed,
139
00:09:03,960 --> 00:09:08,000
like the bodies in
the volcanic ash of Pompeii.
140
00:09:11,400 --> 00:09:13,840
Robert knows from the geology
141
00:09:13,840 --> 00:09:18,400
that anything he finds at Tanis
will be tantalisingly close
142
00:09:18,400 --> 00:09:21,640
to the end
of the age of the dinosaurs
143
00:09:21,640 --> 00:09:23,880
and could be so well preserved
144
00:09:23,880 --> 00:09:25,880
that it could reveal new evidence
145
00:09:25,880 --> 00:09:28,800
that will bring this time period
to life
146
00:09:28,800 --> 00:09:32,160
in a way
no-one has ever done before.
147
00:09:35,840 --> 00:09:38,800
Robert digs at Tanis each summer,
148
00:09:38,800 --> 00:09:42,880
the only time the weather
allows him to do so.
149
00:09:42,880 --> 00:09:46,400
Come on down,
check out this lens over here.
150
00:09:46,400 --> 00:09:50,240
In order to understand how the
impact affected life on Earth,
151
00:09:50,240 --> 00:09:53,240
you really need to get
a very clear picture
152
00:09:53,240 --> 00:09:55,800
of what the world was like
right before.
153
00:09:55,800 --> 00:09:58,440
That is a critical part
of the story.
154
00:10:00,440 --> 00:10:03,680
Palaeontologists Dr David Burnham
155
00:10:03,680 --> 00:10:08,200
and Loren Gurche have been
digging with Robert for years.
156
00:10:10,720 --> 00:10:13,240
Oh, wow!
157
00:10:13,240 --> 00:10:15,400
See...see the brown? Yep.
158
00:10:15,400 --> 00:10:17,000
That might be a tubercle
right there.
159
00:10:17,000 --> 00:10:20,480
And it seems today is their
lucky day.
160
00:10:20,480 --> 00:10:23,320
Oh, my God! Look at that!
Look at that.
161
00:10:23,320 --> 00:10:24,760
Look, the scales are preserved!
162
00:10:24,760 --> 00:10:27,240
Holy crap! Like doing
a freaking dissection.
163
00:10:27,240 --> 00:10:30,400
Oh, my God. Biology of Tanis.
164
00:10:30,400 --> 00:10:31,720
Oh, the scale...
165
00:10:31,720 --> 00:10:34,480
Look, look - the wrinkles
continue down that way.
166
00:10:34,480 --> 00:10:36,280
Mine's all nice and wet so far.
167
00:10:36,280 --> 00:10:38,600
The scales are getting smaller
in that direction.
168
00:10:38,600 --> 00:10:39,680
How big are they there?
169
00:10:39,680 --> 00:10:42,400
I got a...I got one with
the projection over here.
170
00:10:42,400 --> 00:10:43,640
What? Oh!
171
00:10:43,640 --> 00:10:44,760
Yeah. Oh.
172
00:10:44,760 --> 00:10:46,640
Yeah, there's the protuberance
right there.
173
00:10:46,640 --> 00:10:49,840
I've only seen that on one other
specimen, in life. Yep.
174
00:10:49,840 --> 00:10:51,760
This is the closest thing
to getting to touch
175
00:10:51,760 --> 00:10:53,160
a living, breathing dinosaur.
176
00:10:53,160 --> 00:10:54,600
It is.
177
00:10:54,600 --> 00:10:57,040
They found something extraordinary.
178
00:10:58,200 --> 00:11:00,720
It is so exceedingly rare -
179
00:11:00,720 --> 00:11:03,360
a piece of triceratops skin
in the Hell Creek formation.
180
00:11:06,320 --> 00:11:08,480
It may look like
an impression in the rock,
181
00:11:08,480 --> 00:11:12,760
but this is skin
that has been fossilised
182
00:11:12,760 --> 00:11:16,240
and, over millions of years,
has turned to stone.
183
00:11:17,560 --> 00:11:22,920
Triceratops bones are relatively
common finds in Hell Creek,
184
00:11:22,920 --> 00:11:28,840
but skin in such condition as this
is very rare indeed.
185
00:11:28,840 --> 00:11:32,560
The size and the patterning
of the scales,
186
00:11:32,560 --> 00:11:35,160
together with the age
and location of the rocks
187
00:11:35,160 --> 00:11:38,640
where it was found,
strongly suggests
188
00:11:38,640 --> 00:11:41,760
that this is
from a triceratops.
189
00:11:41,760 --> 00:11:46,080
The brown colour contains
traces of organic material.
190
00:11:46,080 --> 00:11:49,080
So it might even be possible
from this
191
00:11:49,080 --> 00:11:51,960
to work out
which pigments were in it.
192
00:11:51,960 --> 00:11:54,120
Finding and studying
193
00:11:54,120 --> 00:11:56,520
such well-preserved fossils
as this
194
00:11:56,520 --> 00:11:58,440
helps palaeontologists build
195
00:11:58,440 --> 00:12:02,280
a much more detailed picture
of how these creatures lived.
196
00:12:04,280 --> 00:12:06,040
Combining this information
197
00:12:06,040 --> 00:12:08,960
with insights from scientists
around the world
198
00:12:08,960 --> 00:12:11,000
makes it possible to speculate
199
00:12:11,000 --> 00:12:13,080
about what life
in the Late Cretaceous
200
00:12:13,080 --> 00:12:15,080
might have been like.
201
00:12:23,520 --> 00:12:24,960
We know from bones
202
00:12:24,960 --> 00:12:28,720
that adult triceratops could
reach nine metres in length
203
00:12:28,720 --> 00:12:30,640
and three metres in height.
204
00:12:34,960 --> 00:12:37,080
Marks on the fossil also show us
205
00:12:37,080 --> 00:12:39,680
that this one was badly scarred.
206
00:12:50,080 --> 00:12:52,560
Triceratops were plant-eaters.
207
00:12:56,680 --> 00:12:59,680
Other fossils tell us
that they had sharp beaks
208
00:12:59,680 --> 00:13:03,680
and hundreds of teeth that enabled
them to shred tough plants
209
00:13:03,680 --> 00:13:05,560
such as these cycads.
210
00:13:15,400 --> 00:13:18,400
Almost all adult
triceratops fossils,
211
00:13:18,400 --> 00:13:21,640
including Robert's,
have been found on their own.
212
00:13:23,240 --> 00:13:26,200
So it's possible
that the adults were solitary,
213
00:13:26,200 --> 00:13:28,760
like modern-day male rhinos.
214
00:13:30,920 --> 00:13:33,160
So they were
probably territorial,
215
00:13:33,160 --> 00:13:35,400
chasing rivals away.
216
00:13:41,640 --> 00:13:44,280
And perhaps
marking their territories.
217
00:13:49,720 --> 00:13:52,040
If you weigh more
than an African elephant,
218
00:13:52,040 --> 00:13:54,120
there's not much
that can bother you...
219
00:13:58,720 --> 00:14:01,800
..except perhaps a little mammal.
220
00:14:18,320 --> 00:14:21,200
Robert found these jawbones
221
00:14:21,200 --> 00:14:24,600
in the fossilised burrow at Tanis.
222
00:14:24,600 --> 00:14:27,840
The shape of this tiny bone
and tooth
223
00:14:27,840 --> 00:14:31,160
means it's most likely come
from what's known
224
00:14:31,160 --> 00:14:34,240
as a pediomyid, an early mammal
225
00:14:34,240 --> 00:14:37,240
and a type of marsupial.
226
00:14:40,640 --> 00:14:43,960
Robert also discovered
fossilised nuts and seeds
227
00:14:43,960 --> 00:14:45,240
in the burrow.
228
00:14:46,560 --> 00:14:49,600
So we have an idea about
what it might have eaten.
229
00:14:57,320 --> 00:14:59,240
Robert's finds are adding
230
00:14:59,240 --> 00:15:01,720
to our knowledge
of the complex world
231
00:15:01,720 --> 00:15:04,840
at the very end
of the Late Cretaceous.
232
00:15:04,840 --> 00:15:08,280
And it's not just
the fossilised creatures.
233
00:15:08,280 --> 00:15:10,920
If you walk on damp sand,
234
00:15:10,920 --> 00:15:12,960
you'll leave a trace behind.
235
00:15:17,240 --> 00:15:18,280
A footprint.
236
00:15:19,680 --> 00:15:24,040
The same was true
66 million years ago.
237
00:15:24,040 --> 00:15:28,520
And very, very occasionally,
such traces were preserved.
238
00:15:28,520 --> 00:15:32,120
And that's exactly
what happened here at Tanis.
239
00:15:34,280 --> 00:15:36,640
You know, we won't foil a backside.
240
00:15:36,640 --> 00:15:38,720
Right, we'll just put...
Put plaster right on.
241
00:15:38,720 --> 00:15:39,880
That way you've got...
242
00:15:39,880 --> 00:15:42,400
Robert has discovered
a number of footprints.
243
00:15:42,400 --> 00:15:44,320
Yeah. Let's see.
244
00:15:44,320 --> 00:15:46,640
Looks like a good print. Yeah.
245
00:15:51,080 --> 00:15:53,680
Their shape gives him a clue
246
00:15:53,680 --> 00:15:56,280
as to what might have made them.
247
00:16:01,280 --> 00:16:02,600
If he's right,
248
00:16:02,600 --> 00:16:05,040
they were made by a winged creature,
249
00:16:05,040 --> 00:16:08,080
that might well have liked
a small mammal...
250
00:16:10,880 --> 00:16:12,080
..for lunch.
251
00:16:19,160 --> 00:16:21,640
The footprints are long and narrow
252
00:16:21,640 --> 00:16:23,200
with four toe prints.
253
00:16:24,600 --> 00:16:27,800
Two are slightly longer
than the others,
254
00:16:27,800 --> 00:16:30,760
and that suggests
they were made by...
255
00:16:33,400 --> 00:16:34,800
..a pterosaur.
256
00:16:44,040 --> 00:16:48,200
Pterosaurs are not dinosaurs,
but flying reptiles
257
00:16:48,200 --> 00:16:51,240
on a different branch
of the evolutionary tree.
258
00:17:05,560 --> 00:17:08,200
Male pterosaurs
usually had crests,
259
00:17:08,200 --> 00:17:10,000
while females didn't.
260
00:17:10,000 --> 00:17:13,600
So crests may have been
used in courtship displays.
261
00:17:23,160 --> 00:17:27,200
And we have an indication of
where females laid their eggs,
262
00:17:27,200 --> 00:17:31,120
because evidence suggests
one pterosaur laid hers
263
00:17:31,120 --> 00:17:34,840
in the soft, sandy banks
of the river at Tanis.
264
00:17:50,080 --> 00:17:53,040
And this is a fossilised egg
265
00:17:53,040 --> 00:17:55,960
of a pterosaur
that Robert found there.
266
00:17:57,400 --> 00:18:00,760
The only one ever discovered
in North America.
267
00:18:00,760 --> 00:18:03,160
If you look at it
with the naked eye,
268
00:18:03,160 --> 00:18:07,200
all you see
is a jumble of lines.
269
00:18:07,200 --> 00:18:10,200
But if you examine it
with the latest technology,
270
00:18:10,200 --> 00:18:14,280
you can find out
a wealth of information,
271
00:18:14,280 --> 00:18:16,480
from the chemistry of the bones
272
00:18:16,480 --> 00:18:18,480
to the composition of the shell.
273
00:18:18,480 --> 00:18:21,360
And that, in turn,
can tell us a lot about
274
00:18:21,360 --> 00:18:24,200
how these incredible creatures
lived.
275
00:18:30,200 --> 00:18:32,160
Robert has been given access
276
00:18:32,160 --> 00:18:36,200
to the Diamond Light Source
synchrotron in Oxfordshire.
277
00:18:37,920 --> 00:18:40,080
It's a very powerful research tool
278
00:18:40,080 --> 00:18:42,160
that acts like a giant microscope.
279
00:18:45,280 --> 00:18:48,960
By accelerating electrons
in this huge ring,
280
00:18:48,960 --> 00:18:51,040
the synchrotron creates
beams of light
281
00:18:51,040 --> 00:18:53,560
many times brighter than the sun.
