1 00:00:08,420 --> 00:00:13,780 I'm here in Patagonia in the southern part of South America because, 2 00:00:13,780 --> 00:00:18,941 a few years ago, a man looking for one of his lost sheep found 3 00:00:18,941 --> 00:00:23,090 a simply gigantic bone sticking out of a rock - 4 00:00:23,090 --> 00:00:26,025 a bone that was going to astonish science. 5 00:00:27,910 --> 00:00:31,903 That first bone led to the discovery of over 200 others. 6 00:00:36,580 --> 00:00:42,821 They were all huge - so big that they could only have come from a dinosaur. 7 00:00:42,821 --> 00:00:45,904 And what a dinosaur it would turn out to be! 8 00:00:48,130 --> 00:00:50,860 One that seems to defy the laws of nature. 9 00:00:53,270 --> 00:00:57,010 These bones are part of a skeleton that has remained hidden 10 00:00:57,010 --> 00:01:00,741 and marvellously preserved for 100 million years. 11 00:01:04,811 --> 00:01:08,530 'An international team of scientists assembled to try 12 00:01:08,530 --> 00:01:11,431 'and work out what sort of dinosaur it belonged to.' 13 00:01:13,941 --> 00:01:16,341 It's like a palaeontological crime scene! 14 00:01:17,730 --> 00:01:21,280 Each bone is an important piece of evidence that can give us 15 00:01:21,280 --> 00:01:25,380 information as to what the living creature was actually like. 16 00:01:25,380 --> 00:01:29,061 We'll use the latest forensic technology, 17 00:01:29,061 --> 00:01:33,620 we'll compare it with how giant animals live today 18 00:01:33,620 --> 00:01:38,171 and we'll build a full-size skeleton of this stupendous creature. 19 00:01:40,941 --> 00:01:45,420 And we will try and work out in detail what it looked like 20 00:01:45,420 --> 00:01:46,387 when it was alive. 21 00:01:50,980 --> 00:01:52,340 HE GASPS 22 00:01:52,340 --> 00:01:54,911 Absolutely amazing! 23 00:01:55,980 --> 00:01:58,821 Could it really have been the biggest animal 24 00:01:58,821 --> 00:02:00,265 ever to walk the earth? 25 00:02:19,941 --> 00:02:22,785 Patagonia in southern Argentina. 26 00:02:26,370 --> 00:02:30,704 Like many detective stories, this one began by chance. 27 00:02:33,380 --> 00:02:36,620 A shepherd stumbled across the tip of a huge bone 28 00:02:36,620 --> 00:02:38,360 poking out of the ground. 29 00:02:40,090 --> 00:02:41,102 HORSE SNORTS 30 00:02:46,380 --> 00:02:50,530 Experts from Patagonia's premier palaeontological museum 31 00:02:50,530 --> 00:02:53,100 confirmed it was part of a dinosaur. 32 00:02:53,100 --> 00:02:54,579 THEY SPEAK IN OWN LANGUAGE 33 00:02:58,931 --> 00:03:02,980 But they didn't realise at the time what a truly extraordinary one 34 00:03:02,980 --> 00:03:04,186 it would prove to be. 35 00:03:10,100 --> 00:03:13,500 Dinosaurs of many kinds roamed all over these lands 36 00:03:13,500 --> 00:03:15,941 in the southern end of South America 37 00:03:15,941 --> 00:03:19,020 during what's known as the Cretaceous period, 38 00:03:19,020 --> 00:03:22,831 between 66 and 145 million years ago. 39 00:03:24,941 --> 00:03:28,990 The largest were plant-eaters known as sauropods. 40 00:03:28,990 --> 00:03:33,268 And the largest of them were the titanosaurs. 41 00:03:35,460 --> 00:03:39,010 Giant titanosaur bones are comparatively rare 42 00:03:39,010 --> 00:03:41,820 so very little is known about these dinosaurs. 43 00:03:46,450 --> 00:03:49,351 This new discovery could change all that. 44 00:03:55,340 --> 00:04:01,071 'Like many people, young and old, I'm fascinated by dinosaurs, 45 00:04:01,071 --> 00:04:03,860 'so the chance to join this investigation 46 00:04:03,860 --> 00:04:06,380 'is just too good an opportunity to miss.' 47 00:04:06,380 --> 00:04:08,811 Oh, I'd love to have a go! 48 00:04:08,811 --> 00:04:10,500 HE LAUGHS 49 00:04:10,500 --> 00:04:11,900 I'm sure they'd let you. 50 00:04:11,900 --> 00:04:12,951 HE LAUGHS 51 00:04:12,951 --> 00:04:16,580 'Of course, it's the giants in particular that capture 52 00:04:16,580 --> 00:04:17,672 'the imagination.' 53 00:04:20,180 --> 00:04:22,350 The first sauropods to appear on earth 54 00:04:22,350 --> 00:04:24,620 were comparatively small creatures. 55 00:04:24,620 --> 00:04:28,780 This is the cast of the thigh bone of one of them. 56 00:04:28,780 --> 00:04:32,530 It's not even as big as my thigh bone. 57 00:04:32,530 --> 00:04:39,140 But after about 20 million years, some had become pretty big. 58 00:04:39,140 --> 00:04:43,220 This is a thigh bone from one of those creatures. 59 00:04:43,220 --> 00:04:44,710 But then, after that... 60 00:04:46,420 --> 00:04:51,107 ..our giant appeared. This is its thigh bone. 61 00:04:52,931 --> 00:04:55,104 It's the largest ever found. 62 00:05:04,061 --> 00:05:08,590 Coming across such a bone in your back yard must be quite a shock. 63 00:05:08,590 --> 00:05:11,423 Just ask farm owner Alba Maio. 64 00:05:14,430 --> 00:05:16,220 HENS CLUCK 65 00:05:16,220 --> 00:05:18,518 TRANSLATION: 66 00:05:20,100 --> 00:05:21,670 SHE LAUGHS 67 00:05:21,670 --> 00:05:24,719 TRANSLATION: 68 00:05:35,610 --> 00:05:39,230 Before long, a whole team of fossil-hunting scientists 69 00:05:39,230 --> 00:05:41,152 arrives and starts work. 70 00:05:53,310 --> 00:05:57,895 The thighbone proves to be eight feet, 2.4 metres long. 71 00:06:05,710 --> 00:06:10,260 It's preserved in extraordinary detail, and detail will be 72 00:06:10,260 --> 00:06:13,434 critical to the forensic examination that will follow. 73 00:06:24,150 --> 00:06:28,792 The research team soon turn the site into a vast quarry. 74 00:06:37,740 --> 00:06:42,302 It proves to be one of the biggest dinosaur finds of the century. 75 00:06:45,260 --> 00:06:49,420 Bone after bone emerge from the rocks. 76 00:06:49,420 --> 00:06:51,832 THEY LAUGH 77 00:06:54,390 --> 00:06:56,780 We just found another bone right here. 78 00:06:56,780 --> 00:06:58,790 We weren't expecting it at all. 79 00:06:58,790 --> 00:07:01,600 We just start digging and find it. 80 00:07:03,951 --> 00:07:06,710 Until recently, giant titanosaurs 81 00:07:06,710 --> 00:07:09,470 have only been known from a dozen bones 82 00:07:09,470 --> 00:07:14,032 and our team have already found more than ten times as many. 83 00:07:19,870 --> 00:07:23,540 Dr Diego Pol is the chief palaeontologist 84 00:07:23,540 --> 00:07:25,790 Ieading the investigation. 85 00:07:25,790 --> 00:07:27,740 If you really want to know 86 00:07:27,740 --> 00:07:32,030 what a really gigantic dinosaur looked like, this quarry here 87 00:07:32,030 --> 00:07:34,590 has the potential to answer that question 88 00:07:34,590 --> 00:07:36,694 and that's really exciting for us. 89 00:07:38,260 --> 00:07:39,550 It's really impressive. 90 00:07:39,550 --> 00:07:43,759 When you stand by one of these bones, you really feel tiny. 91 00:07:45,180 --> 00:07:49,190 With so much new evidence, there is a chance of discovering 92 00:07:49,190 --> 00:07:53,798 all kinds of new facts about the mysterious titanosaurs. 93 00:07:56,660 --> 00:07:59,230 It's like a palaeontological crime scene. 94 00:07:59,230 --> 00:08:00,980 It's a really unique thing 95 00:08:00,980 --> 00:08:04,188 that you will not find anywhere else in the world. 