1 00:00:02,000 --> 00:00:07,000 Downloaded from YTS.MX 2 00:00:08,000 --> 00:00:13,000 Official YIFY movies site: YTS.MX 3 00:00:44,020 --> 00:00:47,770 DAVID ATTENBOROUGH: Birds today are the masters of the skies. 4 00:00:52,110 --> 00:00:54,650 But they were not the first creatures to fly, 5 00:00:57,990 --> 00:01:00,620 and they are certainly not the biggest. 6 00:01:03,870 --> 00:01:06,000 The first large animals to leave the ground 7 00:01:06,750 --> 00:01:08,500 were so extraordinary 8 00:01:08,580 --> 00:01:10,750 they're almost beyond imagination. 9 00:01:36,700 --> 00:01:38,610 They were reptiles. 10 00:01:41,530 --> 00:01:43,200 (PTEROSAURS SQUAWKING) 11 00:01:43,790 --> 00:01:45,370 Pterosaurs. 12 00:01:55,920 --> 00:01:59,090 They evolved into a huge variety of species. 13 00:02:04,310 --> 00:02:05,890 (GROWLING) 14 00:02:08,350 --> 00:02:10,850 Some, the size of aeroplanes, 15 00:02:10,940 --> 00:02:13,270 were the largest creatures ever to fly. 16 00:02:15,610 --> 00:02:19,070 They could travel half way around the world in a single flight. 17 00:02:23,950 --> 00:02:26,580 And the pterosaurs' extraordinary abilities 18 00:02:26,620 --> 00:02:30,960 enabled them to dominate the skies of the prehistoric Earth 19 00:02:31,040 --> 00:02:34,090 for a 1 50 million years. 20 00:02:36,590 --> 00:02:41,510 But, why did these magnificent beasts take to the air in the first place? 21 00:02:48,430 --> 00:02:50,060 How did they fly? 22 00:02:52,020 --> 00:02:56,480 And why, after such success, did they vanish? 23 00:03:31,690 --> 00:03:37,150 Something very remarkable happened around 220 million years ago. 24 00:03:39,280 --> 00:03:42,490 The planet then was a very different place. 25 00:03:43,410 --> 00:03:45,620 It was much drier, for a start, 26 00:03:45,700 --> 00:03:48,950 but, in the tropics there were rainforests, 27 00:03:49,040 --> 00:03:50,620 and then, as now, 28 00:03:50,700 --> 00:03:54,750 they were the focus of a great deal of varied wildlife. 29 00:03:55,880 --> 00:03:58,920 In the detail however, they were very different. 30 00:03:59,710 --> 00:04:03,680 Most notably, there were no large creatures in the air. 31 00:04:03,720 --> 00:04:06,760 No bats. No birds. 32 00:04:06,850 --> 00:04:10,640 The stage was set for a remarkable advance 33 00:04:10,720 --> 00:04:12,350 in the history of life. 34 00:04:17,150 --> 00:04:21,150 At that time, the only animals that could fly were insects. 35 00:04:24,530 --> 00:04:27,780 They were tempting food for reptiles. 36 00:04:30,950 --> 00:04:33,040 But if a reptile were to catch them, 37 00:04:33,120 --> 00:04:35,830 it, too, would have to take to the air. 38 00:04:39,460 --> 00:04:42,130 And a hint, of how they might first have done so 39 00:04:42,800 --> 00:04:46,590 can be seen in an animal that is alive today. 40 00:04:55,730 --> 00:04:59,360 This little lizard called Draco, 41 00:05:00,110 --> 00:05:02,940 is found throughout the forests of Southeast Asia. 42 00:05:03,940 --> 00:05:07,740 And it must certainly have had, in the far distant past, 43 00:05:07,820 --> 00:05:10,450 lizard ancestors and cousins 44 00:05:10,530 --> 00:05:12,240 that looked very much like it. 45 00:05:13,370 --> 00:05:18,380 Like them, it finds it food, insects, throughout the forest. 46 00:05:18,460 --> 00:05:21,590 And to do that, it has to get around. 47 00:05:21,710 --> 00:05:25,550 And it has a very interesting way of doing that. 48 00:05:29,390 --> 00:05:33,310 Draco is an excellent climber. 49 00:05:33,390 --> 00:05:36,520 Light in weight and with powerful gripping claws, 50 00:05:36,600 --> 00:05:39,650 it can run along the branches of the highest trees 51 00:05:39,730 --> 00:05:41,400 in pursuit of its prey. 52 00:05:43,940 --> 00:05:46,570 But Draco faces a problem. 53 00:05:46,650 --> 00:05:49,280 How can it travel from one tree to the next 54 00:05:49,370 --> 00:05:53,240 without going all the way back down to the ground and then up again? 55 00:05:54,580 --> 00:05:58,370 The way it has evolved of doing so, gives us a clue 56 00:05:58,460 --> 00:06:02,170 as to how early reptiles may first have taken to the air. 57 00:06:14,720 --> 00:06:15,980 It jumps. 58 00:06:23,520 --> 00:06:26,150 But it does more than just leap. 59 00:06:28,070 --> 00:06:30,200 It extends the width of its body 60 00:06:30,280 --> 00:06:33,830 by opening flaps of skin along its flanks, 61 00:06:36,450 --> 00:06:38,910 and they enable it to glide. 62 00:06:55,760 --> 00:06:58,180 Draco may give us the right idea 63 00:06:58,270 --> 00:07:02,730 as to how gliding, flying, amongst the reptiles started. 64 00:07:03,770 --> 00:07:05,730 But one thing is certain. 65 00:07:05,820 --> 00:07:08,570 Flapping flight, powered flight, 66 00:07:08,650 --> 00:07:12,320 remained the preserve of the insects for a very long time. 67 00:07:13,490 --> 00:07:18,410 And then, one group of reptiles developed even that. 68 00:07:19,330 --> 00:07:23,380 And the evidence of how they did so is really very intriguing. 69 00:07:34,220 --> 00:07:37,930 This is Dorset, on England's south coast. 70 00:07:40,980 --> 00:07:44,190 And this is where my journey into the past begins. 71 00:07:51,950 --> 00:07:54,410 A 90 mile stretch of shoreline here 72 00:07:54,490 --> 00:07:57,790 can tell us a lot about the evolution of flight. 73 00:08:05,830 --> 00:08:08,800 This is the Jurassic Coast. 