1 00:00:17,360 --> 00:00:20,280 Over 66 million years ago... 2 00:00:22,760 --> 00:00:24,600 SCREECHING WAIL 3 00:00:24,600 --> 00:00:26,880 HIGH-PITCHED CLUCKS ..our world... 4 00:00:26,880 --> 00:00:30,040 DEEP SNORT ..was ruled... 5 00:00:30,040 --> 00:00:31,960 ..by dinosaurs... 6 00:00:33,000 --> 00:00:35,040 DEEP BELLOW 7 00:00:36,120 --> 00:00:38,160 HISSES 8 00:00:39,280 --> 00:00:43,120 ..the largest animals that have ever walked the Earth. 9 00:00:50,120 --> 00:00:54,440 Today, dinosaur experts across the globe 10 00:00:54,440 --> 00:00:57,600 are uncovering the bones they left behind... 11 00:01:01,000 --> 00:01:05,400 ..allowing us to imagine how these extraordinary creatures 12 00:01:05,400 --> 00:01:07,040 may have lived... 13 00:01:10,760 --> 00:01:13,320 ..so that we can tell their stories... 14 00:01:17,680 --> 00:01:19,120 ..and they... 15 00:01:20,520 --> 00:01:22,280 ..can walk again. 16 00:01:51,240 --> 00:01:53,280 Eastern Montana. 17 00:01:56,160 --> 00:01:59,360 A vast untamed wilderness... 18 00:02:03,800 --> 00:02:06,840 ..with extraordinary stories to tell. 19 00:02:15,520 --> 00:02:18,440 This is dinosaur country. 20 00:02:26,160 --> 00:02:30,560 Here, a team from the North Carolina Museum of Natural Sciences 21 00:02:30,560 --> 00:02:34,360 is excavating an iconic species, 22 00:02:34,360 --> 00:02:36,320 a triceratops. 23 00:02:37,240 --> 00:02:39,000 - Oh, sweet. 24 00:02:40,040 --> 00:02:43,080 - But this is no ancient giant. 25 00:02:43,080 --> 00:02:46,600 - But it's really small, a very young individual. 26 00:02:48,160 --> 00:02:51,640 - Got a nice baby drake. 27 00:02:51,640 --> 00:02:53,280 A phenomenal find. 28 00:02:54,320 --> 00:02:56,880 - The team calls her Clover. 29 00:03:02,120 --> 00:03:04,240 Studying her bones, 30 00:03:04,240 --> 00:03:06,800 we can begin to imagine her world... 31 00:03:10,520 --> 00:03:15,200 ..and tell her story for the first time. 32 00:03:39,760 --> 00:03:42,160 At the end of the Cretaceous, 33 00:03:42,160 --> 00:03:45,960 North America is a vast expanse of green. 34 00:03:53,760 --> 00:03:55,960 Where Montana is today, 35 00:03:55,960 --> 00:04:00,320 there is a lush landscape of sprawling subtropical forests... 36 00:04:01,760 --> 00:04:04,280 ..crisscrossed by waterways. 37 00:04:07,160 --> 00:04:09,520 This is Laramidia... 38 00:04:12,240 --> 00:04:15,440 ..home to prehistoric giants... 39 00:04:15,440 --> 00:04:17,640 THUDDING FOOTSTEPS 40 00:04:19,280 --> 00:04:20,960 ..and the occasional... 41 00:04:22,480 --> 00:04:24,160 ..not so giant. 42 00:04:29,120 --> 00:04:30,760 TRILLING CALL 43 00:04:30,760 --> 00:04:33,600 Meet Clover, the triceratops. 44 00:04:38,960 --> 00:04:41,400 Barely half a metre tall, 45 00:04:41,400 --> 00:04:43,360 she's the size of a large dog. 46 00:04:55,480 --> 00:04:57,960 PANTS 47 00:05:07,920 --> 00:05:12,040 Despite her size, Clover roams the jungle alone. 48 00:05:21,600 --> 00:05:25,960 These strange white objects mean one thing. 49 00:05:28,480 --> 00:05:29,840 Playtime. 50 00:05:29,840 --> 00:05:32,280 SNUFFLES 51 00:05:40,600 --> 00:05:44,320 But curiosity can be a dangerous thing... 52 00:05:46,000 --> 00:05:47,720 CROAKING CALL 53 00:05:47,720 --> 00:05:50,120 ..when you're living in a land of monsters. 54 00:06:10,920 --> 00:06:13,120 Clover is rare. 55 00:06:15,840 --> 00:06:18,880 The vast majority of triceratops fossils discovered 56 00:06:18,880 --> 00:06:20,480 are from adults. 57 00:06:23,720 --> 00:06:26,800 Clover's remains are a chance to uncover the story 58 00:06:26,800 --> 00:06:28,680 of a youngster... 59 00:06:32,480 --> 00:06:35,640 ..a once-in-a-lifetime opportunity for team leader 60 00:06:35,640 --> 00:06:37,200 Eric Lund. 61 00:06:39,280 --> 00:06:42,160 - Check out these teeth. - Oh, wow. 62 00:06:42,160 --> 00:06:46,080 - Clover's tiny jawbone has been painstakingly reconstructed 63 00:06:46,080 --> 00:06:48,800 by fossil restorer Nikki Simon. 64 00:06:48,800 --> 00:06:50,480 - Isn't she gorgeous? 65 00:06:50,480 --> 00:06:53,600 - She is gorgeous. It's beautiful. 66 00:06:53,600 --> 00:06:57,200 Don't often find upper jaws this complete, 67 00:06:57,200 --> 00:07:00,960 let alone with all the teeth in 'em. 68 00:07:00,960 --> 00:07:02,760 No wear on them. 69 00:07:02,760 --> 00:07:06,480 - The teeth's edges, for slicing through plant material, 70 00:07:06,480 --> 00:07:08,680 are still razor sharp. 71 00:07:08,680 --> 00:07:10,800 - Check 'em out. - Sure. 72 00:07:13,000 --> 00:07:14,600 Oh, yeah. 73 00:07:16,760 --> 00:07:19,040 - These have barely been used. 74 00:07:20,280 --> 00:07:23,560 - They almost look carnivorous. 75 00:07:23,560 --> 00:07:27,360 - The teeth are a clue to Clover's young age. 76 00:07:27,360 --> 00:07:31,600 - Look at how small this upper arm bone is. 77 00:07:31,600 --> 00:07:33,680 - Yeah. Let's see 78 00:07:33,680 --> 00:07:36,040 - By measuring Clover's arm bone... 79 00:07:36,040 --> 00:07:40,120 - A little over a foot. - 34cm. 80 00:07:40,120 --> 00:07:43,360 - ..they can more accurately estimate how old she was. 81 00:07:43,360 --> 00:07:46,680 - She must only have been about three years old. 82 00:07:46,680 --> 00:07:49,080 - Which means she was just a baby. 83 00:07:55,920 --> 00:07:59,400 - A baby...buried all alone. 84 00:08:01,320 --> 00:08:02,760 - Seems to be by herself. 85 00:08:02,760 --> 00:08:05,560 Haven't found any adult bones in this quarry. 86 00:08:05,560 --> 00:08:08,320 - Without the herd, without her mother, 87 00:08:08,320 --> 00:08:09,920 very vulnerable. 88 00:08:14,120 --> 00:08:17,120 - We'll never know why Clover was alone. 89 00:08:19,840 --> 00:08:23,600 What we do know is that in the Late Cretaceous... 90 00:08:25,240 --> 00:08:29,680 ..young, solitary dinosaurs don't last long. 91 00:08:34,720 --> 00:08:36,800 WINGS FLAP 92 00:08:46,360 --> 00:08:48,400 SQUAWKS 93 00:08:49,440 --> 00:08:51,480 HISSES 94 00:08:55,640 --> 00:08:57,600 An infernodrakon... 95 00:08:59,360 --> 00:09:02,800 ..a giant pterosaur, common at the end of the Cretaceous. 96 00:09:04,640 --> 00:09:08,800 With a five-metre wingspan, it tries to intimidate Clover. 97 00:09:12,840 --> 00:09:14,560 INFERNODRAKON HISSES 98 00:09:14,560 --> 00:09:17,680 And then there's the razor-sharp beak. 99 00:09:21,480 --> 00:09:23,880 But Clover is nimble. 100 00:09:40,080 --> 00:09:43,880 And this mother just wants her egg back. 101 00:09:59,720 --> 00:10:03,200 This time, the little triceratops was lucky. 102 00:10:08,080 --> 00:10:12,760 But danger lurks everywhere... 103 00:10:12,760 --> 00:10:15,760 BELLOWING ROAR 104 00:10:15,760 --> 00:10:19,360 ..and it gets much, much bigger. 105 00:10:37,160 --> 00:10:39,240 A mile from Clover's dig site... 106 00:10:40,400 --> 00:10:44,000 ..more fossilised remains are emerging. 107 00:10:44,000 --> 00:10:46,680 HAMMER TAPS 108 00:10:50,320 --> 00:10:52,640 - We've got a bone over here that's very thin, 109 00:10:52,640 --> 00:10:54,840 very slender and very long. 110 00:10:56,120 --> 00:10:59,000 This looks like one of the processes 111 00:10:59,000 --> 00:11:02,120 off of the tail vertebrae, and it helps lock the tail 112 00:11:02,120 --> 00:11:05,360 into a much more rigid structure. 113 00:11:06,640 --> 00:11:09,160 - These thin bones may once have formed 114 00:11:09,160 --> 00:11:12,800 part of a thick, muscular tail six metres long. 115 00:11:14,560 --> 00:11:17,680 But this was no triceratops. 116 00:11:17,680 --> 00:11:21,160 - This is sort of a meat-eating dinosaur feature. 117 00:11:26,360 --> 00:11:30,160 - Palaeontologist Ellis Mulready holds the final clue. 118 00:11:32,160 --> 00:11:33,760 - It's a little bit beat up. 119 00:11:37,480 --> 00:11:41,280 - It's a really thick tooth, designed for crushing bones. 120 00:11:41,280 --> 00:11:44,840 - It's got those kind of drawn-together serrations. 121 00:11:44,840 --> 00:11:46,680 - You can still feel them. 122 00:11:46,680 --> 00:11:49,120 I would love to meet the creature that had this tooth, 123 00:11:49,120 --> 00:11:50,400 but it'd be a bit scary! 124 00:11:50,400 --> 00:11:52,440 - THEY LAUGH - Yeah. 125 00:11:58,280 --> 00:12:03,320 It's a tooth that can only belong to one animal. 126 00:12:03,320 --> 00:12:05,360 LOW, RUMBLING GROWL 127 00:12:07,720 --> 00:12:10,400 SLOW FOOTSTEPS 128 00:12:16,080 --> 00:12:19,160 LOW GROWL 129 00:12:20,440 --> 00:12:22,560 Standing four metres tall... 130 00:12:24,160 --> 00:12:26,960 ..and weighing in at eight tonnes... 131 00:12:33,120 --> 00:12:35,400 ..Tyrannosaurus rex. 132 00:12:46,960 --> 00:12:49,640 With 1.5-metre-long jaws, 133 00:12:49,640 --> 00:12:54,400 the Earth's most infamous predator could swallow Clover whole. 134 00:12:58,200 --> 00:13:00,240 LOW GROWL 135 00:13:00,240 --> 00:13:03,920 Fortunately, the hunter's focus is elsewhere. 136 00:13:11,240 --> 00:13:14,840 Padded feet act like shock absorbers, 137 00:13:14,840 --> 00:13:16,960 keeping its approach quiet. 138 00:13:34,880 --> 00:13:37,640 For T-rex, a light snack. 139 00:13:37,640 --> 00:13:40,480 GROWLS 140 00:13:41,720 --> 00:13:43,880 PANTS 141 00:13:49,240 --> 00:13:53,160 For Clover, a terrifying first encounter. 142 00:13:58,240 --> 00:14:00,240 And it won't be her last. 143 00:14:05,520 --> 00:14:08,960 Up to 20,000 T-rex roam Laramidia. 144 00:14:12,400 --> 00:14:15,440 To survive, Clover needs protection... 145 00:14:17,280 --> 00:14:19,160 ..and fast. 146 00:14:22,360 --> 00:14:24,360 - You ready? - Ready. 147 00:14:25,920 --> 00:14:27,720 - In the search for more clues, 148 00:14:27,720 --> 00:14:31,160 Eric and evolutionary ecologist John Kanipe 149 00:14:31,160 --> 00:14:34,040 are heading deeper into the wilderness. 150 00:14:36,920 --> 00:14:38,800 - So, you asked me about snakes earlier. 151 00:14:38,800 --> 00:14:40,200 - Oh, yeah. 152 00:14:40,200 --> 00:14:42,680 - There's just a baby rattler in the bottom there. 153 00:14:45,080 --> 00:14:49,160 - They want to understand who was sharing the forest with Clover. 154 00:14:50,400 --> 00:14:52,680 - All right. I'm ready when you are. 155 00:15:01,320 --> 00:15:03,920 - It's obvious from the evidence on the ground... 156 00:15:03,920 --> 00:15:06,200 - Got a bit of bone here coming out. 157 00:15:06,200 --> 00:15:09,840 - ..that Clover's world was teeming with other dinosaurs. 158 00:15:09,840 --> 00:15:11,560 - Some bigger pieces. 159 00:15:11,560 --> 00:15:13,400 Pretty busted up. 160 00:15:13,400 --> 00:15:15,560 That's got a bit more surface. 161 00:15:16,960 --> 00:15:22,080 - One familiar species is turning up more than any other. 162 00:15:22,080 --> 00:15:26,320 - Most of them belong to triceratops. 163 00:15:26,320 --> 00:15:29,880 - Triceratops once dominated this area. 164 00:15:31,640 --> 00:15:34,560 - They've been sitting on the surface a really long time. 165 00:15:35,720 --> 00:15:37,520 They're pretty weathered. 166 00:15:55,160 --> 00:15:59,680 - One fossil shows why triceratops were so successful. 167 00:16:01,560 --> 00:16:03,880 - It's like a big brow horn. 168 00:16:11,000 --> 00:16:14,000 Oh, man! It's a bit busted up. 169 00:16:14,000 --> 00:16:16,120 - You can still see where all the blood vessels would be, 170 00:16:16,120 --> 00:16:18,560 even on the horn. - Yeah. 171 00:16:18,560 --> 00:16:22,560 - In life, this horn would have been over a metre long, 172 00:16:22,560 --> 00:16:27,600 and behind it a protective bony shield almost two metres wide. 173 00:16:28,800 --> 00:16:31,760 Here was a creature seemingly custom built 174 00:16:31,760 --> 00:16:34,440 for fighting off large predators. 175 00:16:34,440 --> 00:16:37,680 - Got these big horns on the front of your face, wave them around 176 00:16:37,680 --> 00:16:40,760 and maybe make a T-rex think twice before attacking you. 177 00:16:52,000 --> 00:16:54,800 - Triceratops' formidable defences made it 178 00:16:54,800 --> 00:16:58,440 one of the most successful dinosaur species of its day... 179 00:17:00,960 --> 00:17:03,360 ..meaning an adult triceratops 180 00:17:03,360 --> 00:17:06,200 would be the perfect protector for Clover. 181 00:17:06,200 --> 00:17:09,200 LOW GRUNTS 182 00:17:18,840 --> 00:17:21,360 CLOVER YELPS 183 00:17:24,920 --> 00:17:28,400 This old bull will do nicely. 184 00:17:36,480 --> 00:17:38,480 CLOVER CALLS SOFTLY 185 00:17:48,840 --> 00:17:51,480 LOW GRUNTS 186 00:18:08,480 --> 00:18:10,520 But there's a problem. 187 00:18:14,080 --> 00:18:17,640 Who needs a troublesome youngster following you around? 188 00:18:25,640 --> 00:18:27,880 CALLS SOFTLY 189 00:18:27,880 --> 00:18:30,080 GRUNTS LOUDLY 190 00:18:31,880 --> 00:18:33,920 TRILLING CALL 191 00:18:35,120 --> 00:18:36,960 As another day ends... 192 00:18:38,680 --> 00:18:41,320 ..Clover is still alone... 193 00:18:43,000 --> 00:18:45,640 ..and darkness is setting in. 194 00:18:53,480 --> 00:18:56,360 Eric thinks Clover may have had good reason 195 00:18:56,360 --> 00:18:59,000 to fear the night-time most of all. 196 00:19:07,960 --> 00:19:12,760 Back at base camp, he uses a scan of a T-rex skull 197 00:19:12,760 --> 00:19:15,160 to print a 3D model... 198 00:19:16,480 --> 00:19:18,680 ..of the killer's brain cavity. 199 00:19:29,480 --> 00:19:32,000 - This is the endocast of a T-rex. 200 00:19:35,480 --> 00:19:38,680 For an animal that has a head a metre and a half long, 201 00:19:38,680 --> 00:19:42,360 not a real big brain - a dinosaur's not doing calculus - 202 00:19:42,360 --> 00:19:45,160 but it was enough to do what the animal needed to do. 203 00:19:45,160 --> 00:19:46,800 It was very successful. - Right. 204 00:19:46,800 --> 00:19:48,800 It just needs to process the information. 205 00:19:48,800 --> 00:19:51,360 - Exactly. - It's got a lot of sensory input. 206 00:19:53,200 --> 00:19:56,040 - Though small compared to a human's, 207 00:19:56,040 --> 00:19:59,120 this brain is fine-tuned for hunting. 208 00:20:00,280 --> 00:20:03,560 - We've got these really big olfactory bulbs in the front. 209 00:20:03,560 --> 00:20:06,680 - That's for smell. - That's for smell, yeah. 210 00:20:06,680 --> 00:20:09,840 - T-rex probably had one of the most sensitive noses 211 00:20:09,840 --> 00:20:11,560 of any dinosaur. 212 00:20:11,560 --> 00:20:15,720 - It's probably picking up on minuscule parts per million. 213 00:20:15,720 --> 00:20:18,080 - And it wasn't just the killer's sense of smell 214 00:20:18,080 --> 00:20:20,360 that was supercharged. 215 00:20:20,360 --> 00:20:21,880 - Here, in the middle, 216 00:20:21,880 --> 00:20:25,200 would be the part of the brain that controls vision. 217 00:20:25,200 --> 00:20:28,320 T-rex does...really big eyes, just like an owl, 218 00:20:28,320 --> 00:20:30,040 that take in a lot of light. 219 00:20:31,800 --> 00:20:35,720 - These incredible senses likely made T-rex 220 00:20:35,720 --> 00:20:38,960 a lethal nocturnal hunter. 221 00:20:38,960 --> 00:20:41,360 THUNDER RUMBLES 222 00:20:44,080 --> 00:20:47,160 CREATURES CALL 223 00:20:58,280 --> 00:21:00,440 As darkness descends... 224 00:21:05,640 --> 00:21:08,400 ..it's time to begin the hunt. 225 00:21:14,760 --> 00:21:17,560 Locking on to a telltale scent... 226 00:21:17,560 --> 00:21:20,400 SNUFFLES 227 00:21:25,960 --> 00:21:29,240 ..it seems that supper is nearby. 228 00:21:32,280 --> 00:21:35,440 Whilst most creatures have sought safe places to sleep... 229 00:21:37,320 --> 00:21:38,800 ..Clover is awake. 230 00:21:40,640 --> 00:21:42,520 She must bulk up by a tonne 231 00:21:42,520 --> 00:21:44,720 each year to reach full size, 232 00:21:44,720 --> 00:21:46,960 so feeds often through the night. 233 00:21:50,920 --> 00:21:53,600 In the darkness, she sees little... 234 00:21:57,840 --> 00:22:00,440 ..but T-rex sees her 235 00:22:00,440 --> 00:22:02,120 perfectly. 236 00:22:37,680 --> 00:22:40,120 GRUNTS 237 00:22:46,680 --> 00:22:48,880 THUDDING 238 00:23:02,960 --> 00:23:04,800 SNUFFLES 239 00:23:04,800 --> 00:23:07,000 Saved by her size. 240 00:23:20,880 --> 00:23:23,160 GRUNTS SOFTLY 241 00:23:32,800 --> 00:23:36,280 Luck seems to be on Clover's side. 242 00:23:36,280 --> 00:23:38,680 DISTANT GRUNTS 243 00:23:42,120 --> 00:23:44,120 CLOVER GRUNTS 244 00:23:44,120 --> 00:23:46,960 She survived a close encounter with T-rex. 245 00:23:50,080 --> 00:23:52,440 And from the sound of things... 246 00:23:52,440 --> 00:23:55,040 HOOTING CALL 247 00:23:55,040 --> 00:23:57,760 ..a new ally may be close at hand. 248 00:23:57,760 --> 00:23:59,800 LOW GRUNT 249 00:24:17,400 --> 00:24:21,560 In the search for more giants, the team is putting to the test 250 00:24:21,560 --> 00:24:24,520 the very latest fossil-hunting techniques. 251 00:24:25,880 --> 00:24:29,680 A 66-million-year-old treasure hunt 252 00:24:29,680 --> 00:24:32,400 using 21st-century technology. 253 00:24:34,400 --> 00:24:37,200 - If we fly out towards those badlands, 254 00:24:37,200 --> 00:24:39,360 that would be a great spot. 255 00:24:39,360 --> 00:24:40,840 - BEEPING 256 00:24:40,840 --> 00:24:43,080 - The gyros stabilise. 257 00:24:43,080 --> 00:24:46,280 - Eric's teamed up with palaeontologists Thomas Kaye... 258 00:24:46,280 --> 00:24:48,720 - BEEP - Going for arm. 259 00:24:48,720 --> 00:24:50,360 ..and Dr Michael Pittman. 260 00:24:50,360 --> 00:24:51,720 - Ready to launch. 261 00:24:59,360 --> 00:25:03,920 - Their prototype laser drone scans the ground with UV light... 262 00:25:06,040 --> 00:25:11,160 ..searching for the telltale glow of minerals within ancient fossils... 263 00:25:14,480 --> 00:25:18,360 ..to create a treasure map of prehistoric remains. 264 00:25:20,400 --> 00:25:23,760 - See, here, we've got some specks. 265 00:25:23,760 --> 00:25:26,080 Maybe the size of a tennis ball. 266 00:25:26,080 --> 00:25:28,520 Interesting but, you know, we want the big stuff. 267 00:25:29,640 --> 00:25:31,960 - It's early days for the technology, 268 00:25:31,960 --> 00:25:33,680 and it has limitations. 269 00:25:36,400 --> 00:25:38,680 But one spot on the ground... 270 00:25:38,680 --> 00:25:40,200 - Bang! Look at that. 271 00:25:40,200 --> 00:25:41,880 - ..is glowing brightly. 272 00:25:41,880 --> 00:25:44,400 - So that must be a really big piece. - Yeah, that's big! 273 00:25:53,640 --> 00:25:56,040 - As dawn breaks, 274 00:25:56,040 --> 00:25:58,680 Eric and Nikki head into the badlands 275 00:25:58,680 --> 00:26:00,920 to see this enormous fossil. 276 00:26:05,680 --> 00:26:07,920 - Look how big it is! 277 00:26:10,200 --> 00:26:14,640 - It's the lower leg bone of a truly colossal dinosaur. 278 00:26:15,640 --> 00:26:18,520 - Seems to have been sitting out on the surface for quite some time. 279 00:26:20,160 --> 00:26:22,320 This is a big bone. 280 00:26:22,320 --> 00:26:25,840 This animal would have been, you know, maybe around 281 00:26:25,840 --> 00:26:27,880 six, seven metres long. 282 00:26:29,880 --> 00:26:32,440 - But this is no triceratops. 283 00:26:32,440 --> 00:26:34,280 It's not a T-rex either. 284 00:26:36,360 --> 00:26:39,640 BELLOWING CALLS 285 00:26:41,920 --> 00:26:44,840 Echoing through towering trees... 286 00:26:46,800 --> 00:26:49,360 BELLOWING CALL 287 00:26:54,160 --> 00:26:58,600 ..the calls of perhaps the strangest dinosaurs who roam here.. 288 00:27:04,200 --> 00:27:06,200 BELLOWS CONTINUE 289 00:27:08,920 --> 00:27:10,920 ..Edmontosaurs... 290 00:27:16,920 --> 00:27:21,560 ..herd animals known as the cows of the Cretaceous. 291 00:27:26,600 --> 00:27:29,160 Weighing over six tonnes, 292 00:27:29,160 --> 00:27:32,520 these social creatures tolerate Clover. 293 00:27:36,200 --> 00:27:39,840 As a fellow plant-eater, she's no threat to them. 294 00:27:49,120 --> 00:27:53,160 The herd could give Clover the protection she needs. 295 00:28:00,920 --> 00:28:03,000 CHIRPS 296 00:28:03,000 --> 00:28:05,440 And it's not just safety they offer. 297 00:28:07,320 --> 00:28:09,320 A playmate. 298 00:28:12,520 --> 00:28:15,600 ALL GRUNT AND CALL 299 00:28:57,800 --> 00:29:00,200 In amongst these giants... 300 00:29:06,040 --> 00:29:09,520 ..Clover can begin to feel safe. 301 00:29:15,200 --> 00:29:19,040 But danger is never far away. 302 00:29:26,760 --> 00:29:29,240 HAMMER TAPS 303 00:29:30,640 --> 00:29:36,800 66 million years ago, T-rex ruled over these lands... 304 00:29:39,000 --> 00:29:42,680 ..the apex predator for over two million years. 305 00:29:42,680 --> 00:29:46,320 - As it rolls over, just get your hands under it. 306 00:29:46,320 --> 00:29:49,560 - The team wants to discover how this fearsome hunter 307 00:29:49,560 --> 00:29:51,480 took down its prey. 308 00:29:53,840 --> 00:29:56,520 Inside this protective plaster coat 309 00:29:56,520 --> 00:29:58,920 is the predator's leg bone. 310 00:29:58,920 --> 00:30:01,840 Eric thinks there might be more underneath. 311 00:30:01,840 --> 00:30:03,840 - One, two, three. 312 00:30:06,000 --> 00:30:08,040 - Protruding from the rock... 313 00:30:08,040 --> 00:30:09,920 - That's a bone. 314 00:30:09,920 --> 00:30:12,640 - ..one of the giant's vertebrae. 315 00:30:12,640 --> 00:30:14,840 - Beautiful preservation. 316 00:30:14,840 --> 00:30:17,440 It was a big, big animal. 317 00:30:17,440 --> 00:30:22,480 - It allows Eric to estimate more accurately T-rex's full size. 318 00:30:23,720 --> 00:30:25,920 - On the order of 30 feet, maybe more. 319 00:30:25,920 --> 00:30:27,840 Ten metres, something like that. 320 00:30:32,160 --> 00:30:36,200 - They wrap their discoveries in a protective plaster jacket. 321 00:30:40,680 --> 00:30:43,480 It's just a tiny fraction of T-rex's skeleton... 322 00:30:45,120 --> 00:30:46,880 ..but it's enormous. 323 00:30:48,720 --> 00:30:52,040 - This jacket's probably about 150kg, 324 00:30:52,040 --> 00:30:53,720 200lb, 300lb. 325 00:30:56,320 --> 00:30:58,480 It's just so huge. 326 00:30:58,480 --> 00:31:03,720 - Alive, adult T-rex weighed over eight tonnes, 327 00:31:03,720 --> 00:31:08,600 but this enormous weight may actually have been a hindrance. 328 00:31:08,600 --> 00:31:13,680 - Certainly not the 40mph Jeep-chasing animal of Jurassic Park! 329 00:31:13,680 --> 00:31:17,200 Their physiology just wouldn't allow them to run that fast. 330 00:31:17,200 --> 00:31:18,840 Probably speed walker. 331 00:31:19,840 --> 00:31:24,360 - T-rex probably couldn't run for fear of breaking its own legs... 332 00:31:25,840 --> 00:31:29,480 ..with a top speed of just 15mph or 20mph. 333 00:31:32,320 --> 00:31:36,760 Not exactly slow, but a fast human could outsprint one. 334 00:31:36,760 --> 00:31:38,560 - I think you could. 335 00:31:38,560 --> 00:31:40,720 I think I'm going to take a sharp turn, 336 00:31:40,720 --> 00:31:43,040 and it's going to have a hard time following me. 337 00:31:43,040 --> 00:31:45,080 - You think we only just got - THEY LAUGH 338 00:31:45,080 --> 00:31:47,880 - LAUGHTER to be faster than him. 339 00:31:49,320 --> 00:31:51,440 - Maybe I'm a little overconfident! 340 00:32:01,000 --> 00:32:05,200 - So adult T-rex weren't sprinting after their prey. 341 00:32:10,320 --> 00:32:13,960 This killer relied on another tactic... 342 00:32:17,360 --> 00:32:19,520 ..the element of surprise. 343 00:32:19,520 --> 00:32:21,480 LOW GROWL 344 00:32:21,480 --> 00:32:25,240 As Clover and the Edmontosaurs sleep soundly... 345 00:32:27,720 --> 00:32:31,880 ..T-rex approaches slowly from downwind. 346 00:32:52,480 --> 00:32:54,920 But it's not easy being stealthy... 347 00:32:54,920 --> 00:32:56,960 CRACK 348 00:32:59,160 --> 00:33:01,440 ..when you're the size of a bus. 349 00:33:08,120 --> 00:33:10,640 BLEATS LOUDLY 350 00:33:17,520 --> 00:33:20,120 ROARING 351 00:33:21,880 --> 00:33:25,000 The Edmontosaurs form a defensive line... 352 00:33:28,320 --> 00:33:30,280 ..rearing up on their hind legs 353 00:33:30,280 --> 00:33:32,680 to appear as big as possible. 354 00:33:35,320 --> 00:33:38,160 But holding your nerve isn't easy. 355 00:33:52,360 --> 00:33:55,680 And it only takes one of the herd to panic. 356 00:34:15,120 --> 00:34:17,160 SQUEALS 357 00:34:25,760 --> 00:34:27,720 CHOMPS 358 00:34:27,720 --> 00:34:29,720 A lucky escape for Clover... 359 00:34:31,480 --> 00:34:34,320 ..not for her new friend. 360 00:34:34,320 --> 00:34:36,360 CALLS SOFTLY 361 00:34:41,360 --> 00:34:44,120 With the adult Edmontosaurs on the move... 362 00:34:47,880 --> 00:34:51,800 ..Clover is alone once more. 363 00:35:08,760 --> 00:35:12,600 Survival was a game of chance in the Late Cretaceous, 364 00:35:12,600 --> 00:35:15,800 and the odds were stacked against young dinosaurs like Clover. 365 00:35:19,880 --> 00:35:23,160 The team has tracked down a remarkable fossil 366 00:35:23,160 --> 00:35:25,600 with a chilling tale to tell. 367 00:35:25,600 --> 00:35:28,400 - That's the weirdest baby bundle ever. 368 00:35:29,760 --> 00:35:32,440 - It may look like a nondescript lump of rock 369 00:35:32,440 --> 00:35:35,680 but its shape and texture tell the experts 370 00:35:35,680 --> 00:35:39,760 this is a coprolite - fossilised faeces. 371 00:35:41,960 --> 00:35:45,520 Eric works with fossil-restorer Aubrey Knowles... 372 00:35:46,800 --> 00:35:50,320 - 67.5 centimetres, or 26.5 inches. 373 00:35:50,320 --> 00:35:53,560 - ..to examine this prehistoric poo. 374 00:35:53,560 --> 00:35:55,520 - This is a massive turd. - It's a really big turd. 375 00:35:55,520 --> 00:35:57,600 - ERIC CHUCKLES 376 00:35:58,680 --> 00:36:02,520 Most coprolites can't be attributed to any specific species... 377 00:36:04,240 --> 00:36:06,560 ..but bone fragments within the dino dung 378 00:36:06,560 --> 00:36:09,840 reveal this was the waste product of a meat-eater. 379 00:36:12,240 --> 00:36:14,920 And then there's the matter of size. 380 00:36:16,520 --> 00:36:21,960 - So we're at 15.7 centimetres across, or 6.2 inches. 