2 00:00:10,620 --> 00:00:15,940 I'm here in Patagonia in the southern part of South America because, 3 00:00:15,940 --> 00:00:21,100 a few years ago, a man looking for one of his lost sheep found 4 00:00:21,100 --> 00:00:25,300 a simply gigantic bone sticking out of a rock - 5 00:00:25,300 --> 00:00:28,260 a bone that was going to astonish science. 6 00:00:30,060 --> 00:00:34,140 That first bone led to the discovery of over 200 others. 7 00:00:38,780 --> 00:00:44,980 They were all huge - so big that they could only have come from a dinosaur. 8 00:00:44,980 --> 00:00:48,140 And what a dinosaur it would turn out to be! 9 00:00:50,300 --> 00:00:53,100 One that seems to defy the laws of nature. 10 00:00:55,420 --> 00:00:59,180 These bones are part of a skeleton that has remained hidden 11 00:00:59,180 --> 00:01:03,020 and marvellously preserved for 100 million years. 12 00:01:07,020 --> 00:01:10,580 'An international team of scientists assembled to try 13 00:01:10,580 --> 00:01:13,660 'and work out what sort of dinosaur it belonged to.' 14 00:01:16,100 --> 00:01:18,580 It's like a palaeontological crime scene! 15 00:01:19,900 --> 00:01:23,460 Each bone is an important piece of evidence that can give us 16 00:01:23,460 --> 00:01:27,540 information as to what the living creature was actually like. 17 00:01:27,540 --> 00:01:31,220 We'll use the latest forensic technology, 18 00:01:31,220 --> 00:01:35,780 we'll compare it with how giant animals live today 19 00:01:35,780 --> 00:01:40,460 and we'll build a full-size skeleton of this stupendous creature. 20 00:01:43,140 --> 00:01:47,620 And we will try and work out in detail what it looked like 21 00:01:47,620 --> 00:01:48,660 when it was alive. 22 00:01:53,180 --> 00:01:54,540 HE GASPS 23 00:01:54,540 --> 00:01:57,140 Absolutely amazing! 24 00:01:58,180 --> 00:02:01,020 Could it really have been the biggest animal 25 00:02:01,020 --> 00:02:02,500 ever to walk the earth? 26 00:02:22,140 --> 00:02:25,020 Patagonia in southern Argentina. 27 00:02:28,540 --> 00:02:32,980 Like many detective stories, this one began by chance. 28 00:02:35,540 --> 00:02:38,820 A shepherd stumbled across the tip of a huge bone 29 00:02:38,820 --> 00:02:40,580 poking out of the ground. 30 00:02:42,300 --> 00:02:43,340 HORSE SNORTS 31 00:02:48,540 --> 00:02:52,740 Experts from Patagonia's premier palaeontological museum 32 00:02:52,740 --> 00:02:55,300 confirmed it was part of a dinosaur. 33 00:02:55,300 --> 00:02:56,820 THEY SPEAK IN OWN LANGUAGE 34 00:03:01,140 --> 00:03:05,180 But they didn't realise at the time what a truly extraordinary one 35 00:03:05,180 --> 00:03:06,460 it would prove to be. 36 00:03:12,300 --> 00:03:15,700 Dinosaurs of many kinds roamed all over these lands 37 00:03:15,700 --> 00:03:18,100 in the southern end of South America 38 00:03:18,100 --> 00:03:21,180 during what's known as the Cretaceous period, 39 00:03:21,180 --> 00:03:25,100 between 66 and 145 million years ago. 40 00:03:27,100 --> 00:03:31,180 The largest were plant-eaters known as sauropods. 41 00:03:31,180 --> 00:03:35,500 And the largest of them were the titanosaurs. 42 00:03:37,660 --> 00:03:41,180 Giant titanosaur bones are comparatively rare 43 00:03:41,180 --> 00:03:44,060 so very little is known about these dinosaurs. 44 00:03:48,500 --> 00:03:51,580 This new discovery could change all that. 45 00:03:57,540 --> 00:04:03,100 'Like many people, young and old, I'm fascinated by dinosaurs, 46 00:04:03,100 --> 00:04:06,020 'so the chance to join this investigation 47 00:04:06,020 --> 00:04:08,580 'is just too good an opportunity to miss.' 48 00:04:08,580 --> 00:04:11,020 Oh, I'd love to have a go! 49 00:04:11,020 --> 00:04:12,700 HE LAUGHS 50 00:04:12,700 --> 00:04:14,100 I'm sure they'd let you. 51 00:04:14,100 --> 00:04:15,140 HE LAUGHS 52 00:04:15,140 --> 00:04:18,780 'Of course, it's the giants in particular that capture 53 00:04:18,780 --> 00:04:19,820 'the imagination.' 54 00:04:22,380 --> 00:04:24,540 The first sauropods to appear on earth 55 00:04:24,540 --> 00:04:26,780 were comparatively small creatures. 56 00:04:26,780 --> 00:04:30,980 This is the cast of the thigh bone of one of them. 57 00:04:30,980 --> 00:04:34,740 It's not even as big as my thigh bone. 58 00:04:34,740 --> 00:04:41,340 But after about 20 million years, some had become pretty big. 59 00:04:41,340 --> 00:04:45,420 This is a thigh bone from one of those creatures. 60 00:04:45,420 --> 00:04:46,820 But then, after that... 61 00:04:48,620 --> 00:04:53,340 ..our giant appeared. This is its thigh bone. 62 00:04:54,980 --> 00:04:57,220 It's the largest ever found. 63 00:05:06,260 --> 00:05:10,780 Coming across such a bone in your back yard must be quite a shock. 64 00:05:10,780 --> 00:05:13,660 Just ask farm owner Alba Maio. 65 00:05:16,620 --> 00:05:18,420 HENS CLUCK 66 00:05:18,420 --> 00:05:20,740 TRANSLATION: 67 00:05:22,300 --> 00:05:23,860 SHE LAUGHS 68 00:05:23,860 --> 00:05:26,940 TRANSLATION: 69 00:05:37,820 --> 00:05:41,420 Before long, a whole team of fossil-hunting scientists 70 00:05:41,420 --> 00:05:43,380 arrives and starts work. 71 00:05:55,340 --> 00:06:00,140 The thighbone proves to be eight feet, 2.4 metres long. 72 00:06:07,700 --> 00:06:12,420 It's preserved in extraordinary detail, and detail will be 73 00:06:12,420 --> 00:06:15,660 critical to the forensic examination that will follow. 74 00:06:26,300 --> 00:06:31,020 The research team soon turn the site into a vast quarry. 75 00:06:39,900 --> 00:06:44,540 It proves to be one of the biggest dinosaur finds of the century. 76 00:06:47,420 --> 00:06:51,460 Bone after bone emerge from the rocks. 77 00:06:51,460 --> 00:06:54,060 THEY LAUGH 78 00:06:56,540 --> 00:06:58,980 We just found another bone right here. 79 00:06:58,980 --> 00:07:00,940 We weren't expecting it at all. 80 00:07:00,940 --> 00:07:03,780 We just start digging and find it. 81 00:07:05,980 --> 00:07:08,860 Until recently, giant titanosaurs 82 00:07:08,860 --> 00:07:11,620 have only been known from a dozen bones 83 00:07:11,620 --> 00:07:16,260 and our team have already found more than ten times as many. 84 00:07:22,060 --> 00:07:25,740 Dr Diego Pol is the chief palaeontologist 85 00:07:25,740 --> 00:07:27,980 leading the investigation. 86 00:07:27,980 --> 00:07:29,900 If you really want to know 87 00:07:29,900 --> 00:07:34,220 what a really gigantic dinosaur looked like, this quarry here 88 00:07:34,220 --> 00:07:36,780 has the potential to answer that question 89 00:07:36,780 --> 00:07:38,980 and that's really exciting for us. 90 00:07:40,460 --> 00:07:41,740 It's really impressive. 91 00:07:41,740 --> 00:07:45,980 When you stand by one of these bones, you really feel tiny. 92 00:07:47,380 --> 00:07:51,380 With so much new evidence, there is a chance of discovering 93 00:07:51,380 --> 00:07:55,900 all kinds of new facts about the mysterious titanosaurs. 94 00:07:58,820 --> 00:08:01,420 It's like a palaeontological crime scene. 95 00:08:01,420 --> 00:08:03,180 It's a really unique thing 96 00:08:03,180 --> 00:08:06,420 that you will not find anywhere else in the world. 