74 00:08:17,640 --> 00:08:21,180 Its rocks are full of fossils of prehistoric creatures, 75 00:08:22,980 --> 00:08:27,520 including evidence of the first backboned animals ever to fly. 76 00:08:31,440 --> 00:08:33,900 But wasn't until the 1 9th century 77 00:08:33,990 --> 00:08:37,530 that scientist started putting together those clues 78 00:08:37,620 --> 00:08:39,450 to form a detailed picture 79 00:08:39,540 --> 00:08:41,370 of one of the most dramatic periods 80 00:08:41,450 --> 00:08:43,830 in the whole of the history of life. 81 00:08:44,920 --> 00:08:47,710 And they had an unlikely ally. 82 00:08:47,790 --> 00:08:50,500 A middle aged woman from the local town, 83 00:08:50,590 --> 00:08:53,880 who used to come out to scour these cliffs for those clues. 84 00:08:55,970 --> 00:08:57,930 She'd come in all weathers, 85 00:08:58,010 --> 00:09:01,220 but particularly, after there had been heavy storms, 86 00:09:01,310 --> 00:09:04,060 which might have removed some section of the cliff, 87 00:09:04,140 --> 00:09:07,810 and so exposed specimens that no one had ever seen before. 88 00:09:09,770 --> 00:09:12,190 Her name was Mary Anning. 89 00:09:21,700 --> 00:09:26,540 Mary is, for me, the heroine of this remarkable story. 90 00:09:30,210 --> 00:09:34,840 She had an almost unbelievable talent for unearthing fossils. 91 00:09:42,600 --> 00:09:46,890 In the early 1 800s, science was still the preserve of men. 92 00:09:49,520 --> 00:09:51,980 Yet, what she managed to unearth, 93 00:09:52,070 --> 00:09:56,570 brought academics flocking to her hometown of Lyme Regis. 94 00:10:00,990 --> 00:10:03,870 So extraordinary were her achievements 95 00:10:03,950 --> 00:10:07,830 that some called her, ''The Princess of Palaeontology''. 96 00:10:13,000 --> 00:10:16,340 When you consider Mary Anning's status, 97 00:10:16,470 --> 00:10:19,260 a woman from a working class background, 98 00:10:19,390 --> 00:10:22,140 with no formal education to speak of, 99 00:10:22,180 --> 00:10:26,520 it may seem strange that she acquired such a prestigious reputation, 100 00:10:27,350 --> 00:10:30,230 until, that is, you see what it was that she discovered. 101 00:10:34,070 --> 00:10:36,400 The Natural History Museum in London. 102 00:10:46,660 --> 00:10:50,540 It holds one of the most comprehensive collections of fossils in the world. 103 00:10:56,920 --> 00:10:59,130 And those Mary Anning discovered 104 00:10:59,170 --> 00:11:02,390 are among the very best, and the most important. 105 00:11:06,470 --> 00:11:10,940 A whole section of the museum is filled with her finds. 106 00:11:13,810 --> 00:11:17,940 Most of the creatures she collected were giant aquatic reptiles, 107 00:11:18,110 --> 00:11:21,530 fish eating monsters that dominated the seas. 108 00:11:23,820 --> 00:11:26,200 But she found other things, too. 109 00:11:26,290 --> 00:11:30,210 One of them in particular is the key to our story. 110 00:11:33,830 --> 00:11:35,420 In 1 828, 111 00:11:35,500 --> 00:11:39,670 Mary Anning made one of her most sensational discoveries. 112 00:11:40,880 --> 00:11:41,930 This is it. 113 00:11:42,180 --> 00:11:44,600 It's a small animal, 114 00:11:44,680 --> 00:11:46,390 but its head is missing, 115 00:11:46,470 --> 00:11:48,140 and its spine is missing, 116 00:11:48,220 --> 00:11:50,680 but what remains is fascinating. 117 00:11:51,640 --> 00:11:53,020 Here's its pelvis, 118 00:11:54,310 --> 00:11:56,480 its upper leg, its lower leg, 119 00:11:56,570 --> 00:12:00,030 and there is its foot with its toes. 120 00:12:05,120 --> 00:12:07,240 And here is its arm, 121 00:12:08,490 --> 00:12:11,960 which ends with a hand with fingers. 122 00:12:12,710 --> 00:12:16,960 Except that one of these fingers is hugely elongated, 123 00:12:17,040 --> 00:12:19,880 it runs all the way along here. 124 00:12:22,420 --> 00:12:26,220 And Mary Anning probably realised what that meant. 125 00:12:27,010 --> 00:12:30,270 It meant that that long finger supported a wing. 126 00:12:31,390 --> 00:12:34,060 And as more specimens were discovered, 127 00:12:34,140 --> 00:12:37,610 it was realised that this was certainly a reptile with a wing, 128 00:12:37,690 --> 00:12:40,860 so, it was called ''Pterosaur''. 129 00:12:40,990 --> 00:12:42,610 ''Winged lizard''. 130 00:12:55,460 --> 00:12:58,210 Mary Anning had found the blueprint 131 00:12:58,250 --> 00:13:02,170 for the first large animals ever to fly. 132 00:13:02,260 --> 00:13:04,300 A creature that set the pattern 133 00:13:04,380 --> 00:13:06,800 for a whole new phase of aerial evolution. 134 00:13:12,600 --> 00:13:15,560 It lived 200 million years ago, 135 00:13:15,640 --> 00:13:18,810 at a time when the planet was very different from today. 136 00:13:25,070 --> 00:13:26,660 Much of it was tropical. 137 00:13:30,660 --> 00:13:32,240 (CRICKETS CHIRPING) 138 00:13:36,290 --> 00:13:37,920 (INSECT BUZZING) 139 00:13:42,590 --> 00:13:43,800 (GRUNTING) 140 00:13:46,720 --> 00:13:50,350 The early dinosaurs were rising to dominance. 141 00:13:54,640 --> 00:13:57,190 And flying high above them were the pterosaurs 142 00:13:57,270 --> 00:14:00,310 of the kind whose bones Mary Anning had discovered. 143 00:14:02,440 --> 00:14:04,610 Dimorphodon. 144 00:14:12,120 --> 00:14:13,450 Up here in the trees, 145 00:14:13,540 --> 00:14:16,080 they were safe from those predatory dinosaurs 146 00:14:16,160 --> 00:14:17,370 down on the ground. 