381 00:36:23,400 --> 00:36:24,960 - That's a wide cloaca. 382 00:36:24,960 --> 00:36:27,000 - SHE LAUGHS - That is a very wide bumhole. 383 00:36:28,640 --> 00:36:31,720 - The only large-bodied carnivorous dinosaur 384 00:36:31,720 --> 00:36:34,520 that could have possibly dropped this 385 00:36:34,520 --> 00:36:36,800 would be a T-rex, 386 00:36:36,800 --> 00:36:38,680 so very, very cool. 387 00:36:39,800 --> 00:36:42,160 - It's an astonishing fossil... 388 00:36:43,560 --> 00:36:47,600 ..the excrement of the most notorious predator in history. 389 00:36:47,600 --> 00:36:50,680 - It's interesting how many bones there are 390 00:36:50,680 --> 00:36:53,560 preserved in the dropping. 391 00:36:53,560 --> 00:36:55,360 - By examining coprolites, 392 00:36:55,360 --> 00:36:58,720 it's even possible to identify the killer's victims. 393 00:37:01,160 --> 00:37:03,920 T-rex faeces have been found to contain bones 394 00:37:03,920 --> 00:37:06,880 that are small and smooth. 395 00:37:06,880 --> 00:37:10,600 - That speaks to a more juvenile or young prey. 396 00:37:11,720 --> 00:37:13,640 - The bones of babies. 397 00:37:13,640 --> 00:37:16,960 - Baby dinosaurs would be very vulnerable. 398 00:37:16,960 --> 00:37:18,800 Bite-sized. 399 00:37:18,800 --> 00:37:21,720 - Energy is precious. - Yeah. - Go after easy prey. 400 00:37:24,680 --> 00:37:27,400 - Needing a quarter of a tonne of meat a week 401 00:37:27,400 --> 00:37:30,880 to sustain their enormous bulk, 402 00:37:30,880 --> 00:37:35,360 baby dinosaurs like Clover were a common meal for T-rex. 403 00:37:37,720 --> 00:37:40,040 Nothing is off the menu. 404 00:38:08,720 --> 00:38:12,400 Naive, defenceless 405 00:38:12,400 --> 00:38:14,800 and small enough to swallow whole... 406 00:38:15,920 --> 00:38:19,200 ..Clover would make an excellent snack. 407 00:38:23,960 --> 00:38:26,000 SHRIEKS 408 00:38:34,480 --> 00:38:36,560 GRUNTS 409 00:38:43,840 --> 00:38:45,480 With nowhere to hide... 410 00:38:47,400 --> 00:38:49,720 ..it's a good time 411 00:38:49,720 --> 00:38:53,160 to bump into an old acquaintance. 412 00:39:20,680 --> 00:39:24,040 Few creatures can challenge T-rex, 413 00:39:24,040 --> 00:39:27,600 but a full-grown triceratops might be the only animal 414 00:39:27,600 --> 00:39:29,560 that doesn't need to turn and run. 415 00:39:39,520 --> 00:39:44,000 Who wins in a fight - triceratops or T-rex? 416 00:39:47,400 --> 00:39:51,800 The two giants were locked in an evolutionary arms race, 417 00:39:51,800 --> 00:39:53,840 adapted to battle each other. 418 00:39:56,520 --> 00:39:59,760 But Eric thinks triceratops may have had 419 00:39:59,760 --> 00:40:02,120 a surprising trump card. 420 00:40:04,320 --> 00:40:08,480 This fossilised fragment was once part of the huge frill 421 00:40:08,480 --> 00:40:11,600 extending from the back of the skull, 422 00:40:11,600 --> 00:40:13,880 but it wasn't solid bone. 423 00:40:17,160 --> 00:40:19,720 - All these vascular channels on the surface, 424 00:40:19,720 --> 00:40:23,080 all these pits and grooves that are in it, 425 00:40:23,080 --> 00:40:26,160 go all over the surface of the frill. 426 00:40:27,640 --> 00:40:31,280 This surface was covered in a lot of blood vessels. 427 00:40:32,480 --> 00:40:34,720 - The blood flow suggests to Eric 428 00:40:34,720 --> 00:40:38,400 a triceratops frill was more than just a shield. 429 00:40:40,320 --> 00:40:44,840 - The idea is they could change the colour pattern of their frill, 430 00:40:44,840 --> 00:40:46,880 flash these different colours. 431 00:40:48,520 --> 00:40:50,800 - Pushing all this blood up into its frill, 432 00:40:50,800 --> 00:40:53,520 this would be a great way to send a message. 433 00:40:53,520 --> 00:40:55,880 It would have been really intimidating. 434 00:40:59,440 --> 00:41:02,200 - BELLOWING ROAR 435 00:41:04,800 --> 00:41:06,960 The giants are evenly matched. 436 00:41:20,800 --> 00:41:23,120 Each weighs over eight tonnes. 437 00:41:27,520 --> 00:41:29,760 Each with fearsome weaponry. 438 00:41:33,200 --> 00:41:37,120 But triceratops plays his trump card. 439 00:41:43,080 --> 00:41:45,240 Flushing blood into his frill 440 00:41:45,240 --> 00:41:48,080 creates huge colourful eye spots. 441 00:41:51,040 --> 00:41:55,160 They make triceratops seem even bigger. 442 00:42:17,440 --> 00:42:21,360 But T-rex isn't apex predator for nothing. 443 00:42:55,720 --> 00:42:57,440 Stalemate. 444 00:43:04,840 --> 00:43:10,240 But for T-rex, there's still an easier meal close by. 445 00:43:42,280 --> 00:43:46,600 Most young dinosaurs never made it to adulthood, 446 00:43:46,600 --> 00:43:48,880 and Clover was no exception. 447 00:43:54,800 --> 00:43:57,840 But as the dig season draws to a close... 448 00:43:59,720 --> 00:44:03,080 ..her exact cause of death is still unknown. 449 00:44:04,720 --> 00:44:08,360 - You know, we're not sure how baby Clover died. 450 00:44:08,360 --> 00:44:12,720 In digging her bones up, we haven't found any evidence of predation. 451 00:44:14,760 --> 00:44:17,520 There doesn't seem to be any injuries, 452 00:44:17,520 --> 00:44:20,160 no bite marks, things like that. 453 00:44:20,160 --> 00:44:23,520 Up to this point, it remains a mystery. 454 00:44:25,240 --> 00:44:27,160 - Got it? - All right. 455 00:44:34,640 --> 00:44:36,840 - But we do know one thing. 456 00:44:38,840 --> 00:44:42,840 If Clover had died as a meal for T-rex... 457 00:44:44,800 --> 00:44:47,720 ..there probably wouldn't be any remains at all. 458 00:45:02,680 --> 00:45:06,680 For Clover, it seems as if time has run out. 459 00:45:09,520 --> 00:45:13,240 But she still has one advantage - 460 00:45:13,240 --> 00:45:15,000 her size. 461 00:45:21,040 --> 00:45:23,360 With T-rex distracted... 462 00:45:28,200 --> 00:45:31,400 ..a moment of surprise. 463 00:46:06,880 --> 00:46:10,600 Clover has survived her encounter 464 00:46:10,600 --> 00:46:13,280 with history's most infamous killer. 465 00:46:19,040 --> 00:46:21,800 For now, she's safe. 466 00:46:27,800 --> 00:46:30,320 CALLS SOFTLY 467 00:46:32,640 --> 00:46:35,680 GRUMBLING GRUNTS 468 00:46:54,160 --> 00:46:59,200 And while this old bull may not seek the company of a youngster... 469 00:47:03,280 --> 00:47:07,680 ..Clover's not giving up just yet. 470 00:47:39,040 --> 00:47:41,520 We take the plunge 471 00:47:41,520 --> 00:47:43,360 in the most dangerous river... 472 00:47:43,360 --> 00:47:45,400 GRUNTS CALLS 473 00:47:46,800 --> 00:47:48,760 ..in Earths' history... 474 00:47:52,840 --> 00:47:57,520 ..join the smallest member of the biggest herd... 475 00:47:59,200 --> 00:48:00,960 ..on an epic journey... 476 00:48:03,040 --> 00:48:07,480 ..get up close with the deadliest pack of predators... 477 00:48:12,480 --> 00:48:16,200 ..follow an island giant looking for love... 478 00:48:18,080 --> 00:48:21,760 ..and meet the band of brothers on the run 479 00:48:21,760 --> 00:48:25,880 from a ferocious and cunning adversary. 480 00:48:28,480 --> 00:48:30,520 SQUAWKS 481 00:49:17,360 --> 00:49:19,720 Over 66 million years ago... 482 00:49:23,640 --> 00:49:25,600 SCREECHING WAIL 483 00:49:25,600 --> 00:49:28,080 ..our world was ruled... 484 00:49:28,080 --> 00:49:30,120 BELLOWS 485 00:49:30,120 --> 00:49:31,520 ..by dinosaurs. 486 00:49:39,000 --> 00:49:43,480 The largest animals that have ever walked the Earth. 487 00:49:50,440 --> 00:49:54,200 Today, dinosaur experts across the globe 488 00:49:54,200 --> 00:49:57,440 are uncovering the bones they left behind... 489 00:50:00,840 --> 00:50:05,560 ..allowing us to imagine how these extraordinary creatures 490 00:50:05,560 --> 00:50:07,400 may have lived... 491 00:50:09,160 --> 00:50:12,120 ..so that we can tell their stories. 492 00:50:15,880 --> 00:50:17,760 SHRIEKS 493 00:50:17,760 --> 00:50:19,160 And they... 494 00:50:20,600 --> 00:50:22,240 ..can walk again. 495 00:50:22,240 --> 00:50:23,440 ROARS 496 00:50:57,400 --> 00:51:01,240 Nine million square kilometres of parched sand. 497 00:51:04,720 --> 00:51:09,960 The Sahara Desert is one of the most inhospitable environments 498 00:51:09,960 --> 00:51:12,360 on Earth. 499 00:51:20,720 --> 00:51:24,800 But for dinosaur hunters, like Dr Nizar Ibrahim, 500 00:51:24,800 --> 00:51:29,320 it's a gateway to a lost world. 501 00:51:52,080 --> 00:51:55,680 Deep in a remote part of the desert, known as the Kem Kem, 502 00:51:55,680 --> 00:51:59,760 Nizar and his team are excavating the remains 503 00:51:59,760 --> 00:52:04,000 of one of the largest predatory dinosaurs that ever lived. 504 00:52:06,440 --> 00:52:08,120 - Is it broken there? 505 00:52:08,120 --> 00:52:10,800 - I don't know. It seems to be one bone here and one here. 506 00:52:10,800 --> 00:52:12,160 - Wow. 507 00:52:14,280 --> 00:52:15,920 - A spinosaurus. 508 00:52:17,480 --> 00:52:19,520 - Oh, that is beautiful. 509 00:52:19,520 --> 00:52:21,440 What do you reckon? Maybe a rib? 510 00:52:21,440 --> 00:52:23,200 - Or a rib, yeah. 511 00:52:23,200 --> 00:52:24,600 - I knew we'd find one. 512 00:52:28,560 --> 00:52:30,200 - Using the team's discoveries, 513 00:52:30,200 --> 00:52:34,480 we can imagine how it lived and died... 514 00:52:36,080 --> 00:52:40,320 ..100 million years ago. 515 00:53:03,320 --> 00:53:05,800 In the Late Cretaceous period... 516 00:53:07,880 --> 00:53:11,160 ..Africa has just broken away from South America. 517 00:53:20,840 --> 00:53:23,280 And the land that will become the Sahara... 518 00:53:25,120 --> 00:53:27,560 ..is a river system. 519 00:53:33,600 --> 00:53:38,680 Its waters support acres of scrub and forest 520 00:53:38,680 --> 00:53:43,520 that provide shade from the intense Cretaceous sun. 521 00:53:47,000 --> 00:53:50,360 Perfect for an afternoon nap. 522 00:53:52,360 --> 00:53:55,800 GENTLE SNORTING 523 00:53:57,760 --> 00:54:02,920 This is Sobek the spinosaurus. 524 00:54:09,320 --> 00:54:11,160 11 metres long. 525 00:54:12,760 --> 00:54:16,200 His powerful jaws packed with teeth. 526 00:54:21,720 --> 00:54:25,480 Disturbing this monster's sleep... 527 00:54:25,480 --> 00:54:27,320 ..could have deadly consequences. 528 00:54:28,640 --> 00:54:30,960 HIGH-PITCHED CLUCKING 529 00:54:42,680 --> 00:54:44,680 HIGH-PITCHED CLUCK 530 00:54:47,960 --> 00:54:50,640 LOW GROWL 531 00:55:10,400 --> 00:55:12,760 HIGH-PITCHED WAIL 532 00:55:33,640 --> 00:55:36,040 But this isn't lunch. 533 00:55:36,040 --> 00:55:39,600 HIGH-PITCHED CLUCKING 534 00:55:39,600 --> 00:55:41,440 It's one of his babies. 535 00:55:47,440 --> 00:55:49,760 Sobek is a father. 536 00:55:55,760 --> 00:56:00,280 Like some species of modern birds, once the eggs are laid, 537 00:56:00,280 --> 00:56:04,800 the job of looking after the kids falls to him. 538 00:56:07,280 --> 00:56:08,880 YELPS 539 00:56:16,800 --> 00:56:18,680 YELPS 540 00:56:23,080 --> 00:56:26,560 Sobek must keep his young family alive... 541 00:56:28,040 --> 00:56:30,800 ..until they can fend for themselves. 542 00:56:37,200 --> 00:56:39,600 PNEUMATIC DRILLING 543 00:56:43,400 --> 00:56:45,440 100 million years later... 544 00:56:46,760 --> 00:56:48,760 - Looks like bone. 545 00:56:48,760 --> 00:56:51,000 - You got the location mark all right? 546 00:56:52,560 --> 00:56:56,040 - ...Nizar and the team are starting to uncover evidence 547 00:56:56,040 --> 00:57:00,640 that could shed light on how spinosaurus raised their young. 548 00:57:02,600 --> 00:57:05,040 - See more? Any luck on that side? 549 00:57:06,480 --> 00:57:11,200 - Bones that show Sobek wasn't built like other dinosaurs. 550 00:57:12,680 --> 00:57:16,440 - So, Marco, you can see this nice little curvature here. 551 00:57:16,440 --> 00:57:18,800 I think this is certainly a vertebra. 552 00:57:18,800 --> 00:57:21,000 It's a little fragile, this one. 553 00:57:22,840 --> 00:57:26,600 This vertebra was part of Sobek's six-metre tail. 554 00:57:28,400 --> 00:57:31,760 All right, let's get it out, and let's see if we can find more. 555 00:57:35,960 --> 00:57:40,280 - In total, the team has recovered more than 40 tail bones. 556 00:57:42,040 --> 00:57:44,800 - This will be vertebra number...22? 557 00:57:44,800 --> 00:57:46,840 - Yeah. - OK. 558 00:57:46,840 --> 00:57:50,080 Starting from the smallest one? - We're starting distally, yes. 559 00:57:50,080 --> 00:57:54,280 - And for Nizar and fellow palaeontologist Francesca Borchi, 560 00:57:54,280 --> 00:57:56,560 they reveal something unique. 561 00:57:58,760 --> 00:58:02,040 - What I think is really remarkable is, like, you get close 562 00:58:02,040 --> 00:58:05,360 to the tip of the tail, and you still have these really long spines. 563 00:58:06,960 --> 00:58:10,120 - Spines like these are not found 564 00:58:10,120 --> 00:58:13,120 on the tail bones of other predatory dinosaurs. 565 00:58:14,800 --> 00:58:19,360 - Once you see the shape of the spines, it's quite narrow. 566 00:58:19,360 --> 00:58:21,800 - Yes. - And...and flat. 567 00:58:21,800 --> 00:58:24,040 - Basically just a giant paddle. 568 00:58:24,040 --> 00:58:25,720 - Yeah. 569 00:58:25,720 --> 00:58:29,280 - The more we collect, the more aquatic this thing becomes. - Yeah. 570 00:58:31,640 --> 00:58:37,400 - For Nizar, a thin flat tail can mean only one thing... 571 00:58:41,200 --> 00:58:44,360 ..Spinosaurus was a swimmer. 572 00:58:48,200 --> 00:58:49,680 WATER SPLASHES 573 00:58:56,240 --> 00:59:00,240 Underwater, Sobek is in his element... 574 00:59:01,840 --> 00:59:05,680 ...using his huge tail to power him through the water. 575 00:59:17,000 --> 00:59:20,040 He's guarding a nursery pool, 576 00:59:20,040 --> 00:59:24,160 the place he and his babies call home. 577 00:59:29,800 --> 00:59:34,680 And with Dad's back turned, the kids take to the water. 578 00:59:39,880 --> 00:59:44,560 This secluded backwater is the perfect learner pool. 579 00:59:46,040 --> 00:59:48,280 CROAKS 580 00:59:52,400 --> 00:59:55,640 So, while Sobek's patrolling, 581 00:59:55,640 --> 00:59:59,360 the babies hone their hunting skills. 582 01:00:14,000 --> 01:00:18,720 But it's not long before one of them gets into trouble. 583 01:00:24,640 --> 01:00:26,160 If it doesn't get help soon... 584 01:00:28,320 --> 01:00:32,120 ..this baby will drown. 585 01:01:00,240 --> 01:01:04,640 Dad to the rescue. 586 01:01:06,800 --> 01:01:09,000 CROAKING CALL 587 01:01:50,520 --> 01:01:54,000 With everyone safely back on the bank, 588 01:01:54,000 --> 01:01:57,120 the family settles down to sleep. 589 01:02:06,120 --> 01:02:10,880 But they must soon leave the safety of the nursery pool 590 01:02:10,880 --> 01:02:14,760 and travel somewhere Sobek knows they can catch 591 01:02:14,760 --> 01:02:17,160 far more substantial prey. 592 01:02:23,360 --> 01:02:27,000 And the journey ahead will be fraught with dangers. 593 01:02:36,120 --> 01:02:40,880 Because, although the dig site is barren and lifeless today... 594 01:02:45,920 --> 01:02:51,080 ..Nizar and the team have evidence that when Sobek was alive, 595 01:02:51,080 --> 01:02:53,840 the Kem Kem was far more perilous. 596 01:02:55,520 --> 01:02:57,520 - Lots of big predatory fish. 597 01:02:57,520 --> 01:02:59,560 There's a nice...nice jaw. 598 01:02:59,560 --> 01:03:01,480 Absolute monster. 599 01:03:01,480 --> 01:03:04,920 - Its rivers teemed with massive carnivorous fish... 600 01:03:06,160 --> 01:03:07,600 - Ah, this is nice. 601 01:03:08,840 --> 01:03:11,080 - ..and enormous crocodiles. 602 01:03:11,080 --> 01:03:12,840 - Look at that. 603 01:03:12,840 --> 01:03:14,080 - OK. 604 01:03:15,160 --> 01:03:17,000 - Tip of the snout, right? 605 01:03:17,000 --> 01:03:20,080 This is where the nose end is, essentially. 606 01:03:20,080 --> 01:03:23,320 This will be the size of the biggest crocs today. 607 01:03:23,320 --> 01:03:25,240 Big, nasty elosuchus. 608 01:03:27,120 --> 01:03:30,720 - Elosuchus is an extinct species of croc, 609 01:03:30,720 --> 01:03:33,120 with jaws over a metre long. 610 01:03:34,800 --> 01:03:37,200 - This tooth is very nice. Still here. 611 01:03:37,200 --> 01:03:39,160 - Yeah, they're pretty, er, robust. 612 01:03:43,200 --> 01:03:46,360 - If the rivers were dangerous... 613 01:03:46,360 --> 01:03:49,040 - Carcharodontosaurus tooth. 614 01:03:49,040 --> 01:03:53,080 - ..the land was home to an even more deadly predator. 615 01:03:55,160 --> 01:03:57,040 - Yes, it's very well preserved. 616 01:03:57,040 --> 01:03:59,200 I can see all of the serrations here. 617 01:03:59,200 --> 01:04:01,760 - Like a steak knife, right? 618 01:04:01,760 --> 01:04:07,000 - Carcharodontosaurus was the T-rex of Africa... 619 01:04:07,000 --> 01:04:09,160 ..three metres tall 620 01:04:09,160 --> 01:04:12,160 and armed with more than 50 flesh-cutting teeth. 621 01:04:13,360 --> 01:04:16,160 - Got several T-rex-size predatory dinosaurs, 622 01:04:16,160 --> 01:04:19,720 or even bigger than T-rex, big crocs, giant fish. 623 01:04:19,720 --> 01:04:22,360 - Not very safe. - Yeah. 624 01:04:22,360 --> 01:04:25,360 You know, there are really many different ways to die. 625 01:04:27,840 --> 01:04:31,800 - These lands were once home to more large predators 626 01:04:31,800 --> 01:04:35,000 than anywhere else in Earth's history. 627 01:04:42,960 --> 01:04:45,320 A fearsome collection of carnivores... 628 01:04:46,840 --> 01:04:49,360 ..that Sobek must navigate... 629 01:04:51,040 --> 01:04:53,440 ..if he's to feed his family. 630 01:05:04,040 --> 01:05:07,520 And there's danger lurking at every turn. 631 01:05:09,160 --> 01:05:11,640 CROAKING CALL 632 01:05:19,040 --> 01:05:24,280 Hidden from view, the murky waters are patrolled 633 01:05:24,280 --> 01:05:29,000 by at least eight species of ferocious crocodile. 634 01:05:42,640 --> 01:05:43,960 CROAKING CALL 635 01:05:43,960 --> 01:05:46,080 But that's the least of their worries... 636 01:05:46,080 --> 01:05:47,680 RUSTLING 637 01:05:47,680 --> 01:05:51,120 ..because the family has just entered the territory... 638 01:05:54,000 --> 01:05:56,640 LOW SNARL 639 01:05:56,640 --> 01:05:59,040 ..of carcharodontosaurus. 640 01:06:06,280 --> 01:06:09,600 This fearsome six-tonne killing machine... 641 01:06:12,280 --> 01:06:16,280 ..is also on the hunt for food. 642 01:06:26,640 --> 01:06:28,520 ROARS 643 01:06:28,520 --> 01:06:30,840 SCREECHING 644 01:06:38,360 --> 01:06:41,720 LOW GROWLING 645 01:06:43,160 --> 01:06:45,240 ROARS 646 01:06:47,040 --> 01:06:50,160 ROARING 647 01:06:51,520 --> 01:06:53,720 Time to get the babies to safety. 648 01:06:56,440 --> 01:06:59,600 ROARS 649 01:07:10,040 --> 01:07:13,280 With so many deadly predators around, 650 01:07:13,280 --> 01:07:16,960 it will take everything Sobek's got to reach his destination... 651 01:07:18,520 --> 01:07:23,080 ..without his family becoming someone else's meal. 652 01:07:38,360 --> 01:07:43,040 And not far from the dig site, on a remote plateau... 653 01:07:48,200 --> 01:07:53,040 ..the team has discovered signs of another monster... 654 01:07:53,040 --> 01:07:54,800 - You good? - OK. 655 01:07:54,800 --> 01:07:57,160 - Good. I'm ready to go whenever you are. 656 01:07:57,160 --> 01:08:00,680 - ..evidence that's best seen from the air. 657 01:08:04,520 --> 01:08:06,960 DRONE WHIRS 658 01:08:11,280 --> 01:08:13,840 - So, how many pictures are we taking in total? 659 01:08:13,840 --> 01:08:15,920 - About 500, 600. 660 01:08:21,640 --> 01:08:24,200 - So, if we start down that ridge, 661 01:08:24,200 --> 01:08:27,160 and then work our way over and do that whole site. 662 01:08:41,240 --> 01:08:45,160 - The photographic survey reveals what's hidden here. 663 01:08:48,400 --> 01:08:52,080 Arranged in rows, these aren't just boulders... 664 01:08:54,080 --> 01:08:55,560 ..they're footprints. 665 01:09:00,160 --> 01:09:04,000 This is a dinosaur trackway. 666 01:09:07,840 --> 01:09:10,920 And to identify which dinosaur made it... 667 01:09:10,920 --> 01:09:13,080 - Really big one. - Wow. 668 01:09:13,080 --> 01:09:17,240 - ..Nizar and colleague, Dr Roy Smith, take a closer look. 669 01:09:17,240 --> 01:09:19,160 - You've got this edge here, 670 01:09:19,160 --> 01:09:21,400 and then quite a nice shape around that side, as well. 671 01:09:21,400 --> 01:09:23,400 - Yeah, very nice. 672 01:09:23,400 --> 01:09:27,760 - Each footprint is a cast of the foot that made it. 673 01:09:27,760 --> 01:09:30,240 - So, the claw over there, right? - Yeah, yeah. 674 01:09:30,240 --> 01:09:32,920 And I think there's two more there. - Yeah. 675 01:09:32,920 --> 01:09:35,480 - The back of the foot. - Yeah. 676 01:09:36,960 --> 01:09:39,440 - And at over a metre across, 677 01:09:39,440 --> 01:09:42,120 they're some of the biggest ever found. 678 01:09:42,120 --> 01:09:43,360 - No. - No. 679 01:09:43,360 --> 01:09:45,120 - This is really impressive. - Yeah. 680 01:09:45,120 --> 01:09:46,840 - There's a bit missing, or it would have been even bigger. 681 01:09:46,840 --> 01:09:48,400 - It would have been even bigger. 682 01:09:48,400 --> 01:09:50,760 - We've got a giant here. - Yeah, yeah. 683 01:09:52,360 --> 01:09:54,360 - These footprints were made 684 01:09:54,360 --> 01:09:58,040 by one of the largest dinosaurs that's ever lived. 685 01:10:08,680 --> 01:10:15,440 Titanosaurs - huge long-necked dinosaurs, 14 metres high. 686 01:10:23,040 --> 01:10:25,760 At more than 60 tonnes, 687 01:10:25,760 --> 01:10:29,240 each one weighs as much as a herd of elephants. 688 01:10:30,720 --> 01:10:34,120 DEEP BELLOW 689 01:10:40,040 --> 01:10:42,800 But for one elderly member of the group... 690 01:10:44,440 --> 01:10:47,560 ..this has become its final resting place. 691 01:10:58,240 --> 01:11:02,000 And it could provide Sobek with the food he needs 692 01:11:02,000 --> 01:11:05,040 for his hungry babies. 693 01:11:17,480 --> 01:11:19,960 But they're not the only ones 694 01:11:19,960 --> 01:11:22,320 on the lookout for a free lunch. 695 01:11:23,720 --> 01:11:25,240 LOW GROWL 696 01:11:26,920 --> 01:11:30,040 An adult carcharodontosaurus... 697 01:11:30,040 --> 01:11:32,000 ROARS 698 01:11:33,240 --> 01:11:35,600 CHITTERING 699 01:11:35,600 --> 01:11:38,560 ..has already laid claim to the carcass. 700 01:11:45,120 --> 01:11:47,160 ROARS 701 01:11:47,160 --> 01:11:51,440 With his babies to look after, Sobek can't risk injury... 702 01:11:55,800 --> 01:12:01,160 ..so he must now decide if it's a prize worth fighting for. 703 01:12:01,160 --> 01:12:03,760 GROWLING 704 01:12:21,960 --> 01:12:23,880 Sobek is bigger. 705 01:12:26,120 --> 01:12:30,160 But one bite from these jaws could be fatal. 706 01:12:35,240 --> 01:12:39,160 Sobek's fearsome claws could give him the advantage. 707 01:12:42,840 --> 01:12:46,600 But, crucially, the carcharodontosaurus... 708 01:12:48,800 --> 01:12:51,080 ..is built for hunting on land. 709 01:12:54,400 --> 01:12:57,760 ROARING 710 01:13:02,480 --> 01:13:04,520 HISSES 711 01:13:06,000 --> 01:13:08,400 So Sobek backs down. 712 01:13:15,840 --> 01:13:19,400 BABIES CHITTER 713 01:13:19,400 --> 01:13:21,880 His family won't eat today. 714 01:13:25,920 --> 01:13:28,880 But if they can survive their journey, 715 01:13:28,880 --> 01:13:31,520 a much bigger prize awaits. 716 01:13:45,880 --> 01:13:47,400 As night falls, 717 01:13:47,400 --> 01:13:51,240 Nizar and the team examine an astonishing fossil. 718 01:13:53,640 --> 01:13:56,760 NIZAR: - The place where this was found, it was so narrow 719 01:13:56,760 --> 01:13:59,760 you could only just crawl on your belly, essentially. 720 01:14:01,160 --> 01:14:03,360 - Discovered close to the dig site, 721 01:14:03,360 --> 01:14:07,560 it's the remains of an extinct species of fish. 722 01:14:09,480 --> 01:14:12,040 - This is the head of onchopristis. 723 01:14:13,320 --> 01:14:14,560 The brain case, 724 01:14:14,560 --> 01:14:18,520 the blade-shaped snout, it's all there. 725 01:14:20,880 --> 01:14:24,720 - Onchopristis is commonly known as a sawskate 726 01:14:24,720 --> 01:14:27,200 because of the long snout, lined with barbs, 727 01:14:27,200 --> 01:14:29,000 it used to stun its prey. 728 01:14:30,040 --> 01:14:32,480 - This would have been a fairly slow, 729 01:14:32,480 --> 01:14:35,680 bottom-dwelling skate-like animal. 730 01:14:35,680 --> 01:14:37,160 OK. 731 01:14:38,680 --> 01:14:40,600 But that's insane. 732 01:14:44,600 --> 01:14:47,000 - And with spinosaurus so at home in water, 733 01:14:47,000 --> 01:14:48,800 Nizar has a theory. 734 01:14:50,320 --> 01:14:51,480 - So, this would have been 735 01:14:51,480 --> 01:14:54,760 one of the primary food sources for spinosaurus. 736 01:14:54,760 --> 01:14:58,840 - Incredible. - God, it's amazing. Wow. 737 01:15:07,200 --> 01:15:10,160 - Sawskate could grow up to four metres in length... 738 01:15:13,000 --> 01:15:16,560 ..so a single fish would make a sizeable meal. 739 01:15:32,360 --> 01:15:36,360 But once a year, like rays do today, 740 01:15:36,360 --> 01:15:38,680 it's thought they gathered to breed... 741 01:15:42,400 --> 01:15:43,880 ..in their thousands... 742 01:15:49,520 --> 01:15:52,640 ..providing an incredible feast... 743 01:15:54,560 --> 01:15:57,240 ..that awaits Sobek and his family. 744 01:16:03,680 --> 01:16:05,880 BABIES CHITTER 745 01:16:05,880 --> 01:16:09,160 But in this predator-infested land, 746 01:16:09,160 --> 01:16:12,440 danger can strike at any time. 747 01:16:15,320 --> 01:16:17,280 SCREECHING 748 01:16:25,680 --> 01:16:28,240 HAMMERING AND DRILLING 749 01:16:30,080 --> 01:16:32,240 And 100 million years ago... 750 01:16:33,400 --> 01:16:36,720 ..there weren't just predators on land and in the water. 751 01:16:38,760 --> 01:16:41,320 They were also in the air. 752 01:16:42,520 --> 01:16:46,800 NIZAR: - So, this is a lower jaw of alanqa. 