96 00:08:07,310 --> 00:08:09,510 Patagonia's harsh weather 97 00:08:09,510 --> 00:08:12,110 makes uncovering the fossils exhausting, 98 00:08:12,110 --> 00:08:16,706 but it also endangers the newly-exposed fossils. 99 00:08:19,020 --> 00:08:20,860 THUNDER RUMBLES 100 00:08:20,860 --> 00:08:22,630 A lot of damage from the rain 101 00:08:22,630 --> 00:08:25,980 so we need to protect the bones that are at risk. 102 00:08:25,980 --> 00:08:30,542 I'm really concerned that this already has some cracks. 103 00:08:31,660 --> 00:08:33,580 If the bones aren't protected, 104 00:08:33,580 --> 00:08:36,617 tiny details on their surface could be lost. 105 00:08:42,590 --> 00:08:45,910 To protect the bones, they're covered with, of all things, 106 00:08:45,910 --> 00:08:50,060 wet toilet paper and plaster of Paris. 107 00:08:50,060 --> 00:08:54,110 It's like putting a plaster cast on a broken leg. 108 00:08:56,980 --> 00:08:59,900 There's a rush to get them back to the museum 109 00:08:59,900 --> 00:09:02,801 to begin examining them in minute detail. 110 00:09:08,030 --> 00:09:11,831 A new road has been specially built to enable them 111 00:09:11,831 --> 00:09:14,880 to be transported without too much jolting. 112 00:09:18,980 --> 00:09:23,838 Once at the museum laboratory, the detailed detective work begins. 113 00:09:31,980 --> 00:09:36,060 It's a chance to start putting flesh on bones. 114 00:09:36,060 --> 00:09:39,821 Some really big muscle was going in here. 115 00:09:39,821 --> 00:09:43,390 This animal was so big that it certainly needed 116 00:09:43,390 --> 00:09:46,790 really powerful muscles and very strong attachments 117 00:09:46,790 --> 00:09:49,111 into the bones. 118 00:09:59,263 --> 00:10:02,623 This is a giant vertebra, one of the bones of the spine, 119 00:10:02,623 --> 00:10:05,893 and it's a very important find. 120 00:10:05,893 --> 00:10:08,893 That's because it's likely to provide crucial evidence 121 00:10:08,893 --> 00:10:12,101 for identifying the species of our dinosaur. 122 00:10:17,763 --> 00:10:20,263 Despite weighing up to half a tonne, 123 00:10:20,263 --> 00:10:22,515 these fossils are surprisingly fragile. 124 00:10:26,973 --> 00:10:29,055 It's all rather nerve-racking. 125 00:10:30,513 --> 00:10:34,472 One bone like this has already cracked in half without warning. 126 00:10:39,023 --> 00:10:40,615 Bravo! 127 00:10:50,583 --> 00:10:53,673 THEY LAUGH 128 00:10:53,673 --> 00:10:56,333 And so this is the position as it was in life 129 00:10:56,333 --> 00:10:59,143 with the centre of the backbone there, 130 00:10:59,143 --> 00:11:01,383 then this is the crest on the top. 131 00:11:01,383 --> 00:11:04,613 Right, right, and this belongs to the middle part of the thorax. 132 00:11:04,613 --> 00:11:07,973 Right about here. About that. Yeah, yeah. 133 00:11:07,973 --> 00:11:11,263 'Many more weeks of detailed examination 134 00:11:11,263 --> 00:11:14,175 'will be needed before the backbones reveal all their secrets.' 135 00:11:17,623 --> 00:11:21,223 Surprisingly, perhaps, one of the first things 136 00:11:21,223 --> 00:11:25,944 the team was able to deduce about our titanosaur is its weight. 137 00:11:27,333 --> 00:11:30,303 That's because, after finding the thigh bone, 138 00:11:30,303 --> 00:11:35,468 they discover another huge bone from the front leg - a humerus. 139 00:11:41,743 --> 00:11:45,333 By measuring the circumference of each of these leg bones, 140 00:11:45,333 --> 00:11:48,543 it's possible to estimate how much weight they could support. 141 00:11:48,543 --> 00:11:50,864 Let's see how much. 142 00:11:52,143 --> 00:11:53,883 We'll measure this. 143 00:11:58,253 --> 00:12:02,053 79. 79? Wow! 144 00:12:02,053 --> 00:12:05,463 I'm not sure how that translates to body weight. 145 00:12:05,463 --> 00:12:09,453 Yeah, around 70 tonnes or even more, probably. Wow! 146 00:12:09,453 --> 00:12:10,694 That's really big. 147 00:12:10,694 --> 00:12:12,992 It's amazing. 148 00:12:14,663 --> 00:12:20,533 That evening, Dr Jose Luis Carballido checks his calculations. 149 00:12:39,917 --> 00:12:44,776 Until now, Argentinosaurus was the heaviest known dinosaur. 150 00:12:44,776 --> 00:12:46,869 Ours already looks bigger. 151 00:12:55,183 --> 00:13:00,663 Could this mean it was the largest animal ever to walk the earth? 152 00:13:00,663 --> 00:13:04,053 Could it also be a new species? 153 00:13:04,053 --> 00:13:06,704 We can't be sure...yet. 154 00:13:08,743 --> 00:13:12,533 The rocks of Patagonia, so bare of vegetation, 155 00:13:12,533 --> 00:13:18,631 also contain astonishing evidence of how titanosaurs began their lives. 156 00:13:21,223 --> 00:13:24,623 I've now come nearly 500 miles north 157 00:13:24,623 --> 00:13:27,343 from our Patagonian dinosaur excavation 158 00:13:27,343 --> 00:13:29,704 to a place called Auca Mahuevo. 159 00:13:29,704 --> 00:13:35,704 This is the largest dinosaur nesting ground yet discovered. 160 00:13:35,704 --> 00:13:41,413 The remains of their eggs and their nests are wherever I look. 161 00:13:41,413 --> 00:13:43,773 In fact, it's quite difficult for me 162 00:13:43,773 --> 00:13:48,335 to take a step without walking on a dinosaur eggshell. 163 00:13:54,704 --> 00:13:56,473 Over thousands of years, 164 00:13:56,473 --> 00:13:59,663 the wind and the rain have cleared away the soft rock 165 00:13:59,663 --> 00:14:02,463 that once enclosed these fragments 166 00:14:02,463 --> 00:14:07,947 and they can tell us quite a lot about how titanosaurs reproduced. 167 00:14:09,593 --> 00:14:13,103 Careful excavation has shown that these dinosaurs 168 00:14:13,103 --> 00:14:17,944 Iaid eggs in clutches of up to 30 or 40 at a time. 169 00:14:17,944 --> 00:14:20,944 They would have looked rather like these replicas 170 00:14:20,944 --> 00:14:23,583 because they lay on the surface of the ground, 171 00:14:23,583 --> 00:14:26,593 not covered by soil, but in a shallow depression. 172 00:14:26,593 --> 00:14:27,893 Sometimes, though, 173 00:14:27,893 --> 00:14:30,973 remains of vegetation have been found in some nests, 174 00:14:30,973 --> 00:14:34,913 which suggests that the dinosaurs might have used rotting leaves 175 00:14:34,913 --> 00:14:37,023 to help with the incubation. 176 00:14:37,023 --> 00:14:40,863 The dinosaur that laid these eggs here were medium-sized. 177 00:14:40,863 --> 00:14:43,944 Our dinosaur that we're excavating, 178 00:14:43,944 --> 00:14:46,754 probably laid eggs as big as that. 179 00:14:48,613 --> 00:14:52,704 I'm shown around by Dr Luis Chiappe who, with his team, 180 00:14:52,704 --> 00:14:54,911 discovered this remarkable site. 181 00:14:55,973 --> 00:14:59,864 Dinosaur eggs here were laid on an old river plain. 182 00:15:01,333 --> 00:15:04,273 Then the river flooded and covered the unhatched eggs, 183 00:15:04,273 --> 00:15:06,104 preserving them in mud. 184 00:15:07,213 --> 00:15:10,633 You see, you know, many eggs... 185 00:15:10,633 --> 00:15:12,133 There. 186 00:15:12,133 --> 00:15:15,383 ..for kilometres and kilometres. Here's a nice one. 187 00:15:15,383 --> 00:15:17,624 Oh, that's a huge piece! Yup. 188 00:15:20,213 --> 00:15:23,743 And this is the actual surface of the egg? Yes. 189 00:15:23,743 --> 00:15:24,744 Astounding. 