97 00:08:09,500 --> 00:08:11,660 Patagonia's harsh weather 98 00:08:11,660 --> 00:08:14,260 makes uncovering the fossils exhausting, 99 00:08:14,260 --> 00:08:18,940 but it also endangers the newly-exposed fossils. 100 00:08:21,220 --> 00:08:23,060 THUNDER RUMBLES 101 00:08:23,060 --> 00:08:24,820 A lot of damage from the rain 102 00:08:24,820 --> 00:08:28,180 so we need to protect the bones that are at risk. 103 00:08:28,180 --> 00:08:32,780 I'm really concerned that this already has some cracks. 104 00:08:33,860 --> 00:08:35,740 If the bones aren't protected, 105 00:08:35,740 --> 00:08:38,860 tiny details on their surface could be lost. 106 00:08:44,780 --> 00:08:48,100 To protect the bones, they're covered with, of all things, 107 00:08:48,100 --> 00:08:52,220 wet toilet paper and plaster of Paris. 108 00:08:52,220 --> 00:08:56,340 It's like putting a plaster cast on a broken leg. 109 00:08:59,140 --> 00:09:02,060 There's a rush to get them back to the museum 110 00:09:02,060 --> 00:09:05,020 to begin examining them in minute detail. 111 00:09:10,220 --> 00:09:14,020 A new road has been specially built to enable them 112 00:09:14,020 --> 00:09:17,060 to be transported without too much jolting. 113 00:09:21,020 --> 00:09:26,100 Once at the museum laboratory, the detailed detective work begins. 114 00:09:34,180 --> 00:09:38,260 It's a chance to start putting flesh on bones. 115 00:09:38,260 --> 00:09:41,900 Some really big muscle was going in here. 116 00:09:41,900 --> 00:09:45,540 This animal was so big that it certainly needed 117 00:09:45,540 --> 00:09:48,980 really powerful muscles and very strong attachments 118 00:09:48,980 --> 00:09:51,300 into the bones. 119 00:10:01,460 --> 00:10:04,700 This is a giant vertebra, one of the bones of the spine, 120 00:10:04,700 --> 00:10:08,060 and it's a very important find. 121 00:10:08,060 --> 00:10:10,940 That's because it's likely to provide crucial evidence 122 00:10:10,940 --> 00:10:14,380 for identifying the species of our dinosaur. 123 00:10:19,980 --> 00:10:22,420 Despite weighing up to half a tonne, 124 00:10:22,420 --> 00:10:24,740 these fossils are surprisingly fragile. 125 00:10:29,180 --> 00:10:31,300 It's all rather nerve-racking. 126 00:10:32,660 --> 00:10:36,700 One bone like this has already cracked in half without warning. 127 00:10:41,220 --> 00:10:42,860 Bravo! 128 00:10:52,780 --> 00:10:55,820 THEY LAUGH 129 00:10:55,820 --> 00:10:58,500 And so this is the position as it was in life 130 00:10:58,500 --> 00:11:01,340 with the centre of the backbone there, 131 00:11:01,340 --> 00:11:03,580 then this is the crest on the top. 132 00:11:03,580 --> 00:11:06,780 Right, right, and this belongs to the middle part of the thorax. 133 00:11:06,780 --> 00:11:10,180 - Right about here. - About that. - Yeah, yeah. 134 00:11:10,180 --> 00:11:13,300 'Many more weeks of detailed examination 135 00:11:13,300 --> 00:11:16,420 'will be needed before the backbones reveal all their secrets.' 136 00:11:19,780 --> 00:11:23,420 Surprisingly, perhaps, one of the first things 137 00:11:23,420 --> 00:11:28,180 the team was able to deduce about our titanosaur is its weight. 138 00:11:29,540 --> 00:11:32,500 That's because, after finding the thigh bone, 139 00:11:32,500 --> 00:11:37,700 they discover another huge bone from the front leg - a humerus. 140 00:11:43,940 --> 00:11:47,540 By measuring the circumference of each of these leg bones, 141 00:11:47,540 --> 00:11:50,580 it's possible to estimate how much weight they could support. 142 00:11:50,580 --> 00:11:53,100 Let's see how much. 143 00:11:54,340 --> 00:11:56,100 We'll measure this. 144 00:12:00,460 --> 00:12:04,260 - 79. - 79? Wow! 145 00:12:04,260 --> 00:12:07,660 I'm not sure how that translates to body weight. 146 00:12:07,660 --> 00:12:11,540 - Yeah, around 70 tonnes or even more, probably. - Wow! 147 00:12:11,540 --> 00:12:12,900 That's really big. 148 00:12:12,900 --> 00:12:15,220 It's amazing. 149 00:12:16,820 --> 00:12:22,780 That evening, Dr Jose Luis Carballido checks his calculations. 150 00:12:42,180 --> 00:12:46,820 Until now, Argentinosaurus was the heaviest known dinosaur. 151 00:12:46,820 --> 00:12:49,100 Ours already looks bigger. 152 00:12:57,340 --> 00:13:02,860 Could this mean it was the largest animal ever to walk the earth? 153 00:13:02,860 --> 00:13:06,260 Could it also be a new species? 154 00:13:06,260 --> 00:13:08,940 We can't be sure...yet. 155 00:13:10,900 --> 00:13:14,740 The rocks of Patagonia, so bare of vegetation, 156 00:13:14,740 --> 00:13:20,860 also contain astonishing evidence of how titanosaurs began their lives. 157 00:13:23,420 --> 00:13:26,820 I've now come nearly 500 miles north 158 00:13:26,820 --> 00:13:29,540 from our Patagonian dinosaur excavation 159 00:13:29,540 --> 00:13:31,860 to a place called Auca Mahuevo. 160 00:13:31,860 --> 00:13:37,860 This is the largest dinosaur nesting ground yet discovered. 161 00:13:37,860 --> 00:13:43,620 The remains of their eggs and their nests are wherever I look. 162 00:13:43,620 --> 00:13:45,940 In fact, it's quite difficult for me 163 00:13:45,940 --> 00:13:50,580 to take a step without walking on a dinosaur eggshell. 164 00:13:56,900 --> 00:13:58,660 Over thousands of years, 165 00:13:58,660 --> 00:14:01,860 the wind and the rain have cleared away the soft rock 166 00:14:01,860 --> 00:14:04,620 that once enclosed these fragments 167 00:14:04,620 --> 00:14:10,180 and they can tell us quite a lot about how titanosaurs reproduced. 168 00:14:11,780 --> 00:14:15,300 Careful excavation has shown that these dinosaurs 169 00:14:15,300 --> 00:14:20,100 laid eggs in clutches of up to 30 or 40 at a time. 170 00:14:20,100 --> 00:14:23,140 They would have looked rather like these replicas 171 00:14:23,140 --> 00:14:25,740 because they lay on the surface of the ground, 172 00:14:25,740 --> 00:14:28,740 not covered by soil, but in a shallow depression. 173 00:14:28,740 --> 00:14:30,100 Sometimes, though, 174 00:14:30,100 --> 00:14:33,180 remains of vegetation have been found in some nests, 175 00:14:33,180 --> 00:14:37,020 which suggests that the dinosaurs might have used rotting leaves 176 00:14:37,020 --> 00:14:39,100 to help with the incubation. 177 00:14:39,100 --> 00:14:43,060 The dinosaur that laid these eggs here were medium-sized. 178 00:14:43,060 --> 00:14:46,140 Our dinosaur that we're excavating, 179 00:14:46,140 --> 00:14:48,980 probably laid eggs as big as that. 180 00:14:50,780 --> 00:14:54,900 I'm shown around by Dr Luis Chiappe who, with his team, 181 00:14:54,900 --> 00:14:57,140 discovered this remarkable site. 182 00:14:58,140 --> 00:15:02,100 Dinosaur eggs here were laid on an old river plain. 183 00:15:03,540 --> 00:15:06,460 Then the river flooded and covered the unhatched eggs, 184 00:15:06,460 --> 00:15:08,340 preserving them in mud. 185 00:15:09,420 --> 00:15:12,820 You see, you know, many eggs... 186 00:15:12,820 --> 00:15:14,220 There. 187 00:15:14,220 --> 00:15:17,580 ..for kilometres and kilometres. Here's a nice one. 188 00:15:17,580 --> 00:15:19,860 - Oh, that's a huge piece! - Yup. 189 00:15:22,380 --> 00:15:25,940 - And this is the actual surface of the egg? - Yes. 190 00:15:25,940 --> 00:15:27,020 Astounding. 191 00:15:29,500 --> 00:15:32,380 Do you suppose they could have been coloured like birds' eggs? 192 00:15:32,380 --> 00:15:34,780 They may. Maybe they were off-white. 