753 01:16:46,800 --> 01:16:48,880 This is a Kem Kem pterosaur. 754 01:16:48,880 --> 01:16:52,120 It is a pretty remarkable specimen. 755 01:16:52,120 --> 01:16:53,360 - Uh-huh. 756 01:16:54,760 --> 01:16:57,200 - Alanqa was a huge flying reptile 757 01:16:57,200 --> 01:16:59,440 with a seven-metre wing span... 758 01:17:02,080 --> 01:17:04,880 ..twice that of any bird alive today. 759 01:17:08,120 --> 01:17:10,800 - Essentially, what we're looking at here is 760 01:17:10,800 --> 01:17:13,240 the skull would be going back, you know. 761 01:17:13,240 --> 01:17:14,960 - Like this. - Yeah, something like this. 762 01:17:14,960 --> 01:17:16,080 - A metre, more or less. 763 01:17:16,080 --> 01:17:18,000 - Yeah. - Pretty big. 764 01:17:18,000 --> 01:17:20,600 - Yeah, it's probably the largest Kem Kem pterosaur. 765 01:17:23,560 --> 01:17:25,320 - Its jaws reveal 766 01:17:25,320 --> 01:17:27,400 what this flying monster would have eaten. 767 01:17:28,440 --> 01:17:30,600 - It's got this really interesting 768 01:17:30,600 --> 01:17:32,160 raised structure here. 769 01:17:32,160 --> 01:17:33,800 It's got, like, a Y shape. - Mm-hm. 770 01:17:33,800 --> 01:17:36,160 - There's a corresponding matching part 771 01:17:36,160 --> 01:17:38,000 in the upper jaw, 772 01:17:38,000 --> 01:17:40,160 and so maybe this was something 773 01:17:40,160 --> 01:17:43,800 that was used to crush hard-shelled prey. 774 01:17:47,240 --> 01:17:50,400 - Although it's adapted to eat shellfish, 775 01:17:50,400 --> 01:17:53,960 alanqa was so big, it didn't need to be picky. 776 01:17:56,560 --> 01:17:58,160 - It's possible that these things 777 01:17:58,160 --> 01:18:00,600 were catching little things on the ground, 778 01:18:00,600 --> 01:18:02,720 you know, when they walk on the ground. 779 01:18:02,720 --> 01:18:06,240 - Maybe little dinosaurs, little crocs, amphibians, 780 01:18:06,240 --> 01:18:08,440 whatever they could catch. 781 01:18:08,440 --> 01:18:09,560 - Yes, yes. 782 01:18:15,320 --> 01:18:19,240 - With alanqa about, no small creature was safe. 783 01:18:21,040 --> 01:18:23,600 ALANQA SHRIEKS 784 01:18:36,200 --> 01:18:38,360 SHRIEKS 785 01:18:42,120 --> 01:18:44,880 To reach the sawskate breeding ground, 786 01:18:44,880 --> 01:18:48,560 Sobek must lead his young family through the forest. 787 01:18:55,080 --> 01:18:56,720 It's their final challenge... 788 01:19:01,240 --> 01:19:02,600 ..but the most deadly. 789 01:19:24,240 --> 01:19:29,280 For alanqa, a young spinosaurus would make a tasty meal. 790 01:19:33,960 --> 01:19:36,000 SQUEAKS 791 01:19:48,480 --> 01:19:50,520 LOW GROWL 792 01:19:53,040 --> 01:19:56,760 And the dense foliage provides perfect cover... 793 01:19:58,480 --> 01:20:00,440 ..for an ambush. 794 01:20:00,440 --> 01:20:02,720 SQUEAKS 795 01:20:05,080 --> 01:20:07,120 SNAP 796 01:20:12,040 --> 01:20:14,080 TWIG SNAPS 797 01:20:33,520 --> 01:20:35,560 SQUEAKS 798 01:21:00,040 --> 01:21:02,080 SQUEAKS 799 01:21:07,800 --> 01:21:09,920 SQUEALS 800 01:21:09,920 --> 01:21:11,760 GRUNTS 801 01:21:13,200 --> 01:21:15,280 Too late. 802 01:21:15,280 --> 01:21:17,320 ROARS 803 01:21:22,320 --> 01:21:23,920 Having come so far... 804 01:21:25,280 --> 01:21:29,080 ..losing one of his babies is a huge blow. 805 01:21:37,040 --> 01:21:39,600 CROAKING CALL 806 01:21:39,600 --> 01:21:42,640 But if Sobek is to keep the others alive, 807 01:21:42,640 --> 01:21:44,160 he must keep moving. 808 01:21:58,680 --> 01:22:01,000 As the family emerges from the forest... 809 01:22:03,040 --> 01:22:05,640 ..their journey's end is in sight. 810 01:22:13,480 --> 01:22:15,520 The sawskate breeding ground... 811 01:22:19,040 --> 01:22:21,760 ..and the promise of plentiful food 812 01:22:21,760 --> 01:22:24,040 for Sobek and his family. 813 01:22:31,480 --> 01:22:33,960 But for his babies to eat, 814 01:22:33,960 --> 01:22:36,960 Sobek will have to fight his way 815 01:22:36,960 --> 01:22:38,360 to the front of the queue. 816 01:22:43,280 --> 01:22:45,320 HAMMERING 817 01:22:49,040 --> 01:22:51,080 INDISTINCT CHATTER 818 01:22:53,800 --> 01:22:55,520 And at the dig, 819 01:22:55,520 --> 01:22:59,840 Nizar and palaeontologist Dr Gabriele Bindellini 820 01:22:59,840 --> 01:23:02,800 have evidence that could reveal 821 01:23:02,800 --> 01:23:06,360 how spinosaurus settled their differences. 822 01:23:10,360 --> 01:23:12,840 NIZAR: - So, I think this is the tallest we've got. 823 01:23:12,840 --> 01:23:14,160 - GABRIELE: - Mm-hm. 824 01:23:14,160 --> 01:23:17,720 And it still miss a good portion at the tip. 825 01:23:19,400 --> 01:23:24,640 - Yeah, I mean, I think we're missing 30, 35, 826 01:23:24,640 --> 01:23:26,600 maybe even 40 centimetres. 827 01:23:26,600 --> 01:23:29,040 - Mm-hm. Which makes it super long. 828 01:23:29,040 --> 01:23:30,360 - Yes. 829 01:23:30,360 --> 01:23:32,920 Do you want to take this end? I'll hold it here. - Mm-hm. 830 01:23:34,960 --> 01:23:37,160 - Over 1.5 metres long, 831 01:23:37,160 --> 01:23:41,480 this is one of the 15 bones that rose up from Sobek's back, 832 01:23:41,480 --> 01:23:44,160 supporting his enormous sail. 833 01:23:47,120 --> 01:23:50,120 - I've tried to visualise all of his other spines. - Mm-hm. 834 01:23:50,120 --> 01:23:52,600 - I mean, it's a massive structure. 835 01:23:57,280 --> 01:23:59,480 - Spinosaurus sails are so big... 836 01:24:01,440 --> 01:24:04,040 ..they must have had an important function. 837 01:24:05,520 --> 01:24:07,600 - It's probably, like, primarily 838 01:24:07,600 --> 01:24:09,040 a display structure to, you know... 839 01:24:09,040 --> 01:24:11,520 - To be seen from the distance. - Yeah, like... 840 01:24:11,520 --> 01:24:13,640 - Peacock. - Yeah, like a peacock's train. 841 01:24:15,160 --> 01:24:18,520 - But unlike a peacock, Nizar believes 842 01:24:18,520 --> 01:24:21,200 the main function of spinosaurus's sail 843 01:24:21,200 --> 01:24:23,960 might not have been to find a mate. 844 01:24:23,960 --> 01:24:26,720 - So, you're one spinosaurus, and you come close 845 01:24:26,720 --> 01:24:28,760 to another spinosaurus's territory... 846 01:24:28,760 --> 01:24:30,560 - Yes. - And what are you going to see? 847 01:24:30,560 --> 01:24:32,720 You're going to see this big sail, right? 848 01:24:32,720 --> 01:24:34,280 And just by looking at the sail, you can go, 849 01:24:34,280 --> 01:24:35,960 "Ooh, there's a really big spinosaurus. 850 01:24:35,960 --> 01:24:37,640 "I'd better not get close to this guy." 851 01:24:37,640 --> 01:24:38,840 - "Stay away from here." 852 01:24:38,840 --> 01:24:40,320 - I think it would be very efficient 853 01:24:40,320 --> 01:24:44,080 at scaring off, erm, other predators or rivals. - Yeah. 854 01:24:52,440 --> 01:24:55,160 - Sobek's intimidating sail 855 01:24:55,160 --> 01:24:57,160 could be just what he needs... 856 01:24:58,560 --> 01:25:01,280 ..to win a prime fishing spot. 857 01:25:11,840 --> 01:25:15,680 Having run the gauntlet of Kem Kem predators, 858 01:25:15,680 --> 01:25:17,680 there's now only one thing 859 01:25:17,680 --> 01:25:21,760 standing between him and feeding his babies. 860 01:25:28,120 --> 01:25:30,560 A rival spinosaurus. 861 01:25:30,560 --> 01:25:32,920 LOW GROWL 862 01:25:35,720 --> 01:25:37,880 ROARS 863 01:25:42,880 --> 01:25:45,600 Sobek must try to intimidate this older male... 864 01:25:48,440 --> 01:25:50,040 ..and take his place on the bank. 865 01:25:50,040 --> 01:25:52,080 ROARS 866 01:25:56,760 --> 01:26:01,200 So he initiates a ritual dance... 867 01:26:01,200 --> 01:26:04,120 BOTH GROWL 868 01:26:04,120 --> 01:26:06,160 ..showing off his sail. 869 01:26:20,280 --> 01:26:23,800 But as a young male, Sobek's sail is smaller... 870 01:26:24,920 --> 01:26:26,960 BOTH GROWL 871 01:26:30,120 --> 01:26:32,840 ROARS 872 01:26:32,840 --> 01:26:35,280 ..and not intimidating enough. 873 01:26:36,520 --> 01:26:38,560 ROARS 874 01:26:48,320 --> 01:26:52,600 Forced from the bank where the fish are easier to catch, 875 01:26:52,600 --> 01:26:54,880 the job of feeding his hungry babies... 876 01:26:57,400 --> 01:26:59,680 ..has just got much more difficult. 877 01:27:05,480 --> 01:27:07,520 HAMMERING AND SCRAPING 878 01:27:16,760 --> 01:27:20,640 - Can we get some measurements, Marco? 879 01:27:23,360 --> 01:27:26,600 - But evidence from the dig... 880 01:27:26,600 --> 01:27:28,800 - 140. 881 01:27:28,800 --> 01:27:31,320 - ..suggests Sobek may have been 882 01:27:31,320 --> 01:27:33,400 well-equipped for the challenge. 883 01:27:34,760 --> 01:27:37,160 CAMERA CLICKS 884 01:27:37,160 --> 01:27:39,560 - It's something we haven't really seen before. 885 01:27:40,560 --> 01:27:42,600 Something new. - Yeah? 886 01:27:43,760 --> 01:27:46,000 - One of the missing foot bones. 887 01:27:46,000 --> 01:27:47,400 - Yeah. 888 01:27:48,640 --> 01:27:53,000 - Sobek's foot bones are similar to those of water birds, 889 01:27:53,000 --> 01:27:55,640 meaning his feet could have been webbed... 890 01:27:56,760 --> 01:27:58,120 - Here we are. 891 01:27:58,120 --> 01:28:00,360 We're going to wrap it in this, tape it, 892 01:28:00,360 --> 01:28:02,720 and this one we're going to put in a plaster jacket. 893 01:28:02,720 --> 01:28:04,880 - ..helping him to swim after his prey. 894 01:28:06,960 --> 01:28:09,600 INDISTINCT CHATTER 895 01:28:09,600 --> 01:28:11,560 - It's a tibia. 896 01:28:11,560 --> 01:28:13,000 Where's the box? 897 01:28:14,680 --> 01:28:18,480 - And if he caught it, Sobek had another adaptation... 898 01:28:20,240 --> 01:28:22,040 - The teeth are really amazing. 899 01:28:23,320 --> 01:28:26,600 - ..that made him a formidable underwater predator. 900 01:28:28,560 --> 01:28:31,960 - If I didn't know spinosaurus was here, 901 01:28:31,960 --> 01:28:35,560 I would say this is a crocodile tooth. 902 01:28:35,560 --> 01:28:39,880 Looking at it, the shape is basically the same, you know? 903 01:28:41,040 --> 01:28:42,640 - Unlike the broad blade-like teeth 904 01:28:42,640 --> 01:28:44,400 of other predatory dinosaurs... 905 01:28:45,680 --> 01:28:50,160 ..spinosaurus teeth are smooth and conical like a crocodile's, 906 01:28:50,160 --> 01:28:52,640 because they both eat the same food. 907 01:28:56,320 --> 01:28:58,160 - This is basically 908 01:28:58,160 --> 01:29:01,840 your main piece of anatomical weaponry 909 01:29:01,840 --> 01:29:03,760 if you're going after fish. - Oh, yeah. 910 01:29:03,760 --> 01:29:05,440 - We're talking really big fish. 911 01:29:05,440 --> 01:29:07,640 Stabbing slippery prey. 912 01:29:07,640 --> 01:29:09,600 - With more than 60 of these teeth 913 01:29:09,600 --> 01:29:10,880 in its long jaws... 914 01:29:10,880 --> 01:29:13,680 - It's conical, it's... 915 01:29:13,680 --> 01:29:16,720 - ..spinosaurus was able to tackle the largest fish. 916 01:29:20,520 --> 01:29:23,320 - Imagine having to hold on to a big sawskate 917 01:29:23,320 --> 01:29:24,720 fighting for its life. 918 01:29:24,720 --> 01:29:27,320 - Yeah, it definitely wasn't an easy catch. 919 01:29:27,320 --> 01:29:29,560 - Yeah, I mean, they put up a real fight. 920 01:29:29,560 --> 01:29:31,960 You need these kind of killing tools, right, 921 01:29:31,960 --> 01:29:33,600 to hold on to the prey. 922 01:29:35,520 --> 01:29:40,200 - Webbed feet and spiky teeth are critical adaptations... 923 01:29:41,560 --> 01:29:45,280 ..that Sobek will need to make a catch. 924 01:30:01,720 --> 01:30:02,920 But even so... 925 01:30:04,560 --> 01:30:06,160 ..success... 926 01:30:11,240 --> 01:30:13,080 ..is far from guaranteed. 927 01:30:16,600 --> 01:30:18,200 Although Sobek is faster... 928 01:30:21,400 --> 01:30:23,600 ..the sawskate is more agile. 929 01:30:34,520 --> 01:30:36,480 Time for a change of tactics. 930 01:30:47,000 --> 01:30:49,600 Attacking from below... 931 01:30:52,080 --> 01:30:53,640 ..like a shark. 932 01:31:20,120 --> 01:31:21,720 Success. 933 01:31:26,760 --> 01:31:31,400 But getting his catch to his family won't be easy. 934 01:31:31,400 --> 01:31:33,440 LOW GROWL 935 01:31:38,080 --> 01:31:40,120 ROARS 936 01:31:43,000 --> 01:31:45,040 WAILS 937 01:31:47,640 --> 01:31:50,040 BOTH ROAR 938 01:31:55,240 --> 01:31:59,040 This time, Sobek is in no mood to give up his kill. 939 01:32:02,440 --> 01:32:04,480 BABIES CHITTER 940 01:32:19,880 --> 01:32:22,840 By leading them to this land of plenty, 941 01:32:22,840 --> 01:32:26,800 Sobek has ensured his babies' survival. 942 01:32:41,440 --> 01:32:43,320 But his moment of triumph... 943 01:32:49,280 --> 01:32:52,240 ..has come at a terrible cost. 944 01:32:55,680 --> 01:32:59,400 - So, these are small parts 945 01:32:59,400 --> 01:33:00,920 of the femur, 946 01:33:00,920 --> 01:33:02,800 of the thigh bone, of our spinosaurus. 947 01:33:02,800 --> 01:33:05,560 - Yeah, wow. - That's really nice, right? 948 01:33:05,560 --> 01:33:07,640 - Slices cut through Sobek's bones 949 01:33:07,640 --> 01:33:09,880 have a disturbing story to tell. 950 01:33:11,000 --> 01:33:13,040 - We looked at some of the sections. 951 01:33:13,040 --> 01:33:17,440 We looked at the growth lines under the microscope, 952 01:33:17,440 --> 01:33:18,720 trying to look at the age. 953 01:33:18,720 --> 01:33:20,280 - Oh, yeah. - They came out pretty nice. 954 01:33:20,280 --> 01:33:21,560 You know, it's not as easy 955 01:33:21,560 --> 01:33:23,920 as reading growth lines on a tree, 956 01:33:23,920 --> 01:33:27,080 but we can narrow it down to an age 957 01:33:27,080 --> 01:33:30,760 of 17 to 19 years at death. 958 01:33:30,760 --> 01:33:33,000 - OK, so he wasn't that old. 959 01:33:33,000 --> 01:33:35,280 - Yeah, like a young adult-ish, you know. 960 01:33:35,280 --> 01:33:37,160 - Mm-hm. 961 01:33:37,160 --> 01:33:39,840 - Other large predatory dinosaurs 962 01:33:39,840 --> 01:33:43,280 are thought to have had a lifespan of about 30 years. 963 01:33:44,680 --> 01:33:47,240 But Sobek's bones reveal 964 01:33:47,240 --> 01:33:50,080 he was barely an adult when he died. 965 01:33:52,720 --> 01:33:55,200 - So, maybe he could have lived a little bit longer. 966 01:33:55,200 --> 01:33:57,080 - Yeah, if we assume a similar kind of lifespan 967 01:33:57,080 --> 01:33:59,760 for a spinosaurus, you know, late 20s, early 30s, 968 01:33:59,760 --> 01:34:02,160 it's a life cut short. 969 01:34:06,600 --> 01:34:10,640 - The evidence hidden within his bones... 970 01:34:10,640 --> 01:34:13,040 BABIES CHITTER 971 01:34:16,240 --> 01:34:19,800 ..suggests Sobek may not have lived 972 01:34:19,800 --> 01:34:21,920 to see his family grow up. 973 01:34:45,520 --> 01:34:47,520 In providing for his babies... 974 01:34:50,720 --> 01:34:53,840 ..he has paid the ultimate price. 975 01:34:59,960 --> 01:35:02,000 BREATHES HEAVILY 976 01:35:12,600 --> 01:35:14,680 GASPS 977 01:35:21,360 --> 01:35:23,400 EXHALES 978 01:35:25,120 --> 01:35:27,200 GROANS SOFTLY 979 01:35:33,040 --> 01:35:35,400 BREATHES SOFTLY 980 01:35:50,040 --> 01:35:54,600 And as the great river ebbs and flows, 981 01:35:54,600 --> 01:35:56,640 it covers his body 982 01:35:56,640 --> 01:35:59,400 with layer upon layer of sediment... 983 01:36:04,320 --> 01:36:07,000 ..preserving Sobek's story 984 01:36:07,000 --> 01:36:10,040 beneath the desert's shifting sands... 985 01:36:13,560 --> 01:36:16,480 ..until he is eventually found... 986 01:36:17,760 --> 01:36:20,720 ..100 million years later. 987 01:36:31,360 --> 01:36:33,480 Next time... 988 01:36:33,480 --> 01:36:36,400 ..a gang of armoured dinosaurs 989 01:36:36,400 --> 01:36:38,480 battles to reach adulthood... 990 01:36:40,720 --> 01:36:43,840 ..hunted by one of the most fearsome predators... 991 01:36:47,960 --> 01:36:50,280 ..that's ever lived. 992 01:37:37,360 --> 01:37:39,880 Over 66 million years ago... 993 01:37:43,000 --> 01:37:44,920 SCREECHING WAIL 994 01:37:44,920 --> 01:37:46,680 HIGH-PITCHED CLUCKS ..our world... 995 01:37:46,680 --> 01:37:48,160 ..was ruled... 996 01:37:49,120 --> 01:37:51,720 ..by dinosaurs. SHRIEKS 997 01:37:51,720 --> 01:37:53,960 DEEP BELLOW 998 01:37:53,960 --> 01:37:55,480 HISSES 999 01:37:57,360 --> 01:37:58,840 GRUNTS 1000 01:37:58,840 --> 01:38:02,720 The largest animals that have ever walked the Earth. 1001 01:38:10,200 --> 01:38:14,080 Today, dinosaur experts across the globe 1002 01:38:14,080 --> 01:38:17,520 are uncovering the bones they left behind... 1003 01:38:20,920 --> 01:38:24,640 ..allowing us to imagine how these extraordinary creatures 1004 01:38:24,640 --> 01:38:26,240 may have lived... 1005 01:38:30,640 --> 01:38:33,440 ..so that we can tell their stories... 1006 01:38:37,840 --> 01:38:39,160 ..and they... 1007 01:38:40,640 --> 01:38:42,040 ..can walk again. 1008 01:38:42,040 --> 01:38:43,080 ROARS 1009 01:39:13,920 --> 01:39:18,320 Utah - in the heart of the American West. 1010 01:39:23,480 --> 01:39:28,800 Home to some of the most spectacular scenery on Earth. 1011 01:39:42,160 --> 01:39:45,200 And the forces that shaped the landscape 1012 01:39:45,200 --> 01:39:47,680 also make it a paradise... 1013 01:39:50,040 --> 01:39:51,840 ..for dinosaur hunters. 1014 01:40:02,240 --> 01:40:04,840 In a remote part of the desert, 1015 01:40:04,840 --> 01:40:07,160 palaeontologists Dr Jim Kirkland... 1016 01:40:08,560 --> 01:40:09,960 ..and Dr Josh Lively... 1017 01:40:10,960 --> 01:40:13,280 ..have made a remarkable discovery. 1018 01:40:13,280 --> 01:40:15,680 - So we've exposed quite a bit of bone, Jim. 1019 01:40:15,680 --> 01:40:16,840 - Yeah. 1020 01:40:21,560 --> 01:40:25,160 - The bones of one of the most heavily armoured dinosaurs... 1021 01:40:28,160 --> 01:40:31,080 ..that ever lived... 1022 01:40:31,080 --> 01:40:34,120 - Oh, that's cool. 1023 01:40:34,120 --> 01:40:35,680 - ..a gastonia. 1024 01:40:35,680 --> 01:40:38,440 - Yeah, you might have a leg there. 1025 01:40:38,440 --> 01:40:40,160 - Using their discoveries, 1026 01:40:40,160 --> 01:40:45,040 we can imagine how this youngster lived and died... 1027 01:40:47,680 --> 01:40:51,040 ..113 million years ago. 1028 01:41:09,480 --> 01:41:11,880 In the Early Cretaceous period... 1029 01:41:15,480 --> 01:41:19,280 ..the land that will become Utah 1030 01:41:19,280 --> 01:41:22,040 was warmer and wetter. 1031 01:41:25,320 --> 01:41:27,720 BIRDSONG 1032 01:41:30,800 --> 01:41:33,280 And what is desert today 1033 01:41:33,280 --> 01:41:36,840 is covered by conifer forests... 1034 01:41:39,280 --> 01:41:42,280 ..and rolling meadows of ferns. 1035 01:41:47,720 --> 01:41:50,440 DEEP ROAR 1036 01:41:54,400 --> 01:41:56,320 Plentiful food... 1037 01:41:58,360 --> 01:42:01,560 ..for groups of plant-eating gastonia... 1038 01:42:06,320 --> 01:42:09,760 ..including youngster...George. 1039 01:42:09,760 --> 01:42:13,720 LOW BELLOWING 1040 01:42:17,280 --> 01:42:19,560 Like all young gastonia, 1041 01:42:19,560 --> 01:42:22,040 he must stick close to his parents... 1042 01:42:31,320 --> 01:42:33,240 ..because danger... 1043 01:42:37,320 --> 01:42:39,400 ..is never far away. 1044 01:42:39,400 --> 01:42:40,680 CHITTERING 1045 01:42:43,600 --> 01:42:45,040 CHITTERING 1046 01:42:48,960 --> 01:42:51,320 Utahraptor. 1047 01:42:51,320 --> 01:42:53,480 SNARLS 1048 01:42:53,480 --> 01:42:57,000 A heavyweight cousin of velociraptor, 1049 01:42:57,000 --> 01:43:00,400 the size of a grizzly bear. 1050 01:43:04,600 --> 01:43:09,200 And they hunt vulnerable young gastonia. 1051 01:43:15,240 --> 01:43:20,400 The ferns providing ideal cover 1052 01:43:20,400 --> 01:43:22,760 for a surprise attack. 1053 01:43:29,400 --> 01:43:31,120 Just yards away, 1054 01:43:31,120 --> 01:43:34,520 George and his family are oblivious... 1055 01:43:36,400 --> 01:43:38,480 ..to the approaching danger. 1056 01:43:57,480 --> 01:43:59,160 SNARLING 1057 01:44:03,320 --> 01:44:07,040 With the raptors within striking distance, 1058 01:44:07,040 --> 01:44:10,000 the gastonia get a lucky break. 1059 01:44:12,000 --> 01:44:13,440 CRUNCH 1060 01:44:13,440 --> 01:44:16,120 SHRIEKING AND ROARING 1061 01:44:26,440 --> 01:44:28,480 Like many modern herd animals, 1062 01:44:28,480 --> 01:44:32,440 the adults form a defensive ring around their young. 1063 01:44:37,920 --> 01:44:40,600 Weighing over a tonne each, 1064 01:44:40,600 --> 01:44:42,400 covered in thick armour... 1065 01:44:46,240 --> 01:44:50,440 ..a group of adult gastonia is virtually invulnerable. 1066 01:45:11,960 --> 01:45:14,120 With one of their group injured, 1067 01:45:14,120 --> 01:45:16,200 the raptors cut their losses. 1068 01:45:26,000 --> 01:45:29,560 But George can't rely on the safety of the herd 1069 01:45:29,560 --> 01:45:31,400 for much longer. 1070 01:45:32,600 --> 01:45:38,800 He's reached adolescence, when, like all young male gastonia, 1071 01:45:38,800 --> 01:45:42,240 it's thought he'll be pushed out of the group. 1072 01:45:44,960 --> 01:45:46,800 SOLITARY BELLOW 1073 01:45:48,960 --> 01:45:50,760 George must now grow up 1074 01:45:50,760 --> 01:45:53,280 without his family to protect him. 1075 01:46:01,000 --> 01:46:03,800 - We'll probably do Dakota, 1076 01:46:03,800 --> 01:46:05,840 and at least one other person too. 1077 01:46:05,840 --> 01:46:09,320 - At the dig, the team is starting to uncover evidence... 1078 01:46:10,680 --> 01:46:13,280 - Is there a bone there coming up from somewhere? 1079 01:46:13,280 --> 01:46:16,560 Try and get your fingers under that if you can reach over. 1080 01:46:16,560 --> 01:46:20,400 - ..that might explain how young gastonia like George 1081 01:46:20,400 --> 01:46:22,880 survived to adulthood... 1082 01:46:22,880 --> 01:46:25,560 - You got one over there. - There's a big guy here. 1083 01:46:25,560 --> 01:46:27,680 - Oh, OK. Looks like a limb bone. 1084 01:46:27,680 --> 01:46:30,640 Might connect to some of this bone right here. 1085 01:46:30,640 --> 01:46:34,160 - ..and the clues are coming thick and fast. 1086 01:46:34,160 --> 01:46:35,760 - Beautiful! - That's bone. 1087 01:46:35,760 --> 01:46:38,640 - Looks like the rib might go into this one. 1088 01:46:41,160 --> 01:46:43,320 - Everywhere they dig, 1089 01:46:43,320 --> 01:46:46,480 bone after bone emerges from the ground. 1090 01:46:48,680 --> 01:46:51,960 - Found a couple of ribs right here, 1091 01:46:51,960 --> 01:46:53,720 going over top of a vertebra, 1092 01:46:53,720 --> 01:46:56,080 and then several pieces of armour. 1093 01:46:56,080 --> 01:46:59,400 A ton of bones just in this small spot. 1094 01:47:00,720 --> 01:47:04,520 It's too many to be from just one individual. 1095 01:47:04,520 --> 01:47:06,400 - Got these thin rib-like sections. 1096 01:47:06,400 --> 01:47:09,960 - Right. - I mean, so far, you know, right in here, 1097 01:47:09,960 --> 01:47:12,120 there's probably parts of two animals. 1098 01:47:13,400 --> 01:47:18,440 - And, intriguingly, all the gastonia found across the site 1099 01:47:18,440 --> 01:47:20,720 appear to be of a similar age. 1100 01:47:22,840 --> 01:47:25,320 - From looking at skeletal remains, 1101 01:47:25,320 --> 01:47:27,760 we're looking at half-grown individuals, 1102 01:47:27,760 --> 01:47:31,200 you know, sub-adults to full adults. 1103 01:47:31,200 --> 01:47:34,560 - Kind of analogous to teenagers, right? - Yeah. 1104 01:47:35,520 --> 01:47:37,480 - All these teenagers found together 1105 01:47:37,480 --> 01:47:40,360 suggests something unexpected. 1106 01:48:01,680 --> 01:48:03,640 BELLOWS 1107 01:48:03,640 --> 01:48:06,200 Since leaving his family group, 1108 01:48:06,200 --> 01:48:09,320 George has been living on his own... 1109 01:48:15,160 --> 01:48:17,360 ..keeping deep in the forest... 1110 01:48:19,040 --> 01:48:22,160 ..where it's easier to hide from predators. 1111 01:48:22,160 --> 01:48:24,880 SNUFFLES AND GRUNTS 1112 01:48:36,520 --> 01:48:40,000 But it's not long before he comes face-to-face... 1113 01:48:41,800 --> 01:48:44,160 ..with another young male. 1114 01:48:44,160 --> 01:48:46,720 GRUMBLING ROARS 1115 01:48:52,320 --> 01:48:54,120 And it looks... 1116 01:48:56,400 --> 01:48:58,880 ..like he means business. 1117 01:49:26,240 --> 01:49:30,040 Gastonia's skulls and necks are specially adapted 1118 01:49:30,040 --> 01:49:32,040 to act like shock absorbers. 1119 01:49:38,800 --> 01:49:40,880 But this isn't a fight. 1120 01:49:49,440 --> 01:49:54,040 This is how gastonia make friends. 1121 01:49:59,040 --> 01:50:01,400 Of all the armoured dinosaurs... 1122 01:50:04,440 --> 01:50:08,080 ..they're one of the only known social species. 1123 01:50:12,160 --> 01:50:15,480 George has just joined a group. 1124 01:50:22,760 --> 01:50:25,400 It's a huge step forward, 1125 01:50:25,400 --> 01:50:28,160 dramatically increasing his chances 1126 01:50:28,160 --> 01:50:30,320 of making it to adulthood. 1127 01:50:37,840 --> 01:50:41,480 This gang of teenage boys will stay together 1128 01:50:41,480 --> 01:50:45,200 until they're tough enough to fend for themselves... 1129 01:50:51,800 --> 01:50:55,840 ..because until their armour is fully developed, 1130 01:50:55,840 --> 01:50:57,600 they're vulnerable. 1131 01:51:07,440 --> 01:51:09,760 - Just working our way around these elements, 1132 01:51:09,760 --> 01:51:12,040 trying to get around this big femur here. 1133 01:51:13,280 --> 01:51:16,720 - At the dig, amongst the gastonia bones.... 1134 01:51:16,720 --> 01:51:19,440 - Hey, Josh? Check this out. What is that? 1135 01:51:19,440 --> 01:51:22,560 - ..the team makes an unexpected discovery. 1136 01:51:22,560 --> 01:51:24,680 - Oh, wow. 1137 01:51:24,680 --> 01:51:26,720 That's really neat. 1138 01:51:26,720 --> 01:51:28,960 It's definitely not gastonia. 1139 01:51:34,080 --> 01:51:35,560 Hey, Jim? - Yeah. 1140 01:51:37,200 --> 01:51:39,560 - Heather found something interesting 1141 01:51:39,560 --> 01:51:42,680 and, uh, I'm wondering if you could tell me 1142 01:51:42,680 --> 01:51:45,160 whether or not it is what I think it is. 1143 01:51:45,160 --> 01:51:46,840 - A nice curve. 