1 00:00:08,717 --> 00:00:11,386 {\an8}Dinosaurs ruled the planet 2 00:00:11,386 --> 00:00:14,806 {\an8}for over 150 million years. 3 00:00:15,682 --> 00:00:18,727 They occupied almost every corner of the globe 4 00:00:19,311 --> 00:00:23,148 and came in almost every shape and size imaginable. 5 00:00:24,358 --> 00:00:27,402 Some were truly extraordinary. 6 00:00:27,402 --> 00:00:28,487 [grunts] 7 00:00:30,822 --> 00:00:34,535 We now know that T. rex was a powerful swimmer, 8 00:00:36,787 --> 00:00:40,082 Velociraptors were cunning, feathered hunters, 9 00:00:42,000 --> 00:00:45,963 and that some dinosaurs had the most bizarre behavior. 10 00:00:48,841 --> 00:00:52,594 But new discoveries are being made almost every day 11 00:00:52,594 --> 00:00:57,641 that tell us more about life on this planet 66 million years ago. 12 00:00:58,225 --> 00:01:01,019 [bellowing, rumbling] 13 00:01:02,604 --> 00:01:05,482 [David Attenborough] This time on Prehistoric Planet, 14 00:01:05,482 --> 00:01:08,026 - we reveal new animals... - [roars] 15 00:01:09,403 --> 00:01:13,740 ...and new insight into their quest to find a partner... 16 00:01:14,491 --> 00:01:15,492 [chirps] 17 00:01:15,492 --> 00:01:18,203 ...the challenges faced by raising a family... 18 00:01:18,203 --> 00:01:19,413 [bellows] 19 00:01:19,413 --> 00:01:21,415 ...and their titanic battles. 20 00:01:22,207 --> 00:01:23,292 [rumbling] 21 00:01:23,292 --> 00:01:24,835 [bellows] 22 00:01:25,460 --> 00:01:26,670 [roars] 23 00:01:27,629 --> 00:01:29,423 - [roars] - [squawking] 24 00:01:29,423 --> 00:01:33,969 Journey to a time when nature put on its greatest show. 25 00:01:37,514 --> 00:01:41,727 This is Prehistoric Planet 2. 26 00:02:02,456 --> 00:02:07,836 The mouth of a river in southern Europe 66 million years ago. 27 00:02:11,507 --> 00:02:16,970 In the aftermath of a tropical storm, debris is drifting downstream. 28 00:02:20,682 --> 00:02:22,726 [flies buzzing] 29 00:02:22,726 --> 00:02:28,065 And amongst the wreckage, rafts of vegetation ripped from the land. 30 00:02:31,235 --> 00:02:35,948 For a weary pterosaur, this one may be a welcome place to rest... 31 00:02:36,823 --> 00:02:38,825 [lapping] 32 00:02:42,287 --> 00:02:44,540 ...but it's far from safe. 33 00:02:49,044 --> 00:02:50,546 [droning] 34 00:02:50,546 --> 00:02:52,673 - [animal grunts] - [squawking] 35 00:03:00,514 --> 00:03:01,765 [squawks] 36 00:03:05,769 --> 00:03:09,231 A huge mosasaur, a deadly underwater hunter, 37 00:03:09,731 --> 00:03:11,775 is looking for an easy meal. 38 00:03:16,154 --> 00:03:21,535 - [squawking] - Such as this little dinosaur, Zalmoxes. 39 00:03:27,332 --> 00:03:29,501 Staying here is too risky. 40 00:03:31,253 --> 00:03:34,715 - He needs a larger raft, and quickly. - [squawking continues] 41 00:03:41,597 --> 00:03:43,849 There's little choice but to swim for it. 42 00:03:58,906 --> 00:04:00,282 [grunts] 43 00:04:04,286 --> 00:04:06,788 [sniffing] 44 00:04:12,586 --> 00:04:14,630 He is not the first here. 45 00:04:16,882 --> 00:04:17,882 [sniffs] 46 00:04:20,219 --> 00:04:21,553 Another castaway. 47 00:04:22,763 --> 00:04:24,139 A female. 48 00:04:25,390 --> 00:04:26,391 [grunts] 49 00:04:29,978 --> 00:04:32,356 Their raft is drifting out to sea. 50 00:04:38,320 --> 00:04:39,321 [squawks] 51 00:04:45,827 --> 00:04:48,914 Sometimes, castaways on rafts like these 52 00:04:49,706 --> 00:04:53,252 are washed up on the shores of the distant islands. 53 00:04:57,548 --> 00:05:02,010 If they're very lucky, this pair could become pioneers. 