282
00:19:00,160 --> 00:19:04,440
Robert and paleobiologist
Dr Victoria Egerton
283
00:19:04,440 --> 00:19:07,480
now want to turn that beam
onto the egg fossil
284
00:19:07,480 --> 00:19:10,920
to discover more
about its chemical make-up.
285
00:19:10,920 --> 00:19:13,560
We're pretty much lined up
on the skeleton,
286
00:19:13,560 --> 00:19:15,440
but we might have to move
the stage a little bit
287
00:19:15,440 --> 00:19:18,320
to get to the right part. Sure.
288
00:19:18,320 --> 00:19:23,400
Meanwhile, Robert can reveal
the creature inside.
289
00:19:23,400 --> 00:19:25,520
And this?
290
00:19:25,520 --> 00:19:28,760
Who made this wonderful thing?
291
00:19:28,760 --> 00:19:32,080
I got replicas of the bones
from inside that egg
292
00:19:32,080 --> 00:19:34,520
and I restored the remainder
293
00:19:34,520 --> 00:19:35,560
and put together
294
00:19:35,560 --> 00:19:37,920
what the skeleton would've
looked like when it hatched.
295
00:19:37,920 --> 00:19:40,000
That's how big the creature
would've been
296
00:19:40,000 --> 00:19:41,440
outside the egg, if it had hatched.
297
00:19:41,440 --> 00:19:46,440
So this is the baby.
How big was it going to grow?
298
00:19:46,440 --> 00:19:49,160
These very long neck vertebrae
here
299
00:19:49,160 --> 00:19:52,320
are what really gave part
of the story away to us,
300
00:19:52,320 --> 00:19:54,840
because those long bones
match very, very closely
301
00:19:54,840 --> 00:19:56,480
with the azhdarchid pterosaurs.
302
00:19:56,480 --> 00:19:58,160
That is the giant pterosaurs.
303
00:19:58,160 --> 00:20:00,280
Oh, they were the whoppers,
weren't they?
304
00:20:00,280 --> 00:20:03,360
I mean, what, 25 feet?
305
00:20:03,360 --> 00:20:04,880
Wingspan? Some of them.
306
00:20:04,880 --> 00:20:09,240
This probably had a wingspan,
maybe 15 feet, five metres.
307
00:20:09,240 --> 00:20:12,000
Well, it looks as though
it could take off, really.
308
00:20:12,000 --> 00:20:14,000
It's easy to picture
something like that
309
00:20:14,000 --> 00:20:16,160
just hatching out of the egg
and fluttering out,
310
00:20:16,160 --> 00:20:18,000
almost like a little bat.
311
00:20:22,880 --> 00:20:27,360
They've scanned the egg,
here and in America.
312
00:20:29,120 --> 00:20:31,640
Victoria has the results.
313
00:20:33,480 --> 00:20:36,720
So what have you learned
from the synchrotron image?
314
00:20:36,720 --> 00:20:39,120
What we have here is a chemical map
315
00:20:39,120 --> 00:20:42,960
of calcium directly within
the bones of this animal.
316
00:20:42,960 --> 00:20:47,080
That tells us that these bones
were already hardened.
317
00:20:47,080 --> 00:20:50,880
So it might be ready to fly
not long after it hatches.
318
00:20:50,880 --> 00:20:53,440
OK. Can you see any sign
of the shell,
319
00:20:53,440 --> 00:20:54,840
and what sort of shell was it?
320
00:20:54,840 --> 00:20:58,120
We can. What I can show you...
321
00:20:58,120 --> 00:20:59,520
Ah!
322
00:20:59,520 --> 00:21:02,600
..is we can see the rim
of the egg in sulphur.
323
00:21:02,600 --> 00:21:07,560
Does that tell you whether it was
a hard shell or a soft shell?
324
00:21:07,560 --> 00:21:09,160
We have been looking at this.
325
00:21:09,160 --> 00:21:14,360
We can see folding occurring,
and this unusual undulation.
326
00:21:14,360 --> 00:21:16,160
If it were a hard egg,
327
00:21:16,160 --> 00:21:19,080
we would expect splintered bits
and broken bits,
328
00:21:19,080 --> 00:21:21,200
just like a chicken egg.
329
00:21:21,200 --> 00:21:23,000
This helped to tell us
that it was soft.
330
00:21:23,000 --> 00:21:25,200
So it was perhaps like a turtle?
331
00:21:25,200 --> 00:21:26,520
Absolutely.
332
00:21:26,520 --> 00:21:29,040
That's not the case, is it,
with dinosaurs?
333
00:21:29,040 --> 00:21:32,120
Many dinosaurs laid
hard-shelled eggs. Yes.
334
00:21:32,120 --> 00:21:35,400
So this is a new discovery
about azhdarchid pterosaurs?
335
00:21:35,400 --> 00:21:37,760
Absolutely. This is something
336
00:21:37,760 --> 00:21:40,000
that we are confirming
for the first time.
337
00:21:40,000 --> 00:21:41,360
Huh!
338
00:21:41,360 --> 00:21:44,640
That flying pterosaurs
had eggs like turtles.
339
00:21:44,640 --> 00:21:45,720
Yes.
340
00:21:45,720 --> 00:21:48,360
Much more reptilianlike
than birdlike.
341
00:21:48,360 --> 00:21:50,720
And that can potentially
tell us more
342
00:21:50,720 --> 00:21:54,120
about the environment
in which these eggs were laid.
343
00:21:54,120 --> 00:21:55,920
How interesting. Yeah.
344
00:22:04,240 --> 00:22:08,160
Creatures that lay soft eggs
tend to bury them
345
00:22:08,160 --> 00:22:09,800
in order to protect them.
346
00:22:15,480 --> 00:22:18,040
So female pterosaurs
probably looked for
347
00:22:18,040 --> 00:22:21,280
places like Tanis
to lay their eggs...
348
00:22:23,960 --> 00:22:28,000
..because the sandy soil here
is just soft enough
349
00:22:28,000 --> 00:22:31,200
for the hatchling to dig itself out.
350
00:22:32,960 --> 00:22:36,480
Now the pterosaur
just has to make sure
351
00:22:36,480 --> 00:22:38,040
that the hole...
352
00:22:39,560 --> 00:22:41,040
..is perfect.
353
00:22:57,640 --> 00:22:59,200
Success!
354
00:23:00,680 --> 00:23:03,080
But it's not over yet.
355
00:23:03,080 --> 00:23:06,520
Pterosaurs had two ovaries,
356
00:23:06,520 --> 00:23:09,240
and they laid their eggs in pairs.
357
00:23:19,000 --> 00:23:21,040
Here on the sandbank,
358
00:23:21,040 --> 00:23:25,240
sandwiched between the river
and these glorious trees,
359
00:23:25,240 --> 00:23:28,240
life at Tanis
seemed to be thriving.
360
00:23:28,240 --> 00:23:30,240
Whoops!
361
00:23:30,240 --> 00:23:32,160
Never a dull moment.
362
00:23:32,160 --> 00:23:35,200
But all that was about to change.
363
00:23:42,520 --> 00:23:45,840
The chain of events that led to the
extinction of the dinosaurs
364
00:23:45,840 --> 00:23:50,960
began in the distant past,
deep in space.
365
00:23:55,400 --> 00:23:59,520
Most scientists think it all started
in a ring of dust,
366
00:23:59,520 --> 00:24:03,280
rocks, and debris
known as the asteroid belt.
367
00:24:06,520 --> 00:24:09,000
It's usually an uneventful place.
368
00:24:12,920 --> 00:24:16,080
But it's thought that many,
many millions of years ago,
369
00:24:16,080 --> 00:24:19,240
a rock was bumped
into a new orbit...
370
00:24:23,760 --> 00:24:27,720
..and diverted onto a collision
course with Planet Earth.
371
00:24:40,400 --> 00:24:43,200
Robert is building a vivid picture
372
00:24:43,200 --> 00:24:45,440
of Late Cretaceous life
at Tanis.
373
00:24:48,120 --> 00:24:51,840
And the team have found some more
well-preserved footprints.
374
00:24:53,160 --> 00:24:56,520
So these are animals that were
actually walking in the water?
375
00:24:56,520 --> 00:24:58,560
These guys would've been
essentially on
376
00:24:58,560 --> 00:25:00,080
a mushy river bank going down
377
00:25:00,080 --> 00:25:01,800
to drink at some point.
378
00:25:01,800 --> 00:25:04,960
You know, animals tend to
congregate around the rivers.
379
00:25:04,960 --> 00:25:07,680
This print is 30 centimetres long.
380
00:25:08,880 --> 00:25:11,240
So I think this is from
a type of dinosaur
381
00:25:11,240 --> 00:25:13,160
that we call a duck-billed dinosaur.
382
00:25:13,160 --> 00:25:16,800
And they would've been
very common in the Cretaceous.
383
00:25:16,800 --> 00:25:19,120
They ate the plants in the area
384
00:25:19,120 --> 00:25:21,640
and they got very large -
30 feet long.
385
00:25:23,280 --> 00:25:24,840
And there are more.
386
00:25:24,840 --> 00:25:28,600
This track, you see all the toes
are very well preserved.
387
00:25:28,600 --> 00:25:31,680
You even see a nail print
at the tips of the toes.
388
00:25:31,680 --> 00:25:34,000
So the little toenails
dug into the mud.
389
00:25:34,000 --> 00:25:35,240
I love this one.
390
00:25:39,960 --> 00:25:43,120
This is Robert's prized footprint.
391
00:25:43,120 --> 00:25:46,040
It has three toes,
392
00:25:46,040 --> 00:25:49,560
and it's longer than it is wide.
393
00:25:49,560 --> 00:25:54,160
So it's very likely to be
a carnivorous dinosaur.
394
00:25:54,160 --> 00:25:56,680
It's so well preserved
that you can see
395
00:25:56,680 --> 00:26:00,240
the mark left by
its sharp claw there.
396
00:26:01,480 --> 00:26:03,040
Hell Creek is well known
397
00:26:03,040 --> 00:26:06,960
for one carnivore in particular -
T-rex.
398
00:26:08,040 --> 00:26:12,480
This footprint is too small
for an adult T-rex,
399
00:26:12,480 --> 00:26:16,480
but it's possible that it was made
by a young one.
400
00:26:26,560 --> 00:26:30,320
Robert also found this at Tanis -
401
00:26:30,320 --> 00:26:32,800
the crown of a tooth.
402
00:26:32,800 --> 00:26:36,800
Its shape and its serrated edge
403
00:26:36,800 --> 00:26:39,200
are indications that it comes
404
00:26:39,200 --> 00:26:40,960
from an adult T-rex.
405
00:27:06,360 --> 00:27:09,000
Bite marks found on T-rex bones
406
00:27:09,000 --> 00:27:12,000
show that they ate other T-rexes.
407
00:27:13,640 --> 00:27:16,320
And a youngster
would make an easy catch.
408
00:27:21,840 --> 00:27:23,680
But not this time.
409
00:27:33,040 --> 00:27:36,320
Very few footprints
are preserved as fossils
410
00:27:36,320 --> 00:27:38,200
in Hell Creek.
411
00:27:38,200 --> 00:27:40,520
So if you find several
in one place,
412
00:27:40,520 --> 00:27:42,160
as Robert has done,
413
00:27:42,160 --> 00:27:43,720
it's a reasonable assumption
414
00:27:43,720 --> 00:27:47,120
that there would've been
many more nearby.
415
00:27:50,440 --> 00:27:53,160
And that supports the idea
416
00:27:53,160 --> 00:27:57,880
that dinosaurs and pterosaurs
were thriving at Tanis
417
00:27:57,880 --> 00:27:59,960
shortly before the impact.
418
00:28:07,480 --> 00:28:09,040
And if they were thriving...
419
00:28:11,760 --> 00:28:15,440
..they must have been reproducing.
420
00:28:22,080 --> 00:28:25,080
Fossils from dinosaurs
similar to T-rex
421
00:28:25,080 --> 00:28:28,280
show they may have laid
around 20 eggs
422
00:28:28,280 --> 00:28:30,280
in a circular nest.
423
00:28:35,840 --> 00:28:38,280
It's possible that, like crocodiles,
424
00:28:38,280 --> 00:28:41,680
they partly covered their eggs
to keep them warm.