1144 01:51:47,760 --> 01:51:50,280 Yeah, that's a small 1145 01:51:50,280 --> 01:51:53,800 therapod metacarpal end bone. 1146 01:51:53,800 --> 01:51:56,440 Could be a juvenile Utahraptor. 1147 01:52:01,960 --> 01:52:07,320 - Utahraptor bones found alongside the young gastonia... 1148 01:52:07,320 --> 01:52:10,160 - All right, I was right! It's a therapod metacarpal. 1149 01:52:10,160 --> 01:52:11,680 - Yeah, confirm. 1150 01:52:11,680 --> 01:52:15,600 - ..suggest that throughout the gastonia's adolescence... 1151 01:52:15,600 --> 01:52:17,760 CHUCKLES 1152 01:52:17,760 --> 01:52:21,160 ..Utahraptor was an ever-present threat. 1153 01:52:25,400 --> 01:52:28,080 TAPPING 1154 01:52:29,360 --> 01:52:33,160 And Josh and Jim have evidence that shows 1155 01:52:33,160 --> 01:52:35,600 just how deadly they could be. 1156 01:52:37,240 --> 01:52:40,640 A cast of a Utahraptor toe claw. 1157 01:52:43,720 --> 01:52:45,840 - You know, you put the claw itself - you know, 1158 01:52:45,840 --> 01:52:47,320 this is the bone underlying it. 1159 01:52:47,320 --> 01:52:49,760 Just to be conservative, we could say it comes out 1160 01:52:49,760 --> 01:52:52,480 to about there, you know, in length. - Yeah. 1161 01:52:53,600 --> 01:52:55,360 - 30cm long, 1162 01:52:55,360 --> 01:53:00,280 these killing claws were Utahraptor's primary weapon. 1163 01:53:01,520 --> 01:53:04,840 - This thing might be kicking through inch-thick hide, 1164 01:53:04,840 --> 01:53:06,520 so fast you can barely see it. 1165 01:53:06,520 --> 01:53:09,360 Wam-wam-wam-wam! This thing's just punching lots of holes, 1166 01:53:09,360 --> 01:53:11,000 which would do a lot of damage. 1167 01:53:12,240 --> 01:53:15,000 - These claws are the perfect tool 1168 01:53:15,000 --> 01:53:18,880 for puncturing the weak armour of young gastonia. 1169 01:53:20,320 --> 01:53:22,800 - Maybe you have to think of it more as a can-opener. 1170 01:53:22,800 --> 01:53:24,840 - Yeah, if it can flip it over, 1171 01:53:24,840 --> 01:53:27,200 use that to slice open the belly. 1172 01:53:28,160 --> 01:53:31,000 - Yeah. These things are one of the most formidable predators 1173 01:53:31,000 --> 01:53:32,760 that ever lived. 1174 01:53:44,280 --> 01:53:46,480 - Holding their toe claws off the ground 1175 01:53:46,480 --> 01:53:48,400 to keep them razor-sharp... 1176 01:53:48,400 --> 01:53:50,000 HISSES 1177 01:53:54,280 --> 01:53:56,080 ..Utahraptor... 1178 01:53:57,440 --> 01:54:00,560 ..is a finely tuned killing machine. 1179 01:54:04,200 --> 01:54:05,760 GRUNTS 1180 01:54:05,760 --> 01:54:08,040 SCREECHES 1181 01:54:08,040 --> 01:54:10,040 And this adult male... 1182 01:54:12,880 --> 01:54:15,920 ..and the group he leads 1183 01:54:15,920 --> 01:54:17,960 have just entered the forest... 1184 01:54:19,000 --> 01:54:21,080 LOW BELLOWING 1185 01:54:21,080 --> 01:54:26,000 ..following the trail of George and the gastonia gang. 1186 01:54:36,720 --> 01:54:39,080 But hidden beneath the thick undergrowth... 1187 01:54:41,000 --> 01:54:42,480 SCREECHES 1188 01:54:42,480 --> 01:54:45,360 ..finding them won't be easy. 1189 01:54:54,200 --> 01:54:58,040 So the young raptors streak ahead... 1190 01:54:58,040 --> 01:54:59,480 SQUAWKING 1191 01:54:59,480 --> 01:55:01,320 ..to try and flush them out... 1192 01:55:08,360 --> 01:55:11,600 ..while the adults follow behind, 1193 01:55:11,600 --> 01:55:13,960 ready to make the kill. 1194 01:55:28,880 --> 01:55:30,920 With Utahraptor's eyesight 1195 01:55:30,920 --> 01:55:33,440 as sharp as modern birds of prey... 1196 01:55:35,680 --> 01:55:37,280 ..even the slightest movement... 1197 01:55:39,560 --> 01:55:41,080 ..could be fatal. 1198 01:55:41,080 --> 01:55:42,640 HISSES 1199 01:55:49,600 --> 01:55:52,080 So when they hear the raptors coming... 1200 01:55:52,080 --> 01:55:53,960 SCREECH 1201 01:55:55,320 --> 01:55:58,160 ..the gastonia freeze. 1202 01:56:05,080 --> 01:56:07,440 LOW GRUNTING 1203 01:56:21,840 --> 01:56:23,960 The juveniles have missed them. 1204 01:56:23,960 --> 01:56:26,400 PANTS 1205 01:56:28,680 --> 01:56:32,280 But George must hold his nerve 1206 01:56:32,280 --> 01:56:35,160 because the deadliest threat is still to come. 1207 01:56:37,800 --> 01:56:39,640 SNUFFLING GRUNT 1208 01:56:39,640 --> 01:56:41,080 THUDDING FOOTSTEPS 1209 01:56:43,120 --> 01:56:44,800 The group leader. 1210 01:56:58,560 --> 01:57:00,520 HISSES 1211 01:57:24,480 --> 01:57:25,920 GRUNTS 1212 01:57:25,920 --> 01:57:27,720 It's a close call. 1213 01:57:37,560 --> 01:57:40,760 GRUNTS QUIETLY 1214 01:57:41,800 --> 01:57:44,240 But every day George and the gang survive 1215 01:57:44,240 --> 01:57:48,200 is a day closer to the safety of adulthood. 1216 01:57:56,800 --> 01:57:58,680 And emerging from the ground... 1217 01:58:00,200 --> 01:58:03,480 ..clues that reveal even young gastonia... 1218 01:58:04,960 --> 01:58:07,280 ..would have been no pushover. 1219 01:58:07,280 --> 01:58:09,080 BLOWS 1220 01:58:10,160 --> 01:58:12,120 - Well, you should be getting close, I think. 1221 01:58:12,120 --> 01:58:14,000 - Hey, Josh. 1222 01:58:14,000 --> 01:58:17,280 Get in my section, tell me what you think. 1223 01:58:17,280 --> 01:58:19,240 - So... 1224 01:58:21,960 --> 01:58:24,120 - There's so much here. 1225 01:58:24,120 --> 01:58:26,400 Plenty of osteoderms. 1226 01:58:26,400 --> 01:58:28,960 - And they're coming out pretty solid, then? - Yeah. 1227 01:58:31,120 --> 01:58:35,120 - Osteoderms are the bones that made up the gastonia's armour. 1228 01:58:36,400 --> 01:58:38,240 - That's a real nice one. - Oh, yeah. 1229 01:58:38,240 --> 01:58:42,320 So you can kind of see on this one that kind of ridge right there, 1230 01:58:42,320 --> 01:58:45,440 that keel, that would point up. 1231 01:58:45,440 --> 01:58:48,680 - Makes for a spikey dinosaur. - It really does, yeah. 1232 01:58:50,000 --> 01:58:54,840 - In life, each osteoderm was covered by a thick scale... 1233 01:58:55,880 --> 01:58:59,440 - Now, this is one of the nicest ones we've had so far. 1234 01:58:59,440 --> 01:59:01,360 This would have been on the back of the animal. 1235 01:59:02,320 --> 01:59:04,720 - ..which would have created an armoured plate. 1236 01:59:07,360 --> 01:59:10,120 - Where you see the hollow base that these have, 1237 01:59:10,120 --> 01:59:11,720 they're for blood vessels, 1238 01:59:11,720 --> 01:59:14,000 bringing nutrients up into this bone, 1239 01:59:14,000 --> 01:59:16,360 to grow that big scale that was on top. 1240 01:59:17,600 --> 01:59:20,640 There's a lot of armour on these animals. 1241 01:59:24,320 --> 01:59:29,120 - It's a discovery that reveals the gastonia's armour 1242 01:59:29,120 --> 01:59:31,200 was nearly fully formed. 1243 01:59:45,760 --> 01:59:47,480 But the team has evidence 1244 01:59:47,480 --> 01:59:51,040 Utahraptor was one step ahead. 1245 01:59:57,960 --> 02:00:02,920 Revealed by an astonishing fossil found near the site 1246 02:00:02,920 --> 02:00:05,560 and taken to the lab for analysis. 1247 02:00:06,480 --> 02:00:09,040 - Ah, it's a gold mine. 1248 02:00:09,040 --> 02:00:10,400 Yeah. - It really is. 1249 02:00:11,920 --> 02:00:15,120 - Entombed in this nine-ton block of sandstone... 1250 02:00:16,720 --> 02:00:20,160 ..the team has discovered the remains of an entire group 1251 02:00:20,160 --> 02:00:21,800 of Utahraptors. 1252 02:00:23,200 --> 02:00:24,320 - And over here, 1253 02:00:24,320 --> 02:00:28,360 we've got the string of articulated vertebrae. 1254 02:00:28,360 --> 02:00:31,200 - Yeah. I mean, that's just beautiful. 1255 02:00:31,200 --> 02:00:33,200 - And hidden amongst the hundreds 1256 02:00:33,200 --> 02:00:37,520 of perfectly preserved teeth and claws and bones... 1257 02:00:37,520 --> 02:00:39,800 - Yeah, that's the great thing about this block. 1258 02:00:39,800 --> 02:00:41,240 We'll have so much material. 1259 02:00:41,240 --> 02:00:44,880 - ..curator Don DeBlieux has found something that could be 1260 02:00:44,880 --> 02:00:47,200 Utahraptor's deadliest weapon. 1261 02:00:48,320 --> 02:00:51,360 - We got this beautiful little top of a skull, 1262 02:00:51,360 --> 02:00:53,000 and then we flipped it over. 1263 02:00:56,000 --> 02:00:58,760 Right here is the impression of the brain. 1264 02:01:00,280 --> 02:01:01,760 - For a dinosaur, 1265 02:01:01,760 --> 02:01:05,680 this young Utahraptor brain is very large. 1266 02:01:05,680 --> 02:01:08,600 - Yeah, certainly remarkable, given the size. 1267 02:01:09,640 --> 02:01:11,760 Yeah, that would be a very intelligent animal. 1268 02:01:11,760 --> 02:01:15,320 - They would have been the most intelligent animal of its time. 1269 02:01:15,320 --> 02:01:19,600 - Oh, certainly. Utahraptor would have been capable of 1270 02:01:19,600 --> 02:01:21,360 some pretty complex behaviours. 1271 02:01:32,920 --> 02:01:36,840 - Spring has turned to summer. 1272 02:01:47,600 --> 02:01:49,880 And as the dry season sets in... 1273 02:01:49,880 --> 02:01:51,800 GRUNTING 1274 02:01:51,800 --> 02:01:55,960 ..George and the gastonia gang leave the forest to find water. 1275 02:02:05,920 --> 02:02:08,880 They're still unruly teenagers... 1276 02:02:08,880 --> 02:02:10,040 GRUNTING 1277 02:02:13,720 --> 02:02:16,760 ..but now in near-adult bodies. 1278 02:02:30,360 --> 02:02:32,600 And at the edge of the water hole, 1279 02:02:32,600 --> 02:02:35,480 clay-rich soil provides the gang 1280 02:02:35,480 --> 02:02:37,360 with essential minerals... 1281 02:02:39,440 --> 02:02:43,160 ..vital for strengthening their armour. 1282 02:02:50,400 --> 02:02:53,840 And now the gastonia are tougher, 1283 02:02:53,840 --> 02:02:56,360 they're no longer an easy kill. 1284 02:03:01,360 --> 02:03:04,080 So the raptors change tactics. 1285 02:03:04,080 --> 02:03:08,000 DEEP BELLOWING 1286 02:03:08,000 --> 02:03:10,840 The group leader attracts their attention. 1287 02:03:13,480 --> 02:03:15,560 HISSES 1288 02:03:17,960 --> 02:03:20,920 ..and uses his brightly coloured wing feathers... 1289 02:03:25,720 --> 02:03:27,200 ..to create... 1290 02:03:29,240 --> 02:03:31,040 ..a diversion. 1291 02:03:50,040 --> 02:03:52,160 Like a fox in a henhouse... 1292 02:03:53,720 --> 02:03:57,320 ..the kill triggers the leader's predatory instinct. 1293 02:03:58,640 --> 02:04:00,320 SCREECHES 1294 02:04:09,800 --> 02:04:12,360 Trapped at the water's edge... 1295 02:04:14,480 --> 02:04:18,600 ..it looks like George's luck has run out. 1296 02:04:18,600 --> 02:04:20,360 GRUNTS 1297 02:04:26,280 --> 02:04:28,320 INDISTINCT CONVERSATION 1298 02:04:34,720 --> 02:04:36,000 But at the dig, 1299 02:04:36,000 --> 02:04:38,840 Josh and the team have made a discovery. 1300 02:04:43,440 --> 02:04:45,640 They've come to retrieve a fossil 1301 02:04:45,640 --> 02:04:48,440 that may shed light on events that happened here 1302 02:04:48,440 --> 02:04:51,320 130 million years ago. 1303 02:04:53,280 --> 02:04:54,840 - So, Don, I was originally thinking 1304 02:04:54,840 --> 02:04:56,240 it was down this drainage, 1305 02:04:56,240 --> 02:04:57,920 but looking at it now, I actually think 1306 02:04:57,920 --> 02:05:00,720 it's further over that way. - Yeah, I think you're right. 1307 02:05:00,720 --> 02:05:04,440 - But collecting it from the steep cliff face... 1308 02:05:04,440 --> 02:05:06,880 - Damn! This is going to be tough. 1309 02:05:06,880 --> 02:05:08,360 - ..won't be easy. 1310 02:05:11,320 --> 02:05:14,800 - It might be further that way, that's the thing. 1311 02:05:18,960 --> 02:05:23,080 - Oh, there it is. - Yeah, that's totally it. 1312 02:05:23,080 --> 02:05:25,440 - Yeah. - So, Don, I think 1313 02:05:25,440 --> 02:05:28,640 if you want to bring the back board over here 1314 02:05:28,640 --> 02:05:30,920 and then we can go ahead and start strapping it down. 1315 02:05:32,240 --> 02:05:35,160 With your legs. - Do it. 1316 02:05:35,160 --> 02:05:38,160 - This is a fossilised foot cast. 1317 02:05:38,160 --> 02:05:41,200 - Big man on campus. - All right. 1318 02:05:41,200 --> 02:05:44,120 - All right, you got it. March on. - Got it. 1319 02:05:48,320 --> 02:05:50,520 - It formed when a dinosaur footprint 1320 02:05:50,520 --> 02:05:53,320 filled with silt and dust, 1321 02:05:53,320 --> 02:05:57,640 but over millions of years was compressed into solid rock... 1322 02:05:58,920 --> 02:06:00,720 - Like that, OK? Just like that. 1323 02:06:01,880 --> 02:06:03,640 - Luckily, it's not super fragile. 1324 02:06:05,280 --> 02:06:08,760 - ..creating a cast of the foot that made it. 1325 02:06:12,320 --> 02:06:13,720 - All right. 1326 02:06:13,720 --> 02:06:17,400 - One, two, three. - It definitely gets easier up here. 1327 02:06:17,400 --> 02:06:18,760 - OK. 1328 02:06:18,760 --> 02:06:20,320 OK. 1329 02:06:20,320 --> 02:06:23,920 - But which dinosaur does it belong to? 1330 02:06:30,760 --> 02:06:32,360 - Wow. 1331 02:06:32,360 --> 02:06:34,000 That's really cool. 1332 02:06:34,000 --> 02:06:37,680 We've got three big, wide toes on this footprint, 1333 02:06:37,680 --> 02:06:39,880 so that eliminates a couple dinosaurs right off the bat. 1334 02:06:39,880 --> 02:06:41,200 - Yeah. 1335 02:06:41,200 --> 02:06:44,560 - If it was gastonia, it'd have four toes. 1336 02:06:46,840 --> 02:06:49,080 And it's unlikely to be a predator 1337 02:06:49,080 --> 02:06:51,640 because there are no claws. 1338 02:06:51,640 --> 02:06:53,400 - Most likely a plant-eater. 1339 02:06:53,400 --> 02:06:57,160 - Yeah, I think a good candidate could be some sort of bipedal 1340 02:06:57,160 --> 02:07:00,600 plant-eating dinosaur, kind of like planicoxa. 1341 02:07:00,600 --> 02:07:02,240 - Right, we're at the right level for those guys. 1342 02:07:02,240 --> 02:07:03,840 Or close. - Absolutely. 1343 02:07:06,320 --> 02:07:10,360 - Planicoxa were beaked, stocky dinosaurs that lived in herds. 1344 02:07:11,560 --> 02:07:13,720 - You can imagine them travelling together 1345 02:07:13,720 --> 02:07:15,320 and moving long distances. 1346 02:07:15,320 --> 02:07:17,520 - For sure. - Maybe gastonia was year-round 1347 02:07:17,520 --> 02:07:19,800 and these dinosaurs were more seasonal. 1348 02:07:23,280 --> 02:07:24,440 - All right. 1349 02:07:26,040 --> 02:07:27,840 You guide us, Steph. 1350 02:07:27,840 --> 02:07:30,720 - Finding planicoxa footprints here 1351 02:07:30,720 --> 02:07:32,520 is an important discovery... 1352 02:07:35,920 --> 02:07:40,240 ..because it suggests they migrated through this landscape. 1353 02:07:40,240 --> 02:07:42,280 BELLOWING 1354 02:07:57,280 --> 02:07:59,120 SNARLS 1355 02:08:06,120 --> 02:08:07,680 BELLOWS 1356 02:08:07,680 --> 02:08:10,320 As the group leader closes in on George... 1357 02:08:11,320 --> 02:08:13,240 HIGH-PITCHED ROARING 1358 02:08:14,720 --> 02:08:19,280 ..a herd of planicoxa pass close by. 1359 02:08:19,280 --> 02:08:21,640 HIGH-PITCHED ROARING 1360 02:08:26,040 --> 02:08:29,120 And without any armour, 1361 02:08:29,120 --> 02:08:31,360 they're a much easier kill... 1362 02:08:31,360 --> 02:08:33,120 GRUNTING 1363 02:08:43,840 --> 02:08:45,560 ..handing George... 1364 02:08:49,960 --> 02:08:51,640 ..a very lucky escape. 1365 02:09:01,040 --> 02:09:03,880 But as the dry season intensifies, 1366 02:09:03,880 --> 02:09:06,560 the planicoxa herds will move on. 1367 02:09:11,120 --> 02:09:15,920 So, as George and the gastonia gang return to the forest, 1368 02:09:15,920 --> 02:09:18,000 they know it won't be long 1369 02:09:18,000 --> 02:09:22,480 until the raptors are hunting them down once more. 1370 02:09:35,800 --> 02:09:37,680 But coming out of the ground... 1371 02:09:37,680 --> 02:09:39,720 - Let's see how long this is. 1372 02:09:39,720 --> 02:09:42,600 - ..further evidence the gastonia buried here... 1373 02:09:42,600 --> 02:09:46,920 - We're looking at about 31.5cm long. 1374 02:09:46,920 --> 02:09:49,360 - ..were more than capable of defending themselves. 1375 02:09:49,360 --> 02:09:53,400 - The proximal width, where it attaches to the tail, 1376 02:09:53,400 --> 02:09:57,920 looks like about 17.5cm wide. - Yeah. 1377 02:09:57,920 --> 02:10:01,680 - So, yeah, this is one of these specialised spikes 1378 02:10:01,680 --> 02:10:04,800 along the tail. - Like, sticking out? 1379 02:10:04,800 --> 02:10:06,640 - Yeah, yeah. So it'll be sticking out 1380 02:10:06,640 --> 02:10:08,000 from the sides of the tail. 1381 02:10:08,000 --> 02:10:13,080 You can imagine this with a big scale over top of it, 1382 02:10:13,080 --> 02:10:14,680 a bit piece of keratin, 1383 02:10:14,680 --> 02:10:17,600 so this would have come to a very sharp point. 1384 02:10:17,600 --> 02:10:20,760 And these, we think, were used as a weapon. 1385 02:10:24,280 --> 02:10:27,440 - These blade-like spikes 1386 02:10:27,440 --> 02:10:29,920 were positioned along the entire length 1387 02:10:29,920 --> 02:10:31,600 of the gastonias' tails. 1388 02:10:37,160 --> 02:10:40,280 And Jim and Don have uncovered something 1389 02:10:40,280 --> 02:10:44,160 that shows just how these weapons were used. 1390 02:10:44,160 --> 02:10:46,920 - And then, as I was trying to work on that, 1391 02:10:46,920 --> 02:10:49,920 I hit something over here. 1392 02:10:49,920 --> 02:10:53,160 So this is a femur, the upper-leg bone. 1393 02:10:53,160 --> 02:10:55,040 - That's a pretty sizeable femur. 1394 02:10:55,040 --> 02:10:56,840 - And then as I dug around, 1395 02:10:56,840 --> 02:10:59,160 I see we have a complete tibia, lower-leg bone. 1396 02:10:59,160 --> 02:11:00,520 - Yeah. 1397 02:11:00,520 --> 02:11:03,360 You can see how short, you know, the lower leg is, 1398 02:11:03,360 --> 02:11:06,520 while the upper leg, about half the length... 1399 02:11:06,520 --> 02:11:10,040 - Right. - ..which is, you know, the exact opposite 1400 02:11:10,040 --> 02:11:12,320 than what you see in a running animal. 1401 02:11:14,280 --> 02:11:18,800 - Gastonia had a top speed of around 5mph... 1402 02:11:20,960 --> 02:11:23,920 ..because their hind legs weren't built for running. 1403 02:11:25,480 --> 02:11:28,440 They were adapted for a very different purpose. 1404 02:11:30,280 --> 02:11:33,640 - Certainly, these things are not just simple bones. 1405 02:11:33,640 --> 02:11:36,240 They have huge muscle attachment points, 1406 02:11:36,240 --> 02:11:39,520 so they've developed powerful legs for serious, 1407 02:11:39,520 --> 02:11:41,800 strong manoeuvrability. - Stocky guys, 1408 02:11:41,800 --> 02:11:43,240 just standing their ground. 1409 02:11:43,240 --> 02:11:46,360 - You just see these things just holding on the ground 1410 02:11:46,360 --> 02:11:50,000 and swinging their tail with those big blades, 1411 02:11:50,000 --> 02:11:52,680 just like the one over there they already pulled out. 1412 02:11:52,680 --> 02:11:53,920 - Yeah, that big boy. 1413 02:11:53,920 --> 02:11:55,240 - Yeah. Slashing across, 1414 02:11:55,240 --> 02:11:59,000 and probably reach head-high easily, 1415 02:11:59,000 --> 02:12:03,520 and literally slap a Utahraptor, you know, right in the face. 1416 02:12:06,520 --> 02:12:10,360 - Gastonia's powerful hind legs and spiked tails... 1417 02:12:15,200 --> 02:12:19,320 ..mean George and the gang are now formidable adversaries. 1418 02:12:24,360 --> 02:12:26,640 RUNNING STEPS 1419 02:12:29,440 --> 02:12:32,640 But with the dry season now at its height, 1420 02:12:32,640 --> 02:12:34,400 and the planicoxa gone... 1421 02:12:37,920 --> 02:12:40,640 ..the raptors are starving. 1422 02:12:47,280 --> 02:12:51,120 Desperate for food, they must take any opportunity... 1423 02:12:57,200 --> 02:12:59,200 ..to make a kill. 1424 02:13:10,120 --> 02:13:12,120 But now nearly fully grown, 1425 02:13:12,120 --> 02:13:16,240 the gastonia gang will stand and fight. 1426 02:13:18,560 --> 02:13:21,400 HISSES 1427 02:13:21,400 --> 02:13:23,320 BELLOWING 1428 02:13:25,840 --> 02:13:27,880 HISSES 1429 02:13:32,800 --> 02:13:34,920 And this time, 1430 02:13:34,920 --> 02:13:38,080 they've got the weapons to defend themselves. 1431 02:13:51,040 --> 02:13:55,080 The gastonia now have the upper hand. 1432 02:13:59,680 --> 02:14:01,840 But driven by hunger, 1433 02:14:01,840 --> 02:14:05,800 the raptors have no choice but to attack. 1434 02:14:05,800 --> 02:14:07,840 HISSES 1435 02:14:25,400 --> 02:14:27,400 BELLOWS 1436 02:14:29,120 --> 02:14:31,560 With the group leader fatally wounded... 1437 02:14:35,680 --> 02:14:38,760 ..the remaining raptors back down. 1438 02:14:42,200 --> 02:14:43,960 BELLOWS 1439 02:14:48,040 --> 02:14:52,480 But George's moment of triumph will be short-lived. 1440 02:15:00,200 --> 02:15:04,720 The hot summer months bring a new danger. 1441 02:15:11,600 --> 02:15:13,240 Something revealed by 1442 02:15:13,240 --> 02:15:16,320 a completely different type of evidence... 1443 02:15:18,080 --> 02:15:21,200 ..found alongside the gastonia bones. 1444 02:15:28,400 --> 02:15:32,760 Palaeobotanist Dr Carol Hotton 1445 02:15:32,760 --> 02:15:36,640 is an expert in ancient pollen. 1446 02:15:42,920 --> 02:15:45,600 - Howdy, Carol. - Hey, Jim, take a look. 1447 02:15:45,600 --> 02:15:48,560 There's some interesting grains right in the centre. 1448 02:15:49,680 --> 02:15:52,920 So, if you see those little round grains 1449 02:15:52,920 --> 02:15:55,200 that look like flat tyres, 1450 02:15:55,200 --> 02:15:59,280 that's pollen from an extinct conifer. 1451 02:16:00,360 --> 02:16:04,160 And, um, there's another grain. 1452 02:16:06,160 --> 02:16:09,600 That's a member of the cypress family. 1453 02:16:09,600 --> 02:16:11,000 - Hmm. 1454 02:16:11,000 --> 02:16:13,760 - That was well adapted to dry conditions. 1455 02:16:17,720 --> 02:16:20,400 - All the pollen Carol has identified 1456 02:16:20,400 --> 02:16:25,280 belongs to trees that lived in a parched, arid environment. 1457 02:16:30,400 --> 02:16:32,680 130 million years ago, 1458 02:16:32,680 --> 02:16:37,760 the forest that covered the dig site was a tinder box. 1459 02:16:40,680 --> 02:16:43,360 - You can see all through the field 1460 02:16:43,360 --> 02:16:46,360 black pieces. - Yeah, little shards. 1461 02:16:46,360 --> 02:16:49,240 - Yeah, little shards. - Twiggy-looking things 1462 02:16:49,240 --> 02:16:50,800 that are pretty small for twigs. 1463 02:16:50,800 --> 02:16:55,000 - Right. In all probability, they represent charcoal. 1464 02:16:55,000 --> 02:16:57,640 It's unlikely to be anything else, 1465 02:16:57,640 --> 02:17:01,160 and I see that in all my pollen samples. 1466 02:17:03,840 --> 02:17:06,080 - There's only one thing 1467 02:17:06,080 --> 02:17:09,240 that could have produced so much charcoal. 1468 02:17:13,880 --> 02:17:15,920 THUNDER ROLLS 1469 02:17:19,840 --> 02:17:22,200 The long, dry summer months 1470 02:17:22,200 --> 02:17:26,520 have created a time bomb. 1471 02:17:31,520 --> 02:17:34,480 As wildfire rages through the parched forest... 1472 02:17:40,200 --> 02:17:42,680 ..it threatens the gastonia 1473 02:17:42,680 --> 02:17:45,080 and the surviving raptors. 1474 02:17:45,080 --> 02:17:46,840 CHITTERS 1475 02:17:46,840 --> 02:17:48,520 SCREECHES 1476 02:18:04,680 --> 02:18:06,400 BELLOWING 1477 02:18:06,400 --> 02:18:10,080 But George is slow to react to the danger. 1478 02:18:13,520 --> 02:18:15,480 BELLOWS 1479 02:18:21,560 --> 02:18:23,160 SQUAWKS 1480 02:18:33,920 --> 02:18:36,880 With a top speed around 20mph, 1481 02:18:36,880 --> 02:18:40,600 the raptors soon reach a clearing in the forest. 1482 02:18:48,600 --> 02:18:51,120 SQUAWKS 1483 02:18:51,120 --> 02:18:55,080 But they're trapped between the flames 1484 02:18:55,080 --> 02:18:57,800 and a treacherous marshy swamp. 1485 02:19:04,520 --> 02:19:08,840 And George and the gastonia gang aren't far behind. 1486 02:19:17,280 --> 02:19:21,760 The flames driving the two mortal enemies together... 1487 02:19:24,760 --> 02:19:30,000 ..for one final showdown. 1488 02:19:37,280 --> 02:19:39,160 GRUNTS 1489 02:19:43,360 --> 02:19:44,880 - This one is... 1490 02:19:44,880 --> 02:19:46,760 - But back at the lab... 1491 02:19:46,760 --> 02:19:48,480 - Oh, that's just... 1492 02:19:48,480 --> 02:19:51,840 - ..the sandstone block filled with raptor bones... 1493 02:19:51,840 --> 02:19:53,960 - Now, this one here... 1494 02:19:53,960 --> 02:19:56,600 - ..has one last secret to reveal. 1495 02:19:56,600 --> 02:19:57,760 - ..right size... 1496 02:19:57,760 --> 02:19:59,840 Nice little jaw right there. 1497 02:19:59,840 --> 02:20:02,800 - Oh, yeah. I see the teeth on that. 1498 02:20:02,800 --> 02:20:05,800 - The amazing thing is that all these delicate little teeth 1499 02:20:05,800 --> 02:20:07,880 are all still in place in their sockets. 1500 02:20:07,880 --> 02:20:10,880 - Oh, it's really remarkable to have it so well preserved. 1501 02:20:12,160 --> 02:20:14,520 - Such high levels of preservation... 1502 02:20:14,520 --> 02:20:16,680 - Hard to tell. - And certainly this, 1503 02:20:16,680 --> 02:20:19,120 you know, still has the teeth included. 1504 02:20:19,120 --> 02:20:23,480 - ..tell the team the bones have not been disturbed. 1505 02:20:23,480 --> 02:20:28,960 The block captures the very moment the raptors died. 1506 02:20:30,160 --> 02:20:32,120 - And interesting that 1507 02:20:32,120 --> 02:20:35,440 all the best-preserved bones all seem to be in this sand. 1508 02:20:35,440 --> 02:20:40,040 - Yeah. It suggests that sand is part of why they died, 1509 02:20:40,040 --> 02:20:41,680 why they're so well preserved. 1510 02:20:44,040 --> 02:20:46,680 - Although the sand is solid today, 1511 02:20:46,680 --> 02:20:50,080 Jim believes that when the raptors died, 1512 02:20:50,080 --> 02:20:51,600 it was liquid. 