147 00:14:21,670 --> 00:14:25,510 And there were plenty of flying insects for them to catch and eat. 148 00:14:47,360 --> 00:14:50,950 But these early flying reptiles were pioneers. 149 00:14:51,030 --> 00:14:56,250 And it maybe that,just occasionally, they were a little clumsy on the wing. 150 00:14:57,750 --> 00:14:59,460 (SQUAWKING) 151 00:15:08,380 --> 00:15:09,470 (SQUAWKING) 152 00:15:31,610 --> 00:15:35,240 Sometimes, as their bodies lay on the sea floor, 153 00:15:35,330 --> 00:15:37,620 they were slowly covered with mud, 154 00:15:37,700 --> 00:15:41,920 that over millenia, eventually turned to stone. 155 00:15:50,220 --> 00:15:52,630 Fossils of pterosaurs have been discovered 156 00:15:52,720 --> 00:15:54,510 in many parts of the world. 157 00:15:54,640 --> 00:15:57,930 In Africa, Asia and South America. 158 00:15:58,060 --> 00:16:02,980 But the very first were found here, at Solnhofen, in Southern Germany. 159 00:16:09,940 --> 00:16:13,030 This limestone has been quarried for building purposes, 160 00:16:13,160 --> 00:16:15,070 since Roman times. 161 00:16:22,250 --> 00:16:24,170 But those who work here 162 00:16:24,250 --> 00:16:27,170 sometimes find something far more valuable 163 00:16:27,250 --> 00:16:29,460 than just roof tiles. 164 00:16:40,310 --> 00:16:42,180 The discoveries made here 165 00:16:42,270 --> 00:16:45,650 make this one of the most important places in all over the world 166 00:16:45,770 --> 00:16:49,320 for anybody who's interested in pterosaurs. 167 00:16:49,440 --> 00:16:52,070 And the perfection of their preservation 168 00:16:52,150 --> 00:16:55,240 has enabled us to unlock many of the secrets 169 00:16:55,360 --> 00:16:58,580 about how these wonderful animals flew. 170 00:17:00,950 --> 00:17:03,750 The Solnhofen limestone formed on the floor 171 00:17:03,830 --> 00:17:05,960 of a shallow tropical lagoon, 172 00:17:06,040 --> 00:17:09,420 protected from the currents of the open sea by a reef. 173 00:17:11,170 --> 00:17:14,590 So, its waters were still, and they were few currents 174 00:17:14,680 --> 00:17:16,760 to disturb the rotting bodies. 175 00:17:21,470 --> 00:17:22,640 (GRUNTING) 176 00:17:24,600 --> 00:17:27,400 The rock here is really extraordinary. 177 00:17:28,150 --> 00:17:33,280 When it's fresh, it's very solid, hard building stone. 178 00:17:33,400 --> 00:17:34,530 Excellent. 179 00:17:34,950 --> 00:17:38,280 But when the frost gets at it, it begins to split. 180 00:17:38,370 --> 00:17:40,280 And when it's really weathered, 181 00:17:40,370 --> 00:17:45,160 you can open blocks of it like leaves of a book. 182 00:17:45,250 --> 00:17:48,170 Like that, for example. 183 00:17:49,040 --> 00:17:54,340 And sometimes there's something written on these leaves, 184 00:17:54,420 --> 00:17:55,630 but mostly 185 00:17:57,720 --> 00:17:58,970 nothing. 186 00:17:59,890 --> 00:18:01,970 And maybe for... 187 00:18:02,600 --> 00:18:04,220 (CHUCKLING) 188 00:18:05,180 --> 00:18:08,400 I was going to say, ''Maybe there's nothing.'' 189 00:18:08,560 --> 00:18:12,190 But, on this one, there's a perfect little ammonite, 190 00:18:13,030 --> 00:18:14,110 a shellfish. 191 00:18:16,610 --> 00:18:19,410 This quarry has produced so many fossils 192 00:18:19,490 --> 00:18:24,200 that the town's castle has been turned into a museum to house them. 193 00:18:26,910 --> 00:18:29,460 The majority are sea creatures, 194 00:18:31,040 --> 00:18:33,920 but sometimes, there are animals that fell into the water 195 00:18:34,000 --> 00:18:36,010 from the skies above. 196 00:18:36,090 --> 00:18:37,510 Pterosaurs. 197 00:18:39,050 --> 00:18:41,510 Here is one that did. 198 00:18:44,810 --> 00:18:48,020 It's a kind called Rhamphorhynchus. 199 00:18:48,140 --> 00:18:52,270 Not only are its bones still connected, as they were in life, 200 00:18:52,360 --> 00:18:55,730 you can even see something of its soft parts. 201 00:18:58,110 --> 00:19:02,950 This one of the most perfect pterosaur fossils ever found. 202 00:19:03,120 --> 00:19:08,370 And it's a miracle, bearing in mind it's a 1 50 million years old, 203 00:19:08,460 --> 00:19:11,830 and yet it's complete in all the tiny details. 204 00:19:18,380 --> 00:19:20,880 It had a long bony tail, 205 00:19:24,680 --> 00:19:27,560 long toes on its feet. 206 00:19:31,650 --> 00:19:36,110 Its spine and its ribs still connected. 207 00:19:42,320 --> 00:19:44,740 Its jaws have long teeth 208 00:19:44,830 --> 00:19:48,620 which would've enabled it to snatch fish from the surface of the lagoon. 209 00:19:55,460 --> 00:19:59,800 But the most fascinating parts of its anatomy are its wings. 210 00:20:01,510 --> 00:20:06,180 They are supported as in all pterosaurs by a hugely elongated finger. 211 00:20:11,560 --> 00:20:13,440 This is the wing membrane, 212 00:20:13,520 --> 00:20:17,150 which, in life, would have been less than a millimetre thick, 213 00:20:17,230 --> 00:20:21,070 and yet, it's so perfectly preserved you can see within it 214 00:20:21,150 --> 00:20:24,070 all the tiny details of little structures 215 00:20:24,160 --> 00:20:26,330 that would have given that membrane strength. 216 00:20:32,410 --> 00:20:35,830 There are rows of tiny fibres called actinofibrils, 217 00:20:36,710 --> 00:20:39,590 which may have given it precise muscular control 218 00:20:39,670 --> 00:20:41,630 right across the wing surface. 