54 00:05:09,601 --> 00:05:12,020 [grunting] 55 00:05:14,106 --> 00:05:20,153 And may establish a new population, which eventually becomes a new species... 56 00:05:25,409 --> 00:05:27,286 unlike anything seen before. 57 00:05:35,002 --> 00:05:37,629 The longer an island has been isolated, 58 00:05:38,463 --> 00:05:41,758 the more different its animal inhabitants may become. 59 00:05:41,758 --> 00:05:43,552 [dinosaur roars] 60 00:05:45,095 --> 00:05:47,556 These small islands in southern Europe 61 00:05:48,182 --> 00:05:52,853 are home to a strange, rather shy hadrosaur. 62 00:05:54,271 --> 00:05:55,314 [animal bellows] 63 00:05:59,943 --> 00:06:05,908 Feeding amongst these pine saplings, Tethyshadros. 64 00:06:14,917 --> 00:06:17,127 [grunts] 65 00:06:19,671 --> 00:06:21,882 [chitters, grunts] 66 00:06:25,844 --> 00:06:29,431 Just a quarter of the size of its giant cousins on the mainland, 67 00:06:30,098 --> 00:06:33,143 it stands no taller than a human being. 68 00:06:40,108 --> 00:06:44,780 With its unique serrated bill, it can forage among the tough vegetation. 69 00:06:54,164 --> 00:06:58,460 Hunters like T. rex have never reached this little island, 70 00:06:59,711 --> 00:07:03,674 so it should be a safe place for a mother to raise her brood. 71 00:07:03,674 --> 00:07:05,717 [bellows] 72 00:07:11,598 --> 00:07:14,226 But not necessarily. 73 00:07:18,939 --> 00:07:20,566 [grunts] 74 00:07:25,696 --> 00:07:27,239 [grunting] 75 00:07:33,620 --> 00:07:34,538 [bellows] 76 00:07:34,538 --> 00:07:36,164 [dinosaurs roaring] 77 00:07:47,342 --> 00:07:48,177 [grunting] 78 00:07:48,177 --> 00:07:49,970 Hatzegopteryx. 79 00:07:50,846 --> 00:07:52,222 [chittering] 80 00:07:54,099 --> 00:07:56,560 Giant predatory pterosaurs. 81 00:08:00,647 --> 00:08:05,360 The best chance of escape is beneath the canopy of the taller trees. 82 00:08:05,360 --> 00:08:06,445 [roars] 83 00:08:09,323 --> 00:08:10,991 [roars] 84 00:08:16,121 --> 00:08:19,708 These small calves have been left behind among the saplings. 85 00:08:22,377 --> 00:08:24,671 [grunting] 86 00:08:24,671 --> 00:08:26,965 Mother and young are separated. 87 00:08:29,968 --> 00:08:31,428 [rumbles] 88 00:08:35,765 --> 00:08:37,226 [roaring] 89 00:08:38,852 --> 00:08:42,397 Hatzegopteryx are very intelligent pterosaurs. 90 00:08:44,691 --> 00:08:48,987 Now that the element of surprise has gone, they change tactics. 91 00:08:51,782 --> 00:08:53,575 Spreading out across the clearing, 92 00:08:53,575 --> 00:08:56,828 they try to flush out any prey that might still be there. 93 00:08:59,957 --> 00:09:01,333 [Hatzegopteryx roars] 94 00:09:05,712 --> 00:09:09,550 The youngsters' best hope is to stay completely still... 95 00:09:14,263 --> 00:09:15,514 [roars] 96 00:09:15,514 --> 00:09:18,642 ...and not to run. 97 00:09:23,939 --> 00:09:25,732 [screeching] 98 00:09:35,367 --> 00:09:36,410 [roars] 99 00:09:41,248 --> 00:09:42,249 [screeches] 100 00:09:44,793 --> 00:09:46,587 [roars] 101 00:09:51,967 --> 00:09:55,137 These two are lucky to be back with their mother. 102 00:09:57,681 --> 00:09:58,807 [roars] 103 00:10:09,193 --> 00:10:14,239 The island-hopping pterosaurs move on to try their luck elsewhere. 104 00:10:21,288 --> 00:10:23,665 [bellows] 105 00:10:27,169 --> 00:10:29,963 The hadrosaurs can return to feeding. 106 00:10:43,060 --> 00:10:46,396 The island of Madagascar has been separated 107 00:10:46,396 --> 00:10:50,442 from the African mainland for 80 million years. 108 00:10:53,570 --> 00:10:57,366 So long that most of its animals are now very different 109 00:10:58,075 --> 00:10:59,910 from any to be found elsewhere. 