193 00:15:34,780 --> 00:15:37,260 - We can't tell really. - Yeah. 194 00:15:37,260 --> 00:15:40,460 Well, we can see all the tiny pores on the surface. 195 00:15:40,460 --> 00:15:41,580 And the texture. 196 00:15:41,580 --> 00:15:44,220 Yeah. What a beautiful piece. 197 00:15:44,220 --> 00:15:47,540 You must admit it's pretty romantic. 198 00:15:47,540 --> 00:15:49,060 THEY LAUGH 199 00:15:49,060 --> 00:15:50,380 I think it's incredible. 200 00:15:50,380 --> 00:15:52,220 I think it's absolutely extraordinary 201 00:15:52,220 --> 00:15:54,340 and I must put it back where I found it. 202 00:15:54,340 --> 00:15:55,380 Thank you. 203 00:15:58,900 --> 00:16:03,180 The fragments could tell us quite a lot about how the dinosaurs nested. 204 00:16:04,460 --> 00:16:07,700 But some, amazingly, can do even more than that. 205 00:16:12,980 --> 00:16:17,740 All these examples have something quite special. 206 00:16:17,740 --> 00:16:20,980 This one is my favourite. 207 00:16:20,980 --> 00:16:28,180 And what you can see is a very large patch of baby dinosaur skin. 208 00:16:29,420 --> 00:16:31,180 How wonderful! 209 00:16:31,180 --> 00:16:32,380 It's extraordinary. 210 00:16:32,380 --> 00:16:36,500 - And this is not just an impression, this is the mineralised skin. - It is. 211 00:16:36,500 --> 00:16:38,100 Yeah. 212 00:16:38,100 --> 00:16:39,980 Astounding. 213 00:16:39,980 --> 00:16:42,940 The eggs were not just preserving the bones, 214 00:16:42,940 --> 00:16:45,820 - they were also preserving the skin of these babies. - Yeah. 215 00:16:47,100 --> 00:16:49,100 This was just on the surface. 216 00:16:49,100 --> 00:16:52,860 I remember picking this up and brushing it a little bit 217 00:16:52,860 --> 00:16:54,500 and then using my hand lens 218 00:16:54,500 --> 00:17:00,500 and looking at this exact patch of skin and I realised that 219 00:17:00,500 --> 00:17:05,780 we had found something that no person had ever seen before. 220 00:17:05,780 --> 00:17:10,860 - You are the first human being ever to see a baby dinosaur's skin. - Yes. 221 00:17:10,860 --> 00:17:12,500 It was just an amazing... 222 00:17:12,500 --> 00:17:15,020 amazing moment. 223 00:17:15,020 --> 00:17:17,340 It must have been very close to hatching. 224 00:17:17,340 --> 00:17:21,620 - It's almost complete, this thing. - Yes, that's what we believe. 225 00:17:21,620 --> 00:17:23,660 And then a flood... 226 00:17:23,660 --> 00:17:25,140 Killed them all. 227 00:17:25,140 --> 00:17:28,660 - Unfortunately for them, good for us. - Yes. 228 00:17:31,140 --> 00:17:35,820 Luis Chiappe has dozens of complete eggs in his museum and 229 00:17:35,820 --> 00:17:40,060 he allows me to examine some of his most precious specimens for myself. 230 00:17:44,020 --> 00:17:46,180 There are many other remarkable things 231 00:17:46,180 --> 00:17:48,780 in these astonishing time capsules. 232 00:17:48,780 --> 00:17:53,060 This one has got, perfectly clearly, the limb bones. 233 00:17:56,260 --> 00:17:58,700 Here is a skull. 234 00:17:58,700 --> 00:18:01,140 That's the orbit of the eye, 235 00:18:01,140 --> 00:18:04,180 there's the lower jaw, there's the snout. 236 00:18:07,820 --> 00:18:09,740 This one also has a skull, 237 00:18:09,740 --> 00:18:15,260 but on the tip of the snout you can see a little spike which is like the 238 00:18:15,260 --> 00:18:20,420 egg tooth that a bird embryo has to help it crack itself out of a shell. 239 00:18:23,900 --> 00:18:28,100 And here is a replica of what the complete, 240 00:18:28,100 --> 00:18:30,940 un-crushed shell must have looked like. 241 00:18:34,100 --> 00:18:36,180 With all these details, 242 00:18:36,180 --> 00:18:39,940 it is possible to imagine how a baby titanosaur entered the world. 243 00:18:41,420 --> 00:18:42,860 BABY SQUEAKS 244 00:18:50,980 --> 00:18:54,260 To get an idea of how these youngsters might have lived, 245 00:18:54,260 --> 00:18:59,380 we can compare them with their closest living relatives - birds. 246 00:19:02,220 --> 00:19:05,980 Rather like baby ostriches, a young titanosaur 247 00:19:05,980 --> 00:19:10,460 would have been able to walk soon after hatching. 248 00:19:14,460 --> 00:19:17,500 They may well have gathered into groups to give some safety 249 00:19:17,500 --> 00:19:20,740 from predators, as young ostriches do. 250 00:19:34,220 --> 00:19:38,020 Microscopic analysis of dinosaur leg bones show rings, 251 00:19:38,020 --> 00:19:40,060 rather like tree rings, 252 00:19:40,060 --> 00:19:43,860 and these indicate that titanosaurs grew very swiftly 253 00:19:43,860 --> 00:19:45,300 early in their lives 254 00:19:45,300 --> 00:19:48,940 and they could have lived for some 50 years, 255 00:19:48,940 --> 00:19:51,100 plenty of time to become enormous. 256 00:19:53,020 --> 00:19:56,180 The team now has 150 bones of our titanosaur, 257 00:19:56,180 --> 00:19:59,540 enough to get an idea, not only of its weight, 258 00:19:59,540 --> 00:20:01,580 but also its height and length. 259 00:20:02,860 --> 00:20:06,020 Now, the plan is to build a life-size reproduction 260 00:20:06,020 --> 00:20:07,820 of the complete skeleton. 261 00:20:24,300 --> 00:20:28,540 It's a challenge to find a place big enough to house an animal that's 262 00:20:28,540 --> 00:20:33,100 four times longer than a London bus and nearly twice its height. 263 00:20:33,100 --> 00:20:37,340 But Diego thinks he's found one. It's an old wool warehouse. 264 00:20:41,980 --> 00:20:45,660 One, two, three, four, 265 00:20:45,660 --> 00:20:49,340 five, six, seven... 266 00:20:49,340 --> 00:20:52,300 We have been looking for a place that is big enough 267 00:20:52,300 --> 00:20:53,900 to fit our dinosaur. 268 00:20:57,740 --> 00:20:58,900 This seems to be it. 269 00:20:58,900 --> 00:21:00,940 This is a warehouse that we could use, 270 00:21:00,940 --> 00:21:04,540 not only in terms of the length, this is 70 metres long, 271 00:21:04,540 --> 00:21:07,180 but also it's very important in terms of the height. 272 00:21:07,180 --> 00:21:09,940 So we need a place not only long, but really high. 273 00:21:10,940 --> 00:21:13,180 It really needs a little bit of decoration, 274 00:21:13,180 --> 00:21:15,380 but I think it will do it. 275 00:21:15,380 --> 00:21:16,820 It's going to be awesome! 276 00:21:19,940 --> 00:21:22,380 Putting the skeleton together will help us 277 00:21:22,380 --> 00:21:25,860 understand the particular challenges of being such a giant. 278 00:21:31,900 --> 00:21:36,700 So, next, an international team of skeleton builders arrive 279 00:21:36,700 --> 00:21:41,340 to scan the bones ready to make a 3-D computer model of each of them. 280 00:21:49,220 --> 00:21:54,780 3-D scanning, accurate to 0.01 of a millimetre, 281 00:21:54,780 --> 00:21:59,220 allows images of the bones to be placed in a virtual reality world 282 00:21:59,220 --> 00:22:03,100 so that they can now be examined from all points of view 283 00:22:03,100 --> 00:22:05,780 without needing eight people to lift them. 284 00:22:09,260 --> 00:22:12,460 One of the mysteries surrounding our dinosaur is, 285 00:22:12,460 --> 00:22:15,980 how could an animal as big as it was actually move about? 