219 00:20:46,430 --> 00:20:48,510 You can also see from this fossil 220 00:20:48,600 --> 00:20:52,310 how pterosaurs managed their wings when they weren't flying. 221 00:20:57,060 --> 00:21:01,280 Here, at the base of this long finger, 222 00:21:01,360 --> 00:21:02,990 is the miracle joint, 223 00:21:03,070 --> 00:21:07,700 which enabled the pterosaurs to move their fingers in any direction. 224 00:21:07,780 --> 00:21:10,370 And that was a huge advantage 225 00:21:10,450 --> 00:21:14,960 because it allowed them to fold up their wings when they landed. 226 00:21:16,540 --> 00:21:18,090 (SQUAWKING) 227 00:21:33,810 --> 00:21:36,980 The pterosaurs had evolved a brilliant first solution 228 00:21:37,100 --> 00:21:40,150 to the problems of travelling through the air. 229 00:21:42,280 --> 00:21:46,160 But they were about to become even better aeronauts. 230 00:21:51,490 --> 00:21:55,870 About 50 million years after the first winged pterosaur 231 00:21:56,000 --> 00:21:58,790 came something much more advanced. 232 00:22:01,840 --> 00:22:05,050 It lived in a region of the planet that is now China. 233 00:22:11,350 --> 00:22:12,850 Its skeleton was unearthed 234 00:22:12,930 --> 00:22:15,770 by one of the world's leading experts on pterosaurs, 235 00:22:16,060 --> 00:22:17,600 Dr David Unwin. 236 00:22:17,850 --> 00:22:23,070 So, here's one of the pterosaurs that we found last year in China. 237 00:22:24,070 --> 00:22:26,450 ATTENBOROUGH: He named it after Charles Darwin. 238 00:22:29,110 --> 00:22:30,450 Darwinopterus. 239 00:22:31,660 --> 00:22:33,700 ATTENBOROUGH: Gosh, it's very beautiful. 240 00:22:33,830 --> 00:22:35,790 It's almost complete, isn't it? 241 00:22:35,870 --> 00:22:38,000 UNWIN: It's absolutely complete. 242 00:22:39,040 --> 00:22:42,130 We can tell that from things like this long tail, 243 00:22:42,920 --> 00:22:46,300 that we're dealing with a rather primitive kind of pterosaur. 244 00:22:46,380 --> 00:22:49,300 These are classic features of that group. 245 00:22:49,970 --> 00:22:53,640 But revelation came when we looked at the neck, 246 00:22:53,720 --> 00:22:57,850 and in particular at the skull, because that's quite astonishing. 247 00:23:01,730 --> 00:23:04,110 ATTENBOROUGH: Why, it's huge, isn't it? 248 00:23:04,190 --> 00:23:05,530 I mean, that's... 249 00:23:06,150 --> 00:23:07,740 longer than the body. 250 00:23:10,070 --> 00:23:12,570 UNWIN: The jaws themselves are really very powerful 251 00:23:12,660 --> 00:23:15,540 and it's got some big pointed teeth as well. 252 00:23:17,330 --> 00:23:21,420 This is a skull which looks like that of a really advanced pterosaur. 253 00:23:21,830 --> 00:23:25,420 But, the rest of the body looks really quite primitive. 254 00:23:25,840 --> 00:23:30,430 So we've got this weird mix of characters, primitive and advanced. 255 00:23:30,760 --> 00:23:33,430 This is a little bit like Frankenstein's monster. 256 00:23:43,480 --> 00:23:44,690 (ROARING) 257 00:23:53,620 --> 00:23:56,910 ATTENBOROUGH: The big head and pointed teeth of Darwinopterus 258 00:23:57,040 --> 00:24:00,000 makes it clear that this was a predator. 259 00:24:01,210 --> 00:24:04,040 So it must have been very agile in the air. 260 00:24:17,060 --> 00:24:20,480 But, this pterosaur wasn't just eating insects. 261 00:25:04,440 --> 00:25:07,560 Pterosaur wings were clearly very efficient in the air. 262 00:25:08,730 --> 00:25:10,780 But they evolved at a cost. 263 00:25:13,820 --> 00:25:15,490 (PTEROSAUR SHRIEKING) 264 00:25:25,420 --> 00:25:29,960 Using wireframe computer simulations of pterosaur movement, 265 00:25:30,050 --> 00:25:33,840 David Unwin has investigated how they moved on the ground. 266 00:25:38,010 --> 00:25:42,310 UNWIN: What I've done is feed to the vital statistics of this pterosaur 267 00:25:42,390 --> 00:25:43,680 into the computer, 268 00:25:44,100 --> 00:25:47,480 and build this model that you can see on the screen. 269 00:25:51,780 --> 00:25:54,990 ATTENBOROUGH: It's easy to see that walking on flat surfaces 270 00:25:55,070 --> 00:25:57,070 would have been quite difficult for it. 271 00:25:58,450 --> 00:26:00,490 Did they always move around like that? 272 00:26:01,330 --> 00:26:03,910 Well, we can try and get him to stand 273 00:26:04,040 --> 00:26:06,870 just on the hind limbs alone, like a bird, 274 00:26:06,960 --> 00:26:09,000 but when you do that, 275 00:26:09,460 --> 00:26:12,670 the thing you can see is not very well balanced at all. 276 00:26:12,760 --> 00:26:14,670 Looks quite unstable, and worst still, 277 00:26:14,760 --> 00:26:17,590 the tail is actually catching on the ground. 278 00:26:23,470 --> 00:26:25,140 (PTEROSAUR CALLING SOFTLY) 279 00:26:28,230 --> 00:26:33,860 So, now we can see him standing, in this four-legged pose. 280 00:26:37,030 --> 00:26:39,990 The winged membranes, which are attached to the hind limbs, 281 00:26:40,070 --> 00:26:41,240 get in the way somewhat. 282 00:26:41,330 --> 00:26:44,160 It doesn't look all that comfortable on the ground. 