190 00:15:27,313 --> 00:15:30,223 Do you suppose they could have been coloured like birds' eggs? 191 00:15:30,223 --> 00:15:32,574 They may. Maybe they were off-white. 192 00:15:32,574 --> 00:15:35,183 We can't tell really. Yeah. 193 00:15:35,183 --> 00:15:38,253 Well, we can see all the tiny pores on the surface. 194 00:15:38,253 --> 00:15:39,383 And the texture. 195 00:15:39,383 --> 00:15:42,033 Yeah. What a beautiful piece. 196 00:15:42,033 --> 00:15:45,463 You must admit it's pretty romantic. 197 00:15:45,463 --> 00:15:46,853 THEY LAUGH 198 00:15:46,853 --> 00:15:48,183 I think it's incredible. 199 00:15:48,183 --> 00:15:50,033 I think it's absolutely extraordinary 200 00:15:50,033 --> 00:15:52,133 and I must put it back where I found it. 201 00:15:52,133 --> 00:15:53,134 Thank you. 202 00:15:56,704 --> 00:16:00,913 The fragments could tell us quite a lot about how the dinosaurs nested. 203 00:16:02,313 --> 00:16:05,476 But some, amazingly, can do even more than that. 204 00:16:10,783 --> 00:16:15,543 All these examples have something quite special. 205 00:16:15,543 --> 00:16:18,834 This one is my favourite. 206 00:16:18,834 --> 00:16:25,945 And what you can see is a very large patch of baby dinosaur skin. 207 00:16:27,223 --> 00:16:29,113 How wonderful! 208 00:16:29,113 --> 00:16:30,183 It's extraordinary. 209 00:16:30,183 --> 00:16:34,313 And this is not just an impression, this is the mineralised skin. It is. 210 00:16:34,313 --> 00:16:35,903 Yeah. 211 00:16:35,903 --> 00:16:37,824 Astounding. 212 00:16:37,824 --> 00:16:40,783 The eggs were not just preserving the bones, 213 00:16:40,783 --> 00:16:43,707 they were also preserving the skin of these babies. Yeah. 214 00:16:44,903 --> 00:16:46,933 This was just on the surface. 215 00:16:46,933 --> 00:16:50,673 I remember picking this up and brushing it a little bit 216 00:16:50,673 --> 00:16:52,303 and then using my hand lens 217 00:16:52,303 --> 00:16:58,343 and looking at this exact patch of skin and I realised that 218 00:16:58,343 --> 00:17:03,574 we had found something that no person had ever seen before. 219 00:17:03,574 --> 00:17:08,704 You are the first human being ever to see a baby dinosaur's skin. Yes. 220 00:17:08,704 --> 00:17:10,313 It was just an amazing... 221 00:17:10,313 --> 00:17:12,863 amazing moment. 222 00:17:12,863 --> 00:17:15,133 It must have been very close to hatching. 223 00:17:15,133 --> 00:17:19,423 It's almost complete, this thing. Yes, that's what we believe. 224 00:17:19,423 --> 00:17:21,473 And then a flood... 225 00:17:21,473 --> 00:17:23,063 Killed them all. 226 00:17:23,063 --> 00:17:26,430 Unfortunately for them, good for us. Yes. 227 00:17:28,983 --> 00:17:33,673 Luis Chiappe has dozens of complete eggs in his museum and 228 00:17:33,673 --> 00:17:37,837 he allows me to examine some of his most precious specimens for myself. 229 00:17:41,943 --> 00:17:44,063 There are many other remarkable things 230 00:17:44,063 --> 00:17:46,633 in these astonishing time capsules. 231 00:17:46,633 --> 00:17:50,842 This one has got, perfectly clearly, the limb bones. 232 00:17:54,063 --> 00:17:56,503 Here is a skull. 233 00:17:56,503 --> 00:17:58,943 That's the orbit of the eye, 234 00:17:58,943 --> 00:18:01,912 there's the lower jaw, there's the snout. 235 00:18:05,633 --> 00:18:07,574 This one also has a skull, 236 00:18:07,574 --> 00:18:13,143 but on the tip of the snout you can see a little spike which is like the 237 00:18:13,143 --> 00:18:18,194 egg tooth that a bird embryo has to help it crack itself out of a shell. 238 00:18:21,743 --> 00:18:25,903 And here is a replica of what the complete, 239 00:18:25,903 --> 00:18:28,724 un-crushed shell must have looked like. 240 00:18:31,913 --> 00:18:34,033 With all these details, 241 00:18:34,033 --> 00:18:37,708 it is possible to imagine how a baby titanosaur entered the world. 242 00:18:39,223 --> 00:18:40,633 BABY SQUEAKS 243 00:18:48,773 --> 00:18:52,113 To get an idea of how these youngsters might have lived, 244 00:18:52,113 --> 00:18:57,153 we can compare them with their closest living relatives - birds. 245 00:19:00,063 --> 00:19:03,793 Rather like baby ostriches, a young titanosaur 246 00:19:03,793 --> 00:19:08,184 would have been able to walk soon after hatching. 247 00:19:12,303 --> 00:19:15,473 They may well have gathered into groups to give some safety 248 00:19:15,473 --> 00:19:18,522 from predators, as young ostriches do. 249 00:19:32,113 --> 00:19:35,824 Microscopic analysis of dinosaur leg bones show rings, 250 00:19:35,824 --> 00:19:37,913 rather like tree rings, 251 00:19:37,913 --> 00:19:41,663 and these indicate that titanosaurs grew very swiftly 252 00:19:41,663 --> 00:19:43,153 early in their lives 253 00:19:43,153 --> 00:19:46,763 and they could have lived for some 50 years, 254 00:19:46,763 --> 00:19:48,845 plenty of time to become enormous. 255 00:19:50,834 --> 00:19:53,993 The team now has 150 bones of our titanosaur, 256 00:19:53,993 --> 00:19:57,353 enough to get an idea, not only of its weight, 257 00:19:57,353 --> 00:19:59,355 but also its height and length. 258 00:20:00,663 --> 00:20:03,834 Now, the plan is to build a life-size reproduction 259 00:20:03,834 --> 00:20:05,586 of the complete skeleton. 260 00:20:22,153 --> 00:20:26,353 It's a challenge to find a place big enough to house an animal that's 261 00:20:26,353 --> 00:20:30,913 four times longer than a London bus and nearly twice its height. 262 00:20:30,913 --> 00:20:35,122 But Diego thinks he's found one. It's an old wool warehouse. 263 00:20:39,783 --> 00:20:43,473 One, two, three, four, 264 00:20:43,473 --> 00:20:47,143 five, six, seven... 265 00:20:47,143 --> 00:20:50,113 We have been looking for a place that is big enough 266 00:20:50,113 --> 00:20:51,683 to fit our dinosaur. 267 00:20:55,553 --> 00:20:56,704 This seems to be it. 268 00:20:56,704 --> 00:20:58,763 This is a warehouse that we could use, 269 00:20:58,763 --> 00:21:02,343 not only in terms of the length, this is 70 metres long, 270 00:21:02,343 --> 00:21:05,023 but also it's very important in terms of the height. 271 00:21:05,023 --> 00:21:07,708 So we need a place not only long, but really high. 272 00:21:08,763 --> 00:21:10,993 It really needs a little bit of decoration, 273 00:21:10,993 --> 00:21:13,193 but I think it will do it. 274 00:21:13,193 --> 00:21:14,592 It's going to be awesome! 275 00:21:17,783 --> 00:21:20,203 Putting the skeleton together will help us 276 00:21:20,203 --> 00:21:23,627 understand the particular challenges of being such a giant. 277 00:21:29,704 --> 00:21:34,663 So, next, an international team of skeleton builders arrive 278 00:21:34,663 --> 00:21:39,123 to scan the bones ready to make a 3- D computer model of each of them. 279 00:21:47,183 --> 00:21:52,633 3- D scanning, accurate to 0.01 of a millimetre, 280 00:21:52,633 --> 00:21:57,073 allows images of the bones to be placed in a virtual reality world 281 00:21:57,073 --> 00:22:00,943 so that they can now be examined from all points of view 282 00:22:00,943 --> 00:22:03,707 without needing eight people to lift them. 283 00:22:07,113 --> 00:22:10,303 One of the mysteries surrounding our dinosaur is, 284 00:22:10,303 --> 00:22:13,795 how could an animal as big as it was actually move about? 