110 00:11:00,494 --> 00:11:01,620 [animal hisses] 111 00:11:18,262 --> 00:11:19,638 [hisses] 112 00:11:19,638 --> 00:11:21,849 This is Simosuchus. 113 00:11:25,310 --> 00:11:29,690 It's not a dinosaur but a miniature relative of crocodiles. 114 00:11:30,732 --> 00:11:33,360 One that lives almost entirely on land 115 00:11:34,403 --> 00:11:38,574 and is strictly vegetarian. 116 00:11:52,212 --> 00:11:57,092 Simosuchus have tough, armored bodies which protect them from attack 117 00:11:57,092 --> 00:11:58,802 by the island's predators. 118 00:12:00,888 --> 00:12:03,724 So they can risk dropping their guard... 119 00:12:04,391 --> 00:12:05,601 [rumbling] 120 00:12:07,895 --> 00:12:08,896 ...sometimes. 121 00:12:10,439 --> 00:12:12,149 [animal rumbles] 122 00:12:18,155 --> 00:12:23,702 Majungasaurus, Madagascar's top hunter. 123 00:12:31,627 --> 00:12:32,628 [rumbles] 124 00:12:34,338 --> 00:12:37,341 This particular female is blind in one eye, 125 00:12:38,634 --> 00:12:44,473 so she finds it hard to make a kill, and she's now very hungry. 126 00:12:47,976 --> 00:12:48,852 [screeches] 127 00:12:53,899 --> 00:12:55,317 [screeching] 128 00:13:03,408 --> 00:13:06,995 The Simosuchus have a network of escape routes 129 00:13:06,995 --> 00:13:09,414 that lead them to their underground burrows. 130 00:13:12,584 --> 00:13:16,880 Once inside, they block the entrance with their heavily armored backs. 131 00:13:17,381 --> 00:13:18,882 [snorts, grunts] 132 00:13:18,882 --> 00:13:20,008 [hisses] 133 00:13:28,892 --> 00:13:29,726 [hisses] 134 00:13:32,020 --> 00:13:34,648 This little male is unlucky. 135 00:13:35,399 --> 00:13:38,610 [growls, snarls] 136 00:13:38,610 --> 00:13:40,988 But he's not helpless. 137 00:13:40,988 --> 00:13:42,072 [hissing] 138 00:13:55,836 --> 00:14:00,340 Reverse charges, tail swipes and aggressive kicks. 139 00:14:02,134 --> 00:14:03,760 [Majungasaurus growls] 140 00:14:03,760 --> 00:14:04,970 [grunts, hissing] 141 00:14:17,191 --> 00:14:20,694 The hunter's snout is too broad to reach very far inside. 142 00:14:22,821 --> 00:14:24,406 [growls] 143 00:14:33,165 --> 00:14:38,921 But just to be on the safe side, the Simosuchus digs even deeper. 144 00:14:39,421 --> 00:14:41,173 [roars] 145 00:14:47,554 --> 00:14:52,226 For the Majungasaurus, yet another hunt has ended in failure. 146 00:15:03,946 --> 00:15:09,034 Simosuchus is not the only evolutionary oddity to thrive on Madagascar. 147 00:15:14,581 --> 00:15:19,920 The island is also home to another group of very unusual animals. 148 00:15:24,091 --> 00:15:25,092 Mammals. 149 00:15:34,226 --> 00:15:36,728 This is a female Adalatherium. 150 00:15:38,939 --> 00:15:40,774 She's less than two feet long. 151 00:15:40,774 --> 00:15:45,279 But even so, she's still one of the largest mammals to have yet evolved. 152 00:15:51,243 --> 00:15:54,830 She spends most of her waking hours searching for food. 153 00:16:03,463 --> 00:16:08,051 At the end of this tunnel, there are eggs... 154 00:16:11,430 --> 00:16:14,474 - [sniffing] - ...potentially a rich source of protein. 155 00:16:21,565 --> 00:16:24,568 But she doesn't eat this particular clutch. 156 00:16:28,071 --> 00:16:30,824 These are her own eggs. 157 00:16:32,576 --> 00:16:34,912 And this is her burrow. 158 00:16:48,258 --> 00:16:50,552 The eggs are starting to hatch. 