286 00:22:19,220 --> 00:22:21,140 The computer data allows us 287 00:22:21,140 --> 00:22:24,780 to put our dinosaur leg bones together in 3-D 288 00:22:24,780 --> 00:22:29,700 and then compare the arrangement with what we know about living animals. 289 00:22:40,220 --> 00:22:43,780 Elephants are the largest land animal alive today. 290 00:22:47,380 --> 00:22:51,940 They, like titanosaurs, have to move their massive bodies around 291 00:22:51,940 --> 00:22:55,380 without their bones shattering under the enormous weight. 292 00:23:02,180 --> 00:23:05,260 I've come to meet Professor John Hutchinson 293 00:23:05,260 --> 00:23:08,140 here at ZSL Whipsnade Zoo. 294 00:23:09,220 --> 00:23:12,580 He's studied elephants for many years and has joined the team 295 00:23:12,580 --> 00:23:17,100 that's investigating the internal workings of our titanosaur. 296 00:23:17,100 --> 00:23:20,140 We have about a one-metre long pressure sensitive mat out there 297 00:23:20,140 --> 00:23:23,660 with several thousand sensors in it and it's telling us, in very 298 00:23:23,660 --> 00:23:27,420 high resolution, what the pressure on an elephant's foot is like. 299 00:23:28,540 --> 00:23:31,500 We can see on the elephant's foot here... 300 00:23:31,500 --> 00:23:33,820 - Here she goes... - Oh, yeah! Great. 301 00:23:33,820 --> 00:23:35,540 - Oh, that was a perfect one! - Bull's-eye! 302 00:23:36,660 --> 00:23:38,740 The pressure hits the ground, 303 00:23:38,740 --> 00:23:42,340 rolls over and then pushes off with its toenails. 304 00:23:43,860 --> 00:23:48,300 So we can see there some hot colours, or reds and oranges, 305 00:23:48,300 --> 00:23:52,740 on the toenails of Melvin's foot indicating high pressure. 306 00:23:52,740 --> 00:23:56,380 And then some cooler colours back towards the heel pad 307 00:23:56,380 --> 00:23:59,340 in the greens and light blue. 308 00:23:59,340 --> 00:24:00,940 That's low pressure. 309 00:24:00,940 --> 00:24:04,940 So elephants are supporting most of their weight on their toenails. 310 00:24:04,940 --> 00:24:08,220 That pressure gets transmitted up to their toe bones 311 00:24:08,220 --> 00:24:11,980 and then up to their wrists and ankles and so forth. 312 00:24:14,740 --> 00:24:19,180 John's analysis suggests that our titanosaur's legs, 313 00:24:19,180 --> 00:24:20,980 like those of an elephant, 314 00:24:20,980 --> 00:24:25,420 were placed vertically beneath the body like strong, massive columns. 315 00:24:28,620 --> 00:24:31,780 This arrangement transmits the weight to the toes 316 00:24:31,780 --> 00:24:36,620 and then spreads the force, using fatty pads in the back feet, 317 00:24:36,620 --> 00:24:38,460 as shock absorbers. 318 00:24:39,940 --> 00:24:43,940 But our titanosaur had one other adaptation to help them walk - 319 00:24:43,940 --> 00:24:45,820 one that elephants lack. 320 00:24:50,260 --> 00:24:53,660 A clue to this can be seen on the giant thighbone. 321 00:24:55,220 --> 00:24:57,500 - How's it going? - Good, good. 322 00:24:57,500 --> 00:25:01,860 Ben Garrod specialises in reconstructing skeletons 323 00:25:01,860 --> 00:25:05,220 and he's joining the team to look at the bones in detail. 324 00:25:06,740 --> 00:25:10,180 Marks on them show clearly where the muscles were attached. 325 00:25:11,380 --> 00:25:14,340 - That's halfway down the femur, isn't it, that big lump there... - Yes. 326 00:25:14,340 --> 00:25:17,020 ..for these massive muscle and, I guess, tendon attachments? 327 00:25:18,140 --> 00:25:22,540 This lump is where a huge muscle was attached to the femur. 328 00:25:24,060 --> 00:25:26,540 The other end of this muscle was connected to bones 329 00:25:26,540 --> 00:25:28,460 like these in the tail. 330 00:25:29,660 --> 00:25:32,860 It's this connection that helped our dinosaur to walk. 331 00:25:34,140 --> 00:25:37,140 They've got so much strength and so much rigidity up there. 332 00:25:37,140 --> 00:25:41,380 They actually used their tails to help move, to help their propulsion. 333 00:25:41,380 --> 00:25:45,580 - So they had massive muscles and tendons from... - Help...? 334 00:25:45,580 --> 00:25:48,420 Yes, so the movement of the tail actually pulled the hind legs 335 00:25:48,420 --> 00:25:50,300 backwards and then raised them forwards. 336 00:25:50,300 --> 00:25:51,340 Oh, I see. 337 00:25:53,180 --> 00:25:54,860 I must try that sometime! 338 00:25:54,860 --> 00:25:56,380 LAUGHTER 339 00:25:59,460 --> 00:26:03,740 The largest lizard alive today, the Komodo dragon, 340 00:26:03,740 --> 00:26:05,900 has a similar adaptation. 341 00:26:07,500 --> 00:26:11,580 The swing of their tail helps their back legs move more efficiently. 342 00:26:16,300 --> 00:26:18,900 Of course, our dinosaur was different, 343 00:26:18,900 --> 00:26:21,780 not least because it weighed over 500 times more. 344 00:26:23,420 --> 00:26:26,940 And that makes John Hutchinson suspect that it would have 345 00:26:26,940 --> 00:26:29,620 had to deal with another problem - 346 00:26:29,620 --> 00:26:33,140 one also faced by passengers on long-haul flights. 347 00:26:34,540 --> 00:26:38,700 Pressure in the legs of big animals is a really big problem. 348 00:26:38,700 --> 00:26:42,420 If blood stays down there too long, it's going to pool and clot. 349 00:26:43,460 --> 00:26:47,340 Much like airline socks that humans use, large animals, 350 00:26:47,340 --> 00:26:51,620 again and again, have evolved very thick elastic skin 351 00:26:51,620 --> 00:26:56,060 around their lower limb that helps to keep that pressure very high. 352 00:26:56,060 --> 00:26:57,660 Actually, I can empathise. 353 00:26:57,660 --> 00:27:01,260 I have to wear those same kind of stockings to get my blood 354 00:27:01,260 --> 00:27:02,940 back up my long legs! 355 00:27:04,220 --> 00:27:06,460 Time to thank our helpful elephant. 356 00:27:06,460 --> 00:27:08,660 You're a lovely thing. Yes, you... 357 00:27:08,660 --> 00:27:12,220 Oh, you want one! OK, in you go. 358 00:27:12,220 --> 00:27:15,260 Thanks. Thanks, pal. 359 00:27:16,620 --> 00:27:17,780 That's all I've got! 360 00:27:20,180 --> 00:27:24,660 A giant animal like an elephant also needs a huge heart to pump 361 00:27:24,660 --> 00:27:26,540 blood around its body. 362 00:27:26,540 --> 00:27:28,540 And so did our titanosaur. 363 00:27:44,580 --> 00:27:46,780 Its heart must have been immense. 364 00:27:50,220 --> 00:27:53,980 From our new, detailed knowledge of the skeleton, John Hutchinson 365 00:27:53,980 --> 00:27:57,700 has calculated that it was more than six feet in circumference. 366 00:28:04,740 --> 00:28:08,380 It probably weighed 230 kilos 367 00:28:08,380 --> 00:28:13,420 and would have had to shift 90 litres of blood with a single beat. 368 00:28:13,420 --> 00:28:14,460 There's one! 369 00:28:18,700 --> 00:28:23,100 And it would have had to repeat that beat every five seconds. 370 00:28:23,100 --> 00:28:24,180 HEART BEATS 371 00:28:24,180 --> 00:28:25,340 There it goes again. 372 00:28:29,980 --> 00:28:32,740 Weighing more than three grown men, 373 00:28:32,740 --> 00:28:35,020 it would have been extraordinarily powerful. 