285 00:22:17,013 --> 00:22:18,993 The computer data allows us 286 00:22:18,993 --> 00:22:22,633 to put our dinosaur leg bones together in 3-D 287 00:22:22,633 --> 00:22:27,491 and then compare the arrangement with what we know about living animals. 288 00:22:38,073 --> 00:22:41,554 Elephants are the largest land animal alive today. 289 00:22:45,353 --> 00:22:49,793 They, like titanosaurs, have to move their massive bodies around 290 00:22:49,793 --> 00:22:53,160 without their bones shattering under the enormous weight. 291 00:23:00,033 --> 00:23:03,103 I've come to meet Professor John Hutchinson 292 00:23:03,103 --> 00:23:06,083 here at ZSL Whipsnade Zoo. 293 00:23:07,073 --> 00:23:10,433 He's studied elephants for many years and has joined the team 294 00:23:10,433 --> 00:23:14,953 that's investigating the internal workings of our titanosaur. 295 00:23:14,953 --> 00:23:17,993 We have about a one-metre long pressure sensitive mat out there 296 00:23:17,993 --> 00:23:21,513 with several thousand sensors in it and it's telling us, in very 297 00:23:21,513 --> 00:23:25,210 high resolution, what the pressure on an elephant's foot is like. 298 00:23:26,383 --> 00:23:29,303 We can see on the elephant's foot here... 299 00:23:29,303 --> 00:23:31,663 Here she goes... Oh, yeah! Great. 300 00:23:31,663 --> 00:23:33,324 Oh, that was a perfect one! Bull's-eye! 301 00:23:34,464 --> 00:23:36,584 The pressure hits the ground, 302 00:23:36,584 --> 00:23:40,156 rolls over and then pushes off with its toenails. 303 00:23:41,714 --> 00:23:46,143 So we can see there some hot colours, or reds and oranges, 304 00:23:46,143 --> 00:23:50,594 on the toenails of Melvin's foot indicating high pressure. 305 00:23:50,594 --> 00:23:54,233 And then some cooler colours back towards the heel pad 306 00:23:54,233 --> 00:23:57,163 in the greens and light blue. 307 00:23:57,163 --> 00:23:58,793 That's low pressure. 308 00:23:58,793 --> 00:24:02,783 So elephants are supporting most of their weight on their toenails. 309 00:24:02,783 --> 00:24:06,073 That pressure gets transmitted up to their toe bones 310 00:24:06,073 --> 00:24:12,663 and then up to their wrists and ankles and so forth. 311 00:24:12,663 --> 00:24:16,993 John's analysis suggests that our titanosaur's legs, 312 00:24:16,993 --> 00:24:18,873 Iike those of an elephant, 313 00:24:18,873 --> 00:24:23,207 were placed vertically beneath the body like strong, massive columns. 314 00:24:26,464 --> 00:24:29,633 This arrangement transmits the weight to the toes 315 00:24:29,633 --> 00:24:34,423 and then spreads the force, using fatty pads in the back feet, 316 00:24:34,423 --> 00:24:36,243 as shock absorbers. 317 00:24:37,743 --> 00:24:41,743 But our titanosaur had one other adaptation to help them walk - 318 00:24:41,743 --> 00:24:43,677 one that elephants lack. 319 00:24:48,073 --> 00:24:51,440 A clue to this can be seen on the giant thighbone. 320 00:24:53,023 --> 00:24:55,363 How's it going? Good, good. 321 00:24:55,363 --> 00:24:59,673 Ben Garrod specialises in reconstructing skeletons 322 00:24:59,673 --> 00:25:03,006 and he's joining the team to look at the bones in detail. 323 00:25:04,594 --> 00:25:07,950 Marks on them show clearly where the muscles were attached. 324 00:25:09,233 --> 00:25:12,193 That's halfway down the femur, isn't it, that big lump there... Yes. 325 00:25:12,193 --> 00:25:14,923 ..for these massive muscle and, I guess, tendon attachments? 326 00:25:15,943 --> 00:25:20,277 This lump is where a huge muscle was attached to the femur. 327 00:25:21,913 --> 00:25:24,353 The other end of this muscle was connected to bones 328 00:25:24,353 --> 00:25:26,241 Iike these in the tail. 329 00:25:27,474 --> 00:25:30,693 It's this connection that helped our dinosaur to walk. 330 00:25:31,983 --> 00:25:34,993 They've got so much strength and so much rigidity up there. 331 00:25:34,993 --> 00:25:39,173 They actually used their tails to help move, to help their propulsion. 332 00:25:39,173 --> 00:25:43,373 So they had massive muscles and tendons from... Help...? 333 00:25:43,373 --> 00:25:46,273 Yes, so the movement of the tail actually pulled the hind legs 334 00:25:46,273 --> 00:25:48,213 backwards and then raised them forwards. 335 00:25:48,213 --> 00:25:49,100 Oh, I see. 336 00:25:50,983 --> 00:25:52,663 I must try that sometime! 337 00:25:52,663 --> 00:25:54,153 LAUGHTER 338 00:25:57,273 --> 00:26:01,553 The largest lizard alive today, the Komodo dragon, 339 00:26:01,553 --> 00:26:03,669 has a similar adaptation. 340 00:26:05,353 --> 00:26:09,346 The swing of their tail helps their back legs move more efficiently. 341 00:26:14,143 --> 00:26:16,733 Of course, our dinosaur was different, 342 00:26:16,733 --> 00:26:19,543 not least because it weighed over 500 times more. 343 00:26:21,433 --> 00:26:24,743 And that makes John Hutchinson suspect that it would have 344 00:26:24,743 --> 00:26:27,633 had to deal with another problem - 345 00:26:27,633 --> 00:26:30,921 one also faced by passengers on long-haul flights. 346 00:26:32,343 --> 00:26:36,533 Pressure in the legs of big animals is a really big problem. 347 00:26:36,533 --> 00:26:40,173 If blood stays down there too long, it's going to pool and clot. 348 00:26:41,273 --> 00:26:45,153 Much like airline socks that humans use, large animals, 349 00:26:45,153 --> 00:26:49,423 again and again, have evolved very thick elastic skin 350 00:26:49,423 --> 00:26:53,903 around their lower limb that helps to keep that pressure very high. 351 00:26:53,903 --> 00:26:55,454 Actually, I can empathise. 352 00:26:55,454 --> 00:26:59,073 I have to wear those same kind of stockings to get my blood 353 00:26:59,073 --> 00:27:00,870 back up my long legs! 354 00:27:02,023 --> 00:27:04,273 Time to thank our helpful elephant. 355 00:27:04,273 --> 00:27:06,464 You're a lovely thing. Yes, you... 356 00:27:06,464 --> 00:27:10,033 Oh, you want one! OK, in you go. 357 00:27:10,033 --> 00:27:13,013 Thanks. Thanks, pal. 358 00:27:14,433 --> 00:27:15,536 That's all I've got! 359 00:27:17,993 --> 00:27:22,454 A giant animal like an elephant also needs a huge heart to pump 360 00:27:22,454 --> 00:27:24,353 blood around its body. 361 00:27:24,353 --> 00:27:26,298 And so did our titanosaur. 362 00:27:42,533 --> 00:27:44,592 Its heart must have been immense. 363 00:27:48,063 --> 00:27:51,783 From our new, detailed knowledge of the skeleton, John Hutchinson 364 00:27:51,783 --> 00:27:55,469 has calculated that it was more than six feet in circumference. 365 00:28:02,543 --> 00:28:06,223 It probably weighed 230 kilos 366 00:28:06,223 --> 00:28:11,233 and would have had to shift 90 litres of blood with a single beat. 367 00:28:11,233 --> 00:28:12,234 There's one! 368 00:28:16,503 --> 00:28:20,893 And it would have had to repeat that beat every five seconds. 369 00:28:20,893 --> 00:28:21,993 HEART BEATS 370 00:28:21,993 --> 00:28:23,108 There it goes again. 371 00:28:27,793 --> 00:28:30,543 Weighing more than three grown men, 372 00:28:30,543 --> 00:28:32,795 it would have been extraordinarily powerful. 