159 00:17:15,743 --> 00:17:18,829 The hatchlings' eyes have not yet opened, 160 00:17:18,829 --> 00:17:24,837 but instinctively, they head towards their mother to feed on milk. 161 00:17:28,882 --> 00:17:32,553 She produces it from modified sweat glands on her belly, 162 00:17:33,554 --> 00:17:36,557 and for now, it's all the food they need. 163 00:17:49,361 --> 00:17:50,195 [chittering] 164 00:17:50,195 --> 00:17:54,741 Two months later, and the cubs have more than quadrupled in size. 165 00:17:56,994 --> 00:17:58,829 To produce enough milk for them, 166 00:17:58,829 --> 00:18:01,832 their mother must herself eat a great deal. 167 00:18:04,251 --> 00:18:09,173 So every night, she has to leave the safety of the den in order to feed. 168 00:18:27,858 --> 00:18:31,236 Her eyesight, like that of many burrowing animals, 169 00:18:31,236 --> 00:18:33,071 is not very sensitive. 170 00:18:37,326 --> 00:18:40,537 She relies instead on her acute hearing. 171 00:18:42,164 --> 00:18:43,457 [rumbling] 172 00:18:45,209 --> 00:18:47,920 And if she hears something that might be dangerous, 173 00:18:47,920 --> 00:18:49,963 she stays perfectly still. 174 00:18:51,465 --> 00:18:52,466 [rumbles] 175 00:18:56,970 --> 00:18:58,514 Trouble avoided. 176 00:19:01,642 --> 00:19:06,021 She returns to searching in the earth for roots and seeds. 177 00:19:19,576 --> 00:19:21,286 [grunting] 178 00:19:21,995 --> 00:19:26,667 The cubs are growing fast and so are their appetites. 179 00:19:32,673 --> 00:19:37,052 The female is now having to search almost nonstop for food. 180 00:19:44,476 --> 00:19:48,146 So her cubs are left unguarded for hours at a time. 181 00:19:54,570 --> 00:19:55,737 [chitters] 182 00:19:58,699 --> 00:20:00,242 Masiakasaurus. 183 00:20:05,080 --> 00:20:06,081 A hunter. 184 00:20:06,081 --> 00:20:10,627 And one particularly well-adapted for catching burrowing prey. 185 00:20:10,627 --> 00:20:12,421 [sniffing] 186 00:20:14,923 --> 00:20:17,134 With its long neck and narrow head, 187 00:20:17,134 --> 00:20:20,429 it can investigate any hole that might contain a meal. 188 00:20:30,606 --> 00:20:31,607 [chittering] 189 00:20:55,005 --> 00:20:59,218 But hunters may themselves become the hunted. 190 00:20:59,885 --> 00:21:01,220 [hisses, roars] 191 00:21:11,396 --> 00:21:17,152 Madtsoia, a snake nearly 25 feet long, squeezes its prey to death. 192 00:21:20,739 --> 00:21:23,867 This neighborhood has now become rather dangerous. 193 00:21:30,916 --> 00:21:32,960 [cubs grunting] 194 00:21:46,932 --> 00:21:52,771 As night falls, the mother leads her young out of the burrow for the very first time. 195 00:22:01,238 --> 00:22:04,992 For now, at least, they must stay close together. 196 00:22:19,840 --> 00:22:24,928 In the far south of the planet, on the islands of the Antarctic Peninsula, 197 00:22:25,470 --> 00:22:28,557 winter brings months of freezing temperatures. 198 00:22:32,227 --> 00:22:35,981 Here, too, being part of a family brings benefits. 199 00:22:36,857 --> 00:22:38,859 [grunting] 200 00:22:43,071 --> 00:22:47,284 A thermal camera reveals a huddle of glowing bodies. 201 00:22:55,959 --> 00:22:57,169 Imperobator. 202 00:22:58,504 --> 00:22:59,505 Hunters. 203 00:23:04,051 --> 00:23:07,596 Like most dinosaurs, they are warm-blooded. 204 00:23:10,182 --> 00:23:13,310 But to stay warm, they need a lot of food. 205 00:23:14,978 --> 00:23:18,148 So they must make a kill every few days if they can. 206 00:23:25,614 --> 00:23:28,951 Fresh snow muffles the sound of their footsteps, 207 00:23:28,951 --> 00:23:33,205 enabling them to move undetected through the forest in search of prey. 208 00:23:38,836 --> 00:23:40,254 A Morrosaurus. 