283 00:26:44,240 --> 00:26:48,290 And in fact, when we look at the claws on the hands and the toes, 284 00:26:48,370 --> 00:26:50,580 we find that they're really not well suited 285 00:26:50,670 --> 00:26:52,840 to life on the ground at all. 286 00:26:53,380 --> 00:26:55,050 Where's he off to now? 287 00:26:57,170 --> 00:26:58,340 (ATTENBOROUGH EXCLAIMS) 288 00:26:58,430 --> 00:26:59,760 (LAUGHING) 289 00:26:59,840 --> 00:27:02,180 And now we see, it looks a lot more happy, 290 00:27:02,260 --> 00:27:04,220 just hanging up there, 291 00:27:04,310 --> 00:27:07,140 just as they would have done on trees and cliffs... 292 00:27:07,230 --> 00:27:09,190 -Yeah. -...back in the Jurassic. 293 00:27:09,940 --> 00:27:10,980 (EXCLAIMS) 294 00:27:11,560 --> 00:27:12,900 (CHUCKLES) 295 00:27:13,360 --> 00:27:16,240 ATTENBOROUGH: So, early pterosaurs, with their long tails, 296 00:27:16,320 --> 00:27:20,320 probably spent most of their time hanging from vertical surfaces 297 00:27:20,410 --> 00:27:23,240 like cliffs and the trunks of trees. 298 00:27:30,370 --> 00:27:33,380 But, if they were to spread beyond those environments, 299 00:27:33,460 --> 00:27:36,590 they would have to change the shape of their bodies. 300 00:27:40,510 --> 00:27:44,140 This fossil is 1 40 million years old. 301 00:27:46,180 --> 00:27:49,440 It has the enlarged head of an advanced pterosaur, 302 00:27:49,520 --> 00:27:51,190 but its tail is different. 303 00:27:51,270 --> 00:27:52,940 It's become much shorter. 304 00:27:59,530 --> 00:28:03,070 And this short-tail species wasn't alone. 305 00:28:06,040 --> 00:28:08,870 It was clearly a very successful modification. 306 00:28:10,830 --> 00:28:14,960 There were many like it, with these new style short-tails 307 00:28:15,040 --> 00:28:17,460 and reduced hind flight membranes. 308 00:28:31,190 --> 00:28:35,440 Here, in France, at Crayssac, in the valley of the Lot, 309 00:28:35,520 --> 00:28:39,150 discoveries have been made that give us a unique insight 310 00:28:39,230 --> 00:28:42,240 into the lives of these new style pterosaurs. 311 00:28:47,580 --> 00:28:52,250 The short-tail creatures that appeared, are called ''pterodactyls''. 312 00:28:53,170 --> 00:28:54,830 This is one of them. 313 00:28:54,960 --> 00:28:56,960 The loss of the tail 314 00:28:57,040 --> 00:28:59,170 had given them greater mobility in the air, 315 00:28:59,250 --> 00:29:02,420 but at the cost of a certain amount of stability. 316 00:29:02,510 --> 00:29:06,470 But also, the membrane between the two legs, have split. 317 00:29:06,550 --> 00:29:09,560 And that too, probably helped them in steering. 318 00:29:10,140 --> 00:29:13,270 But flying was only part of their lives. 319 00:29:21,780 --> 00:29:24,740 The sea in which these limestones formed, 320 00:29:24,820 --> 00:29:26,870 was here quite shallow. 321 00:29:26,950 --> 00:29:29,450 And not far away, there was a beach. 322 00:29:29,990 --> 00:29:35,290 And there, pterosaurs left particularly vivid evidence of their presence. 323 00:29:40,130 --> 00:29:43,090 Fossils, not of the animals themselves, 324 00:29:43,170 --> 00:29:46,550 but traces that only revealed themselves after dark. 325 00:29:53,350 --> 00:29:57,270 The best way to look for fossils here, is at night. 326 00:29:57,810 --> 00:30:00,900 Because then, you can control the light, 327 00:30:00,980 --> 00:30:04,190 and makes sure that it shines almost horizontally 328 00:30:04,280 --> 00:30:06,240 across the surface of the rock. 329 00:30:06,280 --> 00:30:10,280 And so, expose every tiny little mark and ripple. 330 00:30:25,970 --> 00:30:30,350 The muddy sand here was once soft, but firm. 331 00:30:30,430 --> 00:30:34,850 And in consequence, it retained the tracks of animals that moved over it. 332 00:30:38,560 --> 00:30:40,900 In fact, there are so many of them here, 333 00:30:40,980 --> 00:30:45,360 that it seems that this particular beach was a kind of pterosaur runway. 334 00:30:53,950 --> 00:30:55,870 Here is a track 335 00:30:55,950 --> 00:31:00,750 that extends for 1 1 feet, between three and four metres. 336 00:31:01,880 --> 00:31:05,130 The most distinct tracks are made by the feet. 337 00:31:05,340 --> 00:31:07,590 There's one, there's another, 338 00:31:09,090 --> 00:31:10,680 there's another. 339 00:31:10,890 --> 00:31:13,350 But, outside these footprints, 340 00:31:13,390 --> 00:31:16,520 there are other, rather more indistinct prints, 341 00:31:16,600 --> 00:31:19,770 which are made by the knuckles of the hand, 342 00:31:19,850 --> 00:31:22,110 without the little finger, which, of course, 343 00:31:22,190 --> 00:31:25,030 is enormously extended, and it supports the wing membrane, 344 00:31:25,110 --> 00:31:27,150 and is cocked up in the air. 345 00:31:27,280 --> 00:31:30,030 There's one, there's another, 346 00:31:31,280 --> 00:31:34,240 there's another, and there's another. 347 00:31:35,870 --> 00:31:38,160 And when you examine the footprints, 348 00:31:38,370 --> 00:31:42,710 you can see that they have four toes. 349 00:31:43,170 --> 00:31:44,840 Not five, four. 350 00:31:45,050 --> 00:31:49,630 That's a sign that these were made by short-tailed pterosaurs. 351 00:31:50,760 --> 00:31:53,720 And the distance between the feet varies. 352 00:31:54,050 --> 00:31:57,520 Sometimes it's relatively short, sometimes it's longer. 353 00:31:57,890 --> 00:32:01,190 And that's because these animals moved at different speeds. 354 00:32:01,310 --> 00:32:04,860 When they were moving at speed, they took bigger strides. 355 00:32:05,770 --> 00:32:10,400 So, these show, this marvellous deposit shows that 356 00:32:10,490 --> 00:32:14,450 short-tails, on the ground, were really very nimble indeed. 