373 00:28:38,633 --> 00:28:43,023 And in order to pump blood around the body at high pressure 374 00:28:43,023 --> 00:28:47,373 and then into the delicate lungs at a lower pressure, 375 00:28:47,373 --> 00:28:52,253 it's thought that our titanosaur's heart had four chambers - 376 00:28:52,253 --> 00:28:54,551 more like that of a bird than a reptile. 377 00:28:59,663 --> 00:29:04,383 So, a powerful heart pumped the blood to the extremities of the body, 378 00:29:04,383 --> 00:29:06,999 but how did the blood get back? 379 00:29:10,503 --> 00:29:15,183 As in an elephant, a combination of fatty footpads 380 00:29:15,183 --> 00:29:19,597 and tight skin are thought to have forced the blood from its legs... 381 00:29:20,943 --> 00:29:22,535 ..all the way back to its heart. 382 00:29:37,474 --> 00:29:43,344 Toronto, Canada, and the world's biggest dinosaur-making factory. 383 00:29:51,383 --> 00:29:55,584 The team is building a life-size skeleton of this vast creature 384 00:29:55,584 --> 00:30:01,363 to be unveiled in Diego's warehouse in Argentina in six months' time. 385 00:30:04,263 --> 00:30:08,433 First, they have to turn all the information from the 3-D scans 386 00:30:08,433 --> 00:30:10,253 into each individual bone. 387 00:30:14,233 --> 00:30:17,623 State-of-the-art robots carve moulds from polystyrene 388 00:30:17,623 --> 00:30:20,535 so that the bones can be cast in fibreglass. 389 00:30:36,953 --> 00:30:41,743 Up until now, the fossil bones have been the main focus of the dig 390 00:30:41,743 --> 00:30:43,704 but the rock that surrounds the fossils 391 00:30:43,704 --> 00:30:46,623 also holds important information. 392 00:30:46,623 --> 00:30:51,943 The nature of the layers of rock in which these fossils lie can tell us 393 00:30:51,943 --> 00:30:56,585 a great deal about how they got to be where they are and how old they are. 394 00:30:57,858 --> 00:31:01,898 Some of these layers are volcanic ash which must have come 395 00:31:01,898 --> 00:31:06,164 from a volcano erupting every now and then somewhere in the neighbourhood. 396 00:31:10,668 --> 00:31:15,435 And this ash around the bones can tell us how old the fossils are. 397 00:31:17,028 --> 00:31:19,538 Scientists worked out that all these fossils 398 00:31:19,538 --> 00:31:22,098 dated from the Cretaceous period 399 00:31:22,098 --> 00:31:23,818 but better than that, 400 00:31:23,818 --> 00:31:31,463 they dated them precisely to 101.6 million years old. 401 00:31:38,788 --> 00:31:41,709 By a detailed forensic examination 402 00:31:41,709 --> 00:31:44,948 and comparisons with living creatures, 403 00:31:44,948 --> 00:31:49,749 the team have deduced a great deal about the life of our titanosaur. 404 00:31:53,658 --> 00:31:58,178 We now know when it lived, how big it was, 405 00:31:58,178 --> 00:32:02,668 how it moved and what its young might have looked like. 406 00:32:02,668 --> 00:32:05,637 We've even calculated its heart rate. 407 00:32:13,308 --> 00:32:17,508 In an investigation of this scale, sometimes the most important 408 00:32:17,508 --> 00:32:21,028 information comes not from the most eye-catching evidence 409 00:32:21,028 --> 00:32:23,781 but from quite tiny details. 410 00:32:27,858 --> 00:32:33,478 Here is something that I really hoped the excavation was going to find. 411 00:32:36,158 --> 00:32:37,511 It's a tooth. 412 00:32:39,018 --> 00:32:43,818 And it's tiny compared with the size of the huge animals 413 00:32:43,818 --> 00:32:45,308 from which it came. 414 00:32:46,618 --> 00:32:51,308 Teeth can tell you a huge amount about an animal. 415 00:32:51,308 --> 00:32:55,068 And if you look at the tip, you can see that it has been 416 00:32:55,068 --> 00:32:59,589 worn into two facets on either side. 417 00:32:59,589 --> 00:33:04,898 And that tells us that this tooth engaged with the teeth on the other 418 00:33:04,898 --> 00:33:10,308 side in an alternate way like that, not head-on but one on either side. 419 00:33:10,308 --> 00:33:13,428 So this animal, like a pair of scissors, 420 00:33:13,428 --> 00:33:17,948 just nipped off the vegetation on which it was feeding. 421 00:33:17,948 --> 00:33:22,818 Enormous though it was, just nipped off little leaves 422 00:33:22,818 --> 00:33:24,798 and here are fossils 423 00:33:24,798 --> 00:33:28,438 of some of the different kinds of plants on which it might have fed... 424 00:33:29,908 --> 00:33:34,299 ..cycads, ferns and conifers. 425 00:33:44,068 --> 00:33:46,228 One thing these plants have in common 426 00:33:46,228 --> 00:33:50,346 is that they're all very fibrous and hard to digest. 427 00:33:51,698 --> 00:33:55,308 To get enough nutrients from such poor quality foods 428 00:33:55,308 --> 00:33:59,551 our titanosaur would have had to eat them in vast quantities. 429 00:34:03,738 --> 00:34:07,959 A descendent of one of these plants still grows in Patagonia today. 430 00:34:11,978 --> 00:34:16,228 200 million years ago when South America, Australia 431 00:34:16,228 --> 00:34:19,668 and Antarctica were all joined together to form 432 00:34:19,668 --> 00:34:22,538 a supercontinent called Gondwana, 433 00:34:22,538 --> 00:34:25,678 a particular kind of vegetation was dominant - 434 00:34:25,678 --> 00:34:27,020 they were conifers. 435 00:34:28,158 --> 00:34:31,148 They continued to survive to 100 million years ago 436 00:34:31,148 --> 00:34:35,339 when our titanosaurs were roaming the land and a few still 437 00:34:35,339 --> 00:34:40,978 survive today. Here in the foothills of the Andes is one of them. 438 00:34:40,978 --> 00:34:44,391 The monkey puzzle tree called araucaria. 439 00:34:49,748 --> 00:34:52,798 Trees, like araucaria, show that the dinosaurs 440 00:34:52,798 --> 00:34:54,823 must have had another problem. 441 00:34:56,418 --> 00:34:59,508 These conifers, apart from being poor-quality fodder, 442 00:34:59,508 --> 00:35:03,035 can grow to over 130 feet in height. 443 00:35:05,228 --> 00:35:10,029 They would have been out of reach for many animals but not our titanosaur. 444 00:35:15,538 --> 00:35:16,744 Here, boys, come on. 445 00:35:20,788 --> 00:35:26,340 It's pretty clear why a long neck is useful for a land-living animal. 446 00:35:27,628 --> 00:35:31,828 It enables it to reach vegetation which is growing high up 447 00:35:31,828 --> 00:35:36,388 at the top trees that other ground-based animals couldn't reach 448 00:35:36,388 --> 00:35:40,548 and it must have been much the same for titanosaur, 449 00:35:40,548 --> 00:35:43,738 except we know from the fossils that titanosaur's neck was 450 00:35:43,738 --> 00:35:45,638 very, very much longer. 451 00:35:47,618 --> 00:35:52,268 And that enabled it to sweep its head in a great wide arc 452 00:35:52,268 --> 00:35:56,158 and even to reach between two tree trunks that happened to be 453 00:35:56,158 --> 00:35:59,828 growing close together to get other vegetation. 454 00:35:59,828 --> 00:36:00,829 What about that? 455 00:36:04,178 --> 00:36:08,228 This enormous reach would have saved our titanosaur a lot of energy. 456 00:36:09,599 --> 00:36:13,194 It only needed to move its neck to feed, not its whole body. 457 00:36:16,868 --> 00:36:20,599 But how did it eat enough of this poor-quality food to survive? 458 00:36:22,188 --> 00:36:24,782 Elephants face a similar challenge today. 