209 00:23:40,963 --> 00:23:42,714 [chittering] 210 00:23:46,593 --> 00:23:51,390 A plant eater for whom winter is inevitably a very hard time. 211 00:23:55,018 --> 00:23:57,145 [dinosaur roaring] 212 00:24:06,780 --> 00:24:10,284 Imperobators specialize in hunting such prey. 213 00:24:11,952 --> 00:24:13,537 [Imperobators chittering] 214 00:24:23,422 --> 00:24:26,133 The Morrosaurus is faster than its pursuers. 215 00:24:32,639 --> 00:24:34,683 But it's outnumbered by the pack. 216 00:24:49,072 --> 00:24:53,952 The Imperobators' long-feathered tails give them remarkable maneuverability. 217 00:25:05,047 --> 00:25:07,925 The chase has reached the very edge of the forest. 218 00:25:10,511 --> 00:25:14,473 Beyond lies a frozen lake, half a mile wide. 219 00:25:15,974 --> 00:25:21,355 The clear, open space could give the faster Morrosaurus an advantage. 220 00:25:24,066 --> 00:25:26,485 But the frozen surface is treacherous. 221 00:25:26,485 --> 00:25:28,111 [chittering] 222 00:25:35,994 --> 00:25:39,665 With the Imperobator closing in, it isn't much of a choice. 223 00:25:52,052 --> 00:25:53,303 [growls] 224 00:26:03,689 --> 00:26:04,982 [growls] 225 00:26:15,033 --> 00:26:16,034 [snarls, screeches] 226 00:26:17,661 --> 00:26:19,079 A misplaced step. 227 00:26:19,788 --> 00:26:24,251 A chance for the Morrosaurus to sprint beyond the predators' reach. 228 00:26:28,338 --> 00:26:30,257 But this is an island, 229 00:26:30,257 --> 00:26:33,552 so hunters and hunted will almost certainly meet again. 230 00:26:44,646 --> 00:26:47,107 Some islands are so small 231 00:26:47,107 --> 00:26:50,027 that they have no large land-living residents. 232 00:26:53,238 --> 00:26:56,408 But they may, nonetheless, get visitors. 233 00:27:03,665 --> 00:27:05,000 Hatzegopteryx. 234 00:27:13,592 --> 00:27:18,472 This male has arrived carrying a 40-pound Tethyshadros carcass. 235 00:27:19,598 --> 00:27:21,725 A prize from a recent hunt. 236 00:27:25,103 --> 00:27:26,104 [rumbles] 237 00:27:29,691 --> 00:27:34,404 He is 15 feet tall, with a wingspan of over 30 feet. 238 00:27:36,323 --> 00:27:39,868 Hatzegopteryx are Europe's top predators. 239 00:27:42,538 --> 00:27:47,459 But this male has come here to reveal another side to his character. 240 00:28:21,702 --> 00:28:26,999 He has constructed a display to make it clear to any females passing overhead 241 00:28:27,708 --> 00:28:30,043 that he is looking for a mate. 242 00:28:32,671 --> 00:28:36,508 But he might have a very long wait before he gets a response. 243 00:28:44,808 --> 00:28:46,143 [Hatzegopteryx chittering] 244 00:28:56,820 --> 00:29:00,324 - [bellows, growls] - At last. A female. 245 00:29:04,870 --> 00:29:06,455 She seems interested, 246 00:29:06,455 --> 00:29:09,166 but a little more persuasion might be necessary. 247 00:29:10,709 --> 00:29:12,753 And he needs to be careful. 248 00:29:14,004 --> 00:29:16,173 One well-aimed peck from her beak 249 00:29:16,673 --> 00:29:20,010 could quickly bring his whole mating season to an end. 250 00:29:25,766 --> 00:29:29,937 His display must demonstrate that he has the good genes 251 00:29:29,937 --> 00:29:32,606 that her young would do well to inherit. 252 00:29:35,442 --> 00:29:38,904 The dead dinosaur suggests that he's a good hunter 253 00:29:38,904 --> 00:29:42,449 and carrying it here has proved that he's a strong flyer. 254 00:29:45,953 --> 00:29:51,416 But if she is impressed, she isn't showing it yet. 255 00:29:55,754 --> 00:30:00,300 Time to produce some new evidence of his eligibility. 256 00:30:00,300 --> 00:30:02,636 [rumbling] 257 00:30:04,513 --> 00:30:08,016 Head lifts invite her to come closer. 