374 00:28:40,660 --> 00:28:45,180 And in order to pump blood around the body at high pressure 375 00:28:45,180 --> 00:28:49,580 and then into the delicate lungs at a lower pressure, 376 00:28:49,580 --> 00:28:54,460 it's thought that our titanosaur's heart had four chambers - 377 00:28:54,460 --> 00:28:56,780 more like that of a bird than a reptile. 378 00:29:01,860 --> 00:29:06,580 So, a powerful heart pumped the blood to the extremities of the body, 379 00:29:06,580 --> 00:29:09,220 but how did the blood get back? 380 00:29:12,700 --> 00:29:17,380 As in an elephant, a combination of fatty footpads 381 00:29:17,380 --> 00:29:21,820 and tight skin are thought to have forced the blood from its legs... 382 00:29:23,140 --> 00:29:24,780 ..all the way back to its heart. 383 00:29:39,660 --> 00:29:45,580 Toronto, Canada, and the world's biggest dinosaur-making factory. 384 00:29:53,580 --> 00:29:57,740 The team is building a life-size skeleton of this vast creature 385 00:29:57,740 --> 00:30:03,620 to be unveiled in Diego's warehouse in Argentina in six months' time. 386 00:30:06,420 --> 00:30:10,620 First, they have to turn all the information from the 3-D scans 387 00:30:10,620 --> 00:30:12,500 into each individual bone. 388 00:30:16,340 --> 00:30:19,780 State-of-the-art robots carve moulds from polystyrene 389 00:30:19,780 --> 00:30:22,780 so that the bones can be cast in fibreglass. 390 00:30:39,020 --> 00:30:43,900 Up until now, the fossil bones have been the main focus of the dig 391 00:30:43,900 --> 00:30:45,900 but the rock that surrounds the fossils 392 00:30:45,900 --> 00:30:48,780 also holds important information. 393 00:30:48,780 --> 00:30:54,100 The nature of the layers of rock in which these fossils lie can tell us 394 00:30:54,100 --> 00:30:58,860 a great deal about how they got to be where they are and how old they are. 395 00:30:59,940 --> 00:31:03,940 Some of these layers are volcanic ash which must have come 396 00:31:03,940 --> 00:31:08,260 from a volcano erupting every now and then somewhere in the neighbourhood. 397 00:31:12,860 --> 00:31:17,660 And this ash around the bones can tell us how old the fossils are. 398 00:31:19,180 --> 00:31:21,740 Scientists worked out that all these fossils 399 00:31:21,740 --> 00:31:24,300 dated from the Cretaceous period 400 00:31:24,300 --> 00:31:26,020 but better than that, 401 00:31:26,020 --> 00:31:33,700 they dated them precisely to 101.6 million years old. 402 00:31:40,980 --> 00:31:43,860 By a detailed forensic examination 403 00:31:43,860 --> 00:31:47,140 and comparisons with living creatures, 404 00:31:47,140 --> 00:31:51,860 the team have deduced a great deal about the life of our titanosaur. 405 00:31:55,820 --> 00:32:00,220 We now know when it lived, how big it was, 406 00:32:00,220 --> 00:32:04,860 how it moved and what its young might have looked like. 407 00:32:04,860 --> 00:32:07,900 We've even calculated its heart rate. 408 00:32:15,460 --> 00:32:19,660 In an investigation of this scale, sometimes the most important 409 00:32:19,660 --> 00:32:23,220 information comes not from the most eye-catching evidence 410 00:32:23,220 --> 00:32:26,020 but from quite tiny details. 411 00:32:30,020 --> 00:32:35,540 Here is something that I really hoped the excavation was going to find. 412 00:32:38,300 --> 00:32:39,580 It's a tooth. 413 00:32:41,180 --> 00:32:45,860 And it's tiny compared with the size of the huge animals 414 00:32:45,860 --> 00:32:47,540 from which it came. 415 00:32:48,780 --> 00:32:53,460 Teeth can tell you a huge amount about an animal. 416 00:32:53,460 --> 00:32:57,220 And if you look at the tip, you can see that it has been 417 00:32:57,220 --> 00:33:01,740 worn into two facets on either side. 418 00:33:01,740 --> 00:33:07,060 And that tells us that this tooth engaged with the teeth on the other 419 00:33:07,060 --> 00:33:12,460 side in an alternate way like that, not head-on but one on either side. 420 00:33:12,460 --> 00:33:15,580 So this animal, like a pair of scissors, 421 00:33:15,580 --> 00:33:20,100 just nipped off the vegetation on which it was feeding. 422 00:33:20,100 --> 00:33:25,020 Enormous though it was, just nipped off little leaves 423 00:33:25,020 --> 00:33:26,940 and here are fossils 424 00:33:26,940 --> 00:33:30,660 of some of the different kinds of plants on which it might have fed... 425 00:33:32,060 --> 00:33:36,540 ..cycads, ferns and conifers. 426 00:33:46,100 --> 00:33:48,260 One thing these plants have in common 427 00:33:48,260 --> 00:33:52,540 is that they're all very fibrous and hard to digest. 428 00:33:53,860 --> 00:33:57,460 To get enough nutrients from such poor quality foods 429 00:33:57,460 --> 00:34:01,780 our titanosaur would have had to eat them in vast quantities. 430 00:34:05,900 --> 00:34:10,180 A descendent of one of these plants still grows in Patagonia today. 431 00:34:14,140 --> 00:34:18,380 200 million years ago when South America, Australia 432 00:34:18,380 --> 00:34:21,860 and Antarctica were all joined together to form 433 00:34:21,860 --> 00:34:24,700 a supercontinent called Gondwana, 434 00:34:24,700 --> 00:34:27,860 a particular kind of vegetation was dominant - 435 00:34:27,860 --> 00:34:29,260 they were conifers. 436 00:34:30,300 --> 00:34:33,300 They continued to survive to 100 million years ago 437 00:34:33,300 --> 00:34:37,500 when our titanosaurs were roaming the land and a few still 438 00:34:37,500 --> 00:34:43,140 survive today. Here in the foothills of the Andes is one of them. 439 00:34:43,140 --> 00:34:46,460 The monkey puzzle tree called araucaria. 440 00:34:51,900 --> 00:34:54,980 Trees, like araucaria, show that the dinosaurs 441 00:34:54,980 --> 00:34:57,020 must have had another problem. 442 00:34:58,580 --> 00:35:01,700 These conifers, apart from being poor-quality fodder, 443 00:35:01,700 --> 00:35:05,140 can grow to over 130 feet in height. 444 00:35:07,380 --> 00:35:12,260 They would have been out of reach for many animals but not our titanosaur. 445 00:35:17,580 --> 00:35:18,980 Here, boys, come on. 446 00:35:22,940 --> 00:35:28,580 It's pretty clear why a long neck is useful for a land-living animal. 447 00:35:29,780 --> 00:35:33,980 It enables it to reach vegetation which is growing high up 448 00:35:33,980 --> 00:35:38,380 at the top trees that other ground-based animals couldn't reach 449 00:35:38,380 --> 00:35:42,700 and it must have been much the same for titanosaur, 450 00:35:42,700 --> 00:35:45,900 except we know from the fossils that titanosaur's neck was 451 00:35:45,900 --> 00:35:47,860 very, very much longer. 452 00:35:49,780 --> 00:35:54,420 And that enabled it to sweep its head in a great wide arc 453 00:35:54,420 --> 00:35:58,300 and even to reach between two tree trunks that happened to be 454 00:35:58,300 --> 00:36:02,020 growing close together to get other vegetation. 455 00:36:02,020 --> 00:36:03,060 What about that? 456 00:36:06,340 --> 00:36:10,460 This enormous reach would have saved our titanosaur a lot of energy. 457 00:36:11,660 --> 00:36:15,420 It only needed to move its neck to feed, not its whole body. 458 00:36:19,020 --> 00:36:22,820 But how did it eat enough of this poor-quality food to survive? 459 00:36:24,340 --> 00:36:27,020 Elephants face a similar challenge today. 