1513 02:20:53,440 --> 02:20:56,320 - You know, what killed them is what buried them. 1514 02:20:56,320 --> 02:20:58,400 Given the geology of the setting, 1515 02:20:58,400 --> 02:21:03,520 most likely we're looking at a mass mortality tied to quicksand. 1516 02:21:13,920 --> 02:21:15,480 - SQUAWKS 1517 02:21:18,920 --> 02:21:20,440 BELLOWS 1518 02:21:25,440 --> 02:21:27,720 HISSING 1519 02:21:34,960 --> 02:21:36,480 SHRIEKS 1520 02:21:37,800 --> 02:21:39,600 SQUAWKING 1521 02:21:45,200 --> 02:21:48,320 Panicked, the raptors run into trouble. 1522 02:21:55,560 --> 02:21:57,640 BLEATS 1523 02:22:16,320 --> 02:22:18,240 With the raptors out of the way... 1524 02:22:19,560 --> 02:22:22,240 ..George has the chance to escape. 1525 02:22:45,160 --> 02:22:47,040 LOW BELLOWING 1526 02:22:47,040 --> 02:22:48,560 But they're struggling. 1527 02:22:51,560 --> 02:22:54,760 The very things that protected them from the raptors... 1528 02:22:56,360 --> 02:23:00,480 ..heavy armour and short, stocky legs... 1529 02:23:05,600 --> 02:23:08,000 GRUNTS AND PANTS 1530 02:23:09,640 --> 02:23:12,160 ..mean George and the gang 1531 02:23:12,160 --> 02:23:15,440 are too slow to escape the fire. 1532 02:23:15,440 --> 02:23:17,960 PANTS 1533 02:23:29,760 --> 02:23:31,440 One by one... 1534 02:23:33,640 --> 02:23:36,760 ..the smoke takes its toll. 1535 02:23:50,240 --> 02:23:52,240 Buried where they fell... 1536 02:23:55,280 --> 02:23:58,680 ..the landscape is transformed around them. 1537 02:24:05,920 --> 02:24:09,160 Layer upon layer of rock builds up... 1538 02:24:11,240 --> 02:24:13,040 ..as the aeons pass... 1539 02:24:14,440 --> 02:24:19,280 ..and the continents silently drift across the face of the Earth... 1540 02:24:25,360 --> 02:24:29,160 ..until George and the gang are finally found... 1541 02:24:31,680 --> 02:24:35,360 ..130 million years later. 1542 02:24:51,520 --> 02:24:52,840 Next time... 1543 02:24:53,960 --> 02:24:56,600 ..T-Rex's lethal, faster cousin. 1544 02:25:02,360 --> 02:25:06,080 A young hunter fighting for her place 1545 02:25:06,080 --> 02:25:08,640 in the most ferocious pack on Earth. 1546 02:25:57,740 --> 02:26:00,420 Over 66 million years ago... 1547 02:26:02,700 --> 02:26:05,340 SCREECHING WAIL 1548 02:26:05,340 --> 02:26:07,220 HIGH-PITCHED CLUCKS ..our world... 1549 02:26:07,220 --> 02:26:09,460 DEEP SNORT ..was ruled... 1550 02:26:10,900 --> 02:26:13,660 ..by dinosaurs. 1551 02:26:13,660 --> 02:26:15,300 DEEP BELLOW 1552 02:26:15,300 --> 02:26:17,700 HISSES 1553 02:26:19,900 --> 02:26:24,180 The largest animals that have ever walked the Earth. 1554 02:26:24,180 --> 02:26:27,020 ROARS 1555 02:26:30,620 --> 02:26:35,220 Today, dinosaur experts across the globe 1556 02:26:35,220 --> 02:26:38,380 are uncovering the bones they left behind... 1557 02:26:43,140 --> 02:26:47,900 ..allowing us to imagine how these creatures may have lived... 1558 02:26:53,860 --> 02:26:58,500 ..so that we can tell their stories, and they... 1559 02:27:01,700 --> 02:27:04,020 ..can walk again. 1560 02:27:27,700 --> 02:27:29,100 Western Canada. 1561 02:27:31,940 --> 02:27:36,580 Today, a majestic landscape of snow-capped peaks... 1562 02:27:37,980 --> 02:27:39,700 ..turquoise lakes... 1563 02:27:42,780 --> 02:27:44,660 ..and mighty rivers... 1564 02:27:46,380 --> 02:27:48,900 ..that erode the ancient bedrock. 1565 02:27:50,500 --> 02:27:54,140 The perfect conditions for dinosaur-hunting. 1566 02:28:00,100 --> 02:28:02,740 Here, on the banks of Red Deer River... 1567 02:28:04,140 --> 02:28:07,580 ..palaeontologists from the University of Alberta... 1568 02:28:09,300 --> 02:28:13,340 ..are unearthing the final resting place of a super-predator. 1569 02:28:16,020 --> 02:28:19,460 - Oh, wow. Yeah, that's really nice. 1570 02:28:19,460 --> 02:28:22,660 - Looks like a toe claw. - Wonderful find. 1571 02:28:22,660 --> 02:28:27,620 - Albertosaurus - T-rex's deadly cousin. 1572 02:28:30,580 --> 02:28:33,340 These are the remains of a teenager. 1573 02:28:35,020 --> 02:28:37,380 The team calls her Rose. 1574 02:28:38,500 --> 02:28:40,620 - Holy cow! 1575 02:28:40,620 --> 02:28:42,140 - Oh, wow. - It keeps going. 1576 02:28:43,420 --> 02:28:46,060 - Inspired by their discoveries... 1577 02:28:49,620 --> 02:28:52,060 ..we can imagine her story. 1578 02:29:06,260 --> 02:29:08,460 In the Late Cretaceous, 1579 02:29:08,460 --> 02:29:13,300 North America is split in two by a vast inland sea. 1580 02:29:17,740 --> 02:29:22,660 On its western shores, a sprawling expanse of dense forests 1581 02:29:22,660 --> 02:29:24,820 and rugged coastlines. 1582 02:29:27,580 --> 02:29:29,260 Laramidia. 1583 02:29:30,780 --> 02:29:33,340 A land in crisis. 1584 02:29:34,820 --> 02:29:39,780 Atmospheric changes have forced temperatures down by two degrees. 1585 02:29:41,820 --> 02:29:44,020 A seemingly small change, 1586 02:29:44,020 --> 02:29:48,140 but enough to push the delicate ecosystem out of balance. 1587 02:29:49,620 --> 02:29:52,300 SQUAWKS 1588 02:29:52,300 --> 02:29:54,220 SHRIEKING CRIES 1589 02:29:56,700 --> 02:29:58,820 Food is scarce. 1590 02:30:01,860 --> 02:30:03,540 Even... 1591 02:30:04,900 --> 02:30:06,260 ..for an apex predator. 1592 02:30:06,260 --> 02:30:08,580 RUMBLING BREATHS 1593 02:30:10,820 --> 02:30:13,740 Standing two-and-a-half metres tall, 1594 02:30:13,740 --> 02:30:15,900 and weighing in at one tonne... 1595 02:30:18,100 --> 02:30:21,700 ..this is Rose... 1596 02:30:21,700 --> 02:30:23,300 ..the Albertosaurus. 1597 02:30:27,780 --> 02:30:30,300 It's been a week since she last ate. 1598 02:30:35,740 --> 02:30:38,340 But in her sights... 1599 02:30:38,340 --> 02:30:40,860 ..an arrhinoceratops, 1600 02:30:40,860 --> 02:30:43,100 an older cousin of triceratops. 1601 02:30:49,020 --> 02:30:51,900 A chance for Rose to satisfy her hunger. 1602 02:31:05,460 --> 02:31:09,420 Rose might just be the fastest land predator on the planet... 1603 02:31:12,500 --> 02:31:15,340 ..sprinting at up to 30mph. 1604 02:31:24,500 --> 02:31:27,500 BELLOWS 1605 02:31:27,500 --> 02:31:29,460 ROARS 1606 02:31:34,460 --> 02:31:36,380 But Rose has miscalculated. 1607 02:31:39,860 --> 02:31:43,420 At two tonnes, her target is twice her weight... 1608 02:31:44,820 --> 02:31:47,180 ..with horns almost a metre long. 1609 02:31:52,060 --> 02:31:53,780 Rose is starving. 1610 02:32:02,380 --> 02:32:05,940 But the risk of injury is just too great. 1611 02:32:09,740 --> 02:32:11,860 Dinner will have to wait. 1612 02:32:26,380 --> 02:32:29,260 71 million years later, 1613 02:32:29,260 --> 02:32:31,980 this team of palaeontologists... 1614 02:32:31,980 --> 02:32:34,980 - Hey, guys, how's it going? - Hey, Mark, look at this. 1615 02:32:34,980 --> 02:32:37,780 - ..led by Mark Powers, 1616 02:32:37,780 --> 02:32:40,220 is uncovering Rose's secrets... 1617 02:32:40,220 --> 02:32:43,300 - Found new bones! - Whoa, no way! 1618 02:32:44,340 --> 02:32:45,980 - ..piece by piece. 1619 02:32:45,980 --> 02:32:47,580 - You couldn't ask for better... 1620 02:32:47,580 --> 02:32:50,340 - No. - ..better separation. - You really couldn't. 1621 02:32:50,340 --> 02:32:53,540 - Each day, more remains emerge from the ground. 1622 02:32:53,540 --> 02:32:55,900 - Ohh! - Whoa! - Oh, my God. 1623 02:32:55,900 --> 02:32:57,580 - Yeah! Yeah, clean it off. 1624 02:32:57,580 --> 02:32:59,980 - CHEERING - There it is! 1625 02:33:00,980 --> 02:33:04,980 Today's discovery - Rose's leg bones. 1626 02:33:04,980 --> 02:33:06,580 - Oh, that's so cool. 1627 02:33:11,900 --> 02:33:16,180 - Each fossil is exposed and restored, 1628 02:33:16,180 --> 02:33:20,340 allowing the team to delve deeper into the story of 1629 02:33:20,340 --> 02:33:23,140 this long-lost super-predator. 1630 02:33:23,140 --> 02:33:25,420 - This is looking really good. 1631 02:33:25,420 --> 02:33:29,820 - Mark works with limb specialist Christiana Garros 1632 02:33:29,820 --> 02:33:32,460 to examine the bones from Rose's shin. 1633 02:33:33,620 --> 02:33:36,220 - The tibia is not actually that huge, 1634 02:33:36,220 --> 02:33:39,020 compared to some of the bigger ones I've seen, at least. - No. 1635 02:33:39,020 --> 02:33:43,420 - Albertosaurus is an older relative of Tyrannosaurus Rex... 1636 02:33:44,700 --> 02:33:46,780 - It's about 79cm. - OK. 1637 02:33:46,780 --> 02:33:48,060 - Something like that. 1638 02:33:48,060 --> 02:33:51,500 - ..but it's becoming clear she was a very different beast 1639 02:33:51,500 --> 02:33:53,060 to her more famous cousin. 1640 02:33:53,060 --> 02:33:56,980 - So, long limbs, but the ones of T-rex are quite a bit bulkier, 1641 02:33:56,980 --> 02:33:58,580 aren't they? - Absolutely. 1642 02:33:58,580 --> 02:34:01,380 Rose kind of really embodies what Albertosaurus is. 1643 02:34:01,380 --> 02:34:04,620 It's a very legsy animal, especially compared to things like T-rex, 1644 02:34:04,620 --> 02:34:07,860 which was incredibly huge. - Yeah. - Incredibly chunky. 1645 02:34:07,860 --> 02:34:09,900 Quick, fast, dangerous. 1646 02:34:09,900 --> 02:34:11,500 Still has powerful jaws. - Yeah. 1647 02:34:11,500 --> 02:34:14,420 Maybe the optimal amount of scary for my taste, 1648 02:34:14,420 --> 02:34:16,620 that's for sure. - Absolutely. 1649 02:34:17,700 --> 02:34:20,180 - But speed was far from the only weapon 1650 02:34:20,180 --> 02:34:22,140 in the Albertosaurus arsenal. 1651 02:34:29,260 --> 02:34:32,260 More bones are coming out of the ground. 1652 02:34:32,260 --> 02:34:33,860 - Oh, that's bone. 1653 02:34:33,860 --> 02:34:35,820 - But these don't belong to Rose. 1654 02:34:35,820 --> 02:34:38,900 - It does look like a bone from one of the digits. 1655 02:34:38,900 --> 02:34:40,740 - And that's definitely Albertosaurus, right? 1656 02:34:40,740 --> 02:34:42,100 - Yeah, absolutely. 1657 02:34:42,100 --> 02:34:46,420 - And each bone seems to come from a different-sized Albertosaurus. 1658 02:34:46,420 --> 02:34:47,820 - This is a huge one. 1659 02:34:53,380 --> 02:34:55,260 - Dinosaur hunters have discovered 1660 02:34:55,260 --> 02:34:58,300 as many as 26 individuals buried here. 1661 02:35:01,260 --> 02:35:03,940 - To try and say any piece belongs to any one individual 1662 02:35:03,940 --> 02:35:06,500 is kind of tough to do, cos there are so many of them. 1663 02:35:07,900 --> 02:35:10,860 It's clearly a mass grave of Albertosaurus, 1664 02:35:10,860 --> 02:35:14,180 where many individuals died together in this spot. 1665 02:35:15,620 --> 02:35:17,300 - And if they died together... 1666 02:35:19,620 --> 02:35:21,700 ..they likely lived together, too. 1667 02:35:36,260 --> 02:35:38,780 LOW GROWLING 1668 02:35:46,580 --> 02:35:50,020 In the cave Rose calls home, 1669 02:35:50,020 --> 02:35:51,820 she's far from alone. 1670 02:35:53,260 --> 02:35:55,740 SNIFFS 1671 02:35:55,740 --> 02:35:57,660 GRUNTS 1672 02:36:04,860 --> 02:36:08,460 Albertosaurus are social animals. 1673 02:36:12,260 --> 02:36:14,820 They live and hunt together, 1674 02:36:14,820 --> 02:36:17,340 forming strong, intimate bonds. 1675 02:36:28,780 --> 02:36:32,860 Rose has paired with this male Albertosaurus the same age. 1676 02:36:38,060 --> 02:36:40,860 A source of comfort... 1677 02:36:40,860 --> 02:36:43,180 ..in times of scarcity. 1678 02:36:46,500 --> 02:36:50,660 It's been over a week since the Albertosaurus last made a kill. 1679 02:36:54,260 --> 02:36:58,780 And starvation isn't the only threat hanging over Rose. 1680 02:37:00,580 --> 02:37:03,580 RUMBLING GRUNT 1681 02:37:07,980 --> 02:37:09,380 The matriarch. 1682 02:37:14,300 --> 02:37:16,380 Racked with intense hunger, 1683 02:37:16,380 --> 02:37:18,220 she could turn on her own. 1684 02:37:26,540 --> 02:37:30,300 And Rose is bottom of the pecking order. 1685 02:37:44,980 --> 02:37:46,940 If she hopes to survive, 1686 02:37:46,940 --> 02:37:50,420 she'll have to prove herself when it matters most. 1687 02:37:58,740 --> 02:38:01,500 It's time to go hunting. 1688 02:38:18,620 --> 02:38:20,220 - Ready? - Let's go. 1689 02:38:27,300 --> 02:38:31,540 - Mark's teamed up with dinosaur anatomy specialist Henry Sharpe. 1690 02:38:37,220 --> 02:38:40,620 They're venturing further up Red Deer River 1691 02:38:40,620 --> 02:38:43,140 on the hunt for more giants. 1692 02:38:44,500 --> 02:38:47,420 - There's some wonderful prospecting rocks up there. 1693 02:39:01,260 --> 02:39:03,780 - They reach an ancient river system, 1694 02:39:03,780 --> 02:39:06,540 dating from the same time period as Rose. 1695 02:39:09,060 --> 02:39:11,740 And the first clue... 1696 02:39:11,740 --> 02:39:13,220 - We got a rib here. 1697 02:39:14,300 --> 02:39:17,460 - ..to what might have fed the Albertosaurus pack. 1698 02:39:17,460 --> 02:39:21,580 - Given its cross-section and its size, maybe Edmontosaurus. 1699 02:39:21,580 --> 02:39:23,380 - I'd say Edmontosaurus, yeah. 1700 02:39:25,660 --> 02:39:30,700 - Edmontosaurus - a plant-eating, duck-billed dinosaur. 1701 02:39:32,580 --> 02:39:35,780 - Edmontosaurus can get up to 30 feet long. 1702 02:39:35,780 --> 02:39:38,100 - Ten metres here. - Jeez! 1703 02:39:38,100 --> 02:39:40,660 - Yeah. These things were huge. 1704 02:39:43,700 --> 02:39:45,900 - But a single Edmontosaurus 1705 02:39:45,900 --> 02:39:48,900 wouldn't feed a hungry pack of Albertosaurus for long. 1706 02:39:52,660 --> 02:39:54,180 - Holy cow! 1707 02:39:57,180 --> 02:39:59,260 - PANTING: - Oh, my God. 1708 02:39:59,260 --> 02:40:01,140 - At the top of an escarpment... 1709 02:40:02,500 --> 02:40:04,940 - Look at the size of these honkers! 1710 02:40:04,940 --> 02:40:07,140 - ..more fossils. 1711 02:40:07,140 --> 02:40:09,340 Not bone... 1712 02:40:09,340 --> 02:40:10,900 ..but footprints. 1713 02:40:12,420 --> 02:40:15,060 - You can see, they got the big front toe 1714 02:40:15,060 --> 02:40:16,820 and the two toes on the side. 1715 02:40:16,820 --> 02:40:19,340 It's much wider than it is long, 1716 02:40:19,340 --> 02:40:23,020 which is classic Edmontosaurus, duck-billed dinosaur. 1717 02:40:25,100 --> 02:40:26,820 - From the pattern of these prints, 1718 02:40:26,820 --> 02:40:29,660 it looks as though these trackways couldn't have been made 1719 02:40:29,660 --> 02:40:30,780 by a single creature. 1720 02:40:32,460 --> 02:40:35,940 - I've got about 16-17 tracks exposed here. 1721 02:40:37,540 --> 02:40:40,260 - Today, there are just a few footprints. 1722 02:40:40,260 --> 02:40:42,340 But when they were created, 1723 02:40:42,340 --> 02:40:44,940 there would have been many, many more. 1724 02:40:46,140 --> 02:40:49,420 - We have lots of footprints from various different individuals, 1725 02:40:49,420 --> 02:40:52,100 various different ages all congregating together, 1726 02:40:52,100 --> 02:40:54,860 so they definitely moved in herds, lived in herds. 1727 02:40:54,860 --> 02:40:57,660 - Yeah. You imagine, like, herds of wildebeest, 1728 02:40:57,660 --> 02:41:00,820 and these animals were the size of one to two elephants. 1729 02:41:03,300 --> 02:41:05,780 - These fossilised footsteps suggest 1730 02:41:05,780 --> 02:41:08,420 this corner of Canada once played host... 1731 02:41:09,940 --> 02:41:11,940 TRUMPETING ROARS 1732 02:41:13,420 --> 02:41:17,380 ..to one of the most remarkable sights in Earth's history. 1733 02:41:28,180 --> 02:41:31,540 A migrating Edmontosaurus herd. 1734 02:41:37,140 --> 02:41:42,220 Thousands of plant-eating dinosaurs moving as one. 1735 02:41:49,940 --> 02:41:52,660 But an individual adult Edmontosaurus can be 1736 02:41:52,660 --> 02:41:56,980 three times the weight of even the largest Albertosaurus. 1737 02:42:00,300 --> 02:42:02,380 BIRDSONG 1738 02:42:20,860 --> 02:42:25,980 Working as a pack is the only way to take down such colossal prey. 1739 02:42:39,140 --> 02:42:42,060 Higher ground will provide the perfect vantage point... 1740 02:42:44,300 --> 02:42:46,060 ..to mount an attack. 1741 02:42:52,620 --> 02:42:54,100 At this time of year, 1742 02:42:54,100 --> 02:42:56,980 this area should be teeming with Edmontosaurus... 1743 02:43:06,260 --> 02:43:08,740 ..but the herds are nowhere to be seen. 1744 02:43:12,420 --> 02:43:14,420 LOW GROWLING 1745 02:43:20,180 --> 02:43:21,820 ROARS 1746 02:43:29,980 --> 02:43:33,740 This is a time of intense geological upheaval. 1747 02:43:39,060 --> 02:43:40,860 As the continents move... 1748 02:43:43,820 --> 02:43:46,660 ..the land buckles and splits. 1749 02:43:50,220 --> 02:43:53,420 Lava and ash engulf the landscape... 1750 02:44:07,300 --> 02:44:10,340 ..forcing this Edmontosaurus herd 1751 02:44:10,340 --> 02:44:12,540 to take a much longer route north this year. 1752 02:44:25,620 --> 02:44:30,620 They're still many miles away from the starving Albertosaurus. 1753 02:44:40,100 --> 02:44:43,180 For the pack, the delay spells disaster. 1754 02:44:49,340 --> 02:44:51,060 But on the horizon... 1755 02:44:52,820 --> 02:44:55,260 ..Rose spots an opportunity. 1756 02:45:10,900 --> 02:45:14,500 From the wind-carved rocks by Rose's dig site, 1757 02:45:14,500 --> 02:45:18,900 palaeontologist Colton Coppock has made an important discovery. 1758 02:45:22,580 --> 02:45:24,860 - Yeah. 1759 02:45:24,860 --> 02:45:26,580 - So, here's a bit of the shaft. 1760 02:45:26,580 --> 02:45:28,820 - Tiny fragments of finger bone 1761 02:45:28,820 --> 02:45:33,060 belonging to one of the most bizarre creatures of the Cretaceous... 1762 02:45:33,060 --> 02:45:34,980 - And here's the condyle. - What?! 1763 02:45:34,980 --> 02:45:37,060 - So, it looks like it might be from a digit. 1764 02:45:37,060 --> 02:45:38,980 - There's a condyle? - Yeah. 1765 02:45:38,980 --> 02:45:42,380 - ..including a rare condyle, part of the knuckle joint. 1766 02:45:42,380 --> 02:45:45,580 - Very nice. - I'm afraid to touch it. 1767 02:45:45,580 --> 02:45:49,380 - Yeah. It's just so small and so delicate. - Yeah. 1768 02:45:49,380 --> 02:45:54,020 - You can see the internal structure of the bone right there. 1769 02:45:54,020 --> 02:45:56,220 - The fossil's paper-thin exterior 1770 02:45:56,220 --> 02:45:59,260 tells Mark this bone was built for flying. 1771 02:46:01,140 --> 02:46:03,060 But this was no bird. 1772 02:46:03,060 --> 02:46:07,060 - Even in birds, the bone is usually a lot thicker on the outer surface. 1773 02:46:07,060 --> 02:46:08,180 - This is very strange. 1774 02:46:09,700 --> 02:46:12,140 - It can only belong to one creature. 1775 02:46:14,900 --> 02:46:16,540 SQUAWKING 1776 02:46:16,540 --> 02:46:21,980 A colossal flying reptile with a six-metre wingspan. 1777 02:46:24,780 --> 02:46:28,780 Cryodrakon - a giant pterosaur. 1778 02:46:37,820 --> 02:46:42,700 They feed on an enormous ammonite washed up on the spring tide. 1779 02:46:50,180 --> 02:46:51,540 SQUAWKS 1780 02:46:56,820 --> 02:47:01,180 The cryodrakon would make a fine meal for Rose and her mate... 1781 02:47:03,660 --> 02:47:06,060 ..if they can catch one. 1782 02:47:15,140 --> 02:47:16,620 SQUAWKS 1783 02:47:21,300 --> 02:47:23,660 Approaching from downwind, 1784 02:47:23,660 --> 02:47:26,340 and with the pterosaurs' attention on their meal... 1785 02:47:27,460 --> 02:47:29,660 ..the youngsters close in. 1786 02:47:59,260 --> 02:48:01,220 SQUAWKING 1787 02:48:02,820 --> 02:48:04,620 SCREECHES 1788 02:48:14,220 --> 02:48:16,820 At last, a chance to feed. 1789 02:48:33,580 --> 02:48:35,580 But the pair's absence from the pack... 1790 02:48:37,020 --> 02:48:39,140 ..hasn't gone unnoticed. 1791 02:48:39,140 --> 02:48:42,380 RUMBLING GRUNT 1792 02:48:57,300 --> 02:49:01,820 Life in an Albertosaurus pack was fraught with brutality. 1793 02:49:04,420 --> 02:49:07,500 And 71 million years later, 1794 02:49:07,500 --> 02:49:10,700 this violence is still written in the bones. 1795 02:49:13,580 --> 02:49:18,060 Mark and anatomist Dr Greg Funston examine the jawbones of 1796 02:49:18,060 --> 02:49:22,300 one of the largest Albertosaurus ever discovered. 1797 02:49:22,300 --> 02:49:25,100 - We do actually get a few scars along here, 1798 02:49:25,100 --> 02:49:27,060 and they're kind of evenly spaced. 1799 02:49:27,060 --> 02:49:29,940 Some are raised, and some are deep gouges. 1800 02:49:29,940 --> 02:49:31,660 - So, could these be bite marks? 1801 02:49:32,860 --> 02:49:37,060 - An astonishing 65% of Albertosaurus skulls found here 1802 02:49:37,060 --> 02:49:40,900 have teeth marks scratched into the bone itself. 1803 02:49:43,020 --> 02:49:46,660 - Near your finger, there's a little gouge in that one, too. 1804 02:49:46,660 --> 02:49:49,380 - Look at that. - That's deep. - Yeah. 1805 02:49:49,380 --> 02:49:53,260 It actually looks like the tooth came down from over the top. 1806 02:49:53,260 --> 02:49:55,900 That would've required tremendous amount of force, 1807 02:49:55,900 --> 02:49:59,740 from this diving angle, to actually remove that piece of bone. 1808 02:49:59,740 --> 02:50:03,580 - Only another Albertosaurus could inflict this injury. 1809 02:50:06,500 --> 02:50:08,820 - The biggest predator in this ecosystem, 1810 02:50:08,820 --> 02:50:11,300 and it's still getting beaten up day to day. 1811 02:50:12,300 --> 02:50:14,020 They're maybe tussling for food, 1812 02:50:14,020 --> 02:50:15,740 like you see on the savanna today, 1813 02:50:15,740 --> 02:50:17,980 where lions will eat in a certain order. 1814 02:50:19,300 --> 02:50:21,580 - You got two hungry Albertosaurus. 1815 02:50:21,580 --> 02:50:24,100 One of them is going to want to eat first. 1816 02:50:24,100 --> 02:50:25,620 Only one can. 1817 02:50:56,140 --> 02:50:59,740 - RUMBLING GROWL 1818 02:50:59,740 --> 02:51:01,220 As pack leader... 1819 02:51:03,580 --> 02:51:07,380 ..the matriarch is eyeing up the youngsters' kill. 1820 02:51:07,380 --> 02:51:09,540 GROWLING 1821 02:51:13,340 --> 02:51:16,540 Rose is determined to defend her prize. 1822 02:51:23,060 --> 02:51:25,540 But the matriarch... 1823 02:51:25,540 --> 02:51:28,540 ..leaves her in no doubt who's in charge. 1824 02:51:43,500 --> 02:51:45,260 GRUNTS 1825 02:51:56,820 --> 02:51:59,780 Hungry and badly wounded, 1826 02:51:59,780 --> 02:52:02,340 Rose has learnt a painful lesson. 1827 02:52:07,140 --> 02:52:09,260 She'll have to play by the rules 1828 02:52:09,260 --> 02:52:10,900 if she wants to survive. 1829 02:52:20,060 --> 02:52:23,780 But the evidence coming out of the ground suggests 1830 02:52:23,780 --> 02:52:27,300 not all of the Albertosaurus behaviour was violent. 1831 02:52:32,220 --> 02:52:36,580 Mark and Henry examine one of the most intriguing discoveries. 1832 02:52:38,020 --> 02:52:41,220 Rose's tiny, fossilised arm bones. 1833 02:52:42,940 --> 02:52:46,740 - So, we got the upper arm here, and the forearm down there. 1834 02:52:46,740 --> 02:52:49,540 And up here, this is the hand, right? 1835 02:52:49,540 --> 02:52:51,180 - This is like the palm of the hand. 1836 02:52:52,580 --> 02:52:55,140 - Nobody's quite sure what Albertosaurus used 1837 02:52:55,140 --> 02:52:56,820 its minuscule arms for... 1838 02:52:58,100 --> 02:53:01,740 ..but the strange positioning has given Mark an idea. 1839 02:53:01,740 --> 02:53:04,340 - It's quite possible the resting position of the arm 1840 02:53:04,340 --> 02:53:06,220 was to have a more flared finger, 1841 02:53:06,220 --> 02:53:09,500 sticking outwards rather than, you know, kind of down by the side, 1842 02:53:09,500 --> 02:53:10,540 like a chicken wing. 1843 02:53:10,540 --> 02:53:12,980 - So, if this was my arm, it would kind of be flared out like that? 1844 02:53:12,980 --> 02:53:15,140 - Yeah, you'd be kind of doing one of these things. 1845 02:53:15,140 --> 02:53:17,180 - Almost jazz hands. - Yeah, exactly. 1846 02:53:17,180 --> 02:53:20,660 - So, Albertosaurus is clearly using its arms for something. 1847 02:53:20,660 --> 02:53:23,980 I mean, modern birds have a wide variety of mating displays 1848 02:53:23,980 --> 02:53:26,620 and behaviours. - Mm-hm, yeah. 1849 02:53:26,620 --> 02:53:30,660 - Mark believes these seemingly useless arms may have been 1850 02:53:30,660 --> 02:53:33,660 vital tools for bonding. 1851 02:53:33,660 --> 02:53:35,860 - So, if you're going to live in a group, you've got to have ways 1852 02:53:35,860 --> 02:53:38,340 of communicating with one another that go beyond just, you know, 1853 02:53:38,340 --> 02:53:39,980 grunting and staring at each other, 1854 02:53:39,980 --> 02:53:42,980 so maybe they're using their hands side by side on the flank, 1855 02:53:42,980 --> 02:53:44,460 reassuring one another. 1856 02:53:44,460 --> 02:53:46,780 - Telling each other, "It's going to be OK, it's fine". 1857 02:53:46,780 --> 02:53:48,900 - A morale boost. - Yeah, exactly. - Yeah. 1858 02:54:15,980 --> 02:54:18,020 - SNORTS AND GRUNTS 1859 02:54:21,340 --> 02:54:24,860 Starving, shaken, and badly wounded... 1860 02:54:26,820 --> 02:54:28,940 ..Rose needs comfort. 1861 02:54:30,380 --> 02:54:32,820 DEEP GRUNT 1862 02:54:41,660 --> 02:54:47,180 The young Albertosaurus take time out together to groom. 1863 02:54:52,580 --> 02:54:55,140 A soothing ritual... 1864 02:54:55,140 --> 02:54:57,180 SOFT GRUNTS 1865 02:55:00,420 --> 02:55:02,580 ..that strengthens their bond. 1866 02:55:36,460 --> 02:55:38,500 As a new day dawns... 1867 02:55:39,780 --> 02:55:43,540 ..the pack's luck may be about to change. 1868 02:55:57,380 --> 02:56:00,380 The Edmontosaurus have finally made it to 1869 02:56:00,380 --> 02:56:01,900 their summer feeding ground. 1870 02:56:13,860 --> 02:56:17,260 Not a moment too soon for the starving Albertosaurus. 1871 02:56:21,860 --> 02:56:25,300 And despite their young age, Rose, her mate, 1872 02:56:25,300 --> 02:56:29,340 and the other youngsters will play a crucial role in the hunt. 1873 02:56:32,660 --> 02:56:35,660 The fate of the whole pack depends on them. 1874 02:56:47,620 --> 02:56:49,820 Close to Rose's dig site, 1875 02:56:49,820 --> 02:56:52,580 a remarkable new fossil is emerging. 