459 00:36:26,268 --> 00:36:31,058 An elephant can collect and chew about 130 kilos - 460 00:36:31,058 --> 00:36:34,232 that's 300 pounds of vegetation in a day. 461 00:36:35,388 --> 00:36:39,392 But our titanosaur could have eaten five times that amount. 462 00:36:41,138 --> 00:36:44,978 It's been estimated that a large titanosaur would eat enough 463 00:36:44,978 --> 00:36:47,879 plant material to fill a skip in a single day. 464 00:36:49,418 --> 00:36:51,397 So how did they digest it all? 465 00:36:52,518 --> 00:36:54,778 Elephants solved the problem by giving their food 466 00:36:54,778 --> 00:36:59,556 Iong preparatory chews but titanosaurs didn't bother. 467 00:37:01,398 --> 00:37:04,988 They simply gathered leaves by nipping them off 468 00:37:04,988 --> 00:37:06,785 and then swallowing them whole. 469 00:37:09,058 --> 00:37:12,028 But that in turn would mean that they needed a bigger 470 00:37:12,028 --> 00:37:15,668 and longer gut to digest all that unchewed food. 471 00:37:17,668 --> 00:37:19,628 And it might well have taken ten days 472 00:37:19,628 --> 00:37:21,698 for food to pass through their system. 473 00:37:24,028 --> 00:37:30,038 A bigger gut needs a bigger body so titanosaurs grew bigger and bigger 474 00:37:30,038 --> 00:37:33,701 until they approached the limits of what their bones could support. 475 00:37:43,868 --> 00:37:48,828 Two years after the dig began, a strange cargo arrives, 476 00:37:48,828 --> 00:37:51,672 having made a 7,000 mile journey from Canada. 477 00:37:59,599 --> 00:38:01,748 Dozens of packing cases later 478 00:38:01,748 --> 00:38:05,320 and all the bones are finally in Diego's warehouse. 479 00:38:14,268 --> 00:38:17,248 Assembling the skeleton can finally begin. 480 00:38:20,878 --> 00:38:24,878 The 3-D data used to make the skeleton has also been used 481 00:38:24,878 --> 00:38:26,869 to create a computer model. 482 00:38:28,228 --> 00:38:30,349 It means I can get a preview 483 00:38:30,349 --> 00:38:32,988 of what the final skeleton will look like. 484 00:38:32,988 --> 00:38:36,058 The first thing is these very, very lovely legs. 485 00:38:36,058 --> 00:38:38,599 If we turn it around, they are very, very column-like 486 00:38:38,599 --> 00:38:40,138 and this is like elephants 487 00:38:40,138 --> 00:38:44,708 but interestingly this titanosaur had slightly splayed legs, 488 00:38:44,708 --> 00:38:48,778 at an angle of about five degrees and this slight change would have 489 00:38:48,778 --> 00:38:52,498 really increased the ability to take all that extra weight. 490 00:38:52,498 --> 00:38:54,958 Can you see the splay because of the joint or 491 00:38:54,958 --> 00:38:57,138 because of the shape of the bone? A bit of both. 492 00:38:57,138 --> 00:38:59,908 You can tell from the shape of the bone and from where certain 493 00:38:59,908 --> 00:39:03,238 parts of the bones form and how they sit and then how the bones fit 494 00:39:03,238 --> 00:39:06,498 with one another you can really tell how it would have sat in real life. 495 00:39:06,498 --> 00:39:09,948 Another thing you can see is a very, very long neck. 496 00:39:09,948 --> 00:39:14,028 And we just found out that ours had 15 bones in its neck. 497 00:39:14,028 --> 00:39:16,988 Interestingly, some of them were five or six times longer than 498 00:39:16,988 --> 00:39:18,188 they were wide. 499 00:39:18,188 --> 00:39:21,038 These incredibly long vertebrae and there's lots of them. 500 00:39:21,038 --> 00:39:23,138 Why does it have such a long tail? 501 00:39:23,138 --> 00:39:26,988 Well, a couple of reasons. If you've got an animal this big with 502 00:39:26,988 --> 00:39:29,908 a neck this long, the last thing you want to be is top-heavy. 503 00:39:29,908 --> 00:39:33,628 And research has just shown that the centre of gravity 504 00:39:33,628 --> 00:39:37,553 in this animal was somewhere right in the middle of the chest cavity. 505 00:39:38,898 --> 00:39:44,148 So the heavy tail counterbalances the exceedingly long neck. 506 00:39:44,148 --> 00:39:47,508 But judging from the size of the muscle attachments, 507 00:39:47,508 --> 00:39:49,863 the tail was also immensely strong. 508 00:39:51,418 --> 00:39:56,219 It had huge muscles from around here right down to about a third 509 00:39:56,219 --> 00:39:58,948 of the way down the tail, somewhere around here. 510 00:39:58,948 --> 00:40:02,308 So that would be solid flesh? Yep, muscle tissue, other tissue, 511 00:40:02,308 --> 00:40:03,349 Iigaments, tendons. 512 00:40:03,349 --> 00:40:05,718 Do you think they might have fought with it? 513 00:40:05,718 --> 00:40:07,349 Possibly. Thrashing it about? 514 00:40:07,349 --> 00:40:09,788 It could've been used as a defence mechanism 515 00:40:09,788 --> 00:40:12,678 so you're walking up to that as a predator, the last thing you 516 00:40:12,678 --> 00:40:14,782 want to be is on the receiving end. Don't put me into it! 517 00:40:18,108 --> 00:40:19,143 Yeah. 518 00:40:29,068 --> 00:40:34,118 The long and painstaking examination of the backbone has now borne fruit 519 00:40:34,118 --> 00:40:36,507 and Ben has got some important news. 520 00:40:42,548 --> 00:40:45,858 This is a vertebrae here from right high up in the back, 521 00:40:45,858 --> 00:40:47,339 right near the shoulder blades. 522 00:40:47,339 --> 00:40:52,868 And the most important thing is this little ridge that ends in this 523 00:40:52,868 --> 00:40:55,918 big lump and this is only found in this particular dinosaur 524 00:40:55,918 --> 00:40:59,188 so from that and a few other physical differences, 525 00:40:59,188 --> 00:41:02,589 we think we have got a brand-new, exciting species. 526 00:41:05,068 --> 00:41:08,393 So our titanosaur is not only a giant, 527 00:41:08,393 --> 00:41:11,692 it is indeed a new species of dinosaur. 528 00:41:13,849 --> 00:41:18,489 Examining the spinal bones also reveal something about how it coped 529 00:41:18,489 --> 00:41:20,252 with life as a giant. 530 00:41:22,769 --> 00:41:25,966 This is where the spinal cord would have passed. 531 00:41:27,769 --> 00:41:30,779 So this hole straight through here? Mm-hm. 532 00:41:30,779 --> 00:41:32,609 The whole nerve centre, as it were, 533 00:41:32,609 --> 00:41:35,129 the cable carrying all the nerves. From the base of the tail 534 00:41:35,129 --> 00:41:39,249 right to the skull. It's very small. It is, yeah. Ours is what? 535 00:41:39,249 --> 00:41:42,343 About thumb width. So it's not all that much bigger. No. 536 00:41:45,019 --> 00:41:47,988 This cord was well over 100 feet long. 537 00:41:50,399 --> 00:41:53,879 It would have taken about a second for a nerve impulse 538 00:41:53,879 --> 00:41:56,029 to go from its tail to its brain. 539 00:41:57,889 --> 00:42:01,108 And what's more, the spine has revealed another surprise. 540 00:42:02,249 --> 00:42:05,537 It is full of holes, rather like a Swiss cheese. 541 00:42:08,460 --> 00:42:12,460 The neck bones of titanosaurs contain so many holes 542 00:42:12,460 --> 00:42:16,889 and spaces that they weighed around 35% less than 543 00:42:16,889 --> 00:42:20,649 they would have done had they been made of solid bone. 544 00:42:20,649 --> 00:42:24,099 The leg bones of modern birds are much the same. 545 00:42:24,099 --> 00:42:28,689 And those spaces serve another very important function. 