425
00:28:57,240 --> 00:29:00,360
For one T-rex, a misfortune.
426
00:29:07,360 --> 00:29:10,080
But for all dinosaurs...
427
00:29:11,280 --> 00:29:14,320
..a disaster was looming.
428
00:29:27,320 --> 00:29:31,720
Deep in space,
the asteroid was approaching.
429
00:29:36,440 --> 00:29:38,440
Its journey would take it through
the orbit
430
00:29:38,440 --> 00:29:41,240
of our neighbouring planet, Mars.
431
00:29:46,880 --> 00:29:48,720
Had the two collided,
432
00:29:48,720 --> 00:29:51,800
a catastrophe on Earth
would've been avoided.
433
00:30:00,640 --> 00:30:02,560
But it was not to be...
434
00:30:04,120 --> 00:30:06,800
..and Earth's fate was sealed.
435
00:30:20,560 --> 00:30:22,560
As Robert's dig continues,
436
00:30:22,560 --> 00:30:24,640
his vision of what happened at Tanis
437
00:30:24,640 --> 00:30:27,480
is finally starting to come
together.
438
00:30:29,480 --> 00:30:32,320
It seems the sandbank was full
of life.
439
00:30:32,320 --> 00:30:34,840
T-rex, triceratops,
440
00:30:34,840 --> 00:30:36,080
little mammals,
441
00:30:36,080 --> 00:30:40,000
alongside the footprints of
other dinosaurs and pterosaurs,
442
00:30:40,000 --> 00:30:42,040
all in a very small area.
443
00:30:43,840 --> 00:30:45,800
You see the scales?
444
00:30:45,800 --> 00:30:47,840
I do. Oh, my God.
445
00:30:47,840 --> 00:30:50,080
That excites me just looking at it!
446
00:30:51,960 --> 00:30:55,560
Then Robert finds
something truly remarkable.
447
00:30:58,880 --> 00:31:01,600
See the cracks already forming?
Look at that.
448
00:31:01,600 --> 00:31:04,520
So we're going to have to really
monitor that before we glue it.
449
00:31:04,520 --> 00:31:06,880
Cos this is getting vulnerable
now.
450
00:31:06,880 --> 00:31:09,320
An almost complete creature.
451
00:31:12,440 --> 00:31:14,800
To get this block out,
we're freezing it.
452
00:31:21,440 --> 00:31:24,360
Robert is about to attempt
something tricky.
453
00:31:26,200 --> 00:31:28,760
Steady... Let's go.
454
00:31:30,640 --> 00:31:33,640
To get the fossil out
in one piece, they're trying
455
00:31:33,640 --> 00:31:36,120
to freeze it using liquid nitrogen
456
00:31:36,120 --> 00:31:39,280
at almost 200 degrees below zero.
457
00:31:45,080 --> 00:31:46,440
Watch your footing.
458
00:31:47,720 --> 00:31:49,880
Loren, I'm worried
about brittleness here.
459
00:31:49,880 --> 00:31:53,200
Get that hammer. Give this a couple
whacks with the hammer.
460
00:31:54,840 --> 00:31:57,800
OK. Move over five centimetres.
Good.
461
00:32:01,000 --> 00:32:04,600
It's cracked loose. Yep.
OK. It's loose.
462
00:32:04,600 --> 00:32:07,120
So we have to get this out
in one piece.
463
00:32:07,120 --> 00:32:10,160
One, two, three.
464
00:32:11,760 --> 00:32:13,480
Yeehaw!
465
00:32:14,680 --> 00:32:16,640
Total success. Total success.
466
00:32:18,120 --> 00:32:20,800
This is a technique
used in archaeology
467
00:32:20,800 --> 00:32:23,240
for digging up human remains.
468
00:32:23,240 --> 00:32:25,400
We've got enough time
to work with the fossil
469
00:32:25,400 --> 00:32:27,120
and not damage it.
470
00:32:27,120 --> 00:32:29,600
And I couldn't be happier.
471
00:32:32,360 --> 00:32:34,640
And the creature Robert found?
472
00:32:36,120 --> 00:32:37,480
A turtle.
473
00:32:39,560 --> 00:32:43,440
This is the fossil
now it's been cleaned up.
474
00:32:43,440 --> 00:32:46,080
It's lying on its side.
475
00:32:46,080 --> 00:32:48,960
Here's the outline of its shell.
476
00:32:50,280 --> 00:32:54,000
The shape of the shell
and the scalloped edges here
477
00:32:54,000 --> 00:32:56,720
tell us that this was
a baenid turtle.
478
00:33:00,240 --> 00:33:03,520
Robert's baenid turtle
looks very similar
479
00:33:03,520 --> 00:33:05,320
to modern cooter turtles
480
00:33:05,320 --> 00:33:08,720
and lived in the same sort
of freshwater environment.
481
00:33:15,760 --> 00:33:18,920
For a turtle,
Tanis would've been ideal.
482
00:33:22,800 --> 00:33:25,520
Warm, shallow water.
483
00:33:27,760 --> 00:33:29,080
Plenty to eat.
484
00:33:33,880 --> 00:33:36,800
And lots of safe places
in which to warm up
485
00:33:36,800 --> 00:33:38,960
in the Late Cretaceous sunshine.
486
00:33:43,720 --> 00:33:47,320
The turtle fossil Robert found
is almost complete.
487
00:33:47,320 --> 00:33:50,200
This is the underside,
488
00:33:50,200 --> 00:33:55,280
and this brown material up here
is fossilised wood.
489
00:33:55,280 --> 00:33:59,000
It's the end of a stick that passes
right through its body
490
00:33:59,000 --> 00:34:02,200
and comes out just here.
491
00:34:02,200 --> 00:34:04,000
So the evidence points towards
492
00:34:04,000 --> 00:34:06,280
this turtle having been impaled.
493
00:34:09,000 --> 00:34:12,120
A violent end to one of
the many creatures found
494
00:34:12,120 --> 00:34:15,400
in the crumbly rock layer at Tanis.
495
00:34:16,440 --> 00:34:18,080
When I look at the animals
496
00:34:18,080 --> 00:34:20,720
and plants preserved
in the sediments of Tanis
497
00:34:20,720 --> 00:34:22,440
and the footprints beneath it,
498
00:34:22,440 --> 00:34:25,080
I see a picture of
a vibrant ecosystem,
499
00:34:25,080 --> 00:34:29,240
many different dinosaurs,
and a thriving, thriving place.
500
00:34:32,560 --> 00:34:34,480
After ten years of digging,
501
00:34:34,480 --> 00:34:37,600
there is now enough evidence
to piece together
502
00:34:37,600 --> 00:34:39,440
much of the story of Tanis
503
00:34:39,440 --> 00:34:42,080
and the creatures which lived here.
504
00:34:45,600 --> 00:34:49,200
Robert has found so many fossils,
it looks as if,
505
00:34:49,200 --> 00:34:51,600
even at the very end
of the Late Cretaceous,
506
00:34:51,600 --> 00:34:53,680
Tanis was bursting with life.
507
00:34:55,600 --> 00:34:59,440
Full of the giant reptiles
that had dominated the planet
508
00:34:59,440 --> 00:35:02,520
for more than 150 million years.
509
00:35:08,440 --> 00:35:11,640
It's impossible to know
how much longer
510
00:35:11,640 --> 00:35:13,280
their reign would've continued...
511
00:35:16,760 --> 00:35:21,240
..because all this was about to end.
512
00:35:42,480 --> 00:35:44,400
The asteroid hit...
513
00:35:48,080 --> 00:35:52,280
..in what is now the Yucatan
peninsula in Mexico.
514
00:35:55,120 --> 00:35:57,800
It's called the Chicxulub asteroid
515
00:35:57,800 --> 00:36:00,720
after the town nearest
to the centre of its crater.
516
00:36:18,920 --> 00:36:23,160
Any living thing within 900 miles
of the impact...
517
00:36:25,280 --> 00:36:28,120
..was destroyed by the blast.
518
00:36:33,000 --> 00:36:35,840
But what effect
did the impact have on Tanis,
519
00:36:35,840 --> 00:36:38,360
nearly 2,000 miles away?
520
00:36:48,080 --> 00:36:49,640
To find out,
521
00:36:49,640 --> 00:36:53,720
Robert is looking for clues
that might link Tanis
522
00:36:53,720 --> 00:36:56,920
to the actual day the asteroid hit.
523
00:37:02,920 --> 00:37:04,320
We've got some wood,
524
00:37:04,320 --> 00:37:07,320
and pressed up against this
and all intertangled,
525
00:37:07,320 --> 00:37:09,200
we've got the carcasses of fish.
526
00:37:09,200 --> 00:37:10,520
OK.
527
00:37:11,760 --> 00:37:13,720
That's a beautifully preserved
tail,
528
00:37:13,720 --> 00:37:16,640
so that fish is going to be
absolutely gorgeous.
529
00:37:16,640 --> 00:37:19,200
So part of the detail work
that we're doing right now
530
00:37:19,200 --> 00:37:20,840
is going in and checking out
531
00:37:20,840 --> 00:37:24,600
all the individual elements
in this mass death layer.
532
00:37:24,600 --> 00:37:27,840
Some of the evidence
he's found so far
533
00:37:27,840 --> 00:37:31,400
has been hidden inside
the fish themselves.
534
00:37:34,480 --> 00:37:37,640
In more ways than one, it literally
is an operation of a Cretaceous
535
00:37:37,640 --> 00:37:40,640
fish, so we're performing surgery
on this thing.
536
00:37:40,640 --> 00:37:43,680
Robert needs to open this
fish's skull.
537
00:37:45,400 --> 00:37:48,720
And very carefully,
we want to separate this
538
00:37:48,720 --> 00:37:50,200
from the rest of the fish.
539
00:37:51,440 --> 00:37:52,760
OK.
540
00:37:56,320 --> 00:37:58,640
Here we go.
541
00:37:58,640 --> 00:38:00,880
Opening up the fish.
542
00:38:00,880 --> 00:38:03,080
Got a nice ant
that made a home in there.
543
00:38:04,200 --> 00:38:05,880
And beautiful, look at that.
544
00:38:05,880 --> 00:38:08,920
OK, here we have
the gill bars of the fish.
545
00:38:08,920 --> 00:38:11,560
Those are the bars that hold
the filaments of the gills.
546
00:38:12,760 --> 00:38:14,480
And between the gill bars,
547
00:38:14,480 --> 00:38:16,560
all of these clusters
of round objects,
548
00:38:16,560 --> 00:38:18,360
those are the ejecta spherules.
549
00:38:19,400 --> 00:38:23,840
Ejecta spherules are tiny balls
that were once molten rock.
550
00:38:23,840 --> 00:38:26,440
They could be evidence
of what Robert suspects -
551
00:38:26,440 --> 00:38:28,040
that creatures here died
552
00:38:28,040 --> 00:38:30,760
on the day
of the asteroid strike.
553
00:38:31,960 --> 00:38:34,880
Those ejecta spherules
last saw the light of day
554
00:38:34,880 --> 00:38:37,880
when they were flying through
the air 66 billion years ago.
555
00:38:48,400 --> 00:38:52,000
After a large asteroid impact,
556
00:38:52,000 --> 00:38:54,760
a mix of vaporised and molten rock
557
00:38:54,760 --> 00:38:56,880
is propelled into space.
558
00:38:59,840 --> 00:39:01,400
There, it cools,
559
00:39:01,400 --> 00:39:04,600
solidifying
into tiny glass droplets.
560
00:39:06,160 --> 00:39:09,280
Some carry on deeper into space.
561
00:39:11,440 --> 00:39:14,760
But most are pulled back
to Earth by gravity.
562
00:39:22,280 --> 00:39:25,120
After a major asteroid hit,
563
00:39:25,120 --> 00:39:29,840
trillions of ejecta spherules
would fall from the sky.
564
00:39:29,840 --> 00:39:32,040
Then, over millions of years,
565
00:39:32,040 --> 00:39:35,040
pressure and chemical reactions
in the ground
566
00:39:35,040 --> 00:39:38,200
would turn most of them to clay.
567
00:39:38,200 --> 00:39:40,760
They'd look something like this.