1876 02:56:55,100 --> 02:56:56,500 - Wow. 1877 02:57:00,060 --> 02:57:01,420 Very cool. 1878 02:57:04,700 --> 02:57:07,220 - An Edmontosaurus jawbone. 1879 02:57:07,220 --> 02:57:09,220 - Maybe this is the dentary going in here? 1880 02:57:09,220 --> 02:57:11,180 That could be the back part, yeah. 1881 02:57:12,820 --> 02:57:15,620 - But this fossil holds another secret. 1882 02:57:15,620 --> 02:57:17,180 - What have we got up here? 1883 02:57:19,220 --> 02:57:21,620 - That looks like enamel. 1884 02:57:21,620 --> 02:57:25,540 - Look here - serrations. 1885 02:57:25,540 --> 02:57:27,420 - That's incredible. 1886 02:57:28,900 --> 02:57:31,740 - This is no Edmontosaurus tooth. 1887 02:57:33,140 --> 02:57:35,940 This came from a meat-eater. 1888 02:57:37,300 --> 02:57:38,860 - Albertosaurus tooth? 1889 02:57:40,340 --> 02:57:41,980 I think you're right. 1890 02:57:41,980 --> 02:57:43,900 And, since we don't have much of the root, 1891 02:57:43,900 --> 02:57:45,780 it was probably lost during feeding. 1892 02:57:47,140 --> 02:57:49,060 - That is an awesome find. 1893 02:57:50,740 --> 02:57:53,700 - It's clear evidence that the Albertosaurus pack 1894 02:57:53,700 --> 02:57:56,420 did feast on Edmontosaurus. 1895 02:57:59,540 --> 02:58:04,100 But it doesn't help explain how they bought down such enormous prey... 1896 02:58:05,900 --> 02:58:08,900 ..and what role Rose might have played in the hunt. 1897 02:58:19,220 --> 02:58:22,700 - These are Rose's metatarsals from the right leg. 1898 02:58:22,700 --> 02:58:26,460 - Quite narrow and compact for an animal that people usually 1899 02:58:26,460 --> 02:58:28,820 envision as being huge, huh? 1900 02:58:31,260 --> 02:58:34,340 - Mark and Christiana investigate Rose's foot bones... 1901 02:58:36,460 --> 02:58:39,220 - They get a heck of a lot bigger. 1902 02:58:39,220 --> 02:58:42,620 - ..comparing them with the outer foot bones of a fully-grown adult. 1903 02:58:45,140 --> 02:58:49,300 While they're similar in length, they're a very different thickness. 1904 02:58:49,300 --> 02:58:52,380 - So, we can see this one is only about 1905 02:58:52,380 --> 02:58:54,700 three-and-a-half centimetres in width, 1906 02:58:54,700 --> 02:58:56,540 whereas, we look at this one, 1907 02:58:56,540 --> 02:58:58,940 we have...almost double that. 1908 02:58:58,940 --> 02:59:01,220 So, it's about 6cm in width. 1909 02:59:01,220 --> 02:59:03,580 Absolutely a beast - and the same thing can be said 1910 02:59:03,580 --> 02:59:05,060 about the other metatarsal. 1911 02:59:06,540 --> 02:59:10,660 - Rose was almost as tall as the largest Albertosaurus, 1912 02:59:10,660 --> 02:59:13,140 but just half the weight. 1913 02:59:13,140 --> 02:59:16,140 - She was definitely going to be much more agile and quick 1914 02:59:16,140 --> 02:59:17,620 than these big individuals, 1915 02:59:17,620 --> 02:59:20,580 which probably had a lot more difficulty picking up speed. 1916 02:59:23,340 --> 02:59:26,820 - Large Albertosaurus were unlikely to reach high speeds 1917 02:59:26,820 --> 02:59:28,580 due to their enormous weight. 1918 02:59:33,220 --> 02:59:36,420 Meaning Rose and the other youngsters must take on 1919 02:59:36,420 --> 02:59:38,500 the most dangerous of jobs. 1920 02:59:45,300 --> 02:59:47,540 LOW GROWLING 1921 02:59:57,860 --> 03:00:01,100 Rose and her mate split off from the pack. 1922 03:00:06,500 --> 03:00:10,180 As the swiftest runners, they must identify a target... 1923 03:00:14,940 --> 03:00:17,500 ..and separate it from the herd. 1924 03:00:25,060 --> 03:00:29,060 But they're a fraction of the weight of the largest Edmontosaurus. 1925 03:00:29,060 --> 03:00:31,020 HISSING 1926 03:00:38,660 --> 03:00:42,420 Impulsive and inexperienced, 1927 03:00:42,420 --> 03:00:46,820 Rose's mate blindly charges into the herd... 1928 03:00:46,820 --> 03:00:48,940 BELLOWING 1929 03:00:53,020 --> 03:00:56,420 ..trying to take down one of these enormous creatures alone. 1930 03:00:58,900 --> 03:01:00,580 DISTANT ROAR 1931 03:01:11,420 --> 03:01:14,460 DISTANT ROAR SCREECHES 1932 03:01:30,500 --> 03:01:33,380 Rose has lost her closest companion. 1933 03:01:41,460 --> 03:01:46,140 And each failed hunt brings her and the rest of the pack 1934 03:01:46,140 --> 03:01:48,060 closer to starvation. 1935 03:02:02,860 --> 03:02:05,220 BIRDS CALL 1936 03:02:10,540 --> 03:02:13,460 But Albertosaurus were successful, 1937 03:02:13,460 --> 03:02:15,260 even in times of adversity. 1938 03:02:16,900 --> 03:02:19,140 They were the dominant predator in Western Canada 1939 03:02:19,140 --> 03:02:22,020 for over three million years. 1940 03:02:25,380 --> 03:02:27,340 At Rose's dig site, 1941 03:02:27,340 --> 03:02:30,740 part of the reason behind their success might be emerging. 1942 03:02:35,980 --> 03:02:37,660 - This bit right here. 1943 03:02:37,660 --> 03:02:39,820 - An unassuming fragment of bone. 1944 03:02:41,020 --> 03:02:42,900 - It looks interesting. 1945 03:02:42,900 --> 03:02:45,060 - I thought it was a rock, actually. 1946 03:02:45,060 --> 03:02:47,420 But it's got a pretty interesting texture. 1947 03:02:47,420 --> 03:02:48,980 It looks like Albertosaurus. 1948 03:02:48,980 --> 03:02:53,380 And this roughened area looks to me like the border of an eye socket. 1949 03:02:54,780 --> 03:02:57,060 - Is this a part of Rose's skull? 1950 03:03:00,340 --> 03:03:01,700 - That is part of the skull. 1951 03:03:01,700 --> 03:03:05,180 It's probably an indication that the skull is in several pieces at least, 1952 03:03:05,180 --> 03:03:08,060 so we'll have to keep our eyes out for any loose skull bones 1953 03:03:08,060 --> 03:03:10,500 that might be scattered about amongst the site. 1954 03:03:18,300 --> 03:03:20,060 - Whoa! 1955 03:03:20,060 --> 03:03:21,700 It's Rose's ghost! 1956 03:03:27,620 --> 03:03:30,500 - The team estimates Rose's skull would have been about 1957 03:03:30,500 --> 03:03:32,340 two-thirds of a metre long. 1958 03:03:33,660 --> 03:03:38,540 Big, but not big enough to take down huge prey like Edmontosaurus. 1959 03:03:40,340 --> 03:03:43,380 But maybe she didn't have to. 1960 03:03:43,380 --> 03:03:46,580 Mark and Colton re-examine the jawbones of one of 1961 03:03:46,580 --> 03:03:48,620 the largest Albertosaurus. 1962 03:03:48,620 --> 03:03:51,060 - Just look how big and robust this jaw is. 1963 03:03:51,060 --> 03:03:53,180 It's absolutely crazy. 1964 03:03:53,180 --> 03:03:55,540 - There's quite a few tooth sockets on this side. 1965 03:03:56,740 --> 03:03:59,180 - It's the final piece of the puzzle, 1966 03:03:59,180 --> 03:04:02,900 revealing the pack's sophisticated hunting strategy. 1967 03:04:02,900 --> 03:04:05,460 - Altogether, 68 teeth in the jaw. 1968 03:04:06,460 --> 03:04:09,100 - Lots of points of entry into the body, 1969 03:04:09,100 --> 03:04:11,980 so, basically, instead of using the arms to grapple with prey, 1970 03:04:11,980 --> 03:04:13,420 it's all about the head. 1971 03:04:15,900 --> 03:04:19,620 - These jaws were built to apply brutal force. 1972 03:04:21,140 --> 03:04:24,220 - A bite force that's probably upwards of several tonnes. 1973 03:04:24,220 --> 03:04:26,580 There's not much that can, you know, protect itself from that, 1974 03:04:26,580 --> 03:04:28,940 once they have their eyes on you. - Yeah. 1975 03:04:30,980 --> 03:04:34,900 - Rose's speed and the bite force of these bigger animals... 1976 03:04:36,620 --> 03:04:38,660 ..make for a deadly combination. 1977 03:04:40,380 --> 03:04:43,460 - We could say that Rose was the runner, and this was the muscle. 1978 03:04:43,460 --> 03:04:46,620 When Rose got the animals out on their own, 1979 03:04:46,620 --> 03:04:49,180 big predator like this probably would've come out 1980 03:04:49,180 --> 03:04:50,540 and just finished the job. 1981 03:04:58,860 --> 03:05:02,420 - LOW GRUNTING 1982 03:05:09,380 --> 03:05:11,820 Rose may have lost her mate 1983 03:05:11,820 --> 03:05:14,300 but she must now work with the other youngsters 1984 03:05:14,300 --> 03:05:16,340 to find the easiest target. 1985 03:05:20,900 --> 03:05:23,900 But with one failed hunt already, 1986 03:05:23,900 --> 03:05:25,460 the pressure is on. 1987 03:05:36,460 --> 03:05:39,340 SNORTS 1988 03:05:39,340 --> 03:05:41,460 BELLOWS 1989 03:05:51,420 --> 03:05:54,420 Rearing up on their hind legs, 1990 03:05:54,420 --> 03:05:56,620 the Edmontosaurus are too powerful. 1991 03:05:56,620 --> 03:05:58,460 BELLOWS 1992 03:06:01,580 --> 03:06:03,580 But Rose bides her time... 1993 03:06:07,380 --> 03:06:10,380 ..until she spots an older individual. 1994 03:06:14,620 --> 03:06:16,980 One that might be weaker than the others. 1995 03:06:23,020 --> 03:06:24,820 BELLOWS 1996 03:06:39,180 --> 03:06:41,740 BELLOWS 1997 03:06:41,740 --> 03:06:44,620 Rose can't take this Edmontosaurus down alone. 1998 03:06:47,700 --> 03:06:49,860 But she can steer her prey... 1999 03:06:53,460 --> 03:06:56,540 ..right towards the killing jaws 2000 03:06:56,540 --> 03:06:57,980 of the matriarch. 2001 03:07:01,940 --> 03:07:04,300 BELLOWS SNARLS 2002 03:07:04,300 --> 03:07:06,580 But there's still fight in this old bull. 2003 03:07:21,140 --> 03:07:22,780 SCREECHES 2004 03:07:27,580 --> 03:07:28,620 GROWLS 2005 03:07:30,940 --> 03:07:33,940 Rose has played her part to perfection. 2006 03:07:35,980 --> 03:07:38,700 Finally, the pack can feed. 2007 03:07:48,700 --> 03:07:50,540 And this time... 2008 03:07:53,620 --> 03:07:57,060 ...Rose gets her share of the spoils. 2009 03:08:18,980 --> 03:08:20,780 - All right. Who's ready to jacket? 2010 03:08:21,900 --> 03:08:24,140 Coming your way! 2011 03:08:24,140 --> 03:08:25,940 - Grab those. 2012 03:08:25,940 --> 03:08:29,820 - The team is eager to get their finds back to the lab... 2013 03:08:29,820 --> 03:08:32,980 ...to learn more about this extraordinary creature. 2014 03:08:34,540 --> 03:08:38,220 They carefully wrap their discoveries in protective plaster. 2015 03:08:38,220 --> 03:08:41,540 - Sorry, everyone in the vicinity is going to receive plaster 2016 03:08:41,540 --> 03:08:44,060 on their clothes and body, so... 2017 03:08:48,260 --> 03:08:49,660 - One, two, three. 2018 03:08:49,660 --> 03:08:51,180 - Oh-oh-oh... 2019 03:08:51,180 --> 03:08:53,580 - It's OK, it's OK, there's lots of rock, there's lots of rock. 2020 03:08:53,580 --> 03:08:56,660 - They flip them, ready for transport back to base. 2021 03:08:56,660 --> 03:08:59,140 - Perfect. Beautiful. 2022 03:08:59,140 --> 03:09:00,540 Now just the third one. 2023 03:09:06,220 --> 03:09:08,300 Go! Flip. 2024 03:09:08,300 --> 03:09:10,020 - Watch your feet, watch your feet. 2025 03:09:11,580 --> 03:09:14,380 - But some of Rose's remains are too heavy 2026 03:09:14,380 --> 03:09:17,060 to carry down the hillside. 2027 03:09:17,060 --> 03:09:20,060 So, Mark has called in a little help. 2028 03:09:21,500 --> 03:09:24,380 - Oh...love that sound. 2029 03:09:27,340 --> 03:09:28,820 Hold on to your hats! 2030 03:09:33,900 --> 03:09:38,180 - One false move, and all the team's work would be destroyed. 2031 03:09:43,620 --> 03:09:45,460 With ropes attached... 2032 03:09:49,980 --> 03:09:52,820 ..Rose soars through the air. 2033 03:09:52,820 --> 03:09:55,340 - Go, Rose! - Yeah! 2034 03:10:15,380 --> 03:10:19,500 - But these ancient lands hold one final surprise 2035 03:10:19,500 --> 03:10:21,100 for the dino hunters. 2036 03:10:22,500 --> 03:10:24,300 - What have you got there, champ? 2037 03:10:24,300 --> 03:10:27,500 - Colton has made a once-in-a-lifetime discovery. 2038 03:10:27,500 --> 03:10:30,420 - Oh, what? - What is that? 2039 03:10:30,420 --> 03:10:33,780 - Wait, hold on, that's a... What?! - Whoa. 2040 03:10:33,780 --> 03:10:35,700 - A tiny jawbone. 2041 03:10:41,140 --> 03:10:42,740 - What's this a jaw of? 2042 03:10:42,740 --> 03:10:44,900 - It's an Albertosaurus. 2043 03:10:44,900 --> 03:10:47,340 - It's so tiny. 2044 03:10:47,340 --> 03:10:50,260 - This is a baby Albertosaurus. 2045 03:10:50,260 --> 03:10:52,380 - That's beautiful. - Like a baby. 2046 03:10:52,380 --> 03:10:54,660 - Yeah, probably only about a year old. 2047 03:10:54,660 --> 03:10:57,020 Think this is the youngest individual we have. 2048 03:10:58,860 --> 03:11:01,180 I mean, I had to put it down for a sec to make sure 2049 03:11:01,180 --> 03:11:04,220 - CHRISTINA LAUGHS I wasn't hallucinating. 2050 03:11:05,500 --> 03:11:07,580 - Just scratch it like a puppy. - Yeah. - Look. 2051 03:11:07,580 --> 03:11:09,020 - THEY LAUGH 2052 03:11:09,020 --> 03:11:12,140 It's more evidence of the success of the Albertosaurus. 2053 03:11:18,340 --> 03:11:22,500 And maybe, the baby belonged to one of the pack females. 2054 03:11:25,660 --> 03:11:28,140 Perhaps even Rose herself. 2055 03:11:33,340 --> 03:11:35,500 LOW GROWLING 2056 03:11:41,660 --> 03:11:46,260 As to how Rose died, we may never know. 2057 03:11:46,260 --> 03:11:47,820 - Show-and-tell time. 2058 03:11:48,980 --> 03:11:51,380 - Causes of death rarely fossilise. 2059 03:11:53,060 --> 03:11:55,380 - So cute! - That's awesome. 2060 03:11:55,380 --> 03:11:58,300 - Wow, the comparison really pulled it together. - Yeah. 2061 03:11:58,300 --> 03:12:00,780 It's not even as long as the tooth. 2062 03:12:00,780 --> 03:12:02,340 - Oh, my God! 2063 03:12:10,700 --> 03:12:13,380 - And, though her death is a mystery... 2064 03:12:15,620 --> 03:12:18,900 ..now at least, we can tell the story 2065 03:12:18,900 --> 03:12:21,100 of how she may have lived. 2066 03:12:32,420 --> 03:12:35,740 Rose, the young Albertosaurus... 2067 03:12:37,980 --> 03:12:40,220 ..earned her rightful place... 2068 03:12:42,860 --> 03:12:45,980 ..hunting and surviving... 2069 03:12:48,300 --> 03:12:50,540 ..with her pack by her side. 2070 03:13:11,140 --> 03:13:13,460 Next time... 2071 03:13:13,460 --> 03:13:15,900 ..a toddler makes a perilous journey... 2072 03:13:19,460 --> 03:13:22,540 ..joining one of the largest dinosaur herds 2073 03:13:22,540 --> 03:13:24,100 that ever lived... 2074 03:13:25,380 --> 03:13:27,580 ..in its fight for survival. 2075 03:14:17,340 --> 03:14:19,580 Over 66 million years ago... 2076 03:14:20,860 --> 03:14:23,740 SCREECHING 2077 03:14:24,780 --> 03:14:27,020 ..our world was ruled... 2078 03:14:27,020 --> 03:14:28,220 SNARLS 2079 03:14:28,220 --> 03:14:29,860 ROARS 2080 03:14:29,860 --> 03:14:31,260 ..by dinosaurs. 2081 03:14:31,260 --> 03:14:32,380 GROWLS 2082 03:14:32,380 --> 03:14:34,220 BELLOWING 2083 03:14:39,020 --> 03:14:43,540 The largest animals that have ever walked the Earth. 2084 03:14:45,540 --> 03:14:46,660 SCREECHES 2085 03:14:50,260 --> 03:14:54,260 Today, dinosaur experts across the globe 2086 03:14:54,260 --> 03:14:57,580 are uncovering the bones they left behind... 2087 03:15:00,980 --> 03:15:05,540 ..allowing us to imagine how these extraordinary creatures 2088 03:15:05,540 --> 03:15:07,540 may have lived... 2089 03:15:10,540 --> 03:15:13,500 ..so that we can tell their stories... 2090 03:15:17,940 --> 03:15:19,060 ..and they... 2091 03:15:20,420 --> 03:15:22,100 ..can walk again. 2092 03:15:22,100 --> 03:15:23,140 ROARS 2093 03:15:51,700 --> 03:15:55,580 Deep in the ancient forests of Alberta, Canada... 2094 03:15:58,420 --> 03:16:00,980 LOW CONVERSATION 2095 03:16:02,100 --> 03:16:04,700 ..a team of dinosaur hunters 2096 03:16:04,700 --> 03:16:07,660 has come to unearth an astonishing find. 2097 03:16:09,860 --> 03:16:12,900 - We've got at least three bones sticking out here. 2098 03:16:12,900 --> 03:16:15,660 - Discovered on the edge of a creek... 2099 03:16:16,900 --> 03:16:20,220 ..are the bones of a pachyrhinosaurus... 2100 03:16:23,060 --> 03:16:25,580 ..a unique horned dinosaur. 2101 03:16:29,700 --> 03:16:31,900 Lying here is a toddler... 2102 03:16:31,900 --> 03:16:33,660 - It's such a tiny little bone. 2103 03:16:33,660 --> 03:16:35,620 - ..they call Albie. 2104 03:16:36,700 --> 03:16:38,580 - Don't think I've seen one that small before. 2105 03:16:41,900 --> 03:16:43,500 - And he's not alone. 2106 03:16:44,940 --> 03:16:48,940 He's part of one of the largest dinosaur herds ever found... 2107 03:16:50,340 --> 03:16:53,140 ..numbering in the thousands. 2108 03:16:55,340 --> 03:16:57,540 - We have big adults, we have little babies, 2109 03:16:57,540 --> 03:16:59,220 we have every age in between. 2110 03:16:59,220 --> 03:17:03,180 This was a huge herd of animals. 2111 03:17:04,420 --> 03:17:07,980 - Why so many are buried here is a mystery. 2112 03:17:11,340 --> 03:17:13,260 But by studying the bones, 2113 03:17:13,260 --> 03:17:17,700 we can begin to tell their extraordinary story. 2114 03:17:35,780 --> 03:17:37,940 73 million years ago. 2115 03:17:44,820 --> 03:17:47,940 What will one day be north-western Canada 2116 03:17:47,940 --> 03:17:52,300 is part of a landmass called Laramidia. 2117 03:17:56,140 --> 03:18:00,380 Mountain ranges extend for thousands of miles... 2118 03:18:00,380 --> 03:18:02,260 WIND WHISTLES 2119 03:18:02,260 --> 03:18:07,980 ..towering over a wilderness of dense forested valleys. 2120 03:18:07,980 --> 03:18:09,660 BIRDSONG 2121 03:18:12,020 --> 03:18:14,300 BELLOWING 2122 03:18:15,820 --> 03:18:19,820 This vast terrain is roamed by gigantic groups 2123 03:18:19,820 --> 03:18:22,100 of plant-eating dinosaurs... 2124 03:18:25,580 --> 03:18:28,460 ..that, like today's caribou or elk, 2125 03:18:28,460 --> 03:18:30,860 migrate each season. 2126 03:18:36,540 --> 03:18:40,860 And by far the largest of these prehistoric herds... 2127 03:18:47,980 --> 03:18:49,740 ..are the pachyrhinosaurus. 2128 03:19:00,580 --> 03:19:03,140 A close relative of triceratops, 2129 03:19:03,140 --> 03:19:07,500 these social dinosaurs have spent the winter in the south. 2130 03:19:14,620 --> 03:19:17,980 But with the land now almost completely bare... 2131 03:19:21,900 --> 03:19:24,780 ..staying here would mean starvation. 2132 03:19:33,420 --> 03:19:38,540 So the herd is setting out on an epic 400-mile trek north... 2133 03:19:39,700 --> 03:19:40,980 ..where, by summer, 2134 03:19:40,980 --> 03:19:43,380 the vegetation should be abundant. 2135 03:19:45,100 --> 03:19:47,340 SNORTING AND GRUNTING 2136 03:19:50,620 --> 03:19:53,500 It will be a gruelling journey... 2137 03:19:54,780 --> 03:19:57,540 ..especially if you're one of the youngest... 2138 03:20:00,060 --> 03:20:01,580 ..like Albie. 2139 03:20:16,180 --> 03:20:19,740 At less than a year old, he's only half a metre tall... 2140 03:20:23,100 --> 03:20:24,780 ..which makes keeping up... 2141 03:20:26,300 --> 03:20:28,060 ..a bit of a challenge. 2142 03:20:32,700 --> 03:20:34,620 HE YOWLS 2143 03:20:34,620 --> 03:20:37,900 Even so, he must stay close to his mother... 2144 03:20:39,660 --> 03:20:40,900 HE YOWLS 2145 03:20:40,900 --> 03:20:44,100 ..because the herd aren't the only ones that are hungry. 2146 03:20:44,100 --> 03:20:45,300 SQUAWKING 2147 03:20:49,220 --> 03:20:51,260 Following in their wake, 2148 03:20:51,260 --> 03:20:53,940 an azhdarchid pterosaur. 2149 03:20:58,780 --> 03:21:04,100 With a six-metre wingspan and estimated speed of 60mph... 2150 03:21:08,060 --> 03:21:12,860 ..a young pachyrhinosaurus makes for an easy target. 2151 03:21:21,980 --> 03:21:23,660 HE CALLS 2152 03:21:24,940 --> 03:21:26,700 BELLOWS 2153 03:21:40,420 --> 03:21:42,180 A close call. 2154 03:21:50,940 --> 03:21:54,260 But it's only the start of the challenges they will face... 2155 03:22:02,740 --> 03:22:05,620 ..as the search for food takes them across 2156 03:22:05,620 --> 03:22:08,100 the prehistoric wilderness. 2157 03:22:16,260 --> 03:22:18,340 LOW CONVERSATION 2158 03:22:22,940 --> 03:22:25,140 73 million years later... 2159 03:22:27,660 --> 03:22:30,340 ..the work to understand this enormous herd 2160 03:22:30,340 --> 03:22:32,100 is well under way. 2161 03:22:33,340 --> 03:22:35,900 - There's a pretty large cluster of bones there. 2162 03:22:35,900 --> 03:22:39,420 - Seem to belong, potentially, to a large animal. 2163 03:22:41,540 --> 03:22:43,060 - It's a painstaking process... 2164 03:22:45,500 --> 03:22:47,900 ..led by Dr Emily Bamforth... 2165 03:22:49,460 --> 03:22:51,020 ..who is piecing together 2166 03:22:51,020 --> 03:22:53,740 the journey that brought the herd here. 2167 03:22:59,420 --> 03:23:01,500 And in one corner of the site... 2168 03:23:02,860 --> 03:23:04,740 - Is that a little vertebra? 2169 03:23:05,900 --> 03:23:08,060 - ..something has caught her eye. 2170 03:23:08,060 --> 03:23:10,500 - Oh, man, that is so little! 2171 03:23:11,660 --> 03:23:13,980 - Right in this corner. 2172 03:23:13,980 --> 03:23:17,100 Baby bone, baby bone, baby bone. 2173 03:23:18,940 --> 03:23:23,100 - Emerging from the rock are not just Albie's bones, 2174 03:23:23,100 --> 03:23:25,500 but those of other youngsters. 2175 03:23:30,300 --> 03:23:32,500 And comparing their size... 2176 03:23:33,460 --> 03:23:36,540 - Juvenile vertebra is 7cm. 2177 03:23:36,540 --> 03:23:38,740 That's another really young animal. 2178 03:23:38,740 --> 03:23:42,140 - ..reveals something significant. 2179 03:23:42,140 --> 03:23:46,260 - All of the juveniles here, these are all about a year old. - Wow. 2180 03:23:46,260 --> 03:23:48,220 - They're all the same age... 2181 03:23:49,660 --> 03:23:51,460 ..born around the same time. 2182 03:23:53,460 --> 03:23:54,860 - They have to have been born 2183 03:23:54,860 --> 03:23:57,580 on the previous summer's migration. 2184 03:23:57,580 --> 03:23:59,260 That, to me, is interesting. 2185 03:24:02,180 --> 03:24:05,180 - Emily's findings suggest the herd was making 2186 03:24:05,180 --> 03:24:09,380 its yearly journey for more than just food. 2187 03:24:19,380 --> 03:24:23,420 They were returning to their summer nesting ground. 2188 03:24:30,900 --> 03:24:33,580 And joining them are thousands more... 2189 03:24:37,060 --> 03:24:39,460 ..as every pachyrhinosaurus on the continent... 2190 03:24:41,180 --> 03:24:42,220 ..heads north... 2191 03:24:49,500 --> 03:24:53,100 ..merging into one of the greatest spectacles 2192 03:24:53,100 --> 03:24:54,980 of the prehistoric world. 2193 03:25:04,060 --> 03:25:05,780 BELLOWS 2194 03:25:10,580 --> 03:25:12,940 But with such a colossal gathering... 2195 03:25:15,140 --> 03:25:16,820 ..tension is in the air. 2196 03:25:22,980 --> 03:25:25,020 Breeding season is upon them... 2197 03:25:26,260 --> 03:25:29,180 ..so bulls in the herd must compete 2198 03:25:29,180 --> 03:25:30,900 for their right to mate. 2199 03:25:31,940 --> 03:25:34,820 BELLOWS LOUDLY 2200 03:25:34,820 --> 03:25:36,860 From old veterans... 2201 03:25:42,220 --> 03:25:44,220 ..to their younger rivals. 2202 03:25:51,460 --> 03:25:52,980 And there's only one way... 2203 03:25:54,380 --> 03:25:56,020 ..to prove their worth. 2204 03:26:12,420 --> 03:26:14,620 In a contest as brutal as this... 2205 03:26:14,620 --> 03:26:16,340 ALBIE SQUEAKS 2206 03:26:16,340 --> 03:26:18,940 ..Albie's mother must keep a watchful eye... 2207 03:26:22,940 --> 03:26:26,540 ..making sure he isn't trampled, or even killed. 2208 03:26:41,900 --> 03:26:44,420 But as one of the youngest, 2209 03:26:44,420 --> 03:26:47,420 curiosity gets the better of him. 2210 03:26:50,340 --> 03:26:52,140 ALBIE SQUEAKS 2211 03:27:01,180 --> 03:27:03,340 Using their thick armoured noses... 2212 03:27:08,580 --> 03:27:12,660 ..each male seeks to deliver a bone-shattering blow. 2213 03:27:19,380 --> 03:27:21,340 And the ultimate target... 2214 03:27:23,460 --> 03:27:26,540 ..is behind the other's horned armour. 2215 03:27:31,420 --> 03:27:32,940 The young rival... 2216 03:27:32,940 --> 03:27:34,780 BELLOWS 2217 03:27:34,780 --> 03:27:36,700 ..gains the upper hand. 2218 03:27:39,900 --> 03:27:42,260 GRUNTS 2219 03:27:47,140 --> 03:27:48,420 - That is weird. 2220 03:27:50,540 --> 03:27:54,060 - At the dig site, uncovering what appears to be 2221 03:27:54,060 --> 03:27:55,940 the rib of a huge bull... 2222 03:27:57,380 --> 03:27:59,620 - Seems like the rib trends this way 2223 03:27:59,620 --> 03:28:03,460 but then starts back up that way. 2224 03:28:03,460 --> 03:28:07,060 - ..Emily and her teammate Max Scott 2225 03:28:07,060 --> 03:28:10,300 are finding evidence of a punishing injury. 2226 03:28:13,740 --> 03:28:17,260 - This part of the rib and that part of the rib are slightly offset, 2227 03:28:17,260 --> 03:28:19,100 so it looks as if this rib 2228 03:28:19,100 --> 03:28:21,980 has actually been broken in the middle. 2229 03:28:21,980 --> 03:28:25,820 - Gosh. It seems like it was almost shoved off to one side. 2230 03:28:26,940 --> 03:28:30,180 - The rib is twice as thick as a bear's. 2231 03:28:31,700 --> 03:28:33,020 The fact it snapped 2232 03:28:33,020 --> 03:28:36,820 means this bull suffered a potentially-fatal blow. 2233 03:28:38,660 --> 03:28:41,140 - It would have to be a considerable impact, 2234 03:28:41,140 --> 03:28:44,060 so either the opponent striking it really hard, 2235 03:28:44,060 --> 03:28:46,020 or when it fell sideways. 2236 03:28:46,020 --> 03:28:48,620 Whatever happened, it would have been very painful. 2237 03:28:48,620 --> 03:28:50,140 Like, with an impact this size, 2238 03:28:50,140 --> 03:28:51,740 the rib could puncture the lung. 2239 03:28:59,020 --> 03:29:03,060 - But examining the fossil reveals something curious. 2240 03:29:03,060 --> 03:29:04,940 - It's really bulgy there. 2241 03:29:04,940 --> 03:29:07,060 - So I think that's a bone callus. 2242 03:29:08,180 --> 03:29:13,300 - Bone calluses form over a break as part of the healing process. 