258 00:30:22,322 --> 00:30:25,659 Now, she gives him a little encouragement. 259 00:30:52,436 --> 00:30:56,356 A synchronized dance creates trust between them. 260 00:31:17,127 --> 00:31:18,754 [rumbles] 261 00:31:19,463 --> 00:31:20,589 Another male. 262 00:31:22,633 --> 00:31:26,345 He's much younger, but he could still be a rival. 263 00:31:34,061 --> 00:31:35,646 [grunting] 264 00:31:40,400 --> 00:31:41,401 [groans] 265 00:31:44,404 --> 00:31:45,697 [roars] 266 00:31:48,992 --> 00:31:50,410 That's him dealt with. 267 00:31:56,458 --> 00:31:59,586 Disaster. The female has left. 268 00:32:07,344 --> 00:32:09,513 He may have lost his chance. 269 00:32:17,145 --> 00:32:18,897 [Hatzegopteryx bellows] 270 00:32:25,320 --> 00:32:26,321 She's back. 271 00:32:28,824 --> 00:32:33,495 Seeing off a potential rival might even be another point in his favor. 272 00:32:42,254 --> 00:32:45,215 He continues from where he left off. 273 00:32:54,057 --> 00:32:56,727 One last reminder of his strength. 274 00:33:01,857 --> 00:33:05,068 And this is his only contribution to fatherhood. 275 00:33:15,245 --> 00:33:17,998 It's all over in just a few seconds. 276 00:33:20,417 --> 00:33:25,422 But it's the start of the next generation of these giant flying hunters. 277 00:33:32,429 --> 00:33:34,890 Islands like this may only be small, 278 00:33:36,058 --> 00:33:38,769 but like countless others around the world, 279 00:33:40,437 --> 00:33:43,065 they bear witness to crucial moments 280 00:33:43,065 --> 00:33:46,401 in the lives of some of the most unusual creatures 281 00:33:47,194 --> 00:33:49,571 on the Prehistoric Planet. 282 00:34:09,842 --> 00:34:12,219 During the time of the dinosaurs, 283 00:34:12,761 --> 00:34:18,433 the skies were dominated by flying reptiles called pterosaurs. 284 00:34:23,397 --> 00:34:26,440 There were over 250 species... 285 00:34:28,443 --> 00:34:30,612 and some of them were enormous. 286 00:34:33,824 --> 00:34:36,493 One of the most interesting, because they're the most bizarre, 287 00:34:36,493 --> 00:34:38,411 {\an8}are the azhdarchid pterosaurs. 288 00:34:38,411 --> 00:34:40,831 {\an8}And to try and describe 289 00:34:40,831 --> 00:34:43,292 {\an8}what an azhdarchid pterosaur is like is very difficult. 290 00:34:44,251 --> 00:34:46,170 They stand as tall as giraffes. 291 00:34:46,795 --> 00:34:49,255 They've got heads that may have been two meters long, 292 00:34:49,922 --> 00:34:51,341 wingspans of ten meters. 293 00:34:52,967 --> 00:34:56,096 They're some of the most bizarre things who've ever evolved on Earth. 294 00:34:58,557 --> 00:35:03,145 [Attenborough] Despite their size, these giants were well-adapted for flight. 295 00:35:04,813 --> 00:35:08,025 So why do we think they hunted on the ground? 296 00:35:10,485 --> 00:35:13,071 {\an8}The azhdarchid's wing is a skin membrane 297 00:35:13,071 --> 00:35:17,743 {\an8}supported entirely by a superenlarged fourth finger. 298 00:35:19,453 --> 00:35:23,248 {\an8}This skin membrane extended from the tip of that giant fourth finger 299 00:35:23,248 --> 00:35:26,001 {\an8}all the way to the top of the hind leg. 300 00:35:28,086 --> 00:35:31,465 Azhdarchids were supremely adapted for covering great distance, 301 00:35:31,465 --> 00:35:34,635 but they weren't the kind of animals that were twisting and turning 302 00:35:34,635 --> 00:35:37,012 and making agile movements actually in flight. 303 00:35:39,431 --> 00:35:42,476 [Attenborough] This would've made it hard for azhdarchids 304 00:35:42,476 --> 00:35:44,811 to catch other flying animals. 