357 00:32:15,280 --> 00:32:19,500 And that's probably because the membrane between the legs, 358 00:32:19,580 --> 00:32:22,210 in the short-tails, has been divided. 359 00:32:22,830 --> 00:32:24,750 So the legs have more freedom. 360 00:32:35,390 --> 00:32:37,100 (SQUAWKING) 361 00:33:06,670 --> 00:33:12,010 So, the short-tail species were able to get about on the ground pretty well. 362 00:33:12,470 --> 00:33:14,010 And that was important, 363 00:33:14,090 --> 00:33:17,680 because this enabled them to exploit new sources of food. 364 00:33:18,470 --> 00:33:23,440 Indeed, it might be the case that the future of the pterosaurs 365 00:33:23,520 --> 00:33:26,020 was assured, for some time at least, 366 00:33:26,110 --> 00:33:30,230 not by their ability to fly, but their ability to walk. 367 00:33:51,590 --> 00:33:53,510 This ability to walk 368 00:33:53,590 --> 00:33:56,590 had a profound effect on pterosaur evolution. 369 00:34:01,640 --> 00:34:04,180 There's evidence that from this time on, 370 00:34:04,270 --> 00:34:07,100 all kinds of new species began to emerge 371 00:34:07,190 --> 00:34:09,980 that fed on a wide range of different food. 372 00:34:12,860 --> 00:34:17,910 The short-tails proceeded to diversify into a great number of different forms, 373 00:34:17,990 --> 00:34:21,040 finding food in a great variety of places. 374 00:34:22,040 --> 00:34:25,870 And you can tell what they ate by their skulls. 375 00:34:27,500 --> 00:34:29,170 This one for example, 376 00:34:29,250 --> 00:34:32,550 has, what look like a pair of tweezers on the front, 377 00:34:33,300 --> 00:34:34,670 and very rounded teeth. 378 00:34:35,800 --> 00:34:39,680 It is thought to have been able to dig out, 379 00:34:39,760 --> 00:34:42,470 cockles and mussels from the sand and crush them. 380 00:34:42,560 --> 00:34:45,310 So, this was walking on the ground. 381 00:34:47,270 --> 00:34:51,570 This one, on the other hand, found its food while it was on the wing. 382 00:34:52,150 --> 00:34:55,940 And that it dipped down and seized big fish, 383 00:34:56,070 --> 00:34:58,450 which it stabbed with these teeth. 384 00:34:58,910 --> 00:35:04,620 And then, carried off in its jaws to rip apart, perhaps on the ground. 385 00:35:07,120 --> 00:35:11,250 Others had dense rows of teeth that were so thin 386 00:35:11,340 --> 00:35:13,380 they were scarcely more than bristles. 387 00:35:14,050 --> 00:35:17,930 That enabled these animals to use their jaws like sieves 388 00:35:18,010 --> 00:35:22,890 to filter out small crustaceans such as shrimps and other small morsels. 389 00:35:26,930 --> 00:35:29,940 And some lost their heavy teeth altogether 390 00:35:30,020 --> 00:35:31,690 and evolved beaks. 391 00:35:32,230 --> 00:35:35,070 Adaptations like these were probably influenced, 392 00:35:35,150 --> 00:35:37,610 not only by the different ways of eating, 393 00:35:37,700 --> 00:35:41,030 but by the universal need of all flying animals, 394 00:35:41,120 --> 00:35:43,200 to keep their weight down to a minimum. 395 00:35:49,250 --> 00:35:51,630 So, by about 80 million years ago, 396 00:35:51,670 --> 00:35:54,800 the short-tailed pterosaurs dominated the skies. 397 00:35:57,510 --> 00:36:00,680 Not only were they catching flying insects in mid-air, 398 00:36:00,760 --> 00:36:03,930 they were snatching food from the surface of the seas 399 00:36:04,010 --> 00:36:05,970 and filtering it from the shallows. 400 00:36:10,020 --> 00:36:12,650 This was the pterosaur's heyday. 401 00:36:28,290 --> 00:36:31,870 One species in particular symbolises their success. 402 00:36:34,340 --> 00:36:36,210 It's called Pteranodon. 403 00:36:42,380 --> 00:36:46,100 It was the most common pterosaur of its time, 404 00:36:46,180 --> 00:36:48,180 and it was also very big. 405 00:36:53,150 --> 00:36:57,230 It measured about 1 8 feet from wingtip to wingtip. 406 00:37:11,330 --> 00:37:15,500 But how did such large animals manage to stay airborne? 407 00:37:20,920 --> 00:37:23,970 You can see the answer in this fossilized bone. 408 00:37:25,720 --> 00:37:27,100 It's hollow. 409 00:37:30,180 --> 00:37:34,230 It's been treated with acid, so that you can see inside it. 410 00:37:34,810 --> 00:37:39,940 And inside, it's got a network of struts to support the bone. 411 00:37:40,360 --> 00:37:42,780 So, it was very, very lightweight. 412 00:37:45,320 --> 00:37:49,450 The full extent of these cavities, is revealed by x-rays. 413 00:37:51,040 --> 00:37:56,420 And a cross-section shows that they had another and very valuable function. 414 00:37:59,460 --> 00:38:02,920 This is the upper arm bone of a pterosaur. 415 00:38:03,720 --> 00:38:06,140 And at the top, it has a hole. 416 00:38:06,680 --> 00:38:09,850 And that's a clue, as to how they generated power. 417 00:38:10,100 --> 00:38:13,480 Because it was connected by a tube to the lungs, 418 00:38:13,560 --> 00:38:17,350 and internally, to these cavities. 419 00:38:18,270 --> 00:38:20,150 So, it was in there, 420 00:38:20,730 --> 00:38:25,240 that the pterosaur was able to store air and the oxygen that it contained. 421 00:38:25,610 --> 00:38:29,450 And from that, it could get the power when it really needed it. 422 00:38:33,870 --> 00:38:37,370 With all these ingenious adaptations for flight, 423 00:38:37,460 --> 00:38:40,590 the pterosaurs now had the freedom of the skies. 