546 00:42:28,689 --> 00:42:30,828 They contained air sacs. 547 00:42:33,977 --> 00:42:37,504 These air sacs were connected with the lungs. 548 00:42:41,386 --> 00:42:44,666 So what was their function and how did they work? 549 00:42:44,666 --> 00:42:48,846 They occupied much of the chest and ran along the whole length 550 00:42:48,846 --> 00:42:51,457 of the body along the backbone 551 00:42:51,457 --> 00:42:55,268 to the 17-metre-long neck and then to the head. 552 00:42:58,286 --> 00:43:02,780 It's thought the balloon-like sacs had thin but strong membranes. 553 00:43:05,896 --> 00:43:10,788 These sacs acted like bellows, forcing air into the lungs. 554 00:43:12,696 --> 00:43:17,266 When we breathe in, air flows down into our lungs, 555 00:43:17,266 --> 00:43:21,846 oxygen is absorbed in exchange for carbon dioxide which is then 556 00:43:21,846 --> 00:43:24,546 got rid of when we breathe out. 557 00:43:24,546 --> 00:43:29,506 The air sac system is very much more complex but very much more efficient. 558 00:43:31,856 --> 00:43:36,486 It enabled a titanosaur to take in oxygen continuously, 559 00:43:36,486 --> 00:43:40,047 not just when breathing in but also when breathing out. 560 00:44:04,386 --> 00:44:08,416 Our titanosaur wasn't the only giant living around here. 561 00:44:08,416 --> 00:44:09,576 ROARING 562 00:44:13,746 --> 00:44:19,207 This was a dangerous world, where meat-eaters were giants too. 563 00:44:23,486 --> 00:44:27,656 New evidence from the dig site shows that carnivorous dinosaurs 564 00:44:27,656 --> 00:44:28,987 were here as well. 565 00:44:32,896 --> 00:44:38,696 So these are some of the over 80 teeth we found on the dig site. 566 00:44:38,696 --> 00:44:42,302 And you can feel how sharp they are. 567 00:44:44,926 --> 00:44:48,467 Oh, yes, it's serrated, just like a shark's tooth, in fact. Absolutely. 568 00:44:48,467 --> 00:44:53,457 They actually belong to a family known as a shark-toothed dinosaurs. 569 00:44:53,457 --> 00:44:56,926 We can identify the teeth at the family level. 570 00:44:56,926 --> 00:44:59,816 We know of one species that belonged to that family, 571 00:44:59,816 --> 00:45:03,626 it's called Tyrannotitan chubutensis. 572 00:45:03,626 --> 00:45:04,906 Tyrannotitan? Yeah. 573 00:45:04,906 --> 00:45:10,536 That means a ferocious giant, ferocious beast. Exactly. Good name. 574 00:45:10,536 --> 00:45:13,066 Yeah. Chubutensis is because of the area it comes from? 575 00:45:13,066 --> 00:45:15,457 Yes, this is the Chubut province. 576 00:45:15,457 --> 00:45:16,515 Great. 577 00:45:17,826 --> 00:45:22,354 Tyrannotitan must have been a ferocious-looking beast. 578 00:45:23,386 --> 00:45:26,776 With large eyes, sharp, flesh-eating teeth... 579 00:45:28,986 --> 00:45:34,276 ..and strong legs, it was a fast, alert, meat-eating dinosaur. 580 00:45:38,186 --> 00:45:42,416 And it was as big as T Rex. Really? Not as famous. 581 00:45:42,416 --> 00:45:45,546 Not as famous. Tell that to Hollywood. 582 00:45:45,546 --> 00:45:48,993 I have some bones over there I would like to show you. 583 00:45:50,347 --> 00:45:55,656 So this is one of the tail vertebrae we found at the dig site. 584 00:45:55,656 --> 00:45:58,136 There's something really interesting here. 585 00:45:58,136 --> 00:45:59,826 You can see this groove? Mmm. 586 00:45:59,826 --> 00:46:03,376 Well, this groove was probably a bite mark 587 00:46:03,376 --> 00:46:05,936 made by one of the carnivores. By one of these teeth? 588 00:46:05,936 --> 00:46:08,626 Right. So it was... What do you mean? Like that? 589 00:46:08,626 --> 00:46:13,177 Exactly. Taking the flesh out of their tail. Really? Yeah. 590 00:46:14,426 --> 00:46:15,506 The tender bits. 591 00:46:17,426 --> 00:46:20,566 They would be too. Yeah, absolutely. 592 00:46:20,566 --> 00:46:24,136 Can you determine whether it was a scavenger or it was a hunter? 593 00:46:24,136 --> 00:46:27,496 We don't know if they were dead, I mean, they were scavenging 594 00:46:27,496 --> 00:46:31,296 on the carcasses, or if they were actually hunting and killing them. 595 00:46:32,696 --> 00:46:37,713 Well, it didn't make much difference to the old dinosaur. Yes. 596 00:46:39,776 --> 00:46:42,426 In a detective story, to close the case, 597 00:46:42,426 --> 00:46:45,702 you really want to know how the victim met its end. 598 00:46:47,636 --> 00:46:51,736 If our titanosaur didn't perish in the jaws of a Tyrannotitan, 599 00:46:51,736 --> 00:46:52,998 how did it die? 600 00:46:55,986 --> 00:47:00,186 Clues can be found by the detailed three-dimensional mapping 601 00:47:00,186 --> 00:47:04,702 of the location of every fossil bone, small and large. 602 00:47:07,856 --> 00:47:12,556 That shows that the dig site contains the remains of not just one 603 00:47:12,556 --> 00:47:15,002 but seven different individuals. 604 00:47:16,186 --> 00:47:17,938 All of the new species. 605 00:47:18,986 --> 00:47:23,059 And the first thing to notice is that they are on three different levels. 606 00:47:27,056 --> 00:47:30,016 That's to say the animals must have come here 607 00:47:30,016 --> 00:47:32,701 on at least three different occasions. 608 00:47:38,746 --> 00:47:40,657 But why should they have done that? 609 00:47:49,496 --> 00:47:53,186 There are several theories as to why seven bodies 610 00:47:53,186 --> 00:47:57,426 should have all ended up at this one particular place. 611 00:47:57,426 --> 00:48:00,477 The first is that this was a seasonal climate 612 00:48:00,477 --> 00:48:02,936 and that as the dry season proceeded 613 00:48:02,936 --> 00:48:06,426 this was one of the last remaining pools of water 614 00:48:06,426 --> 00:48:10,635 and when this went, the sauropods that happened to be here died here. 615 00:48:13,936 --> 00:48:19,146 The second is that these bodies were swept down by great rivers 616 00:48:19,146 --> 00:48:23,186 during the rainy season and then where the land levelled out, 617 00:48:23,186 --> 00:48:25,222 so those bodies were dumped. 618 00:48:26,576 --> 00:48:30,826 Analysis of the sediments around the bones shows that there were rivers 619 00:48:30,826 --> 00:48:34,227 gently flowing across this site at the time of their death. 620 00:48:39,986 --> 00:48:42,284 There was no shortage of water to drink. 621 00:48:43,426 --> 00:48:46,196 What's more the rivers were not moving fast enough 622 00:48:46,196 --> 00:48:47,663 to shift such huge bodies. 623 00:48:49,066 --> 00:48:52,786 So the corpses weren't washed here by floodwaters either. 624 00:48:55,656 --> 00:48:58,636 Could there be another reason why they all died in one 625 00:48:58,636 --> 00:49:01,207 place on three different occasions? 626 00:49:03,906 --> 00:49:07,556 We know from layers of ash around the bones that there were 627 00:49:07,556 --> 00:49:10,466 volcanoes erupting in the neighbourhood 628 00:49:10,466 --> 00:49:13,616 so doubtless there were areas where the ground was 629 00:49:13,616 --> 00:49:18,146 warmed by volcanic fumes, just as they are here today. 