2243 03:29:13,300 --> 03:29:15,500 - The bone has broken 2244 03:29:15,500 --> 03:29:19,300 and has actually shifted sideways while the animal was alive, 2245 03:29:19,300 --> 03:29:21,380 and this big bony bump 2246 03:29:21,380 --> 03:29:23,820 healed around it and set it. 2247 03:29:23,820 --> 03:29:25,580 Would have been very painful for the animal, 2248 03:29:25,580 --> 03:29:27,220 but they would have survived it. 2249 03:29:27,220 --> 03:29:29,020 - It's really quite an impressive feat. 2250 03:29:29,020 --> 03:29:31,380 Really shows just how tough he really was. 2251 03:29:36,220 --> 03:29:39,260 - The healed injury is important evidence. 2252 03:29:40,940 --> 03:29:43,100 LABOURED BREATHS 2253 03:29:44,420 --> 03:29:47,180 It suggests the strongest bulls in the herd... 2254 03:29:49,300 --> 03:29:52,100 ..were capable of taking severe punishment... 2255 03:29:54,180 --> 03:29:56,460 BELLOWING 2256 03:29:58,580 --> 03:30:01,620 ..and getting back on their feet. 2257 03:30:11,780 --> 03:30:13,980 BELLOWS 2258 03:30:28,540 --> 03:30:30,700 An ability they'd need... 2259 03:30:32,260 --> 03:30:34,100 ..to come out on top. 2260 03:30:35,220 --> 03:30:37,540 BELLOWS 2261 03:30:42,460 --> 03:30:44,340 GRUNTS 2262 03:30:46,260 --> 03:30:48,780 With a winner firmly established... 2263 03:30:53,380 --> 03:30:57,780 ..the monumental herd continues its journey to the fertile north. 2264 03:31:07,860 --> 03:31:10,100 ALBIE SQUEAKS 2265 03:31:11,900 --> 03:31:14,180 But though the fighting may have subsided... 2266 03:31:15,980 --> 03:31:20,380 ..for Albie, the danger is only just beginning. 2267 03:31:20,380 --> 03:31:21,820 HE WHINES 2268 03:31:31,820 --> 03:31:33,580 In the chaos, 2269 03:31:33,580 --> 03:31:35,860 he has become separated from his mother... 2270 03:31:37,340 --> 03:31:39,220 ..and lost in the crowd. 2271 03:31:47,580 --> 03:31:49,900 In a herd of this magnitude... 2272 03:31:51,860 --> 03:31:54,380 ..finding her won't be easy. 2273 03:32:13,100 --> 03:32:14,620 - Look at this. 2274 03:32:14,620 --> 03:32:16,060 - But at the dig site, 2275 03:32:16,060 --> 03:32:20,900 evidence is emerging that suggests every one of this enormous herd 2276 03:32:20,900 --> 03:32:22,740 may have looked unique. 2277 03:32:24,780 --> 03:32:27,060 - It looks like it's relatively complete 2278 03:32:27,060 --> 03:32:28,980 and this is a big one. 2279 03:32:28,980 --> 03:32:32,860 - Buried in the rock is an incredibly rare find - 2280 03:32:32,860 --> 03:32:35,940 an adult's bony headdress... 2281 03:32:37,100 --> 03:32:38,660 ..known as the frill. 2282 03:32:40,820 --> 03:32:43,660 - This might be the front and that's the back. 2283 03:32:43,660 --> 03:32:45,620 - Yeah, that's what I was thinking too. 2284 03:32:45,620 --> 03:32:47,700 So, like, the nose is over here somewhere, 2285 03:32:47,700 --> 03:32:49,900 and, like, the body is back there. 2286 03:32:49,900 --> 03:32:51,780 - I don't think I've ever seen any 2287 03:32:51,780 --> 03:32:54,100 where one of the middle horns 2288 03:32:54,100 --> 03:32:56,860 is going the opposite direction of the other. 2289 03:32:58,780 --> 03:33:01,540 - Given this frill's highly unusual shape, 2290 03:33:01,540 --> 03:33:06,020 Emily is keen to compare it with others found in the creek. 2291 03:33:09,740 --> 03:33:11,060 - So, on this individual, 2292 03:33:11,060 --> 03:33:14,460 the horns that stick out the side of the frill, 2293 03:33:14,460 --> 03:33:16,220 they're straight, 2294 03:33:16,220 --> 03:33:17,860 whereas this one is interesting. 2295 03:33:17,860 --> 03:33:19,540 This is an asymmetrical frill, 2296 03:33:19,540 --> 03:33:22,380 so this horn is straight 2297 03:33:22,380 --> 03:33:25,300 and that one is curled. 2298 03:33:28,820 --> 03:33:32,060 - Each frill is distinct from the other. 2299 03:33:33,380 --> 03:33:35,580 - It is very striking that these frills, 2300 03:33:35,580 --> 03:33:38,220 despite being from almost exactly the same place 2301 03:33:38,220 --> 03:33:41,140 in the bone bed, from the same community of animals, 2302 03:33:41,140 --> 03:33:43,980 like, they're still very different from one another. 2303 03:33:46,220 --> 03:33:49,540 - Remarkably, no two frills found at the site 2304 03:33:49,540 --> 03:33:51,540 have ever looked the same... 2305 03:33:54,620 --> 03:33:57,140 ..leading the team to think their variation 2306 03:33:57,140 --> 03:33:59,580 served a crucial purpose. 2307 03:33:59,580 --> 03:34:02,020 - Based on the differences in these frill horns, 2308 03:34:02,020 --> 03:34:03,940 it would be very easy for the individuals 2309 03:34:03,940 --> 03:34:05,100 to recognise each other. 2310 03:34:05,100 --> 03:34:07,620 - Yeah. In a herd environment like this, 2311 03:34:07,620 --> 03:34:10,220 it's very important to be able to recognise 2312 03:34:10,220 --> 03:34:12,820 your friends and your family easily. 2313 03:34:20,540 --> 03:34:25,620 - With every member of the herd displaying their own unique frill... 2314 03:34:27,540 --> 03:34:29,700 ALBIE YOWLS 2315 03:34:29,700 --> 03:34:32,420 ..it could help a youngster like Albie... 2316 03:34:34,300 --> 03:34:37,940 ..pick out his mother from the masses... 2317 03:34:44,020 --> 03:34:46,140 ..by scanning each and every one... 2318 03:34:47,660 --> 03:34:49,940 ..for her familiar features. 2319 03:34:56,420 --> 03:34:58,140 HE CALLS 2320 03:35:01,020 --> 03:35:05,100 But in the sea of pachyrhinosaurus streaming past... 2321 03:35:08,700 --> 03:35:10,020 ..she is still... 2322 03:35:11,500 --> 03:35:13,100 ..nowhere to be seen. 2323 03:35:17,700 --> 03:35:19,380 HE YOWLS 2324 03:35:35,500 --> 03:35:37,820 Without his mother's protection... 2325 03:35:39,180 --> 03:35:42,860 ..he has little chance of surviving the long journey... 2326 03:35:44,180 --> 03:35:45,580 ..alone. 2327 03:35:57,780 --> 03:35:59,620 PLAINTIVE BELLOWS 2328 03:36:07,380 --> 03:36:08,740 FOLIAGE SNAPPING 2329 03:36:08,740 --> 03:36:10,060 Until... 2330 03:36:10,060 --> 03:36:11,900 GENTLE GRUNT 2331 03:36:11,900 --> 03:36:13,540 ..finally... 2332 03:36:14,820 --> 03:36:17,620 ..the distinctive outline of a frill... 2333 03:36:20,020 --> 03:36:22,820 ..he knows better than any other. 2334 03:36:29,020 --> 03:36:32,780 And a mother relieved to have found her young. 2335 03:36:32,780 --> 03:36:35,140 YOWLS AND GRUNTS 2336 03:36:37,220 --> 03:36:39,660 BOTH GRUNT SOFTLY 2337 03:36:52,300 --> 03:36:54,140 But though reunited... 2338 03:36:55,620 --> 03:36:58,420 ..there is much danger still ahead. 2339 03:37:14,340 --> 03:37:17,380 30 miles from the main dig site... 2340 03:37:24,980 --> 03:37:28,020 ..Emily and palaeontologist Jackson Sweder... 2341 03:37:29,380 --> 03:37:32,140 ..have travelled to the edge of a forest. 2342 03:37:38,700 --> 03:37:43,540 Here, ancient footprints follow the herd's route. 2343 03:37:45,100 --> 03:37:46,900 - That's a toe. - Yeah. 2344 03:37:46,900 --> 03:37:49,260 - And that's a toe. You seen the third one here? 2345 03:37:49,260 --> 03:37:52,780 See it again, missing that toe? - Maybe... Yeah, missing. - Yeah. 2346 03:37:52,780 --> 03:37:53,820 Once you get your eye in, 2347 03:37:53,820 --> 03:37:57,020 they're actually all over the place. - LAUGHING: - They're everywhere. 2348 03:37:59,220 --> 03:38:03,260 - And one stands out from all the others. 2349 03:38:03,260 --> 03:38:04,900 - Clearly a carnivore. 2350 03:38:06,100 --> 03:38:08,660 And you can even see the claws. 2351 03:38:08,660 --> 03:38:10,500 - That's a point. 2352 03:38:11,580 --> 03:38:13,420 - Big, big animal as well. 2353 03:38:14,860 --> 03:38:18,540 - What, eight metres? - Yeah. 2354 03:38:24,100 --> 03:38:27,220 - To confirm the identity of this large predator... 2355 03:38:28,580 --> 03:38:32,180 ..Emily and Jackson use liquid rubber 2356 03:38:32,180 --> 03:38:36,940 to make a cast that reveals how it moved. 2357 03:38:40,060 --> 03:38:43,380 - The back of the track is shallower than these toes here. 2358 03:38:43,380 --> 03:38:45,260 - The toes are super deep. 2359 03:38:45,260 --> 03:38:47,380 - So it's moving on the front of its feet, 2360 03:38:47,380 --> 03:38:50,300 sort of like the fast animals today, like cheetahs, would do. 2361 03:38:50,300 --> 03:38:53,020 - Definitely wider than it is deep, 2362 03:38:53,020 --> 03:38:54,780 so it can move side to side if it has to. 2363 03:38:54,780 --> 03:38:58,700 - So probably a very agile animal as well. 2364 03:38:59,820 --> 03:39:02,340 - This kind of speed and agility 2365 03:39:02,340 --> 03:39:05,220 belongs to only one predator in the region. 2366 03:39:07,420 --> 03:39:10,260 A terrifying relative of T-rex 2367 03:39:10,260 --> 03:39:12,260 that hunted in packs. 2368 03:39:13,980 --> 03:39:15,060 - Those pachyrhinosaurus 2369 03:39:15,060 --> 03:39:18,460 definitely would have had to worry about this animal. - Yeah. 2370 03:39:18,460 --> 03:39:21,620 - It's very efficient at moving long distances. 2371 03:39:21,620 --> 03:39:23,340 It could follow them for miles 2372 03:39:23,340 --> 03:39:25,020 and just wait for an opportunity. 2373 03:39:27,660 --> 03:39:29,740 - The gorgosaurus. 2374 03:39:29,740 --> 03:39:31,460 QUIET SNARLING 2375 03:39:39,500 --> 03:39:41,340 With exceptional hearing... 2376 03:39:44,140 --> 03:39:48,500 ..and a sense of smell more powerful than any other dinosaur... 2377 03:39:51,660 --> 03:39:54,340 ..it's thought they could track their prey 2378 03:39:54,340 --> 03:39:57,220 from up to ten miles away... 2379 03:40:06,140 --> 03:40:10,500 ..allowing them to ambush at a moment of their choosing. 2380 03:40:26,820 --> 03:40:28,980 Unaware of the approaching threat, 2381 03:40:28,980 --> 03:40:31,700 the herd moves deeper into the forest. 2382 03:40:35,780 --> 03:40:39,220 Surrounded by its narrow pathways... 2383 03:40:44,900 --> 03:40:48,700 ..an attack could come from any direction. 2384 03:40:51,820 --> 03:40:53,980 HE SNUFFLES 2385 03:40:53,980 --> 03:40:55,380 BRANCH SNAPS 2386 03:41:05,780 --> 03:41:09,020 But there is no sign of the danger...yet. 2387 03:41:18,020 --> 03:41:21,780 SNORING 2388 03:41:23,460 --> 03:41:26,300 DISTANT BELLOWING 2389 03:41:28,180 --> 03:41:29,900 SNORTS 2390 03:41:34,300 --> 03:41:36,020 QUIET THUDDING 2391 03:41:39,020 --> 03:41:42,380 DISTANT FOLIAGE SNAPPING 2392 03:41:42,380 --> 03:41:44,220 The sound of intruders... 2393 03:41:46,100 --> 03:41:49,020 ..draws Albie away from the herd. 2394 03:41:49,020 --> 03:41:51,420 FOLIAGE SNAPPING 2395 03:41:56,500 --> 03:42:00,060 But these aren't the stealthy footsteps of a gorgosaurus. 2396 03:42:02,860 --> 03:42:06,620 Something else is closing in. 2397 03:42:20,060 --> 03:42:21,820 - Take care with your footing. 2398 03:42:24,740 --> 03:42:27,820 - Journeying along the herd's migration route, 2399 03:42:27,820 --> 03:42:31,220 Emily and her team have discovered evidence 2400 03:42:31,220 --> 03:42:34,060 of another mysterious dinosaur... 2401 03:42:35,580 --> 03:42:39,620 ..which has emerged on the edge of what is now a river. 2402 03:42:41,860 --> 03:42:43,140 - Oh! 2403 03:42:43,140 --> 03:42:45,980 - Yeah, it's a little chilly. - Oh, yeah, it's cold. 2404 03:42:49,460 --> 03:42:52,260 - Exposed by receding water, 2405 03:42:52,260 --> 03:42:56,700 its fossilised remains are all along the river bank. 2406 03:42:58,660 --> 03:43:00,260 - It's huge. 2407 03:43:02,420 --> 03:43:04,340 It's just packed with stuff. 2408 03:43:04,340 --> 03:43:08,100 It's crazy that it's just kind of sitting out here on the surface. 2409 03:43:08,100 --> 03:43:09,540 Man, that's big. 2410 03:43:11,860 --> 03:43:14,580 It definitely seems to be in a layer here... 2411 03:43:14,580 --> 03:43:16,540 - Whatever this is. 2412 03:43:20,140 --> 03:43:23,860 - And it isn't long before the team hits the jackpot. 2413 03:43:24,900 --> 03:43:26,460 - Oh, my goodness! 2414 03:43:30,540 --> 03:43:32,420 That's a huge bone. 2415 03:43:34,180 --> 03:43:39,180 - Buried in the rock is part of its gigantic hind limb. 2416 03:43:39,180 --> 03:43:40,980 - Do you have a measuring tape? 2417 03:43:40,980 --> 03:43:42,980 - Yeah, let's just take a quick measurement. 2418 03:43:42,980 --> 03:43:47,780 - They can use this to estimate the animal's full size. 2419 03:43:49,260 --> 03:43:50,780 - It's really long. 2420 03:43:50,780 --> 03:43:52,220 Even if it's only to there, 2421 03:43:52,220 --> 03:43:55,780 that's still definitely over a metre. 2422 03:43:55,780 --> 03:43:58,300 - Yeah. I would say, with legs like this, 2423 03:43:58,300 --> 03:44:00,340 it's probably about the size of a school bus, 2424 03:44:00,340 --> 03:44:02,780 around nine metres long or so. That's huge. 2425 03:44:03,780 --> 03:44:06,900 - There's not much that gets bigger than this. 2426 03:44:06,900 --> 03:44:09,980 - Even larger than a gorgosaurus... 2427 03:44:11,180 --> 03:44:15,580 ..its nine-metre length means it could be only one dinosaur. 2428 03:44:22,580 --> 03:44:25,980 And the forest is the ideal place 2429 03:44:25,980 --> 03:44:28,980 for it to find its next meal. 2430 03:44:28,980 --> 03:44:30,740 FOLIAGE SNAPS 2431 03:44:32,620 --> 03:44:35,660 SNORTING 2432 03:44:40,700 --> 03:44:43,260 MUNCHING 2433 03:44:43,260 --> 03:44:46,020 But this isn't a killer. 2434 03:44:46,020 --> 03:44:47,580 ALBIE SQUEAKS 2435 03:44:50,820 --> 03:44:53,220 It's an Edmontosaurus... 2436 03:44:53,220 --> 03:44:55,500 THUDDING STEPS 2437 03:44:55,500 --> 03:44:56,820 MUNCHING 2438 03:44:56,820 --> 03:45:01,260 ..which, along with its herd, is on the same migration north. 2439 03:45:01,260 --> 03:45:02,940 BELLOWS 2440 03:45:04,660 --> 03:45:07,780 As plant-eaters, they pose no threat... 2441 03:45:09,540 --> 03:45:12,060 ..but these six-tonne giants... 2442 03:45:12,060 --> 03:45:13,620 FOLIAGE SNAPS 2443 03:45:14,700 --> 03:45:17,540 FOLIAGE SNAPS ..make a lot of noise. 2444 03:45:17,540 --> 03:45:20,260 FOLIAGE SNAPPING 2445 03:45:20,260 --> 03:45:22,020 DISTANT SQUAWKING 2446 03:45:25,540 --> 03:45:28,540 DISTANT ROARING 2447 03:45:28,540 --> 03:45:30,700 RUMBLING GRUNTS 2448 03:45:31,660 --> 03:45:34,860 ..and it's drawing the pack of hungry gorgosaurus 2449 03:45:34,860 --> 03:45:37,100 straight towards them. 2450 03:45:41,580 --> 03:45:43,460 GRUNTS 2451 03:45:43,460 --> 03:45:45,180 BELLOWS 2452 03:45:47,500 --> 03:45:49,140 BELLOWING 2453 03:46:07,740 --> 03:46:09,620 SNARLING 2454 03:46:11,540 --> 03:46:13,460 IT ROARS 2455 03:46:16,740 --> 03:46:18,300 FOLIAGE SNAPPING 2456 03:46:23,380 --> 03:46:25,620 MUNCHING 2457 03:46:33,380 --> 03:46:36,660 For Albie, it's another narrow escape. 2458 03:46:50,660 --> 03:46:53,060 And as the herd pushes on, 2459 03:46:53,060 --> 03:46:55,980 the aurora lighting up the skies above... 2460 03:46:57,300 --> 03:47:01,260 ..is a sign their journey north is almost over. 2461 03:47:19,460 --> 03:47:21,460 - Do you have a chisel? - Yep. 2462 03:47:21,460 --> 03:47:23,420 - Not far from the main dig site... 2463 03:47:26,660 --> 03:47:29,220 ..Emily and Jackson are finding evidence 2464 03:47:29,220 --> 03:47:31,820 of exactly what the herd was looking for. 2465 03:47:33,700 --> 03:47:35,300 - That's huge. - Yeah. 2466 03:47:35,300 --> 03:47:39,700 - An abundance of food just waiting to be discovered. 2467 03:47:39,700 --> 03:47:42,020 - There's so many different plants here, 2468 03:47:42,020 --> 03:47:43,460 just on this one slab. 2469 03:47:43,460 --> 03:47:46,300 - Not just big leaves like this. 2470 03:47:46,300 --> 03:47:49,340 - Also lots of flowering plants as well. 2471 03:47:49,340 --> 03:47:52,860 All these things would be really great food for pachyrhinosaurus. 2472 03:47:54,140 --> 03:47:56,020 - The plants in these rocks 2473 03:47:56,020 --> 03:47:58,340 would have flourished in the summer... 2474 03:47:59,420 --> 03:48:02,340 ..in time for the herd's nesting season. 2475 03:48:03,980 --> 03:48:05,620 - Looking at all of these plants, 2476 03:48:05,620 --> 03:48:09,020 there's enough food for the adults and the juveniles. 2477 03:48:09,020 --> 03:48:12,820 - More than enough to draw the pachyrhinosaurus up here. 2478 03:48:12,820 --> 03:48:14,020 - And when the babies hatch, 2479 03:48:14,020 --> 03:48:16,020 there's food for the babies as well. 2480 03:48:18,300 --> 03:48:22,980 - This place would mark the end of the herd's long migration. 2481 03:48:28,860 --> 03:48:30,540 A haven 2482 03:48:30,540 --> 03:48:32,700 where they could settle 2483 03:48:32,700 --> 03:48:34,380 and begin to nest. 2484 03:48:34,380 --> 03:48:36,660 BIRDSONG 2485 03:48:38,900 --> 03:48:40,940 LOWING AND GRUNTING 2486 03:49:02,260 --> 03:49:05,420 But while the exhausting 400-mile walk... 2487 03:49:06,580 --> 03:49:08,100 ..may finally be over... 2488 03:49:12,500 --> 03:49:16,660 ..there is one problem they haven't left behind. 2489 03:49:16,660 --> 03:49:19,100 NEARBY SNARLING 2490 03:49:23,020 --> 03:49:25,980 The gorgosaurus have stayed close. 2491 03:49:31,340 --> 03:49:33,300 BELLOWING 2492 03:49:33,300 --> 03:49:37,540 And with the pachyrhinosaurus backed up against the river... 2493 03:49:41,420 --> 03:49:43,740 ..it gives these ferocious predators 2494 03:49:43,740 --> 03:49:45,860 the perfect opportunity... 2495 03:49:47,180 --> 03:49:50,660 ..to pick off one of the herd's more vulnerable members. 2496 03:50:02,580 --> 03:50:04,100 SQUEAKING 2497 03:50:06,180 --> 03:50:07,820 ALBIE SQUEAKS 2498 03:50:07,820 --> 03:50:09,020 SNARLS 2499 03:50:09,020 --> 03:50:10,460 ROARS 2500 03:50:10,460 --> 03:50:12,300 HE SQUEAKS 2501 03:50:12,300 --> 03:50:14,500 But Albie is not alone. 2502 03:50:14,500 --> 03:50:17,100 SHE BELLOWS 2503 03:50:18,220 --> 03:50:22,260 His mother's instinct is to fight. 2504 03:50:33,540 --> 03:50:38,020 But their confrontation is about to pale into insignificance. 2505 03:50:39,020 --> 03:50:41,260 THUNDER CRASHES 2506 03:50:43,540 --> 03:50:45,060 Both predator... 2507 03:50:46,900 --> 03:50:48,700 ..and prey 2508 03:50:48,700 --> 03:50:51,140 face a far greater threat. 2509 03:51:12,340 --> 03:51:16,460 Investigating what happened at the end of the herd's journey... 2510 03:51:16,460 --> 03:51:20,060 - OK, move to the next point. 2511 03:51:21,180 --> 03:51:24,340 - ..and why so many are buried here... 2512 03:51:25,540 --> 03:51:28,700 ..Emily's team is mapping the bones. 2513 03:51:29,780 --> 03:51:32,380 - We've obviously got a pretty large cluster in that corner. 2514 03:51:32,380 --> 03:51:35,820 - Those two are so close together... - They are so, so close together, man. 2515 03:51:35,820 --> 03:51:37,700 It's pretty much, like, right up against... - Yeah. 2516 03:51:37,700 --> 03:51:39,740 All right. - Let's go. 2517 03:51:44,020 --> 03:51:48,860 - They can then scan to create a full 3D model of the site. 2518 03:51:54,340 --> 03:51:55,780 - It's coming through really well. 2519 03:51:55,780 --> 03:51:59,420 - Yeah. You can see the patterning on the surface of the bone. 2520 03:52:00,460 --> 03:52:05,540 - The imaging allows them to see exactly how the fossils are laid out. 2521 03:52:05,540 --> 03:52:08,340 - You can see how the bones are stacked 2522 03:52:08,340 --> 03:52:10,060 on top of each other. 2523 03:52:11,580 --> 03:52:14,620 Everything here is bone. 2524 03:52:14,620 --> 03:52:17,020 There's actually very little rock in between there. 2525 03:52:17,020 --> 03:52:18,860 It's just a solid mass of bone material. 2526 03:52:18,860 --> 03:52:21,300 - You can kind of see ribs of just about every size, 2527 03:52:21,300 --> 03:52:22,980 just even in this one pocket here. 2528 03:52:22,980 --> 03:52:25,060 - And they're clearly all from different individuals, 2529 03:52:25,060 --> 03:52:26,340 cos they're all different sizes. 2530 03:52:27,300 --> 03:52:31,140 - The bones of young and old are jumbled together. 2531 03:52:35,340 --> 03:52:37,900 And there's even more in the ground 2532 03:52:37,900 --> 03:52:39,780 than the team first realised. 2533 03:52:41,060 --> 03:52:43,780 - You think of the sheer density of bones 2534 03:52:43,780 --> 03:52:46,380 in just this little area that we've scanned 2535 03:52:46,380 --> 03:52:48,460 and then put that together with the grid mapping 2536 03:52:48,460 --> 03:52:49,700 - Perfect. - Perfect. 2537 03:52:49,700 --> 03:52:53,420 - ..there's something like 100 to 300 bones per square metre. 2538 03:52:53,420 --> 03:52:55,660 And then we know the bone bed goes back into the hill 2539 03:52:55,660 --> 03:52:57,100 for another kilometre. 2540 03:52:57,100 --> 03:52:58,700 - Good for now. 2541 03:53:00,300 --> 03:53:03,220 - Their findings bring their estimate of pachyrhinosaurus 2542 03:53:03,220 --> 03:53:04,620 preserved at the site... 2543 03:53:06,380 --> 03:53:08,860 ..into the tens of thousands. 2544 03:53:11,500 --> 03:53:14,580 To have died in such large numbers, 2545 03:53:14,580 --> 03:53:17,820 they must have faced a catastrophic event. 2546 03:53:19,580 --> 03:53:21,740 SAW BUZZES 2547 03:53:29,900 --> 03:53:31,260 Looking for answers... 2548 03:53:32,340 --> 03:53:36,900 ..Emily and Max cut deep into the rock that encases the herd. 2549 03:53:39,100 --> 03:53:41,180 EMILY STRAINS 2550 03:53:41,180 --> 03:53:42,740 - Tilt it up. 2551 03:53:42,740 --> 03:53:46,020 I just want to take a look at the cross-section. 2552 03:53:46,020 --> 03:53:49,020 - It reveals a vital clue. 2553 03:53:50,860 --> 03:53:53,180 - Look at this piece! All of that black, 2554 03:53:53,180 --> 03:53:56,100 it's plant material that's been shredded. 2555 03:53:56,100 --> 03:53:58,060 Something has picked up the mud 2556 03:53:58,060 --> 03:54:01,380 and has, like, twisted it with enough energy 2557 03:54:01,380 --> 03:54:02,740 to move the amount of material 2558 03:54:02,740 --> 03:54:04,540 and to shred the plants up like that. 2559 03:54:04,540 --> 03:54:06,100 And that's right in with the bones. 2560 03:54:09,260 --> 03:54:11,260 And all these swirls in here? 2561 03:54:11,260 --> 03:54:14,340 Something dramatic has happened that's involved water. 2562 03:54:15,740 --> 03:54:17,580 You can see where it's actually cut down 2563 03:54:17,580 --> 03:54:20,940 into the rock underneath it, like a fossilised wave. 2564 03:54:20,940 --> 03:54:23,780 And so this was a huge energy event. 2565 03:54:26,380 --> 03:54:30,060 - The evidence all points to one thing. 2566 03:54:31,260 --> 03:54:33,580 THUNDER CRASHES 2567 03:54:35,060 --> 03:54:37,420 PANICKED BELLOWING 2568 03:54:37,420 --> 03:54:40,380 A devastating flash flood... 2569 03:54:46,420 --> 03:54:48,500 ..triggered by huge storms... 2570 03:54:49,940 --> 03:54:51,940 ..raging over the mountains. 2571 03:55:00,980 --> 03:55:03,460 Water cascades into the valley... 2572 03:55:05,100 --> 03:55:07,460 ..swelling into an unstoppable torrent... 2573 03:55:09,780 --> 03:55:12,580 ..that destroys everything in its path. 2574 03:55:28,140 --> 03:55:31,300 DEEP RUMBLING 2575 03:55:31,300 --> 03:55:33,660 GRUNTING AND BELLOWING 2576 03:55:44,100 --> 03:55:45,540 HE SQUEAKS 2577 03:55:47,660 --> 03:55:49,300 As the floodwaters near... 2578 03:55:51,500 --> 03:55:53,860 ..the herd begins to panic. 2579 03:55:58,780 --> 03:56:00,820 Mother and child... 2580 03:56:02,020 --> 03:56:05,420 ..waiting by each other's side. 2581 03:56:05,420 --> 03:56:06,900 ALBIE YOWLS 2582 03:56:16,580 --> 03:56:18,300 HE SQUEAKS 2583 03:56:18,300 --> 03:56:20,620 WATER RUSHING 2584 03:56:41,980 --> 03:56:45,700 Little could have withstood a flood on this scale. 2585 03:57:02,500 --> 03:57:05,740 And for Albie and much of his herd... 2586 03:57:07,660 --> 03:57:09,940 ..it marks a tragic end. 2587 03:57:30,460 --> 03:57:32,820 But despite the devastation, 2588 03:57:32,820 --> 03:57:36,340 this was perhaps not the end for them all. 2589 03:57:50,300 --> 03:57:53,620 Just under 30 miles north of the main dig site... 2590 03:57:53,620 --> 03:57:55,300 - Come on, Esther. 2591 03:57:56,500 --> 03:57:58,900 - ..Emily and Jackson 2592 03:57:58,900 --> 03:58:03,020 have travelled out into the hills of Canada's Grande Prairie... 2593 03:58:05,300 --> 03:58:08,340 ..to investigate an incredible find. 2594 03:58:13,300 --> 03:58:16,860 - So, there's three sites that have been identified. 2595 03:58:16,860 --> 03:58:19,260 - Right. - I think that's one of them. 2596 03:58:20,340 --> 03:58:22,820 And the other two... 2597 03:58:22,820 --> 03:58:24,500 I think there's one over there 2598 03:58:24,500 --> 03:58:27,140 and there's one behind us as well. 2599 03:58:32,380 --> 03:58:36,100 - Across the area, a series of fossils has been unearthed... 2600 03:58:37,060 --> 03:58:40,100 ..that point to an extraordinary possibility. 2601 03:58:42,580 --> 03:58:44,340 - Looks like a toe bone. 2602 03:58:46,460 --> 03:58:48,100 But absolutely tiny. 2603 03:58:48,100 --> 03:58:51,220 - That also is from a very, very small animal. 2604 03:58:51,220 --> 03:58:54,260 Like, that, to me, looks like it's from an animal 2605 03:58:54,260 --> 03:58:57,380 that has either just hatched, like a hatchling, 2606 03:58:57,380 --> 03:58:59,140 or is actually still in the egg, 2607 03:58:59,140 --> 03:59:01,140 an embryonic dinosaur. 2608 03:59:01,140 --> 03:59:04,060 An animal this size has to have been born here. 2609 03:59:05,140 --> 03:59:08,140 - The young belong to both pachyrhinosaurus 2610 03:59:08,140 --> 03:59:10,180 and Edmontosaurus. 2611 03:59:13,140 --> 03:59:16,220 Dinosaurs that were heading for the same destination. 2612 03:59:17,340 --> 03:59:20,900 - To me, it's not a coincidence that they're both here. 2613 03:59:20,900 --> 03:59:25,300 We're only 30 or 40km away from the site of the flood 2614 03:59:25,300 --> 03:59:27,340 so surviving animals could eventually 2615 03:59:27,340 --> 03:59:28,740 have made their way here. 2616 03:59:28,740 --> 03:59:30,700 This might have been the nesting ground 2617 03:59:30,700 --> 03:59:34,140 for both of these megaherbivores after the flood. 