568
00:39:41,840 --> 00:39:45,960
So finding spherules
in the gills of a fish,
569
00:39:45,960 --> 00:39:48,280
as Robert has done at Tanis,
570
00:39:48,280 --> 00:39:50,680
suggests the fish sucked them in
571
00:39:50,680 --> 00:39:53,480
while the spherules
were still falling.
572
00:39:53,480 --> 00:39:55,280
So these creatures could have died
573
00:39:55,280 --> 00:39:58,160
at the time of an asteroid impact.
574
00:40:03,560 --> 00:40:06,960
Once Robert begins to look
for ejecta spherules,
575
00:40:06,960 --> 00:40:08,640
he finds more and more,
576
00:40:08,640 --> 00:40:13,040
and realises the thick,
crumbly layer of rock at Tanis
577
00:40:13,040 --> 00:40:14,440
is full of them.
578
00:40:17,760 --> 00:40:20,000
I mean, this stuff is go...
Oh, my God, look at that one.
579
00:40:20,000 --> 00:40:21,960
These things are just gorgeous.
580
00:40:23,440 --> 00:40:24,840
Ejecta spherules like this
581
00:40:24,840 --> 00:40:27,440
give us a fingerprint
of where they came from.
582
00:40:29,080 --> 00:40:31,120
If these spherules were connected
583
00:40:31,120 --> 00:40:32,880
to the Chicxulub impact,
584
00:40:32,880 --> 00:40:36,000
then the whole crumbly layer
could be full of evidence
585
00:40:36,000 --> 00:40:39,680
of what happened on the day
the asteroid hit.
586
00:40:39,680 --> 00:40:40,960
That's a good one.
587
00:40:40,960 --> 00:40:43,360
Oh, is that a droplet right there?
588
00:40:43,360 --> 00:40:45,320
To see if that's the case,
589
00:40:45,320 --> 00:40:48,960
Robert needs to find a spherule
that hasn't turned to clay.
590
00:40:48,960 --> 00:40:52,760
Oh, my God,
that's a beautiful droplet.
591
00:40:52,760 --> 00:40:54,680
OK.
592
00:40:54,680 --> 00:40:57,800
The small pieces of orange material
593
00:40:57,800 --> 00:40:59,640
that Robert and Loren are digging up
594
00:40:59,640 --> 00:41:01,800
may be able to help.
595
00:41:01,800 --> 00:41:04,840
They're amber.
596
00:41:04,840 --> 00:41:07,320
If there was anything flying
through the air at that time,
597
00:41:07,320 --> 00:41:09,160
this is where it's going to get
caught.
598
00:41:11,480 --> 00:41:14,800
The amber they're collecting
was once sticky resin
599
00:41:14,800 --> 00:41:17,920
oozing out of
a Late Cretaceous tree trunk.
600
00:41:19,720 --> 00:41:22,120
It's a way for the tree
to protect itself,
601
00:41:22,120 --> 00:41:24,920
like a scab forming on a cut.
602
00:41:33,120 --> 00:41:35,960
Anything covered by the resin
would be frozen
603
00:41:35,960 --> 00:41:38,000
in an amber time capsule.
604
00:41:44,480 --> 00:41:46,840
If they find a spherule
preserved in amber,
605
00:41:46,840 --> 00:41:49,400
it could be analysed
606
00:41:49,400 --> 00:41:52,560
to see if it comes from
the Chicxulub asteroid impact.
607
00:41:55,640 --> 00:41:57,080
So during this batch,
608
00:41:57,080 --> 00:42:00,640
we were incredibly lucky
that we came across
609
00:42:00,640 --> 00:42:03,080
two completely unaltered spherules.
610
00:42:04,560 --> 00:42:07,960
This spherule could be
something amazing.
611
00:42:07,960 --> 00:42:12,600
Evidence preserved well enough
to analyse for chemical clues.
612
00:42:15,480 --> 00:42:16,880
If so,
613
00:42:16,880 --> 00:42:21,440
it could link Tanis directly
with the Chicxulub impact
614
00:42:21,440 --> 00:42:23,920
and the last day of the dinosaurs.
615
00:42:31,520 --> 00:42:34,160
To investigate, Robert is joined
616
00:42:34,160 --> 00:42:36,240
at the Diamond Light Source
617
00:42:36,240 --> 00:42:39,120
by Professor of Natural History
Phil Manning,
618
00:42:39,120 --> 00:42:41,440
of the University of Manchester.
619
00:42:41,440 --> 00:42:43,920
They've already run initial tests
620
00:42:43,920 --> 00:42:45,920
on the spherules in America.
621
00:42:45,920 --> 00:42:47,800
What have you found out so far?
622
00:42:47,800 --> 00:42:51,560
These little glass spherules,
these globs
623
00:42:51,560 --> 00:42:53,520
of molten material
from the impact site
624
00:42:53,520 --> 00:42:56,960
have a chemical signal that ties it
with where they came from.
625
00:42:56,960 --> 00:42:58,480
Cos when an asteroid hits,
626
00:42:58,480 --> 00:43:00,680
it melts the ground that it hits,
627
00:43:00,680 --> 00:43:02,920
but also that glass has
628
00:43:02,920 --> 00:43:05,520
a little bit of contamination
from the asteroid itself.
629
00:43:05,520 --> 00:43:08,920
And that gives you a unique
geochemical fingerprint.
630
00:43:08,920 --> 00:43:10,440
We can see once we've scanned it,
631
00:43:10,440 --> 00:43:13,280
and looking at spherules from
other sites in North Dakota,
632
00:43:13,280 --> 00:43:14,960
we can get a baseline
633
00:43:14,960 --> 00:43:19,200
for what the ejecta should look
like when it's related to
634
00:43:19,200 --> 00:43:20,880
the Chicxulub crater.
635
00:43:20,880 --> 00:43:22,440
And you can see each element here
636
00:43:22,440 --> 00:43:24,480
and the ratios of those elements.
637
00:43:24,480 --> 00:43:27,720
And when we look at Tanis,
it's a match.
638
00:43:27,720 --> 00:43:30,480
I mean, it perfectly overlays.
639
00:43:30,480 --> 00:43:33,480
So I think
this is powerful evidence
640
00:43:33,480 --> 00:43:37,080
supporting that Tanis
and Chicxulub are linked.
641
00:43:37,080 --> 00:43:39,120
And what do these findings mean
642
00:43:39,120 --> 00:43:42,040
for the rest of the fossils
that you're finding in Tanis?
643
00:43:42,040 --> 00:43:45,080
This data is key for the
entire site,
644
00:43:45,080 --> 00:43:47,360
because once you have that link
645
00:43:47,360 --> 00:43:50,120
and you know
what impact affected Tanis,
646
00:43:50,120 --> 00:43:53,760
then you essentially know
that every object in that site,
647
00:43:53,760 --> 00:43:56,640
all the animals and the plants
and everything buried
648
00:43:56,640 --> 00:43:58,000
in those sediments,
649
00:43:58,000 --> 00:44:00,640
are linked to the last day
of the Cretaceous.
650
00:44:02,560 --> 00:44:05,480
And the synchrotron here in the UK
651
00:44:05,480 --> 00:44:08,040
reveals something even more
remarkable.
652
00:44:10,440 --> 00:44:15,000
So this is showing
a beautiful synchrotron scan
653
00:44:15,000 --> 00:44:17,400
of the half of one spherule.
654
00:44:17,400 --> 00:44:20,240
The glass is
a good geochemical fingerprint,
655
00:44:20,240 --> 00:44:23,920
and we've got calcium, some iron,
656
00:44:23,920 --> 00:44:25,960
we've got strontium,
657
00:44:25,960 --> 00:44:27,760
but when we look at the
entire thing,
658
00:44:27,760 --> 00:44:30,720
we see something quite unexpected.
659
00:44:30,720 --> 00:44:32,880
That's your entire spherule.
660
00:44:32,880 --> 00:44:34,280
What's this?
661
00:44:34,280 --> 00:44:37,280
In this, we've got
a little bit of a nugget.
662
00:44:37,280 --> 00:44:39,520
There was a little particle
right there.
663
00:44:39,520 --> 00:44:40,760
So we scan it.
664
00:44:40,760 --> 00:44:43,240
And that's a lot of iron
in there.
665
00:44:43,240 --> 00:44:46,080
Over here, we've got chromium,
a big peak in chromium.
666
00:44:46,080 --> 00:44:49,160
Over here, we've got
a big peak in nickel.
667
00:44:49,160 --> 00:44:51,960
And the abundances
of iron, nickel and chromium,
668
00:44:51,960 --> 00:44:53,400
all together,
669
00:44:53,400 --> 00:44:56,120
that matches what you expect
to see in a meteoric body.
670
00:44:56,120 --> 00:44:59,120
That does not match what you
would normally have down here.
671
00:44:59,120 --> 00:45:02,720
So this is
extraterrestrial material?
672
00:45:02,720 --> 00:45:04,960
If you were to sort of grind up
673
00:45:04,960 --> 00:45:10,320
and stuff into a spherule
a piece of meteorite,
674
00:45:10,320 --> 00:45:12,200
that's what it's going to look
like.
675
00:45:12,200 --> 00:45:15,560
This could be a piece of
the Chicxulub asteroid.
676
00:45:15,560 --> 00:45:17,760
A piece of the bullet
that killed the dinosaurs.
677
00:45:17,760 --> 00:45:19,160
No!
678
00:45:25,720 --> 00:45:27,320
Robert could have found
679
00:45:27,320 --> 00:45:30,680
a fragment of the asteroid itself
in Tanis,
680
00:45:30,680 --> 00:45:36,440
physical evidence linking this site
to the Chicxulub impact.
681
00:45:36,440 --> 00:45:39,680
But Tanis is almost 2,000 miles away
682
00:45:39,680 --> 00:45:41,600
from where the asteroid hit.
683
00:45:41,600 --> 00:45:45,400
So exactly how did it cause
the creatures' deaths?
684
00:45:49,080 --> 00:45:51,200
To answer that question,
685
00:45:51,200 --> 00:45:54,880
Robert is searching
in the mass death layer.
686
00:45:57,520 --> 00:46:01,280
Right here, we've got
this intertangled mass of fish.
687
00:46:01,280 --> 00:46:03,800
There's one fish here,
another sturgeon goes this way,
688
00:46:03,800 --> 00:46:05,800
underneath the body of a paddlefish.
689
00:46:05,800 --> 00:46:07,680
There's another sturgeon
that goes this way,
690
00:46:07,680 --> 00:46:11,240
underneath this log, and continues
out the other side.
691
00:46:11,240 --> 00:46:13,400
And his head hit that log
692
00:46:13,400 --> 00:46:16,760
and has deflected downward
at a 90-degree angle.
693
00:46:18,760 --> 00:46:23,840
Robert uncovered a tangled mass of
fossilised creatures and logs
694
00:46:23,840 --> 00:46:26,040
surrounded by spherules
695
00:46:26,040 --> 00:46:30,480
and crushed together
in what's known as a logjam.
696
00:46:30,480 --> 00:46:33,280
He has a theory that
the creatures were swept
697
00:46:33,280 --> 00:46:36,760
to their death in some kind
of turbulent surge of water
698
00:46:36,760 --> 00:46:39,120
and quickly entombed in sediment,
699
00:46:39,120 --> 00:46:41,960
which is why
they're so well preserved.
700
00:46:41,960 --> 00:46:44,720
But what could have caused the wave?
701
00:46:48,560 --> 00:46:51,200
One theory is a tsunami.
702
00:46:55,360 --> 00:46:57,880
The asteroid hit at sea.
703
00:46:57,880 --> 00:46:59,440
Recent studies show
704
00:46:59,440 --> 00:47:03,480
it may have caused a wave
almost a mile high.
705
00:47:16,400 --> 00:47:19,280
The height of the wave
would've gradually reduced
706
00:47:19,280 --> 00:47:21,520
as it spread across the oceans.
707
00:47:23,000 --> 00:47:24,480
In the Late Cretaceous,
708
00:47:24,480 --> 00:47:27,600
North America was divided
by a narrow sea
709
00:47:27,600 --> 00:47:30,840
that's been called
the Western Interior Seaway.
710
00:47:30,840 --> 00:47:33,640
The tsunami could have
travelled up this,
711
00:47:33,640 --> 00:47:35,240
towards Tanis.