630 00:49:18,146 --> 00:49:22,856 We also know that dinosaurs regularly laid their eggs in such places, 631 00:49:22,856 --> 00:49:26,556 doubtless taking advantage of the volcanic warmth to help 632 00:49:26,556 --> 00:49:28,016 incubate their eggs. 633 00:49:28,016 --> 00:49:31,986 So maybe that was the reason why they kept returning to the same place. 634 00:49:38,906 --> 00:49:42,586 Certainly the excavation of the dinosaur egg site 635 00:49:42,586 --> 00:49:44,315 seems to support this. 636 00:49:46,376 --> 00:49:49,016 Nests like these have been found 637 00:49:49,016 --> 00:49:53,626 at four quite widely separated layers in the rocks, 638 00:49:53,626 --> 00:49:58,136 showing that dinosaurs came back to this particular site again 639 00:49:58,136 --> 00:50:01,833 and again and again over a long period of time. 640 00:50:11,826 --> 00:50:16,506 Ash from a volcanic eruption can sometimes fall in such quantities 641 00:50:16,506 --> 00:50:20,385 that the whole vegetation is blanketed by it and killed. 642 00:50:21,866 --> 00:50:24,347 So life in the aftermath of a big eruption 643 00:50:24,347 --> 00:50:26,793 can be very difficult for a plant-eater. 644 00:50:29,576 --> 00:50:34,626 Whatever the explanation, individuals over several generations came 645 00:50:34,626 --> 00:50:37,515 to this one place and died here. 646 00:50:40,357 --> 00:50:41,826 The dig is coming to an end 647 00:50:41,826 --> 00:50:46,556 and the team have assembled a record-breaking number of bones 648 00:50:46,556 --> 00:50:51,596 but they're still hoping to find one last piece of the puzzle - the skull. 649 00:50:51,596 --> 00:50:57,816 So what number's this, 203? Actually this is 223. 23? 650 00:50:57,816 --> 00:50:59,866 Between the seven individuals? 651 00:50:59,866 --> 00:51:01,936 Yeah. Between all the seven individuals we found 652 00:51:01,936 --> 00:51:03,227 here on this site. 653 00:51:03,227 --> 00:51:06,556 If these are neck vertebrae, could they be leading towards a skull? 654 00:51:06,556 --> 00:51:08,306 Yes, that's what were hoping for. 655 00:51:08,306 --> 00:51:11,666 We just found another neck vertebrae over there. 656 00:51:11,666 --> 00:51:14,426 That would be a great triumph if you found a skull, wouldn't it? 657 00:51:14,426 --> 00:51:18,357 There are only three titanosaur skulls known so far. Really? Yeah. 658 00:51:18,357 --> 00:51:21,586 So they're very rare. And that's because they're very fragile. 659 00:51:21,586 --> 00:51:23,586 They're very delicate bones 660 00:51:23,586 --> 00:51:28,796 and they have very light sutures between each of the bones. 661 00:51:28,796 --> 00:51:33,306 OK, well, let's hope you find number four. Yeah. Could be under there. 662 00:51:33,306 --> 00:51:36,707 Could be. We're going for that. Wonderful. 663 00:51:40,536 --> 00:51:42,538 Alas, it was not to be. 664 00:51:47,276 --> 00:51:50,986 So I gather you haven't yet found the skull. Sadly not. 665 00:51:50,986 --> 00:51:54,217 The only thing we have found out of the skull is his tooth. 666 00:51:57,376 --> 00:52:01,586 So to complete the skeleton, the team have to reconstruct one... 667 00:52:01,586 --> 00:52:03,826 Take that piece out of there. 668 00:52:03,826 --> 00:52:07,626 ..basing it on the three skulls of other titanosaur species 669 00:52:07,626 --> 00:52:10,993 to produce one which most suits the single tooth that we have. 670 00:52:18,666 --> 00:52:24,146 The scientific team has discovered, collected, cleaned, 671 00:52:24,146 --> 00:52:29,996 scanned and copied 220 bones of our giant. 672 00:52:29,996 --> 00:52:34,816 Soon it'll be possible to put those copies together to get some idea 673 00:52:34,816 --> 00:52:37,182 of what the living animal actually looked like. 674 00:52:38,386 --> 00:52:42,946 But the fossil bones themselves still have many secrets 675 00:52:42,946 --> 00:52:44,914 that are waiting to be revealed. 676 00:52:53,876 --> 00:52:57,471 All the theory can now be put to the test. 677 00:53:02,386 --> 00:53:06,876 We can finally get the most accurate estimate of our dinosaur's weight 678 00:53:06,876 --> 00:53:08,389 and true size. 679 00:53:22,826 --> 00:53:27,377 It takes two weeks, working day and night, to fit all the bones together. 680 00:53:43,826 --> 00:53:46,522 Wow! God! 681 00:53:49,946 --> 00:53:52,551 Absolutely amazing! 682 00:54:12,306 --> 00:54:13,750 Good gracious! 683 00:54:41,996 --> 00:54:46,227 Well, Diego, are you pleased with it? Yes, we are very pleased. 684 00:54:46,227 --> 00:54:51,107 It is been a lot of work, it has taken 40,000 man-hours to get here 685 00:54:51,107 --> 00:54:54,176 but we're really, really happy with it. 686 00:54:54,176 --> 00:54:57,586 And does it answer some of your questions about the animal? 687 00:54:57,586 --> 00:54:58,756 Oh, yeah, absolutely. 688 00:54:58,756 --> 00:55:00,237 It answers a lot of questions 689 00:55:00,237 --> 00:55:03,676 but the good thing is it raises more questions. 690 00:55:03,676 --> 00:55:07,596 So we have a lot of research to continue on this animal. 691 00:55:07,596 --> 00:55:10,076 It's clear that this thing still wasn't fully grown. 692 00:55:10,076 --> 00:55:12,227 It's massive, but it still had room to go. 693 00:55:12,227 --> 00:55:14,026 You mean the structure of the bones looks as 694 00:55:14,026 --> 00:55:16,746 though they were still growing? Yeah. 695 00:55:16,746 --> 00:55:22,466 So, that raises the really big question, is it the biggest 696 00:55:22,466 --> 00:55:24,266 so far discovered? 697 00:55:24,266 --> 00:55:26,586 Well, according to our estimate, 698 00:55:26,586 --> 00:55:29,237 this animal weighed 70 metric tonnes. 699 00:55:30,466 --> 00:55:34,186 70 metric tonnes. What would that compare with? 700 00:55:34,186 --> 00:55:39,156 That is like 15 African elephants. 15 African elephants? 701 00:55:39,156 --> 00:55:45,946 We are now sure that this animal was 10% larger than Argentinosaurus. 702 00:55:45,946 --> 00:55:47,876 The previous record-holder? 703 00:55:47,876 --> 00:55:49,956 The previous record-holder. So, yes, 704 00:55:49,956 --> 00:55:54,906 we think we have the largest dinosaur ever known. Fantastic! 705 00:55:54,906 --> 00:55:57,146 I can quite believe it. 706 00:55:57,146 --> 00:56:02,506 Congratulations to you. Thank you. Congratulations to he, she or it. 707 00:56:02,506 --> 00:56:04,827 Wonderful! A marvellous, marvellous thing! 708 00:56:23,421 --> 00:56:26,581 Piecing this complex jigsaw puzzle together 709 00:56:26,581 --> 00:56:28,970 has been a fascinating adventure. 710 00:56:31,531 --> 00:56:35,774 It all started with the discovery of one enormous thighbone. 711 00:56:36,811 --> 00:56:41,611 And then a team of 40 worked for over two years to excavate 712 00:56:41,611 --> 00:56:44,781 and put together the near-complete skeleton 713 00:56:44,781 --> 00:56:47,739 of the largest land animal yet discovered. 714 00:56:49,061 --> 00:56:51,781 And so added one further marvel 715 00:56:51,781 --> 00:56:55,615 to the astonishing history of life on earth. 716 00:57:03,651 --> 00:57:07,382 What a thrill it must have been to see it when it was alive. 717 00:57:10,581 --> 00:57:11,582 DEEP BREATHI NG 718 00:57:21,891 --> 00:57:24,439 RUMBLING 719 00:57:39,291 --> 00:57:40,861 RUMBLING 720 00:57:47,651 --> 00:57:48,652 TITANOSAUR ROARS