2618 03:59:37,340 --> 03:59:41,100 - Emily and Jackson are continuing to look for more evidence. 2619 03:59:44,820 --> 03:59:47,300 But this remarkable discovery... 2620 03:59:47,300 --> 03:59:48,700 SQUAWKING 2621 03:59:48,700 --> 03:59:50,340 ..means that maybe... 2622 03:59:55,460 --> 03:59:57,700 ..despite all the odds... 2623 03:59:59,180 --> 04:00:01,820 ..some of the herd did survive... 2624 04:00:06,620 --> 04:00:11,740 ..continuing on to find another place to nest. 2625 04:00:42,740 --> 04:00:44,420 Survivors... 2626 04:00:44,420 --> 04:00:45,740 BELLOWS 2627 04:00:45,740 --> 04:00:49,180 ..with a chance to pave the way... 2628 04:00:52,860 --> 04:00:56,740 ..for the next generation to thrive. 2629 04:01:09,740 --> 04:01:11,620 So that one day... 2630 04:01:16,620 --> 04:01:20,020 ..their herd can rise again. 2631 04:01:21,820 --> 04:01:24,380 BELLOWS 2632 04:01:33,460 --> 04:01:36,780 One of the largest dinosaurs ever to walk the Earth... 2633 04:01:39,340 --> 04:01:40,900 ..goes looking... 2634 04:01:40,900 --> 04:01:42,300 ..for love. 2635 04:01:43,700 --> 04:01:44,820 A quest... 2636 04:01:45,940 --> 04:01:49,540 ..that will become a life-and-death struggle. 2637 04:02:37,360 --> 04:02:40,320 Over 66 million years ago... 2638 04:02:41,560 --> 04:02:43,760 SCREECHING 2639 04:02:44,720 --> 04:02:46,600 ..our world... 2640 04:02:46,600 --> 04:02:48,280 ..was ruled... 2641 04:02:50,280 --> 04:02:52,560 ..by dinosaurs... 2642 04:02:52,560 --> 04:02:54,640 SNARLS 2643 04:02:59,240 --> 04:03:01,200 ..the largest animals 2644 04:03:01,200 --> 04:03:03,440 that have ever walked the Earth. 2645 04:03:10,280 --> 04:03:14,280 Today, dinosaur experts across the globe 2646 04:03:14,280 --> 04:03:17,600 are uncovering the bones they left behind... 2647 04:03:21,000 --> 04:03:22,840 ..allowing us to imagine 2648 04:03:22,840 --> 04:03:26,440 how these extraordinary creatures may have lived... 2649 04:03:30,560 --> 04:03:33,520 ..so that we can tell their stories... 2650 04:03:37,840 --> 04:03:39,320 ..and they... 2651 04:03:40,520 --> 04:03:42,520 ..can walk again. 2652 04:03:42,520 --> 04:03:44,560 ROARS 2653 04:04:11,880 --> 04:04:15,000 Amongst the jagged mountain peaks... 2654 04:04:16,120 --> 04:04:17,840 ..majestic valleys... 2655 04:04:20,840 --> 04:04:25,320 ..and scattered hill towns of central Portugal... 2656 04:04:27,240 --> 04:04:30,040 ..an astonishing discovery has been made... 2657 04:04:36,240 --> 04:04:38,400 A find so remarkable 2658 04:04:38,400 --> 04:04:40,960 it's drawn a team of dinosaur hunters 2659 04:04:40,960 --> 04:04:42,920 from across Europe. 2660 04:04:47,880 --> 04:04:51,600 Buried here are the remains 2661 04:04:51,600 --> 04:04:53,000 of a colossus. 2662 04:04:59,440 --> 04:05:02,720 A monumental long-necked Lusotitan. 2663 04:05:12,800 --> 04:05:15,160 Known as Old Grande... 2664 04:05:16,240 --> 04:05:18,760 ..he's one of the largest dinosaurs 2665 04:05:18,760 --> 04:05:21,000 ever to have lived. 2666 04:05:24,040 --> 04:05:25,920 And using his bones, 2667 04:05:25,920 --> 04:05:29,960 we can begin to imagine this giant's story. 2668 04:05:47,960 --> 04:05:50,480 In the Late Jurassic, 2669 04:05:50,480 --> 04:05:53,400 our planet looks very different. 2670 04:05:57,440 --> 04:06:00,240 Amongst its shifting continents, 2671 04:06:00,240 --> 04:06:05,480 a small landmass known as the Iberian Meseta, 2672 04:06:05,480 --> 04:06:08,800 that one day will include Portugal, 2673 04:06:08,800 --> 04:06:11,880 lies surrounded by ocean. 2674 04:06:13,680 --> 04:06:17,720 An island cut off from the rest of the world. 2675 04:06:19,480 --> 04:06:21,640 CHIRPING 2676 04:06:21,640 --> 04:06:26,360 Dense coniferous forest covers much of the land... 2677 04:06:32,040 --> 04:06:36,200 ..giving way to windswept beaches on the coast. 2678 04:06:36,200 --> 04:06:38,400 SQUAWKING 2679 04:06:40,880 --> 04:06:42,920 MUNCHING 2680 04:06:42,920 --> 04:06:44,960 Here, if you're in luck... 2681 04:06:46,440 --> 04:06:48,560 ..an easy lunch can be found. 2682 04:06:57,960 --> 04:07:01,640 For torvosaurus, the island's top predator, 2683 04:07:01,640 --> 04:07:04,000 it's an opportunity 2684 04:07:04,000 --> 04:07:05,480 worth fighting for. 2685 04:07:05,480 --> 04:07:07,520 SNARLS 2686 04:07:10,240 --> 04:07:12,560 LOW GROWLING 2687 04:07:19,040 --> 04:07:21,080 THUDDING 2688 04:07:23,240 --> 04:07:26,400 But even these four-tonne carnivores... 2689 04:07:31,200 --> 04:07:33,240 ..are no match 2690 04:07:33,240 --> 04:07:36,160 for the enormous Lusotitan - 2691 04:07:36,160 --> 04:07:38,240 Old Grande. 2692 04:07:38,240 --> 04:07:40,600 LOW GRUNTING 2693 04:07:44,760 --> 04:07:47,440 At a staggering 40 tonnes... 2694 04:07:50,840 --> 04:07:55,120 ..he is the undisputed king of the island. 2695 04:08:12,800 --> 04:08:15,280 But as a herbivore, 2696 04:08:15,280 --> 04:08:17,680 he isn't on the hunt for food. 2697 04:08:24,760 --> 04:08:28,080 He's been drawn to the beach by the allure... 2698 04:08:29,920 --> 04:08:31,960 BELLOWS GENTLY 2699 04:08:33,480 --> 04:08:35,400 ..of a female. 2700 04:08:42,440 --> 04:08:44,480 BELLOWS GENTLY 2701 04:08:49,680 --> 04:08:52,320 As an ageing male, 2702 04:08:52,320 --> 04:08:55,520 this may be his last chance to mate. 2703 04:09:09,200 --> 04:09:12,880 But female Lusotitans are only receptive 2704 04:09:12,880 --> 04:09:15,040 for a few weeks of the year... 2705 04:09:17,160 --> 04:09:20,920 ..so he doesn't have long to make an impression. 2706 04:09:46,960 --> 04:09:49,600 150 million years later... 2707 04:09:51,480 --> 04:09:54,840 ..the true scale of Old Grande is emerging 2708 04:09:54,840 --> 04:09:56,840 from deep beneath the ground. 2709 04:10:13,440 --> 04:10:17,200 As the most complete Lusotitan ever found, 2710 04:10:17,200 --> 04:10:20,200 his remains allow the team, 2711 04:10:20,200 --> 04:10:23,880 led by Professor Francisco Ortega 2712 04:10:23,880 --> 04:10:27,120 and Drs Elisabete Malafaia 2713 04:10:27,120 --> 04:10:28,840 and Pedro Mocho... 2714 04:10:30,280 --> 04:10:33,080 ..to piece together the extraordinary dimensions 2715 04:10:33,080 --> 04:10:34,640 of this animal. 2716 04:10:47,560 --> 04:10:50,200 They're starting with how tall he was... 2717 04:10:52,360 --> 04:10:54,160 ..which they can estimate 2718 04:10:54,160 --> 04:10:57,120 using the bones from his gigantic front limb. 2719 04:11:18,200 --> 04:11:21,280 Their calculations make Old Grande 2720 04:11:21,280 --> 04:11:24,920 one of the tallest of his species ever discovered... 2721 04:11:28,640 --> 04:11:32,320 ..which is certainly one way to impress a mate. 2722 04:11:44,840 --> 04:11:48,240 Female Lusotitans may have been most attracted 2723 04:11:48,240 --> 04:11:50,080 to the biggest males... 2724 04:11:50,080 --> 04:11:52,120 SNORTS 2725 04:11:56,040 --> 04:12:00,360 ..a sign their offspring will be healthy and strong. 2726 04:12:04,760 --> 04:12:08,840 So it should be easy for Old Grande to make his mark. 2727 04:12:27,000 --> 04:12:29,080 But it's not all about him. 2728 04:12:36,280 --> 04:12:38,200 Before they will mate, 2729 04:12:38,200 --> 04:12:42,120 female Lusotitans must first wait for the seasonal rains... 2730 04:12:44,040 --> 04:12:46,720 ..making sure there is enough fresh vegetation 2731 04:12:46,720 --> 04:12:48,160 for their young. 2732 04:12:51,880 --> 04:12:54,760 And this year, the rains are late. 2733 04:13:02,120 --> 04:13:06,400 Old Grande has no choice but to wait. 2734 04:13:16,840 --> 04:13:19,680 He must guard her closely 2735 04:13:19,680 --> 04:13:23,560 and hope there is no other suitor close by. 2736 04:13:23,560 --> 04:13:25,640 LOWING 2737 04:13:27,960 --> 04:13:31,720 But love rarely runs smoothly. 2738 04:13:39,080 --> 04:13:42,040 Three miles from where Old Grande was found, 2739 04:13:42,040 --> 04:13:45,200 the team has made an important discovery. 2740 04:14:15,320 --> 04:14:19,480 The fossilised rib is a similar size to Old Grande's. 2741 04:14:21,720 --> 04:14:24,280 But given its distance from the main dig, 2742 04:14:24,280 --> 04:14:26,120 it's unlikely to be his. 2743 04:14:46,920 --> 04:14:50,040 Unearthing two Lusotitans so close together 2744 04:14:50,040 --> 04:14:51,960 is unheard of. 2745 04:14:55,680 --> 04:14:58,200 So the team is keen to learn more. 2746 04:15:03,480 --> 04:15:06,800 They cover the sections of rib in a layer of plaster... 2747 04:15:11,480 --> 04:15:13,280 ..so they can be removed safely... 2748 04:15:15,040 --> 04:15:18,680 ..and examined in one piece, 2749 04:15:18,680 --> 04:15:21,360 which is a massive 3m long. 2750 04:15:44,920 --> 04:15:47,320 Like elephants and rhinos today, 2751 04:15:47,320 --> 04:15:50,600 Lusotitan bulls were likely solitary 2752 04:15:50,600 --> 04:15:52,520 and very territorial. 2753 04:16:08,880 --> 04:16:10,960 Just like Old Grande, 2754 04:16:10,960 --> 04:16:15,120 this rival male would have been searching for a mate, 2755 04:16:15,120 --> 04:16:16,760 creating the potential... 2756 04:16:18,480 --> 04:16:20,880 ..for a dangerous confrontation. 2757 04:16:23,240 --> 04:16:25,320 LOW GROWL 2758 04:16:31,080 --> 04:16:35,680 Although this contender may be younger than Old Grande... 2759 04:16:39,560 --> 04:16:41,920 ..he's not afraid to challenge him 2760 04:16:41,920 --> 04:16:44,320 for the attentions of the female. 2761 04:16:46,160 --> 04:16:48,320 GROWLS 2762 04:17:08,040 --> 04:17:10,160 GROWLS 2763 04:17:10,160 --> 04:17:13,760 Old Grande is a seasoned fighter 2764 04:17:13,760 --> 04:17:16,280 and the largest bull on the island. 2765 04:17:22,720 --> 04:17:24,680 A stern warning... 2766 04:17:29,120 --> 04:17:32,800 ..should be enough to make this upstart back off. 2767 04:17:39,440 --> 04:17:41,800 But all is fair in love... 2768 04:17:43,600 --> 04:17:45,480 ..and war. 2769 04:17:54,080 --> 04:17:56,200 BELLOWING 2770 04:17:59,760 --> 04:18:04,360 The surprise attack leaves Old Grande seriously hurt... 2771 04:18:04,360 --> 04:18:06,440 GRUNTING 2772 04:18:08,280 --> 04:18:10,680 ..his leg badly injured. 2773 04:18:22,600 --> 04:18:25,600 Struggling under his colossal weight... 2774 04:18:28,880 --> 04:18:31,120 ..he is unable to right himself. 2775 04:18:44,200 --> 04:18:45,960 He can only watch... 2776 04:18:47,120 --> 04:18:50,320 ..as the rival takes his place at the female's side. 2777 04:19:01,200 --> 04:19:04,120 For a dinosaur of his size, 2778 04:19:04,120 --> 04:19:08,360 a badly damaged leg could mean the end of the road. 2779 04:19:18,680 --> 04:19:22,160 So could a Lusotitan survive this kind of injury? 2780 04:19:34,080 --> 04:19:38,480 On the coast, a significant piece of evidence might provide the answer. 2781 04:19:42,520 --> 04:19:44,960 But reaching it won't be easy... 2782 04:19:48,880 --> 04:19:52,760 ..because what was once flat ground during the Jurassic 2783 04:19:52,760 --> 04:19:55,400 is now a near-vertical cliff face. 2784 04:20:06,000 --> 04:20:09,640 So Francisco must descend over 100m. 2785 04:20:54,760 --> 04:20:57,800 Etched into the cliff face are footprints 2786 04:20:57,800 --> 04:21:00,600 thought to have been made by a large Lusotitan. 2787 04:21:06,280 --> 04:21:08,960 And they reveal something surprising. 2788 04:22:08,680 --> 04:22:11,720 The discovery of a limping Lusotitan 2789 04:22:11,720 --> 04:22:13,520 is important evidence. 2790 04:22:17,400 --> 04:22:21,000 It suggests that injuries to their enormous limbs... 2791 04:22:23,040 --> 04:22:25,040 ..were survivable. 2792 04:22:37,080 --> 04:22:40,320 Even so, Old Grande is still weak... 2793 04:22:42,240 --> 04:22:44,360 ..and won't last long 2794 04:22:44,360 --> 04:22:46,200 on a damaged leg. 2795 04:22:54,160 --> 04:22:56,400 But he does have a remarkable way... 2796 04:22:57,920 --> 04:23:00,480 ..to speed up the healing process. 2797 04:23:07,440 --> 04:23:10,440 It's known as osteophagia. 2798 04:23:17,880 --> 04:23:20,480 Like modern-day giraffes, 2799 04:23:20,480 --> 04:23:22,720 he supplements his diet 2800 04:23:22,720 --> 04:23:25,600 by breaking apart and swallowing 2801 04:23:25,600 --> 04:23:27,840 the skeletons of dead animals. 2802 04:23:31,640 --> 04:23:34,920 Like the carcass of this pliosaur, 2803 04:23:34,920 --> 04:23:38,480 whose bones are rich in the minerals he needs... 2804 04:23:40,240 --> 04:23:42,440 ..to repair his own body. 2805 04:23:52,400 --> 04:23:54,520 But he's still a long way from recovery... 2806 04:23:56,240 --> 04:23:57,840 ..and a limp like his... 2807 04:23:59,480 --> 04:24:01,720 ..may not have gone unnoticed. 2808 04:24:09,520 --> 04:24:12,120 Following the path of the Lusotitan footprints... 2809 04:24:14,200 --> 04:24:16,400 ..something has caught Francisco's eye. 2810 04:24:44,880 --> 04:24:48,280 The second set of prints is another 85m 2811 04:24:48,280 --> 04:24:50,320 down the sheer cliff face. 2812 04:25:10,080 --> 04:25:13,240 Unable to reach the prints by land, 2813 04:25:13,240 --> 04:25:14,880 the team decides... 2814 04:25:18,080 --> 04:25:20,120 ..to take to the air. 2815 04:25:44,400 --> 04:25:46,040 - Whoa, whoa, whoa. 2816 04:25:46,040 --> 04:25:47,880 I think... 2817 04:25:47,880 --> 04:25:49,320 Oh... 2818 04:25:49,320 --> 04:25:50,720 See? 2819 04:25:56,440 --> 04:25:57,520 - Yeah. 2820 04:26:04,640 --> 04:26:07,520 - The second set of prints follows the same path 2821 04:26:07,520 --> 04:26:09,040 as the Lusotitan. 2822 04:26:12,040 --> 04:26:14,160 But from their distinctive shape, 2823 04:26:14,160 --> 04:26:17,120 it's clear they've been made by a different species. 2824 04:26:37,600 --> 04:26:42,080 Theropods are a group of dinosaurs that includes T-rex. 2825 04:26:45,120 --> 04:26:47,000 But on this island, 2826 04:26:47,000 --> 04:26:50,040 the prints are likely to come from a predator... 2827 04:26:51,840 --> 04:26:54,840 ..Old Grande would be much more familiar with. 2828 04:27:01,440 --> 04:27:03,520 The torvosaurus. 2829 04:27:09,200 --> 04:27:13,240 10m long and over 3m tall, 2830 04:27:13,240 --> 04:27:16,680 this adult female would normally be no match 2831 04:27:16,680 --> 04:27:18,880 for a heathy Lusotitan. 2832 04:27:24,680 --> 04:27:27,240 But the pain in Old Grande's leg 2833 04:27:27,240 --> 04:27:28,960 has become unbearable. 2834 04:27:31,200 --> 04:27:34,520 And he must rest until he can recover. 2835 04:27:36,480 --> 04:27:40,240 It could mean days without food or water, 2836 04:27:40,240 --> 04:27:41,760 leaving him exhausted... 2837 04:27:44,000 --> 04:27:45,680 ..and vulnerable. 2838 04:27:56,160 --> 04:27:58,000 An opportunity this big... 2839 04:28:00,160 --> 04:28:01,920 ..is rare. 2840 04:28:01,920 --> 04:28:04,080 LOW GROWL 2841 04:28:05,840 --> 04:28:08,360 But Old Grande is too strong to take on now. 2842 04:28:14,920 --> 04:28:17,400 So she's prepared to stay close... 2843 04:28:18,760 --> 04:28:20,440 ..and wait. 2844 04:28:44,720 --> 04:28:46,520 As the days pass... 2845 04:28:47,800 --> 04:28:49,840 ..Old Grande rests. 2846 04:28:49,840 --> 04:28:51,920 LOW GRUNTING 2847 04:29:10,760 --> 04:29:12,480 The torvosaurus... 2848 04:29:13,480 --> 04:29:15,200 ..risks an approach. 2849 04:29:29,080 --> 04:29:31,120 SCREECHES 2850 04:29:32,440 --> 04:29:34,480 ROARS 2851 04:29:35,800 --> 04:29:37,360 A close call. 2852 04:29:38,960 --> 04:29:41,040 BELLOWING 2853 04:29:43,520 --> 04:29:46,640 Old Grande must recover soon, 2854 04:29:46,640 --> 04:29:49,120 because next time 2855 04:29:49,120 --> 04:29:51,080 he may not be so lucky. 2856 04:30:43,240 --> 04:30:45,280 BELLOWING 2857 04:30:56,000 --> 04:30:57,760 At long last... 2858 04:30:59,960 --> 04:31:03,000 ..Old Grande's leg is finally on the mend... 2859 04:31:15,000 --> 04:31:18,760 ..and he has unfinished business - 2860 04:31:18,760 --> 04:31:21,960 finding the female that left him behind. 2861 04:31:28,680 --> 04:31:32,920 But both she and his rival are now miles away... 2862 04:31:34,520 --> 04:31:36,760 ..and the clock is ticking. 2863 04:31:44,440 --> 04:31:46,920 He must move as quickly as he can. 2864 04:31:53,520 --> 04:31:56,000 150 million years later... 2865 04:31:57,680 --> 04:32:00,320 ..the team has made a discovery 2866 04:32:00,320 --> 04:32:02,640 that could reveal how fast 2867 04:32:02,640 --> 04:32:05,320 a giant like Old Grande travelled. 2868 04:32:24,080 --> 04:32:28,160 The new find gives the team an almost-complete profile 2869 04:32:28,160 --> 04:32:31,000 of Old Grande's front limb. 2870 04:32:47,560 --> 04:32:49,600 Putting these measurements together 2871 04:32:49,600 --> 04:32:52,440 with their findings from the cliff-side footprints... 2872 04:32:58,240 --> 04:33:00,600 ..they can now calculate his speed. 2873 04:33:15,600 --> 04:33:19,320 It may sound slow, but like modern elephants, 2874 04:33:19,320 --> 04:33:21,960 it's thought Lusotitans could keep up this pace 2875 04:33:21,960 --> 04:33:24,280 over huge distances. 2876 04:33:38,040 --> 04:33:42,400 This is just what Old Grande needs to do 2877 04:33:42,400 --> 04:33:46,440 as he travels miles across the island, 2878 04:33:46,440 --> 04:33:48,400 looking for the female. 2879 04:33:59,120 --> 04:34:01,240 But he's almost out of time. 2880 04:34:01,240 --> 04:34:03,280 THUNDER RUMBLES 2881 04:34:09,800 --> 04:34:12,680 A distant storm 2882 04:34:12,680 --> 04:34:15,640 heralds the arrival of the seasonal rains. 2883 04:34:17,760 --> 04:34:19,800 LOWING 2884 04:34:21,360 --> 04:34:23,440 THUNDER CRACKS 2885 04:34:26,560 --> 04:34:29,560 The female will finally be ready to mate... 2886 04:34:31,000 --> 04:34:35,360 ..leaving Old Grande in danger of missing out to his rival. 2887 04:34:39,920 --> 04:34:42,040 THUD RESOUNDS 2888 04:34:42,040 --> 04:34:45,040 But he's not just relying on his pace alone. 2889 04:34:49,160 --> 04:34:53,840 He's using an extraordinary ability to locate the female... 2890 04:34:57,920 --> 04:35:01,160 ..one he's thought to share with modern-day elephants. 2891 04:35:05,640 --> 04:35:09,520 His stomps send powerful seismic waves 2892 04:35:09,520 --> 04:35:11,040 through the ground. 2893 04:35:16,320 --> 04:35:18,360 SNORTS 2894 04:35:19,440 --> 04:35:21,480 QUIET LOWING 2895 04:35:23,280 --> 04:35:25,120 Many miles away, 2896 04:35:25,120 --> 04:35:27,600 she feels the earth move... 2897 04:35:28,760 --> 04:35:31,440 ..through specialised nerve endings in her feet... 2898 04:35:32,840 --> 04:35:35,000 LOWING 2899 04:35:35,000 --> 04:35:37,120 BELLOWS QUIETLY 2900 04:35:38,520 --> 04:35:40,640 ..and she answers... 2901 04:35:40,640 --> 04:35:42,840 ..her suitor's call. 2902 04:35:42,840 --> 04:35:44,880 THUNDER RUMBLES AND RAIN FALLS 2903 04:35:48,840 --> 04:35:51,400 Detecting her response 2904 04:35:51,400 --> 04:35:54,720 keeps Grande heading in the right direction. 2905 04:35:58,480 --> 04:36:00,640 THUNDER CRACKS 2906 04:36:00,640 --> 04:36:04,480 But he must reach her before he misses his chance. 2907 04:36:13,160 --> 04:36:16,960 At the dig site, a new section of Old Grande's bones 2908 04:36:16,960 --> 04:36:18,680 is emerging from the rock. 2909 04:36:20,880 --> 04:36:22,320 - ..this vertebra. - OK. 2910 04:36:22,320 --> 04:36:23,640 - So perhaps, OK, this is... 2911 04:36:28,200 --> 04:36:32,040 - ..including fossils that belong to his giant tail. 2912 04:36:38,400 --> 04:36:40,440 But laying them out from the biggest on the right... 2913 04:36:41,760 --> 04:36:44,280 ..to the tip on the left, 2914 04:36:44,280 --> 04:36:46,640 Pedro has noticed something unusual. 2915 04:36:58,160 --> 04:37:01,920 One of the bones doesn't belong in the sequence, 2916 04:37:01,920 --> 04:37:04,760 and it's too small to be part of Old Grande. 2917 04:37:17,000 --> 04:37:18,880 It's a significant find... 2918 04:37:20,280 --> 04:37:23,920 ..because a second adult so close to Old Grande 2919 04:37:23,920 --> 04:37:26,920 could mean he did find his mate. 2920 04:37:43,720 --> 04:37:45,800 After miles of walking... 2921 04:37:47,480 --> 04:37:49,240 ..he's reached the area 2922 04:37:49,240 --> 04:37:51,760 where the female last responded to his call. 2923 04:37:53,920 --> 04:37:56,080 BELLOWS QUIETLY 2924 04:38:06,240 --> 04:38:08,480 BELLOWING 2925 04:38:17,480 --> 04:38:19,760 DISTANT BELLOW 2926 04:38:29,440 --> 04:38:31,320 Reunited at last. 2927 04:38:40,960 --> 04:38:43,000 DISTANT BELLOW 2928 04:38:45,760 --> 04:38:47,440 But the moment... 2929 04:38:48,720 --> 04:38:50,400 ..is short-lived. 2930 04:38:50,400 --> 04:38:52,640 THUDDING 2931 04:39:04,000 --> 04:39:06,120 BELLOWING 2932 04:39:08,480 --> 04:39:11,120 The rival male has stayed close... 2933 04:39:12,480 --> 04:39:15,360 ..and he isn't going to give up without a fight. 2934 04:39:16,960 --> 04:39:19,080 BELLOWING 2935 04:39:21,520 --> 04:39:23,600 THUNDER RUMBLES 2936 04:39:31,600 --> 04:39:34,560 Each bull uses his colossal weight... 2937 04:39:36,160 --> 04:39:37,840 ..as a battering ram. 2938 04:39:49,920 --> 04:39:52,760 But these giants are too closely matched. 2939 04:39:59,160 --> 04:40:00,920 So, changing tactics... 2940 04:40:02,960 --> 04:40:05,640 ..they use their teeth 2941 04:40:05,640 --> 04:40:07,800 to inflict intense pain. 2942 04:40:14,800 --> 04:40:17,360 But neither is backing down. 2943 04:40:28,000 --> 04:40:30,440 Taking his chance, 2944 04:40:30,440 --> 04:40:32,520 the rival pins Old Grande. 2945 04:40:34,360 --> 04:40:36,520 BELLOWING 2946 04:40:41,440 --> 04:40:44,520 Rearing up to the height of a four-storey building... 2947 04:40:47,400 --> 04:40:50,440 ..he bears down with his enormous weight. 2948 04:41:01,840 --> 04:41:03,400 But this time... 2949 04:41:05,680 --> 04:41:08,480 ..Old Grande refuses to go down. 2950 04:41:17,280 --> 04:41:19,480 GROANS 2951 04:41:25,960 --> 04:41:28,560 A decisive victory. 2952 04:41:28,560 --> 04:41:30,760 BELLOWING 2953 04:41:41,320 --> 04:41:44,880 But Old Grande still faces one last challenge. 2954 04:41:47,560 --> 04:41:49,120 Persuading the female... 2955 04:41:50,360 --> 04:41:52,960 ..he really is the bull for her. 2956 04:41:58,680 --> 04:42:00,840 MACHINERY WHIRS 2957 04:42:06,000 --> 04:42:09,720 And it could be that Francisco has discovered the key 2958 04:42:09,720 --> 04:42:12,560 to what made Old Grande irresistible. 2959 04:42:23,280 --> 04:42:26,640 It's a series of disc-shaped vertebrae 2960 04:42:26,640 --> 04:42:29,480 that once formed part of his long neck. 2961 04:42:40,280 --> 04:42:43,040 The bones are incredibly fragile... 2962 04:42:45,160 --> 04:42:47,920 ..so the team covers them in a protective membrane. 2963 04:43:01,240 --> 04:43:03,560 But these neck bones are not delicate 2964 04:43:03,560 --> 04:43:05,440 simply because of their age. 2965 04:43:08,640 --> 04:43:11,800 Each one has a hollow structure, 2966 04:43:11,800 --> 04:43:14,720 which may have served a vital purpose. 2967 04:43:46,080 --> 04:43:49,680 This dynamic movement would have allowed Old Grande 2968 04:43:49,680 --> 04:43:54,080 to walk, fight, and, crucially, display. 2969 04:44:01,440 --> 04:44:05,360 It's exactly what he needs to charm the female... 2970 04:44:08,320 --> 04:44:10,880 ..because he hasn't won her over yet. 2971 04:44:10,880 --> 04:44:12,920 LOWING 2972 04:44:31,120 --> 04:44:32,880 Like many birds today... 2973 04:44:34,360 --> 04:44:37,760 ..it's thought he would use his long, lightweight neck 2974 04:44:37,760 --> 04:44:39,640 and flexible tail 2975 04:44:39,640 --> 04:44:42,040 in an elaborate courtship display... 2976 04:44:50,760 --> 04:44:52,880 ..with every move he makes 2977 04:44:52,880 --> 04:44:57,680 carefully assessed by this most discerning of judges. 2978 04:45:03,400 --> 04:45:05,520 And she responds. 2979 04:45:11,440 --> 04:45:14,200 Staying in sync with each other's moves... 2980 04:45:16,480 --> 04:45:19,800 ..will be crucial to proving they're compatible. 2981 04:45:33,400 --> 04:45:35,800 But just as everything was going so well... 2982 04:45:39,360 --> 04:45:42,880 ..Old Grande gets a little overexcited. 2983 04:45:58,040 --> 04:46:00,080 GRUNTS 2984 04:46:00,080 --> 04:46:02,120 LOWING 2985 04:46:03,440 --> 04:46:07,360 Fortunately, he has one last trick up his sleeve. 2986 04:46:22,160 --> 04:46:24,800 Just like modern birds such as frigates... 2987 04:46:26,320 --> 04:46:30,320 ..Old Grande has an inflatable sac to attract attention. 2988 04:46:54,920 --> 04:46:56,880 It seems to have worked. 2989 04:47:01,480 --> 04:47:03,600 LOWING 2990 04:47:19,880 --> 04:47:22,400 And in the hills of central Portugal, 2991 04:47:22,400 --> 04:47:25,560 Pedro, Elisabete, 2992 04:47:25,560 --> 04:47:28,760 and Francisco have also completed their mission... 2993 04:47:31,440 --> 04:47:33,320 ..finishing this year's dig 2994 04:47:33,320 --> 04:47:35,360 with a treasure trove of fossils. 2995 04:47:49,680 --> 04:47:53,200 Even as they pack up, they're already making plans 2996 04:47:53,200 --> 04:47:54,640 to return next year. 2997 04:48:08,040 --> 04:48:12,160 While they may never know how Old Grande met his end... 2998 04:48:15,280 --> 04:48:18,400 ..his bones appear to be entwined 2999 04:48:18,400 --> 04:48:20,760 with a female Lusotitan. 3000 04:48:29,080 --> 04:48:31,040 And so, just maybe, 3001 04:48:31,040 --> 04:48:35,160 with her, he was able to secure his legacy. 3002 04:48:50,880 --> 04:48:53,480 A batch of giant eggs. 3003 04:49:29,040 --> 04:49:31,640 Buried safely beneath the ground... 3004 04:49:33,280 --> 04:49:35,920 ..this next generation of Lusotitans... 3005 04:49:37,600 --> 04:49:39,640 CRACKING 3006 04:49:39,640 --> 04:49:42,400 ..will soon begin their own story.