712
00:47:38,680 --> 00:47:41,440
But there's a big question
about the tsunami idea.
713
00:47:43,040 --> 00:47:45,000
The timing.
714
00:47:45,000 --> 00:47:47,920
Oh, which fish is that?
715
00:47:47,920 --> 00:47:51,040
That's a new...
It's a new contact. New one. Yeah.
716
00:47:51,040 --> 00:47:53,920
If a tsunami killed the fish,
717
00:47:53,920 --> 00:47:55,960
it would have to have hit
718
00:47:55,960 --> 00:47:57,760
while ejecta spherules
were falling...
719
00:47:59,080 --> 00:48:03,160
..because spherules were found
in the fish's gills.
720
00:48:04,880 --> 00:48:10,200
So how long after impact did
the spherules arrive at Tanis?
721
00:48:10,200 --> 00:48:12,680
Pretend this ball of foil
is a piece of ejecta
722
00:48:12,680 --> 00:48:15,840
coming out of the crater. It would
then go on an arc path,
723
00:48:15,840 --> 00:48:17,840
ballistic trajectory,
out of the crater
724
00:48:17,840 --> 00:48:20,400
and to wherever it lands -
in this case, Tanis.
725
00:48:22,480 --> 00:48:25,000
If we know the distance
between myself
726
00:48:25,000 --> 00:48:28,360
and the landing site, and if we know
the size of that ball,
727
00:48:28,360 --> 00:48:31,560
we can accurately calculate how long
it would take to get there.
728
00:48:35,560 --> 00:48:37,480
The result is surprising.
729
00:48:37,480 --> 00:48:39,960
Robert and his team calculated
730
00:48:39,960 --> 00:48:43,320
that these ejecta spherules
landed at Tanis
731
00:48:43,320 --> 00:48:47,680
between 13 minutes
and two hours after the impact.
732
00:48:50,280 --> 00:48:52,320
If a wave killed the fish,
733
00:48:52,320 --> 00:48:55,680
it must also have reached Tanis
within two hours.
734
00:48:59,760 --> 00:49:02,040
Data from recent tsunamis show
735
00:49:02,040 --> 00:49:05,400
even a powerful one would take much
longer than that
736
00:49:05,400 --> 00:49:09,200
to travel almost 2,000 miles
from the impact site
737
00:49:09,200 --> 00:49:10,640
to Tanis.
738
00:49:11,640 --> 00:49:14,280
So if it wasn't a tsunami,
739
00:49:14,280 --> 00:49:17,040
what could have caused
a surge of water at Tanis?
740
00:49:26,320 --> 00:49:30,320
Professor Stein Bondevik
is an expert in tsunamis.
741
00:49:35,800 --> 00:49:38,720
The fjords in Norway
are very special.
742
00:49:40,120 --> 00:49:44,120
We have tall mountains
surrounding bodies of water.
743
00:49:44,120 --> 00:49:47,400
So the water is usually very calm.
744
00:49:47,400 --> 00:49:52,120
In 2011, something very strange
happened.
745
00:49:52,120 --> 00:49:56,480
The water in the fjord
began to move violently.
746
00:49:56,480 --> 00:50:01,080
The height of the water increased
by one and a half metre,
747
00:50:01,080 --> 00:50:05,080
like a maelstrom
with the turbulent water.
748
00:50:05,080 --> 00:50:07,800
Someone said
that the fjord was boiling.
749
00:50:09,400 --> 00:50:11,240
News started to roll in -
750
00:50:11,240 --> 00:50:15,520
there'd been an earthquake
5,000 miles away in Japan.
751
00:50:18,440 --> 00:50:21,240
A journalist from
the local newspaper called me,
752
00:50:21,240 --> 00:50:24,160
and he said that
people were observing waves
753
00:50:24,160 --> 00:50:25,560
here, in the fjords.
754
00:50:27,680 --> 00:50:30,160
I got a video clip of the waves.
755
00:50:30,160 --> 00:50:33,600
I saw immediately that they looked
like a tsunami wave.
756
00:50:33,600 --> 00:50:35,440
So later in the afternoon,
757
00:50:35,440 --> 00:50:38,600
you can see that the fjord is
perfectly calm.
758
00:50:40,240 --> 00:50:41,480
But at the beach here,
759
00:50:41,480 --> 00:50:44,600
you could see that the water
is sloshing back and forth,
760
00:50:44,600 --> 00:50:47,560
and no-one had ever seen
anything like it.
761
00:50:48,920 --> 00:50:52,120
And some people
got very upset and afraid.
762
00:50:55,320 --> 00:51:00,560
A magnitude nine earthquake had
devastated the northeast of Japan,
763
00:51:00,560 --> 00:51:02,560
around Fukushima.
764
00:51:05,440 --> 00:51:09,280
But how did that affect a fjord
so far away?
765
00:51:11,920 --> 00:51:14,840
So no-one in Norway
could feel the earthquake,
766
00:51:14,840 --> 00:51:18,400
but I could see that
the times matched
767
00:51:18,400 --> 00:51:21,200
the arrival of the waves here,
in the fjord.
768
00:51:24,920 --> 00:51:28,200
Eventually,
Stein and his team realised
769
00:51:28,200 --> 00:51:32,960
that this might have something
to do with seismic waves -
770
00:51:32,960 --> 00:51:36,120
shock waves that pass quickly
through the Earth
771
00:51:36,120 --> 00:51:37,680
during an earthquake.
772
00:51:39,080 --> 00:51:42,560
So it took only 12 minutes
before the first signal
773
00:51:42,560 --> 00:51:45,240
of the earthquake in Japan
reached all the way here,
774
00:51:45,240 --> 00:51:46,600
to western Norway.
775
00:51:49,120 --> 00:51:50,920
So it was the seismic waves
776
00:51:50,920 --> 00:51:53,720
that caused the normally calm
water in the fjord
777
00:51:53,720 --> 00:51:56,680
to slosh turbulently
back and forth.
778
00:51:58,480 --> 00:52:03,440
Just thinking of that,
scientifically, it's fantastic.
779
00:52:09,560 --> 00:52:13,360
Could something similar
have happened in Tanis?
780
00:52:13,360 --> 00:52:16,680
A large weather front's
coming through the northwest...
781
00:52:18,120 --> 00:52:20,000
Trying to find out
782
00:52:20,000 --> 00:52:23,240
is geophysicist professor
Mark Richards,
783
00:52:23,240 --> 00:52:26,800
who's been studying the site at
Tanis for several years.
784
00:52:27,920 --> 00:52:30,280
He's working with Robert
to discover
785
00:52:30,280 --> 00:52:33,120
what could have caused
a surge of water here.
786
00:52:40,240 --> 00:52:43,520
A tsunami can't get here
in less than minimum 12 hours.
787
00:52:45,400 --> 00:52:49,240
But seismic waves travelling
from the Yucatan impact site
788
00:52:49,240 --> 00:52:52,120
to North Dakota
can arrive here fairly quickly.
789
00:52:54,400 --> 00:52:58,320
In the Late Cretaceous,
the Western Interior Seaway
790
00:52:58,320 --> 00:53:02,440
that divided North America could
have been connected to Tanis
791
00:53:02,440 --> 00:53:04,360
through a system of rivers.
792
00:53:09,600 --> 00:53:12,080
If you have
a very large body of water,
793
00:53:12,080 --> 00:53:15,080
like the Western Interior Seaway,
794
00:53:15,080 --> 00:53:17,360
and you can shake it back and forth,
795
00:53:17,360 --> 00:53:20,600
you can generate
a large water wave
796
00:53:20,600 --> 00:53:23,200
coming up this river at Tanis.
797
00:53:27,680 --> 00:53:31,400
So seismic waves from the impact
could have caused
798
00:53:31,400 --> 00:53:34,320
surges of water
in the Tanis river system.
799
00:53:35,400 --> 00:53:38,560
The seismic waves
get here quickly enough,
800
00:53:38,560 --> 00:53:40,920
coming up the Tanis river,
801
00:53:40,920 --> 00:53:43,320
inundating this area,
arriving at the same time
802
00:53:43,320 --> 00:53:46,000
these spherules are
still falling out of the air.
803
00:53:48,840 --> 00:53:50,440
The mystery of the wave
804
00:53:50,440 --> 00:53:54,760
and the thick layer of crumbly rock
has been solved.
805
00:53:54,760 --> 00:53:57,280
Seismic waves travelling
through the Earth
806
00:53:57,280 --> 00:54:01,120
could have caused powerful surges of
water at Tanis...
807
00:54:03,760 --> 00:54:06,240
..possibly carrying mud
and marine creatures,
808
00:54:06,240 --> 00:54:10,320
like ammonites, from the Western
Interior Seaway...
809
00:54:13,160 --> 00:54:17,680
..dumping them on the Tanis sandbank
and burying everything
810
00:54:17,680 --> 00:54:20,600
at the same time as spherules fell.
811
00:54:29,000 --> 00:54:30,240
Over millions of years,
812
00:54:30,240 --> 00:54:34,440
the mud would turn into
the layer of crumbly rock.
813
00:54:36,200 --> 00:54:38,280
And that's the beauty of Tanis.
814
00:54:38,280 --> 00:54:41,400
What you're seeing is a deposit
815
00:54:41,400 --> 00:54:45,760
that is literally recording
the last, say,
816
00:54:45,760 --> 00:54:49,600
45 minutes to an hour and a half
of the Cretaceous.
817
00:54:59,760 --> 00:55:02,960
If the extinction
of the dinosaurs was a crime,
818
00:55:02,960 --> 00:55:07,240
the detective solving it
would have plenty of evidence.
819
00:55:07,240 --> 00:55:09,160
They would see
that the asteroid was
820
00:55:09,160 --> 00:55:11,760
in the right place
at the right time.
821
00:55:11,760 --> 00:55:14,360
They would see
that no dinosaurs survived
822
00:55:14,360 --> 00:55:15,800
after the hit.
823
00:55:16,800 --> 00:55:19,120
They would have a piece
of the murder weapon -
824
00:55:19,120 --> 00:55:21,200
a fragment of the asteroid.
825
00:55:21,200 --> 00:55:25,160
But they would be missing
one very important thing -
826
00:55:25,160 --> 00:55:26,720
a body.
827
00:55:31,280 --> 00:55:35,000
No-one has ever found
the fossil of a dinosaur
828
00:55:35,000 --> 00:55:39,360
that was killed by the effects
of the asteroid impact.
829
00:55:39,360 --> 00:55:42,960
But Robert did find
part of a triceratops
830
00:55:42,960 --> 00:55:45,280
in the crumbly layer at Tanis.
831
00:55:45,280 --> 00:55:47,480
So could that be the remains
832
00:55:47,480 --> 00:55:50,360
of a dinosaur
that died on that day?
833
00:55:50,360 --> 00:55:51,880
I'm still dubious about the horn.
834
00:55:51,880 --> 00:55:53,880
I kind of want to keep
the horn in the jacket.
835
00:55:53,880 --> 00:55:55,120
I think if you took it off,
836
00:55:55,120 --> 00:55:56,760
at least take this section off,
837
00:55:56,760 --> 00:55:58,400
to see what's going on under here.
838
00:55:58,400 --> 00:55:59,560
Yeah?
839
00:55:59,560 --> 00:56:04,400
To find out, the team needs to
establish cause of death,
840
00:56:04,400 --> 00:56:07,760
which can be difficult when you only
have a piece of skin
841
00:56:07,760 --> 00:56:09,880
and a horn to go on.
842
00:56:12,000 --> 00:56:16,120
This is the horn
after they've cleaned it up.
843
00:56:16,120 --> 00:56:20,600
The team is particularly
interested in these lines here.
844
00:56:20,600 --> 00:56:23,200
And they found that the fractures go
845
00:56:23,200 --> 00:56:25,800
right through the horn.
846
00:56:25,800 --> 00:56:29,080
So rather than dying
as a result of the impact,
847
00:56:29,080 --> 00:56:32,440
they wondered whether
it had been killed in a fight.
848
00:56:38,160 --> 00:56:40,560
But when they looked at
the fractures in more detail,
849
00:56:40,560 --> 00:56:43,440
they found signs
of new bone growth here.
850
00:56:44,480 --> 00:56:47,880
An indication that
the bone had started to heal.