460 00:36:28,340 --> 00:36:33,220 An elephant can collect and chew about 130 kilos - 461 00:36:33,220 --> 00:36:36,460 that's 300 pounds of vegetation in a day. 462 00:36:37,540 --> 00:36:41,620 But our titanosaur could have eaten five times that amount. 463 00:36:43,300 --> 00:36:47,140 It's been estimated that a large titanosaur would eat enough 464 00:36:47,140 --> 00:36:50,100 plant material to fill a skip in a single day. 465 00:36:51,580 --> 00:36:53,620 So how did they digest it all? 466 00:36:54,660 --> 00:36:56,940 Elephants solved the problem by giving their food 467 00:36:56,940 --> 00:37:01,740 long preparatory chews but titanosaurs didn't bother. 468 00:37:03,420 --> 00:37:07,180 They simply gathered leaves by nipping them off 469 00:37:07,180 --> 00:37:08,980 and then swallowing them whole. 470 00:37:11,220 --> 00:37:14,180 But that in turn would mean that they needed a bigger 471 00:37:14,180 --> 00:37:17,900 and longer gut to digest all that unchewed food. 472 00:37:19,860 --> 00:37:21,780 And it might well have taken ten days 473 00:37:21,780 --> 00:37:23,900 for food to pass through their system. 474 00:37:26,180 --> 00:37:32,180 A bigger gut needs a bigger body so titanosaurs grew bigger and bigger 475 00:37:32,180 --> 00:37:35,940 until they approached the limits of what their bones could support. 476 00:37:46,020 --> 00:37:50,980 Two years after the dig began, a strange cargo arrives, 477 00:37:50,980 --> 00:37:53,900 having made a 7,000 mile journey from Canada. 478 00:38:01,620 --> 00:38:03,780 Dozens of packing cases later 479 00:38:03,780 --> 00:38:07,540 and all the bones are finally in Diego's warehouse. 480 00:38:16,300 --> 00:38:19,420 Assembling the skeleton can finally begin. 481 00:38:23,020 --> 00:38:27,060 The 3-D data used to make the skeleton has also been used 482 00:38:27,060 --> 00:38:29,100 to create a computer model. 483 00:38:30,420 --> 00:38:32,500 It means I can get a preview 484 00:38:32,500 --> 00:38:35,100 of what the final skeleton will look like. 485 00:38:35,100 --> 00:38:38,220 The first thing is these very, very lovely legs. 486 00:38:38,220 --> 00:38:40,740 If we turn it around, they are very, very column-like 487 00:38:40,740 --> 00:38:42,260 and this is like elephants 488 00:38:42,260 --> 00:38:46,860 but interestingly this titanosaur had slightly splayed legs, 489 00:38:46,860 --> 00:38:50,940 at an angle of about five degrees and this slight change would have 490 00:38:50,940 --> 00:38:54,660 really increased the ability to take all that extra weight. 491 00:38:54,660 --> 00:38:57,100 Can you see the splay because of the joint or 492 00:38:57,100 --> 00:38:59,300 - because of the shape of the bone? - A bit of both. 493 00:38:59,300 --> 00:39:01,940 You can tell from the shape of the bone and from where certain 494 00:39:01,940 --> 00:39:05,380 parts of the bones form and how they sit and then how the bones fit 495 00:39:05,380 --> 00:39:08,660 with one another you can really tell how it would have sat in real life. 496 00:39:08,660 --> 00:39:12,100 Another thing you can see is a very, very long neck. 497 00:39:12,100 --> 00:39:16,180 And we just found out that ours had 15 bones in its neck. 498 00:39:16,180 --> 00:39:19,180 Interestingly, some of them were five or six times longer than 499 00:39:19,180 --> 00:39:20,340 they were wide. 500 00:39:20,340 --> 00:39:23,220 These incredibly long vertebrae and there's lots of them. 501 00:39:23,220 --> 00:39:25,260 Why does it have such a long tail? 502 00:39:25,260 --> 00:39:28,980 Well, a couple of reasons. If you've got an animal this big with 503 00:39:28,980 --> 00:39:32,060 a neck this long, the last thing you want to be is top-heavy. 504 00:39:32,060 --> 00:39:35,780 And research has just shown that the centre of gravity 505 00:39:35,780 --> 00:39:39,780 in this animal was somewhere right in the middle of the chest cavity. 506 00:39:41,060 --> 00:39:46,300 So the heavy tail counterbalances the exceedingly long neck. 507 00:39:46,300 --> 00:39:49,660 But judging from the size of the muscle attachments, 508 00:39:49,660 --> 00:39:52,020 the tail was also immensely strong. 509 00:39:53,580 --> 00:39:58,380 It had huge muscles from around here right down to about a third 510 00:39:58,380 --> 00:40:01,100 of the way down the tail, somewhere around here. 511 00:40:01,100 --> 00:40:04,340 - So that would be solid flesh? - Yep, muscle tissue, other tissue, 512 00:40:04,340 --> 00:40:05,500 ligaments, tendons. 513 00:40:05,500 --> 00:40:07,860 Do you think they might have fought with it? 514 00:40:07,860 --> 00:40:09,500 - Possibly. - Thrashing it about? 515 00:40:09,500 --> 00:40:11,900 It could've been used as a defence mechanism 516 00:40:11,900 --> 00:40:14,700 so you're walking up to that as a predator, the last thing you 517 00:40:14,700 --> 00:40:17,020 - want to be is on the receiving end. - Don't put me into it! 518 00:40:20,300 --> 00:40:21,340 Yeah. 519 00:40:31,220 --> 00:40:36,260 The long and painstaking examination of the backbone has now borne fruit 520 00:40:36,260 --> 00:40:38,740 and Ben has got some important news. 521 00:40:44,700 --> 00:40:47,900 This is a vertebrae here from right high up in the back, 522 00:40:47,900 --> 00:40:49,500 right near the shoulder blades. 523 00:40:49,500 --> 00:40:55,020 And the most important thing is this little ridge that ends in this 524 00:40:55,020 --> 00:40:58,060 big lump and this is only found in this particular dinosaur 525 00:40:58,060 --> 00:41:01,340 so from that and a few other physical differences, 526 00:41:01,340 --> 00:41:04,740 we think we have got a brand-new, exciting species. 527 00:41:07,220 --> 00:41:10,500 So our titanosaur is not only a giant, 528 00:41:10,500 --> 00:41:13,940 it is indeed a new species of dinosaur. 529 00:41:16,020 --> 00:41:20,700 Examining the spinal bones also reveal something about how it coped 530 00:41:20,700 --> 00:41:22,500 with life as a giant. 531 00:41:24,980 --> 00:41:28,220 This is where the spinal cord would have passed. 532 00:41:29,940 --> 00:41:32,980 - So this hole straight through here? - Mm-hm. 533 00:41:32,980 --> 00:41:34,780 The whole nerve centre, as it were, 534 00:41:34,780 --> 00:41:37,300 - the cable carrying all the nerves. - From the base of the tail 535 00:41:37,300 --> 00:41:41,420 - right to the skull. - It's very small. - It is, yeah. - Ours is what? 536 00:41:41,420 --> 00:41:44,580 - About thumb width. - So it's not all that much bigger. - No. 537 00:41:47,220 --> 00:41:50,220 This cord was well over 100 feet long. 538 00:41:52,460 --> 00:41:56,100 It would have taken about a second for a nerve impulse 539 00:41:56,100 --> 00:41:58,260 to go from its tail to its brain. 540 00:42:00,060 --> 00:42:03,340 And what's more, the spine has revealed another surprise. 541 00:42:04,420 --> 00:42:07,780 It is full of holes, rather like a Swiss cheese. 542 00:42:10,660 --> 00:42:14,660 The neck bones of titanosaurs contain so many holes 543 00:42:14,660 --> 00:42:19,060 and spaces that they weighed around 35% less than 544 00:42:19,060 --> 00:42:22,860 they would have done had they been made of solid bone. 545 00:42:22,860 --> 00:42:26,300 The leg bones of modern birds are much the same. 546 00:42:26,300 --> 00:42:30,900 And those spaces serve another very important function. 