305 00:35:46,563 --> 00:35:48,690 They must have had a different way to hunt. 306 00:35:50,609 --> 00:35:54,988 One of the most prevalent ideas about how azhdarchid pterosaurs may have fed 307 00:35:54,988 --> 00:35:59,284 is by using this bizarre mechanism of foraging known as skim feeding. 308 00:36:00,494 --> 00:36:04,706 [Attenborough] Today, birds like black skimmers feed in this way. 309 00:36:06,291 --> 00:36:09,211 [Witton] It's the most ridiculous way of getting your food you can imagine. 310 00:36:09,211 --> 00:36:11,547 It's literally pushing your lower jaw through the water 311 00:36:11,547 --> 00:36:13,048 and crashing into your food. 312 00:36:14,967 --> 00:36:18,971 [Attenborough] A skimmer's neck is built to absorb sudden impacts. 313 00:36:21,682 --> 00:36:25,811 But fossils reveal azhdarchids had none of these adaptations. 314 00:36:27,104 --> 00:36:31,066 In fact, they would almost certainly break their necks from just the strain 315 00:36:31,066 --> 00:36:33,485 of trying to push their lower jaws through the water. 316 00:36:36,363 --> 00:36:38,532 [Attenborough] An azhdarchid had no option. 317 00:36:39,908 --> 00:36:42,369 It must have landed to find food. 318 00:36:45,998 --> 00:36:48,792 But could it really walk fast enough to hunt? 319 00:36:51,253 --> 00:36:54,423 Scientists needed evidence to persuade them 320 00:36:54,423 --> 00:36:57,551 that they could do anything more than just waddle. 321 00:36:59,678 --> 00:37:04,057 That evidence comes from 66-million-year-old footprints. 322 00:37:06,059 --> 00:37:08,437 [Witton] The biggest pterosaur track in the world was made 323 00:37:08,437 --> 00:37:10,355 by a walking giant azhdarchid. 324 00:37:11,273 --> 00:37:12,816 That's not only a cool thing to have, 325 00:37:12,816 --> 00:37:15,903 it tells us an awful lot about how efficient they were at walking. 326 00:37:18,405 --> 00:37:20,073 [Attenborough] These tracks show 327 00:37:20,073 --> 00:37:23,160 they held their limbs directly under their body, 328 00:37:24,536 --> 00:37:26,747 giving them an upright stance. 329 00:37:28,749 --> 00:37:30,250 Their feet were padded. 330 00:37:32,252 --> 00:37:34,671 And unlike the small pterosaurs, 331 00:37:34,671 --> 00:37:38,175 their long legs gave them an enormous stride. 332 00:37:40,385 --> 00:37:42,804 [Witton] Although azhdarchids are peculiar-looking animals, 333 00:37:42,804 --> 00:37:44,139 they're moving very efficiently. 334 00:37:44,139 --> 00:37:45,224 [growls] 335 00:37:49,102 --> 00:37:53,315 [Naish] Azhdarchids combined this competent terrestrial walking ability 336 00:37:53,315 --> 00:37:55,526 with this massive long stork-like face. 337 00:37:56,693 --> 00:37:59,071 They almost certainly were predators 338 00:37:59,071 --> 00:38:02,574 that walked around reaching down to grab animals. 339 00:38:07,412 --> 00:38:08,830 [Witton] We have to remember, though, 340 00:38:08,830 --> 00:38:11,333 the throat size of this thing is half a meter wide. 341 00:38:11,333 --> 00:38:13,377 That's about the width of my shoulders. 342 00:38:14,253 --> 00:38:16,755 We would be on the menu for these things 343 00:38:16,755 --> 00:38:18,632 - if they were alive today. - [chitters] 344 00:38:21,260 --> 00:38:22,469 [grunts] 345 00:38:22,469 --> 00:38:27,057 [Attenborough] Pterosaurs would have been an awe-inspiring sight in the sky. 346 00:38:29,268 --> 00:38:30,435 [grunting] 347 00:38:31,228 --> 00:38:36,275 But these giants were even more impressive and terrifying on the ground.