851
00:56:47,880 --> 00:56:50,440
So it looked as though
the triceratops survived
852
00:56:50,440 --> 00:56:52,880
the event that broke its horn.
853
00:56:57,520 --> 00:57:00,280
Could this triceratops
have survived
854
00:57:00,280 --> 00:57:03,000
until the day of the impact?
855
00:57:03,000 --> 00:57:06,640
The team found evidence,
including sagging in the skin,
856
00:57:06,640 --> 00:57:10,400
which suggested that
there was decay underneath.
857
00:57:10,400 --> 00:57:12,800
That means its body had started
to rot
858
00:57:12,800 --> 00:57:16,720
before it was entombed
and preserved by the surge.
859
00:57:16,720 --> 00:57:21,760
So it seems that this dinosaur
didn't die as a result
860
00:57:21,760 --> 00:57:23,720
of the asteroid impact.
861
00:57:25,400 --> 00:57:28,520
Perhaps, in the months
before the impact,
862
00:57:28,520 --> 00:57:30,600
the broken horn put the triceratops
863
00:57:30,600 --> 00:57:33,040
at a disadvantage over its rivals.
864
00:57:48,760 --> 00:57:51,480
And that might have led
to starvation.
865
00:58:13,600 --> 00:58:16,880
Robert has still not found
direct evidence
866
00:58:16,880 --> 00:58:19,840
of a dinosaur that was killed
by the asteroid.
867
00:58:21,040 --> 00:58:23,120
We've got all these bones
in the ground right now.
868
00:58:23,120 --> 00:58:25,920
But the one thing
that we would just dream
869
00:58:25,920 --> 00:58:27,880
of finding is that one dinosaur
870
00:58:27,880 --> 00:58:30,520
that died on the day of the impact.
871
00:58:34,400 --> 00:58:37,560
And the weather
isn't helping his search.
872
00:58:55,440 --> 00:58:57,640
That therapod print is toasted.
873
00:58:57,640 --> 00:58:59,800
Yeah, it was in a low corner.
874
00:58:59,800 --> 00:59:02,840
Look, it's full mud.
It's full of mud and water.
875
00:59:02,840 --> 00:59:05,000
The problem is it's wet, look.
876
00:59:05,000 --> 00:59:07,720
See... If we're not careful,
we're going to lose the print.
877
00:59:09,040 --> 00:59:11,160
And that's the biggest
theropod print we've got.
878
00:59:12,200 --> 00:59:14,800
I see some areas that could use
glue right now, too.
879
00:59:17,320 --> 00:59:20,640
The team is racing
to excavate the footprints,
880
00:59:20,640 --> 00:59:23,080
along with dozens of fish fossils
881
00:59:23,080 --> 00:59:27,800
tangled together in a logjam,
before storms wash them away.
882
00:59:29,160 --> 00:59:30,760
We're up against the clock here.
883
00:59:30,760 --> 00:59:32,600
This stuff that could be
exposed right now
884
00:59:32,600 --> 00:59:34,440
is going to get ruined by the rain.
885
00:59:37,000 --> 00:59:39,600
But then,
Robert comes across something
886
00:59:39,600 --> 00:59:41,280
that looks very unusual.
887
00:59:41,280 --> 00:59:43,040
That's going there.
888
00:59:44,640 --> 00:59:46,320
What is going on right there?
889
00:59:46,320 --> 00:59:48,680
Are we sure
this isn't crocodilian?
890
00:59:48,680 --> 00:59:50,680
That's not crocodilian. No.
891
00:59:50,680 --> 00:59:53,280
Right, let me try
this piece right here.
892
00:59:53,280 --> 00:59:55,920
I'll go in from the top
and then twist up,
893
00:59:55,920 --> 00:59:57,520
and it separates right on that line.
894
00:59:57,520 --> 01:00:00,040
Oh, that's skin right there.
895
01:00:00,040 --> 01:00:02,520
That's actually scaly skin.
Oh, my God.
896
01:00:02,520 --> 01:00:04,360
No, no, no, no, no.
Look, look, look.
897
01:00:04,360 --> 01:00:06,320
Look at that pattern
right there.
898
01:00:06,320 --> 01:00:09,080
Have you ever seen elongated
scales like that before, Dave?
899
01:00:09,080 --> 01:00:11,320
That's insane.
Scuttelates - in birds.
900
01:00:11,320 --> 01:00:13,080
Just careful.
901
01:00:13,080 --> 01:00:15,440
Oh, my God.
It's changing again.
902
01:00:15,440 --> 01:00:16,960
It's changing again.
Oh, my God.
903
01:00:18,240 --> 01:00:21,760
We're seeing it for the first time
in 66 million years.
904
01:00:21,760 --> 01:00:23,720
I think we've got ourselves
a dinosaur.
905
01:00:28,320 --> 01:00:30,000
A dinosaur fossil!
906
01:00:30,000 --> 01:00:33,120
And, unlike the triceratops,
907
01:00:33,120 --> 01:00:37,360
this is located in the logjam,
the mass death layer,
908
01:00:37,360 --> 01:00:41,680
surrounded by the fish
with spherules in their gills.
909
01:00:44,560 --> 01:00:47,440
This is the most incredible thing
that we could possibly imagine here.
910
01:00:47,440 --> 01:00:49,080
The best-case scenario.
911
01:00:49,080 --> 01:00:52,160
We're excavating
this mass death layer of fish
912
01:00:52,160 --> 01:00:55,040
from the surge
sent up by the impact,
913
01:00:55,040 --> 01:00:57,120
and we've got dinosaur remains.
914
01:00:57,120 --> 01:01:00,400
The one thing that we would always
want to find at this site,
915
01:01:00,400 --> 01:01:02,720
and here we've got it.
916
01:01:02,720 --> 01:01:06,440
This is unreal. I-I-I cannot
process this in my brain.
917
01:01:06,440 --> 01:01:09,080
No, I am absolutely blown away
by this.
918
01:01:09,080 --> 01:01:11,520
Just my heart is literally
pumping out of my chest
919
01:01:11,520 --> 01:01:12,920
wondering what is behind there,
920
01:01:12,920 --> 01:01:15,120
just a couple of centimetres
back in the outcrop.
921
01:01:15,120 --> 01:01:16,760
What is waiting for us back there?
922
01:01:18,480 --> 01:01:20,320
Get it out...
923
01:01:20,320 --> 01:01:21,920
This is...
924
01:01:21,920 --> 01:01:23,240
The team keeps digging.
925
01:01:23,240 --> 01:01:25,200
The scales get big again
over on this side.
926
01:01:25,200 --> 01:01:26,760
So this could be a ribcage,
927
01:01:26,760 --> 01:01:28,920
it could be laying against ribs
that are curved.
928
01:01:28,920 --> 01:01:30,480
There's something here.
929
01:01:30,480 --> 01:01:31,960
That's hard. A bit more bone.
930
01:01:31,960 --> 01:01:33,920
That's bone right next
to the skin.
931
01:01:33,920 --> 01:01:35,960
Yeah, that's an articular
surface right there,
932
01:01:35,960 --> 01:01:38,400
so this is either a hip
or a shoulder element.
933
01:01:42,400 --> 01:01:45,560
After hours
of painstaking work...
934
01:01:48,760 --> 01:01:51,160
And we can go
from the thigh of the animal.
935
01:01:51,160 --> 01:01:52,800
There's the knee.
936
01:01:52,800 --> 01:01:55,520
And then you've got
the little calf muscles
937
01:01:55,520 --> 01:01:57,400
of the dinosaur,
they're bulging out,
938
01:01:57,400 --> 01:02:00,360
and you go down
to the anklebones,
939
01:02:00,360 --> 01:02:03,160
and these are the toes
of the feet.
940
01:02:03,160 --> 01:02:05,200
We have got nails
at the tips of the toes.
941
01:02:05,200 --> 01:02:07,040
It's a beautifully preserved leg,
942
01:02:07,040 --> 01:02:08,880
all articulated, covered with skin.
943
01:02:10,000 --> 01:02:13,840
The complete leg of a dinosaur.
944
01:02:13,840 --> 01:02:15,880
In my wildest dreams,
945
01:02:15,880 --> 01:02:18,120
I never expected to find
a dinosaur leg in this deposit.
946
01:02:18,120 --> 01:02:21,480
Yeah. I mean, and then
it's got skin and tissue.
947
01:02:21,480 --> 01:02:23,960
It does look
just like a drumstick.
948
01:02:23,960 --> 01:02:25,840
It looks like
a Thanksgiving turkey,
949
01:02:25,840 --> 01:02:27,600
just laid out in the ground.
950
01:02:27,600 --> 01:02:31,480
And this weird scale pattern
on the thigh of the animal,
951
01:02:31,480 --> 01:02:34,240
which we've never seen
in a dinosaur before.
952
01:02:34,240 --> 01:02:37,000
Well, thescelosaurs don't have
any form of defence,
953
01:02:37,000 --> 01:02:39,240
so they have to have camouflage
or something.
954
01:02:39,240 --> 01:02:40,680
That's a good point.
955
01:02:40,680 --> 01:02:44,240
So this could have been some
sort of a camouflage marking. Yeah.
956
01:02:44,240 --> 01:02:48,000
Robert thinks he has found
the body in question -
957
01:02:48,000 --> 01:02:52,240
a dinosaur that might itself
have witnessed
958
01:02:52,240 --> 01:02:54,080
the cataclysmic impact.
959
01:02:57,280 --> 01:02:59,560
Dinosaur fossils are not known
960
01:02:59,560 --> 01:03:02,440
from the last years
of the Cretaceous.
961
01:03:02,440 --> 01:03:05,040
And it was unclear whether
they were already extinct
962
01:03:05,040 --> 01:03:06,920
or in decline
or what was going on.
963
01:03:06,920 --> 01:03:08,760
So they were just sort of absent.
964
01:03:12,320 --> 01:03:13,760
And this answers that question.
965
01:03:13,760 --> 01:03:16,360
Were dinosaurs still there then?
966
01:03:16,360 --> 01:03:20,480
Well, yes - this one likely
died in that surge.
967
01:03:24,320 --> 01:03:28,920
For such big claims,
Robert needs verification.
968
01:03:31,240 --> 01:03:33,520
He's brought the dinosaur leg
to London
969
01:03:33,520 --> 01:03:36,200
to get a second opinion...
970
01:03:36,200 --> 01:03:38,760
And then here are the pads
of the toes.
971
01:03:38,760 --> 01:03:41,400
We see all those
beautiful scales lined up.
972
01:03:41,400 --> 01:03:43,720
..from Professor Paul Barrett,
973
01:03:43,720 --> 01:03:46,960
an expert
in ornithischian dinosaurs
974
01:03:46,960 --> 01:03:49,840
from the Natural History Museum.
975
01:03:49,840 --> 01:03:52,120
So what do you think
this might be?
976
01:03:52,120 --> 01:03:55,000
When we look at the leg,
it has claws,
977
01:03:55,000 --> 01:03:59,600
like the claws we see in small,
agile, bipedal, running dinosaurs
978
01:03:59,600 --> 01:04:02,000
that are plant-eaters.
979
01:04:02,000 --> 01:04:04,000
We can rule out things
like triceratops,
980
01:04:04,000 --> 01:04:06,400
partly just because
it's not big and stocky.
981
01:04:06,400 --> 01:04:09,600
And the proportions of those legs
are also different
982
01:04:09,600 --> 01:04:11,880
from some of
the other plant-eaters we see,
983
01:04:11,880 --> 01:04:13,760
in that they have
this rather long ankle
984
01:04:13,760 --> 01:04:17,120
and shin, compared with its
thighbone.
985
01:04:17,120 --> 01:04:19,160
So as we narrow
those possibilities down,
986
01:04:19,160 --> 01:04:20,640
what we're left with, probably,
987
01:04:20,640 --> 01:04:22,480
is an animal called a thescelosaur.
988
01:04:31,440 --> 01:04:34,160
Thescelosaurs lived next to rivers
989
01:04:34,160 --> 01:04:37,200
where there was plenty
of rich vegetation to feed on.
990
01:04:39,680 --> 01:04:41,960
They had leaf-shaped teeth,
991
01:04:41,960 --> 01:04:44,000
common amongst herbivores,
992
01:04:44,000 --> 01:04:46,080
and claws
on their short front limbs -
993
01:04:46,080 --> 01:04:48,240
excellent for digging.