547 00:42:30,900 --> 00:42:33,060 They contained air sacs. 548 00:42:35,980 --> 00:42:39,740 These air sacs were connected with the lungs. 549 00:42:43,580 --> 00:42:46,860 So what was their function and how did they work? 550 00:42:46,860 --> 00:42:51,060 They occupied much of the chest and ran along the whole length 551 00:42:51,060 --> 00:42:53,660 of the body along the backbone 552 00:42:53,660 --> 00:42:57,500 to the 17-metre-long neck and then to the head. 553 00:43:00,460 --> 00:43:05,020 It's thought the balloon-like sacs had thin but strong membranes. 554 00:43:08,100 --> 00:43:13,020 These sacs acted like bellows, forcing air into the lungs. 555 00:43:14,900 --> 00:43:19,420 When we breathe in, air flows down into our lungs, 556 00:43:19,420 --> 00:43:24,020 oxygen is absorbed in exchange for carbon dioxide which is then 557 00:43:24,020 --> 00:43:26,700 got rid of when we breathe out. 558 00:43:26,700 --> 00:43:31,740 The air sac system is very much more complex but very much more efficient. 559 00:43:34,020 --> 00:43:38,660 It enabled a titanosaur to take in oxygen continuously, 560 00:43:38,660 --> 00:43:42,260 not just when breathing in but also when breathing out. 561 00:44:06,580 --> 00:44:10,620 Our titanosaur wasn't the only giant living around here. 562 00:44:10,620 --> 00:44:11,660 ROARING 563 00:44:15,780 --> 00:44:21,420 This was a dangerous world, where meat-eaters were giants too. 564 00:44:25,660 --> 00:44:29,860 New evidence from the dig site shows that carnivorous dinosaurs 565 00:44:29,860 --> 00:44:31,220 were here as well. 566 00:44:35,100 --> 00:44:40,900 So these are some of the over 80 teeth we found on the dig site. 567 00:44:40,900 --> 00:44:44,540 And you can feel how sharp they are. 568 00:44:46,980 --> 00:44:50,620 - Oh, yes, it's serrated, just like a shark's tooth, in fact. - Absolutely. 569 00:44:50,620 --> 00:44:55,620 They actually belong to a family known as a shark-toothed dinosaurs. 570 00:44:55,620 --> 00:44:59,100 We can identify the teeth at the family level. 571 00:44:59,100 --> 00:45:01,980 We know of one species that belonged to that family, 572 00:45:01,980 --> 00:45:05,700 it's called Tyrannotitan chubutensis. 573 00:45:05,700 --> 00:45:07,060 - Tyrannotitan? - Yeah. 574 00:45:07,060 --> 00:45:12,740 - That means a ferocious giant, ferocious beast. - Exactly. - Good name. 575 00:45:12,740 --> 00:45:15,260 Yeah. Chubutensis is because of the area it comes from? 576 00:45:15,260 --> 00:45:17,660 Yes, this is the Chubut province. 577 00:45:17,660 --> 00:45:18,740 Great. 578 00:45:20,020 --> 00:45:24,500 Tyrannotitan must have been a ferocious-looking beast. 579 00:45:25,580 --> 00:45:29,020 With large eyes, sharp, flesh-eating teeth... 580 00:45:31,140 --> 00:45:36,500 ..and strong legs, it was a fast, alert, meat-eating dinosaur. 581 00:45:40,380 --> 00:45:44,620 - And it was as big as T Rex. - Really? Not as famous. 582 00:45:44,620 --> 00:45:47,700 - Not as famous. - Tell that to Hollywood. 583 00:45:47,700 --> 00:45:51,220 I have some bones over there I would like to show you. 584 00:45:52,540 --> 00:45:57,780 So this is one of the tail vertebrae we found at the dig site. 585 00:45:57,780 --> 00:46:00,340 There's something really interesting here. 586 00:46:00,340 --> 00:46:01,940 - You can see this groove? - Mmm. 587 00:46:01,940 --> 00:46:05,540 Well, this groove was probably a bite mark 588 00:46:05,540 --> 00:46:07,980 - made by one of the carnivores. - By one of these teeth? 589 00:46:07,980 --> 00:46:10,820 - Right. - So it was... What do you mean? Like that? 590 00:46:10,820 --> 00:46:15,420 - Exactly. Taking the flesh out of their tail. - Really? - Yeah. 591 00:46:16,580 --> 00:46:17,740 The tender bits. 592 00:46:19,580 --> 00:46:22,620 - They would be too. - Yeah, absolutely. 593 00:46:22,620 --> 00:46:26,300 Can you determine whether it was a scavenger or it was a hunter? 594 00:46:26,300 --> 00:46:29,700 We don't know if they were dead, I mean, they were scavenging 595 00:46:29,700 --> 00:46:33,540 on the carcasses, or if they were actually hunting and killing them. 596 00:46:34,860 --> 00:46:39,940 - Well, it didn't make much difference to the old dinosaur. - Yes. 597 00:46:41,940 --> 00:46:44,580 In a detective story, to close the case, 598 00:46:44,580 --> 00:46:47,980 you really want to know how the victim met its end. 599 00:46:49,700 --> 00:46:53,860 If our titanosaur didn't perish in the jaws of a Tyrannotitan, 600 00:46:53,860 --> 00:46:55,220 how did it die? 601 00:46:58,180 --> 00:47:02,380 Clues can be found by the detailed three-dimensional mapping 602 00:47:02,380 --> 00:47:06,980 of the location of every fossil bone, small and large. 603 00:47:10,020 --> 00:47:14,620 That shows that the dig site contains the remains of not just one 604 00:47:14,620 --> 00:47:17,220 but seven different individuals. 605 00:47:18,380 --> 00:47:20,180 All of the new species. 606 00:47:21,140 --> 00:47:25,300 And the first thing to notice is that they are on three different levels. 607 00:47:29,140 --> 00:47:32,180 That's to say the animals must have come here 608 00:47:32,180 --> 00:47:34,940 on at least three different occasions. 609 00:47:40,940 --> 00:47:42,900 But why should they have done that? 610 00:47:51,660 --> 00:47:55,340 There are several theories as to why seven bodies 611 00:47:55,340 --> 00:47:59,580 should have all ended up at this one particular place. 612 00:47:59,580 --> 00:48:02,620 The first is that this was a seasonal climate 613 00:48:02,620 --> 00:48:05,100 and that as the dry season proceeded 614 00:48:05,100 --> 00:48:08,420 this was one of the last remaining pools of water 615 00:48:08,420 --> 00:48:12,700 and when this went, the sauropods that happened to be here died here. 616 00:48:16,100 --> 00:48:21,300 The second is that these bodies were swept down by great rivers 617 00:48:21,300 --> 00:48:25,380 during the rainy season and then where the land levelled out, 618 00:48:25,380 --> 00:48:27,380 so those bodies were dumped. 619 00:48:28,740 --> 00:48:32,980 Analysis of the sediments around the bones shows that there were rivers 620 00:48:32,980 --> 00:48:36,460 gently flowing across this site at the time of their death. 621 00:48:42,140 --> 00:48:44,500 There was no shortage of water to drink. 622 00:48:45,580 --> 00:48:48,380 What's more the rivers were not moving fast enough 623 00:48:48,380 --> 00:48:49,900 to shift such huge bodies. 624 00:48:51,220 --> 00:48:55,020 So the corpses weren't washed here by floodwaters either. 625 00:48:57,820 --> 00:49:00,820 Could there be another reason why they all died in one 626 00:49:00,820 --> 00:49:03,380 place on three different occasions? 627 00:49:06,060 --> 00:49:09,700 We know from layers of ash around the bones that there were 628 00:49:09,700 --> 00:49:12,620 volcanoes erupting in the neighbourhood 629 00:49:12,620 --> 00:49:15,780 so doubtless there were areas where the ground was 630 00:49:15,780 --> 00:49:20,300 warmed by volcanic fumes, just as they are here today. 