424 00:38:47,050 --> 00:38:52,180 But, a new kind of flying reptile had been evolving away from the coast, 425 00:38:52,260 --> 00:38:54,520 in the forests farther inland. 426 00:38:55,180 --> 00:38:59,440 And its arrival would have enormous consequences for the pterosaurs. 427 00:39:06,610 --> 00:39:09,490 In that remarkable quarry in Germany, 428 00:39:09,570 --> 00:39:12,030 another amazing discovery was made. 429 00:39:18,960 --> 00:39:21,920 Among all those shellfish, shrimps and fish, 430 00:39:22,000 --> 00:39:24,420 something utterly new had appeared. 431 00:39:30,640 --> 00:39:32,760 There can be no doubt about what it is. 432 00:39:34,560 --> 00:39:36,060 It's a feather. 433 00:39:39,020 --> 00:39:41,270 And a few months after its discovery, 434 00:39:41,810 --> 00:39:44,110 a quarryman found the fossil of the animal 435 00:39:44,190 --> 00:39:46,320 to which it must have belonged. 436 00:39:49,070 --> 00:39:52,990 Its outstretched wings made it quite clear to anyone 437 00:39:53,080 --> 00:39:55,790 that this was an animal that could fly. 438 00:39:56,410 --> 00:39:58,790 They called it Archaeopteryx. 439 00:40:01,250 --> 00:40:04,040 And this is what it may have looked like in life. 440 00:40:04,880 --> 00:40:08,920 The feathers on its wings are strong and rigid. 441 00:40:09,130 --> 00:40:13,550 So, they don't need to be attached to the legs, as membranes do, 442 00:40:14,350 --> 00:40:17,640 and it leaves the legs free, so that they could run. 443 00:40:18,890 --> 00:40:22,270 The head doesn't have a lightweight beak, 444 00:40:22,350 --> 00:40:23,860 like modern birds. 445 00:40:23,900 --> 00:40:26,230 But it's still very much the head of a reptile 446 00:40:26,320 --> 00:40:28,240 with bony jaws and teeth in it. 447 00:40:29,400 --> 00:40:31,240 And, the tail, too, 448 00:40:31,320 --> 00:40:34,490 has a line of bones running down its legs, 449 00:40:34,580 --> 00:40:36,620 just like a lizard's tail. 450 00:40:37,080 --> 00:40:40,870 So, this is half reptile, half bird. 451 00:40:45,000 --> 00:40:48,260 We now know, that Archaeopteryx was not alone. 452 00:40:48,960 --> 00:40:51,680 There were several different kinds of feathered reptiles 453 00:40:51,760 --> 00:40:53,680 living about this time. 454 00:40:54,470 --> 00:40:58,520 Their skeletons are very rare, perhaps because they lived inland, 455 00:40:58,600 --> 00:41:02,190 where conditions for fossilization were not as good as they were 456 00:41:02,270 --> 00:41:04,020 in the coastal seas. 457 00:41:09,990 --> 00:41:14,070 But it's clear that the pterosaurs now had rivals in the sky. 458 00:41:16,910 --> 00:41:18,410 And, perhaps, in response, 459 00:41:18,490 --> 00:41:21,960 they began to evolve in some quite extraordinary ways. 460 00:41:27,960 --> 00:41:33,260 In Texas, aeronautical engineers are trying to understand the pterosaur, 461 00:41:33,340 --> 00:41:37,010 that is surely one of the oddest creatures that ever flew. 462 00:42:02,710 --> 00:42:05,710 It had a simply enormous head crest. 463 00:42:10,420 --> 00:42:12,760 It's called Tapejara. 464 00:42:17,550 --> 00:42:22,140 This reconstruction of it is the result of seven years of study 465 00:42:22,220 --> 00:42:25,730 by evolutionary biologist Dr Sankar Chatterjee. 466 00:42:29,900 --> 00:42:33,280 He used data from fossils discovered in Brazil, 467 00:42:33,360 --> 00:42:36,320 and he has advanced some revolutionary theories 468 00:42:36,410 --> 00:42:39,450 as to how this animal used its amazing body. 469 00:42:42,040 --> 00:42:43,870 This huge crest 470 00:42:44,870 --> 00:42:48,500 was developed in some kind, like a motion sensor, 471 00:42:48,580 --> 00:42:51,960 so they could pick up if there's a disturbance in the wind, 472 00:42:52,050 --> 00:42:53,920 and they could relay it to the inner ear, 473 00:42:54,050 --> 00:42:56,180 which is a very large ear, 474 00:42:56,260 --> 00:42:58,340 and which is like a gyroscope. 475 00:42:58,470 --> 00:43:01,930 So, nerves in this go down into the brain? 476 00:43:02,010 --> 00:43:03,270 Brain. 477 00:43:03,350 --> 00:43:07,770 So, any factor working on this is going to be relayed to the brain. 478 00:43:07,850 --> 00:43:08,980 Relayed to the... 479 00:43:09,060 --> 00:43:11,400 It's almost like autopilot device. 480 00:43:11,480 --> 00:43:15,530 You know, it's a sensor, also, it is a beautiful steering device. 481 00:43:15,610 --> 00:43:17,990 This is much more extreme than any other. 482 00:43:18,070 --> 00:43:19,320 Extreme. Right. 483 00:43:19,410 --> 00:43:22,700 So, what could this do that the others couldn't do? 484 00:43:23,450 --> 00:43:27,000 One of things, as I said, they could turn very quickly. 485 00:43:27,370 --> 00:43:30,830 So it's like steering, it's like a rudder in front. 486 00:43:30,920 --> 00:43:34,380 So, this enabled them in fact, to be more aerobatic? 487 00:43:34,460 --> 00:43:35,510 Aerobatic, yes. 488 00:44:12,130 --> 00:44:16,380 ATTENBOROUGH: Some specimens of Tapejara show that it had fur. 489 00:44:19,840 --> 00:44:22,890 And that suggests that it was warm-blooded. 490 00:44:27,140 --> 00:44:30,770 Warm blood enables an animal to generate the abundant energy 491 00:44:30,850 --> 00:44:33,310 that's needed for aerobatics. 