994
01:05:05,680 --> 01:05:08,880
But how did
Robert's thescelosaur die?
995
01:05:10,480 --> 01:05:13,400
Could it have been killed
by another dinosaur?
996
01:05:13,400 --> 01:05:15,120
It's a possibility.
997
01:05:15,120 --> 01:05:17,200
This is a relatively agile animal.
998
01:05:17,200 --> 01:05:19,360
And that turn of speed
would've been
999
01:05:19,360 --> 01:05:23,360
its primary defence against the
large predators living alongside it.
1000
01:05:28,760 --> 01:05:32,640
So, to escape a hungry T-rex,
1001
01:05:32,640 --> 01:05:35,040
a thescelosaur's first line
of defence...
1002
01:05:36,360 --> 01:05:37,880
..would've been to run.
1003
01:05:40,560 --> 01:05:44,800
But it may have had
another defensive trick.
1004
01:05:53,280 --> 01:05:54,840
Living next to rivers,
1005
01:05:54,840 --> 01:05:58,640
it's possible thescelosaurs
were able to swim.
1006
01:06:12,040 --> 01:06:14,480
It doesn't seem to me
like there is any evidence
1007
01:06:14,480 --> 01:06:16,160
that this animal was predated -
1008
01:06:16,160 --> 01:06:18,800
none of the obvious tooth marks
1009
01:06:18,800 --> 01:06:20,960
or leftover bits
of carnivore teeth
1010
01:06:20,960 --> 01:06:23,040
to suggest it's been eaten.
1011
01:06:23,040 --> 01:06:25,600
So how do you think it died?
1012
01:06:25,600 --> 01:06:28,560
It didn't have any particularly
nasty diseases when it died,
1013
01:06:28,560 --> 01:06:31,280
as we can see
that the bones look OK.
1014
01:06:31,280 --> 01:06:33,240
So this is an animal
that was probably living
1015
01:06:33,240 --> 01:06:36,480
and healthy at the time
that this happened to it.
1016
01:06:36,480 --> 01:06:41,600
Could this be a victim
of the meteor strike?
1017
01:06:41,600 --> 01:06:43,000
I think it's entirely possible.
1018
01:06:43,000 --> 01:06:45,200
This is actually a shoulder bone,
1019
01:06:45,200 --> 01:06:47,160
and this bone in a living animal
1020
01:06:47,160 --> 01:06:49,200
would actually be way over here.
1021
01:06:49,200 --> 01:06:51,000
And similarly, this little bone here
1022
01:06:51,000 --> 01:06:53,800
would've been from about
maybe a third of the way
1023
01:06:53,800 --> 01:06:55,760
along the tail, maybe halfway down.
1024
01:06:55,760 --> 01:07:00,320
So somehow these two bones
have been telescoped together.
1025
01:07:00,320 --> 01:07:02,760
So maybe this animal's
been tumbled around.
1026
01:07:02,760 --> 01:07:05,400
We've ruled out
a lot of other possible
1027
01:07:05,400 --> 01:07:07,360
causes of death for this animal.
1028
01:07:07,360 --> 01:07:10,320
So it could well be
that this is an animal
1029
01:07:10,320 --> 01:07:12,080
that was there, being tumbled around
1030
01:07:12,080 --> 01:07:13,760
in its death throes, in that river,
1031
01:07:13,760 --> 01:07:15,520
as a result of the asteroid impact.
1032
01:07:16,880 --> 01:07:19,440
Well, it is exactly analogous
1033
01:07:19,440 --> 01:07:22,600
to those human bodies
found in Pompeii.
1034
01:07:22,600 --> 01:07:25,840
It's very similar in terms of
you get that quick entombment.
1035
01:07:25,840 --> 01:07:27,880
Yes. And it's almost as evocative.
1036
01:07:27,880 --> 01:07:30,160
That's absolutely true.
1037
01:07:30,160 --> 01:07:32,440
You've got literally
the blink of an eye
1038
01:07:32,440 --> 01:07:34,320
at the end of the Cretaceous,
1039
01:07:34,320 --> 01:07:36,480
snapped up into history,
and there it is,
1040
01:07:36,480 --> 01:07:39,920
ready to be dug up. Wow.
1041
01:07:51,320 --> 01:07:53,600
After years of investigation,
1042
01:07:53,600 --> 01:07:55,880
Robert has found out a great deal
1043
01:07:55,880 --> 01:07:58,000
about the creatures
which lived at Tanis,
1044
01:07:58,000 --> 01:08:02,600
and he knows that many of them were
alive on that fateful day
1045
01:08:02,600 --> 01:08:05,680
when the asteroid
devastated our planet.
1046
01:08:06,800 --> 01:08:09,000
But how exactly did they die?
1047
01:08:10,000 --> 01:08:13,840
Robert's finds now allow us
to tell the story of that day
1048
01:08:13,840 --> 01:08:16,320
and finally answer that question.
1049
01:08:20,640 --> 01:08:23,600
One of the most important days
in Earth's history
1050
01:08:23,600 --> 01:08:27,520
probably started much like any
other late spring morning.
1051
01:08:32,640 --> 01:08:37,520
We know the season because Robert
found fossils of young fish that
1052
01:08:37,520 --> 01:08:40,200
died at the size they reach
at that time of year.
1053
01:08:40,200 --> 01:08:42,840
This agrees
with evidence already found
1054
01:08:42,840 --> 01:08:44,880
by other scientists.
1055
01:08:47,320 --> 01:08:50,960
Perhaps this day, that would end
with so much death,
1056
01:08:50,960 --> 01:08:53,560
began with something different.
1057
01:08:55,360 --> 01:08:56,960
A new life.
1058
01:09:20,440 --> 01:09:23,760
No-one can be certain
of the exact timings of the day
1059
01:09:23,760 --> 01:09:26,880
when the asteroid collided
with our planet.
1060
01:09:26,880 --> 01:09:31,240
But it's estimated that within
just 40 minutes of the impact,
1061
01:09:31,240 --> 01:09:33,800
the consequences
for the creatures of Tanis
1062
01:09:33,800 --> 01:09:35,360
would have been profound.
1063
01:09:39,480 --> 01:09:40,880
Based on Robert's finds
1064
01:09:40,880 --> 01:09:43,680
and the latest evidence
from other scientists,
1065
01:09:43,680 --> 01:09:47,160
this is how the catastrophe
might have unfolded.
1066
01:09:49,840 --> 01:09:53,360
The asteroid is around
seven miles across,
1067
01:09:53,360 --> 01:09:55,240
bigger than Mount Everest...
1068
01:09:56,800 --> 01:10:01,280
..and travelling at close
to 45,000mph.
1069
01:10:05,080 --> 01:10:07,280
The impact causes an explosion
1070
01:10:07,280 --> 01:10:11,440
bigger than a billion
Hiroshima atomic bombs.
1071
01:10:18,720 --> 01:10:21,600
At Tanis,
almost 2,000 miles away...
1072
01:10:23,200 --> 01:10:25,320
..it's completely silent.
1073
01:10:29,320 --> 01:10:31,240
But at the impact site...
1074
01:10:33,560 --> 01:10:35,480
..the asteroid vaporises.
1075
01:10:37,360 --> 01:10:39,880
More than three trillion
tonnes of rock
1076
01:10:39,880 --> 01:10:41,800
are ejected into space
1077
01:10:41,800 --> 01:10:44,440
in a blast
of super-heated violence.
1078
01:10:49,240 --> 01:10:52,160
Winds higher than 600mph.
1079
01:10:53,640 --> 01:10:58,320
A colossal earthquake, followed
by a ring of massive tsunamis.
1080
01:11:08,800 --> 01:11:10,800
All the while,
the creatures at Tanis
1081
01:11:10,800 --> 01:11:12,680
go about their business...
1082
01:11:16,680 --> 01:11:19,120
..just like any other day.
1083
01:11:37,160 --> 01:11:39,880
The evidence suggests
that baby pterosaurs
1084
01:11:39,880 --> 01:11:43,360
emerge from the egg
ready to fend for themselves.
1085
01:11:46,000 --> 01:11:47,880
And that includes...
1086
01:11:50,480 --> 01:11:51,880
..flying?
1087
01:11:53,360 --> 01:11:54,960
Well, almost.
1088
01:12:03,600 --> 01:12:07,840
Elsewhere, as the devastation
spreads out across North America
1089
01:12:07,840 --> 01:12:09,160
towards Tanis...
1090
01:12:10,800 --> 01:12:13,920
..dinosaurs and creatures
of all shapes and sizes
1091
01:12:13,920 --> 01:12:16,360
are obliterated by the blast.
1092
01:12:27,800 --> 01:12:31,320
At Tanis, for a few more
precious minutes,
1093
01:12:31,320 --> 01:12:33,040
life carries on as usual.
1094
01:12:35,120 --> 01:12:37,320
But the clock is ticking.
1095
01:12:50,840 --> 01:12:54,600
The blast from the impact
never reaches Tanis,
1096
01:12:54,600 --> 01:12:57,120
but seismic shock waves do.
1097
01:13:10,200 --> 01:13:12,200
They are far more powerful
1098
01:13:12,200 --> 01:13:14,640
than any earthquake
ever recorded.
1099
01:13:23,240 --> 01:13:26,680
The thescelosaur might head
for a place of safety...
1100
01:13:31,440 --> 01:13:33,800
..but seismic waves
are now slowly shaking
1101
01:13:33,800 --> 01:13:38,200
the whole region, causing water
to slosh and churn.
1102
01:13:43,520 --> 01:13:46,600
At Tanis,
strange currents in the river
1103
01:13:46,600 --> 01:13:49,240
give a hint
of what is still to come.
1104
01:13:58,240 --> 01:14:01,120
Next, it begins to rain.
1105
01:14:03,240 --> 01:14:06,480
Ejecta spherules
are falling back to Earth.
1106
01:14:14,360 --> 01:14:17,280
As the spherules
begin their fall...
1107
01:14:18,400 --> 01:14:21,720
..friction heats them
until they're red hot.
1108
01:14:28,160 --> 01:14:31,560
Then the heat transfers
to the air.
1109
01:14:33,040 --> 01:14:35,320
Temperatures rise with every second.
1110
01:14:43,760 --> 01:14:47,080
As the heat builds,
the creatures of Tanis
1111
01:14:47,080 --> 01:14:48,720
are fighting for their lives.
1112
01:14:53,840 --> 01:14:56,320
And then, as seismic waves
1113
01:14:56,320 --> 01:14:59,120
continue to slowly rock
the whole region...
1114
01:15:02,640 --> 01:15:05,960
..a violent surge wave
ten metres high
1115
01:15:05,960 --> 01:15:08,280
rushes up the Tanis river.
1116
01:15:27,200 --> 01:15:29,680
Surviving the turbulence
of the surge
1117
01:15:29,680 --> 01:15:32,840
is a challenge
even for the best swimmers.
1118
01:15:44,760 --> 01:15:48,600
Then, the powerful rocking
of the river system
1119
01:15:48,600 --> 01:15:52,240
slowly begins to draw the water
back the way it came.
1120
01:16:01,880 --> 01:16:03,640
Swimming may have saved
1121
01:16:03,640 --> 01:16:06,320
the thescelosaur in the past,
1122
01:16:06,320 --> 01:16:08,120
but not this time.
1123
01:16:13,720 --> 01:16:16,320
A large, robust animal
like a T-rex
1124
01:16:16,320 --> 01:16:18,400
might have survived the surge.
1125
01:16:23,880 --> 01:16:26,240
As might a hard-shelled reptile.
1126
01:16:27,920 --> 01:16:30,760
But there is much more to come.
1127
01:16:30,760 --> 01:16:35,880
As billions of tonnes of superheated
spherules continue to fall,
1128
01:16:35,880 --> 01:16:38,200
the atmosphere gets even hotter...
1129
01:16:40,640 --> 01:16:44,760
..igniting dead leaves
and sparking wildfires.
1130
01:16:51,080 --> 01:16:52,680
Earthquakes,
1131
01:16:52,680 --> 01:16:54,640
fire...
1132
01:16:56,760 --> 01:16:58,240
..devastation.