631 00:49:20,300 --> 00:49:25,020 We also know that dinosaurs regularly laid their eggs in such places, 632 00:49:25,020 --> 00:49:28,700 doubtless taking advantage of the volcanic warmth to help 633 00:49:28,700 --> 00:49:30,180 incubate their eggs. 634 00:49:30,180 --> 00:49:34,220 So maybe that was the reason why they kept returning to the same place. 635 00:49:41,060 --> 00:49:44,780 Certainly the excavation of the dinosaur egg site 636 00:49:44,780 --> 00:49:46,500 seems to support this. 637 00:49:48,540 --> 00:49:51,180 Nests like these have been found 638 00:49:51,180 --> 00:49:55,780 at four quite widely separated layers in the rocks, 639 00:49:55,780 --> 00:50:00,300 showing that dinosaurs came back to this particular site again 640 00:50:00,300 --> 00:50:04,060 and again and again over a long period of time. 641 00:50:13,980 --> 00:50:18,660 Ash from a volcanic eruption can sometimes fall in such quantities 642 00:50:18,660 --> 00:50:22,620 that the whole vegetation is blanketed by it and killed. 643 00:50:24,020 --> 00:50:26,500 So life in the aftermath of a big eruption 644 00:50:26,500 --> 00:50:28,980 can be very difficult for a plant-eater. 645 00:50:31,740 --> 00:50:36,820 Whatever the explanation, individuals over several generations came 646 00:50:36,820 --> 00:50:39,740 to this one place and died here. 647 00:50:42,380 --> 00:50:43,980 The dig is coming to an end 648 00:50:43,980 --> 00:50:48,540 and the team have assembled a record-breaking number of bones 649 00:50:48,540 --> 00:50:53,740 but they're still hoping to find one last piece of the puzzle - the skull. 650 00:50:53,740 --> 00:51:00,020 - So what number's this, 203? - Actually this is 223. - 23? 651 00:51:00,020 --> 00:51:02,020 Between the seven individuals? 652 00:51:02,020 --> 00:51:04,140 Yeah. Between all the seven individuals we found 653 00:51:04,140 --> 00:51:05,380 here on this site. 654 00:51:05,380 --> 00:51:08,700 If these are neck vertebrae, could they be leading towards a skull? 655 00:51:08,700 --> 00:51:10,460 Yes, that's what were hoping for. 656 00:51:10,460 --> 00:51:13,820 We just found another neck vertebrae over there. 657 00:51:13,820 --> 00:51:16,540 That would be a great triumph if you found a skull, wouldn't it? 658 00:51:16,540 --> 00:51:20,500 - There are only three titanosaur skulls known so far. - Really? - Yeah. 659 00:51:20,500 --> 00:51:23,780 - So they're very rare. - And that's because they're very fragile. 660 00:51:23,780 --> 00:51:25,740 They're very delicate bones 661 00:51:25,740 --> 00:51:30,940 and they have very light sutures between each of the bones. 662 00:51:30,940 --> 00:51:35,460 - OK, well, let's hope you find number four. - Yeah. - Could be under there. 663 00:51:35,460 --> 00:51:38,940 - Could be. We're going for that. - Wonderful. 664 00:51:42,580 --> 00:51:44,660 Alas, it was not to be. 665 00:51:49,420 --> 00:51:52,980 - So I gather you haven't yet found the skull. - Sadly not. 666 00:51:52,980 --> 00:51:56,420 The only thing we have found out of the skull is his tooth. 667 00:51:59,540 --> 00:52:03,780 So to complete the skeleton, the team have to reconstruct one... 668 00:52:03,780 --> 00:52:05,980 Take that piece out of there. 669 00:52:05,980 --> 00:52:09,740 ..basing it on the three skulls of other titanosaur species 670 00:52:09,740 --> 00:52:13,180 to produce one which most suits the single tooth that we have. 671 00:52:20,820 --> 00:52:26,180 The scientific team has discovered, collected, cleaned, 672 00:52:26,180 --> 00:52:32,140 scanned and copied 220 bones of our giant. 673 00:52:32,140 --> 00:52:36,980 Soon it'll be possible to put those copies together to get some idea 674 00:52:36,980 --> 00:52:39,380 of what the living animal actually looked like. 675 00:52:40,540 --> 00:52:45,100 But the fossil bones themselves still have many secrets 676 00:52:45,100 --> 00:52:46,980 that are waiting to be revealed. 677 00:52:56,020 --> 00:52:59,660 All the theory can now be put to the test. 678 00:53:04,540 --> 00:53:09,060 We can finally get the most accurate estimate of our dinosaur's weight 679 00:53:09,060 --> 00:53:10,580 and true size. 680 00:53:24,980 --> 00:53:29,620 It takes two weeks, working day and night, to fit all the bones together. 681 00:53:45,980 --> 00:53:48,700 Wow! God! 682 00:53:52,140 --> 00:53:54,740 Absolutely amazing! 683 00:54:14,380 --> 00:54:15,980 Good gracious! 684 00:54:44,140 --> 00:54:48,380 - Well, Diego, are you pleased with it? - Yes, we are very pleased. 685 00:54:48,380 --> 00:54:53,260 It is been a lot of work, it has taken 40,000 man-hours to get here 686 00:54:53,260 --> 00:54:56,340 but we're really, really happy with it. 687 00:54:56,340 --> 00:54:59,740 And does it answer some of your questions about the animal? 688 00:54:59,740 --> 00:55:00,900 Oh, yeah, absolutely. 689 00:55:00,900 --> 00:55:02,380 It answers a lot of questions 690 00:55:02,380 --> 00:55:05,820 but the good thing is it raises more questions. 691 00:55:05,820 --> 00:55:09,740 So we have a lot of research to continue on this animal. 692 00:55:09,740 --> 00:55:12,220 It's clear that this thing still wasn't fully grown. 693 00:55:12,220 --> 00:55:14,340 It's massive, but it still had room to go. 694 00:55:14,340 --> 00:55:16,180 You mean the structure of the bones looks as 695 00:55:16,180 --> 00:55:18,820 - though they were still growing? - Yeah. 696 00:55:18,820 --> 00:55:24,660 So, that raises the really big question, is it the biggest 697 00:55:24,660 --> 00:55:26,460 so far discovered? 698 00:55:26,460 --> 00:55:28,740 Well, according to our estimate, 699 00:55:28,740 --> 00:55:31,420 this animal weighed 70 metric tonnes. 700 00:55:32,620 --> 00:55:36,340 70 metric tonnes. What would that compare with? 701 00:55:36,340 --> 00:55:41,300 - That is like 15 African elephants. - 15 African elephants? 702 00:55:41,300 --> 00:55:48,100 We are now sure that this animal was 10% larger than Argentinosaurus. 703 00:55:48,100 --> 00:55:50,060 The previous record-holder? 704 00:55:50,060 --> 00:55:51,980 The previous record-holder. So, yes, 705 00:55:51,980 --> 00:55:57,100 - we think we have the largest dinosaur ever known. - Fantastic! 706 00:55:57,100 --> 00:55:59,300 I can quite believe it. 707 00:55:59,300 --> 00:56:04,620 - Congratulations to you. - Thank you. - Congratulations to he, she or it. 708 00:56:04,620 --> 00:56:07,020 Wonderful! A marvellous, marvellous thing! 709 00:56:25,580 --> 00:56:28,740 Piecing this complex jigsaw puzzle together 710 00:56:28,740 --> 00:56:31,180 has been a fascinating adventure. 711 00:56:33,580 --> 00:56:37,980 It all started with the discovery of one enormous thighbone. 712 00:56:38,980 --> 00:56:43,780 And then a team of 40 worked for over two years to excavate 713 00:56:43,780 --> 00:56:46,940 and put together the near-complete skeleton 714 00:56:46,940 --> 00:56:49,940 of the largest land animal yet discovered. 715 00:56:51,220 --> 00:56:53,940 And so added one further marvel 716 00:56:53,940 --> 00:56:57,860 to the astonishing history of life on earth. 717 00:57:05,820 --> 00:57:09,620 What a thrill it must have been to see it when it was alive. 718 00:57:12,740 --> 00:57:13,780 DEEP BREATHING 719 00:57:24,060 --> 00:57:26,620 RUMBLING 720 00:57:41,500 --> 00:57:43,100 RUMBLING 721 00:57:49,820 --> 00:57:50,860 TITANOSAUR ROARS