1133
01:17:00,760 --> 01:17:02,800
Little would survive for long,
1134
01:17:02,800 --> 01:17:04,640
on land..
1135
01:17:09,280 --> 01:17:11,080
..or in the air.
1136
01:17:31,400 --> 01:17:35,280
As the air reaches the temperature
of an industrial oven...
1137
01:17:38,240 --> 01:17:40,320
..those that live
deep underground
1138
01:17:40,320 --> 01:17:41,880
may have a better chance.
1139
01:17:49,840 --> 01:17:53,360
As the slow sloshing of
the river system continues...
1140
01:17:56,280 --> 01:17:58,600
..another powerful surge hits.
1141
01:18:19,480 --> 01:18:22,080
There is no escaping
the destruction.
1142
01:18:25,240 --> 01:18:28,280
For many of the creatures
of Tanis,
1143
01:18:28,280 --> 01:18:30,680
their stories end underwater.
1144
01:18:46,280 --> 01:18:50,520
In less than two hours,
the world has changed forever.
1145
01:18:57,200 --> 01:18:59,960
The mud the surge waves leave behind
1146
01:18:59,960 --> 01:19:03,960
will gradually turn into the thick
layer of crumbly rock
1147
01:19:03,960 --> 01:19:06,880
entombing the creatures
which died here...
1148
01:19:09,760 --> 01:19:12,880
..until 66 million years later,
1149
01:19:12,880 --> 01:19:15,200
when they're finally unearthed.
1150
01:19:24,600 --> 01:19:28,920
Robert's finds have helped us
understand in remarkable detail
1151
01:19:28,920 --> 01:19:30,600
what happened at Tanis
1152
01:19:30,600 --> 01:19:34,120
in the minutes
after the asteroid impact.
1153
01:19:34,120 --> 01:19:36,280
But what about
the rest of the world?
1154
01:19:39,400 --> 01:19:42,240
The impact triggered catastrophic
events
1155
01:19:42,240 --> 01:19:45,120
such as earthquakes all over
the planet.
1156
01:19:46,760 --> 01:19:49,240
And as spherules
continued to fall...
1157
01:19:52,280 --> 01:19:55,560
..wildfires may have sprung up
around the globe.
1158
01:19:58,320 --> 01:20:01,600
As that horrific day
drew to a close,
1159
01:20:01,600 --> 01:20:05,400
many of the world's dinosaurs
were already dead.
1160
01:20:10,960 --> 01:20:15,440
Research shows that the angle
at which the asteroid hit
1161
01:20:15,440 --> 01:20:18,440
and the sulphur-rich rocks
at the impact site
1162
01:20:18,440 --> 01:20:20,720
amplified the devastation.
1163
01:20:20,720 --> 01:20:22,680
Billions of tonnes of sulphur
1164
01:20:22,680 --> 01:20:24,960
were ejected into the atmosphere,
1165
01:20:24,960 --> 01:20:26,840
blocking the sunlight.
1166
01:20:28,960 --> 01:20:33,800
Without light, most plants died,
and food became scarce.
1167
01:20:35,600 --> 01:20:38,280
As the weeks and months passed,
1168
01:20:38,280 --> 01:20:41,680
any dinosaur left alive
would've died of hunger.
1169
01:20:44,520 --> 01:20:47,240
In the oceans, it was the same.
1170
01:20:47,240 --> 01:20:50,560
Nearly all of the world's
plankton disappeared,
1171
01:20:50,560 --> 01:20:54,600
leading to the starvation
of most marine creatures.
1172
01:20:56,200 --> 01:20:59,720
It's thought that the nuclear
winter that followed
1173
01:20:59,720 --> 01:21:02,360
caused a global temperature drop
1174
01:21:02,360 --> 01:21:05,320
of at least
25 degrees centigrade.
1175
01:21:05,320 --> 01:21:09,320
The fossil record tells us that this
huge change in climate
1176
01:21:09,320 --> 01:21:13,200
marked the disappearance of three
quarters of all species,
1177
01:21:13,200 --> 01:21:15,040
including the dinosaurs.
1178
01:21:17,520 --> 01:21:22,080
The planet was in semi-darkness
for around a decade,
1179
01:21:22,080 --> 01:21:25,280
as dust and soot
slowly fell to Earth.
1180
01:21:27,080 --> 01:21:29,440
But then came something wonderful.
1181
01:21:31,320 --> 01:21:33,040
A new beginning.
1182
01:21:37,440 --> 01:21:40,160
Once the dust cleared
from the atmosphere
1183
01:21:40,160 --> 01:21:41,840
and the sunlight returned...
1184
01:21:43,360 --> 01:21:47,000
..plant life was gradually restored,
1185
01:21:47,000 --> 01:21:48,960
led by ferns,
1186
01:21:48,960 --> 01:21:53,160
the spores of which had lain
dormant deep underground,
1187
01:21:53,160 --> 01:21:57,160
and the world began
to turn green once more.
1188
01:21:59,360 --> 01:22:01,480
But what about the animals?
1189
01:22:04,160 --> 01:22:07,520
Back at Tanis,
Robert has unearthed something
1190
01:22:07,520 --> 01:22:10,320
that could have helped save
some of the creatures
1191
01:22:10,320 --> 01:22:12,920
from the devastating fires.
1192
01:22:12,920 --> 01:22:14,560
We saw a little thing
poking out,
1193
01:22:14,560 --> 01:22:16,560
so we kind of followed it back.
1194
01:22:16,560 --> 01:22:18,600
And I'm so glad that we did,
1195
01:22:18,600 --> 01:22:20,920
because what we have here
is a fossil burrow
1196
01:22:20,920 --> 01:22:23,680
from an animal 66 million years ago.
1197
01:22:25,280 --> 01:22:27,680
The only animals that
would've been around back then
1198
01:22:27,680 --> 01:22:29,960
that would likely build
a burrow like this
1199
01:22:29,960 --> 01:22:32,880
would be the small mammals,
roughly ferret-sized,
1200
01:22:32,880 --> 01:22:35,440
and also some reptiles.
1201
01:22:35,440 --> 01:22:39,680
If it is from a mammal,
this is sort of a window
1202
01:22:39,680 --> 01:22:42,560
into the lifestyle of some of
our oldest ancestors out here.
1203
01:22:43,600 --> 01:22:45,640
This guy would've burrowed
sideways,
1204
01:22:45,640 --> 01:22:47,080
right into the river bank.
1205
01:22:48,400 --> 01:22:50,480
We actually have
some scratch marks on there
1206
01:22:50,480 --> 01:22:52,680
from the interior
when they were digging it,
1207
01:22:52,680 --> 01:22:55,560
going back,
and he would've lived back here
1208
01:22:55,560 --> 01:22:57,360
and sought shelter
from the dinosaurs
1209
01:22:57,360 --> 01:22:59,640
cos they just did not
want to get eaten.
1210
01:23:06,000 --> 01:23:08,280
Burrows are part of the reason
1211
01:23:08,280 --> 01:23:11,320
that mammals survived
the great extinction.
1212
01:23:13,000 --> 01:23:14,880
During the nuclear winter,
1213
01:23:14,880 --> 01:23:17,080
a burrow would've provided warmth,
1214
01:23:17,080 --> 01:23:20,280
protection,
and a place to store food.
1215
01:23:27,520 --> 01:23:30,880
Mammals that survived
were resourceful omnivores,
1216
01:23:30,880 --> 01:23:34,680
and insects would've been
a plentiful source of food.
1217
01:23:40,360 --> 01:23:44,120
And they had another advantage -
their size.
1218
01:23:46,440 --> 01:23:50,240
If conditions are right,
many animal species get larger
1219
01:23:50,240 --> 01:23:53,200
as they evolve
over millions of years.
1220
01:23:53,200 --> 01:23:56,680
Take T-rex as an example.
1221
01:23:56,680 --> 01:23:59,960
This is a cast of the lower jaw
1222
01:23:59,960 --> 01:24:02,600
of a predecessor, called
gorgosaurus,
1223
01:24:02,600 --> 01:24:05,360
which lived
72 million years ago.
1224
01:24:05,360 --> 01:24:11,280
Whereas this is the cast
of the lower jaw of a T-rex,
1225
01:24:11,280 --> 01:24:13,880
which lived
five million years later.
1226
01:24:13,880 --> 01:24:17,800
Look at the difference in size.
1227
01:24:17,800 --> 01:24:19,200
But the bigger the creature,
1228
01:24:19,200 --> 01:24:21,760
the more energy they need
to stay alive.
1229
01:24:21,760 --> 01:24:25,600
So when catastrophe strikes
and food is scarce,
1230
01:24:25,600 --> 01:24:27,960
the largest tend to die out,
1231
01:24:27,960 --> 01:24:30,920
whilst the smallest
often survive.
1232
01:24:34,040 --> 01:24:35,960
That's one of the reasons
1233
01:24:35,960 --> 01:24:38,400
why many of the smaller mammals
1234
01:24:38,400 --> 01:24:41,200
lived through the great darkness.
1235
01:24:41,200 --> 01:24:43,240
And they weren't alone.
1236
01:24:45,760 --> 01:24:48,960
Robert's fossil turtle
may have been unlucky,
1237
01:24:48,960 --> 01:24:50,680
but many others survived.
1238
01:24:54,400 --> 01:24:57,000
As did crocodiles,
1239
01:24:57,000 --> 01:24:58,800
snakes,
1240
01:24:58,800 --> 01:25:01,720
and many fish species.
1241
01:25:01,720 --> 01:25:04,480
And as for the dinosaurs,
1242
01:25:04,480 --> 01:25:06,960
did the impact
really kill them all?
1243
01:25:06,960 --> 01:25:10,640
Well, this beautiful
fossilised feather
1244
01:25:10,640 --> 01:25:12,680
isn't from a bird,
1245
01:25:12,680 --> 01:25:14,840
but from a predatory dinosaur.
1246
01:25:14,840 --> 01:25:16,560
So we have to be careful
1247
01:25:16,560 --> 01:25:19,800
when we say
that dinosaurs are extinct,
1248
01:25:19,800 --> 01:25:23,880
because what we call birds
originally evolved
1249
01:25:23,880 --> 01:25:26,920
from the smallest
feathered dinosaurs.
1250
01:25:26,920 --> 01:25:29,160
So to be correct, we should say
1251
01:25:29,160 --> 01:25:33,120
all non-avian dinosaurs
are extinct.
1252
01:25:35,920 --> 01:25:38,080
Robert's finds have given us
1253
01:25:38,080 --> 01:25:40,400
a better idea
than ever before...
1254
01:25:42,000 --> 01:25:45,800
..about what happened on the day
that led to the extinction...
1255
01:25:47,840 --> 01:25:51,360
..of the largest beasts
ever to walk the Earth.
1256
01:25:54,760 --> 01:25:57,000
Dinosaurs were perhaps
1257
01:25:57,000 --> 01:26:00,440
some of nature's
most extraordinary creatures,
1258
01:26:00,440 --> 01:26:04,520
dominating the planet
for over 150 million years
1259
01:26:04,520 --> 01:26:06,480
before they became extinct.
1260
01:26:09,200 --> 01:26:12,040
But extinction
comes in different forms,
1261
01:26:12,040 --> 01:26:14,320
and many of the amazing creatures
1262
01:26:14,320 --> 01:26:17,760
and plants alive today
are also threatened.
1263
01:26:17,760 --> 01:26:20,760
It's possible that humanity
is having
1264
01:26:20,760 --> 01:26:23,120
as big an impact on the world
1265
01:26:23,120 --> 01:26:27,880
as the asteroid that ended
the age of the dinosaurs.
1266
01:26:27,880 --> 01:26:31,440
As human beings,
we are unique in our ability
1267
01:26:31,440 --> 01:26:34,520
to learn from the distant past.
1268
01:26:34,520 --> 01:26:39,640
Now we must use that ability
wisely and do our very best
1269
01:26:39,640 --> 01:26:42,040
to protect the millions of species
1270
01:26:42,040 --> 01:26:46,520
for whom, alongside us,
this planet is home.
1271
01:26:47,305 --> 01:27:47,738
Who are the real-world Illuminati ?
Find out @ saveanilluminati.com
99215
Can't find what you're looking for?
Get subtitles in any language from opensubtitles.com, and translate them here.