492 00:44:33,400 --> 00:44:34,770 (SQUAWKING) 493 00:44:46,160 --> 00:44:47,950 But, Dr Chatterjee has another 494 00:44:48,080 --> 00:44:51,120 imaginative and controversial interpretation 495 00:44:51,210 --> 00:44:54,000 of Tapejara's bizarre anatomy. 496 00:44:55,420 --> 00:44:59,130 What we have found special in this model, we did some simulations. 497 00:45:00,170 --> 00:45:02,800 That is, when they simply raise their wing, 498 00:45:02,890 --> 00:45:04,260 they could also sail. 499 00:45:04,350 --> 00:45:08,060 You think that it could not only fly in the air, 500 00:45:08,180 --> 00:45:10,390 but it went down to sail on the sea, is that right? 501 00:45:10,480 --> 00:45:11,640 There's a very good chance 502 00:45:11,730 --> 00:45:14,270 when they land on water during their foraging, 503 00:45:14,360 --> 00:45:19,320 because they are probably hot-blooded, they need lots of food, lots of fish. 504 00:45:19,400 --> 00:45:22,490 And during the foraging, maybe the whole daytime, 505 00:45:22,570 --> 00:45:25,370 you know, they will just eat and eat and eat. 506 00:45:25,450 --> 00:45:28,120 So, how to move? How to cover the large area? 507 00:45:28,200 --> 00:45:32,410 And it looks like that it was a beautiful sailing animal. 508 00:45:32,500 --> 00:45:34,290 Just like a sail boat. 509 00:45:34,580 --> 00:45:37,840 Did the head crest have a function when it was on the water? 510 00:45:38,670 --> 00:45:40,010 I think so. 511 00:45:40,170 --> 00:45:43,380 Basically, when they're sailing, the head crest would be 512 00:45:43,470 --> 00:45:47,350 just like a jib, you know, the very front sail of a sailing boat. 513 00:45:47,430 --> 00:45:49,520 And these two would be the main sail. 514 00:45:49,600 --> 00:45:53,060 And simply by, you know, arranging these three sails, 515 00:45:53,140 --> 00:45:54,850 they could really sail very fast. 516 00:45:58,070 --> 00:45:59,400 (SQUAWKING) 517 00:46:05,860 --> 00:46:08,870 ATTENBOROUGH: Swans and geese today sometimes lift their wings, 518 00:46:08,950 --> 00:46:10,830 to catch gusts of air. 519 00:46:10,910 --> 00:46:13,370 A behaviour called 'goose-winging''. 520 00:46:16,000 --> 00:46:19,460 So perhaps, Tapejara did indeed do something similar. 521 00:46:27,010 --> 00:46:30,850 But big head crests had a much more likely function. 522 00:46:31,970 --> 00:46:33,770 (SQUAWKING) 523 00:46:34,810 --> 00:46:38,730 There are clues of what that might be in animals alive today. 524 00:46:39,400 --> 00:46:42,530 Like this colony of gannets on Bass Rock, 525 00:46:42,610 --> 00:46:44,320 off the coast of Scotland. 526 00:46:50,830 --> 00:46:52,700 Pterosaurs doubtless 527 00:46:52,790 --> 00:46:56,750 would have lived in great groups around the ancient coastlines. 528 00:46:56,830 --> 00:47:00,040 And living in tightly packed communities, 529 00:47:00,130 --> 00:47:01,670 then, as now, 530 00:47:01,750 --> 00:47:05,220 must have led to all kinds of dramas. 531 00:47:05,470 --> 00:47:08,260 Just as it does in communities like this one. 532 00:47:08,760 --> 00:47:10,140 (SQUAWKING) 533 00:47:19,730 --> 00:47:22,110 Gannets nesting close to one another 534 00:47:22,230 --> 00:47:25,030 squabble with their neighbours over food and territory. 535 00:47:26,200 --> 00:47:27,780 (SQUAWKING) 536 00:47:31,660 --> 00:47:35,290 Pterosaurs doubtless also competed with one another, 537 00:47:35,330 --> 00:47:37,830 for the attentions of the opposite sex. 538 00:47:49,180 --> 00:47:50,300 (CHITTERING) 539 00:48:06,610 --> 00:48:07,820 (SQUAWKING) 540 00:48:18,910 --> 00:48:20,870 So, perhaps Tapejara 541 00:48:20,960 --> 00:48:24,460 used its huge head crest in displays to its mate 542 00:48:24,550 --> 00:48:25,710 during the breeding season. 543 00:48:28,590 --> 00:48:32,010 And indulged in the same sort of strutting performances 544 00:48:32,090 --> 00:48:34,640 that so many birds do today. 545 00:48:46,030 --> 00:48:47,940 (BIRDS SQUAWKING) 546 00:48:51,110 --> 00:48:56,330 After their courtship, pterosaurs, just like birds, laid eggs. 547 00:49:01,120 --> 00:49:03,960 This fossilized egg, 548 00:49:04,040 --> 00:49:07,760 which is about the same size as one of these gannet eggs, 549 00:49:07,840 --> 00:49:10,970 is actually the egg of a pterosaur. 550 00:49:11,630 --> 00:49:14,930 And although it's squashed flat, it's marvellously preserved, 551 00:49:15,010 --> 00:49:17,510 so you can see details of the bone inside. 552 00:49:18,600 --> 00:49:21,940 The head, as you'd expect with a bird head, 553 00:49:22,020 --> 00:49:23,350 is quite well formed. 554 00:49:23,440 --> 00:49:25,650 It's amongst these massive bones here. 555 00:49:28,190 --> 00:49:33,030 But whereas a bird's wings will hardly be formed at this stage, 556 00:49:33,240 --> 00:49:35,450 here, the pterosaur wings 557 00:49:35,530 --> 00:49:38,870 have got these well formed bones in them. 558 00:49:39,700 --> 00:49:42,870 And that leads us to one extraordinary conclusion. 559 00:49:44,120 --> 00:49:48,250 A pterosaur chick, when it hatched, 560 00:49:48,380 --> 00:49:51,090 was almost immediately able to fly. 561 00:49:56,680 --> 00:50:01,390 The bones of the pterosaur embryo reveal another extraordinary fact. 562 00:50:02,890 --> 00:50:06,060 They develop in a way quite different from birds. 563 00:50:08,070 --> 00:50:10,570 And what is more, they continue to do so, 564 00:50:10,650 --> 00:50:13,320 even after the young have hatched. 565 00:50:16,160 --> 00:50:19,160 This led to some species becoming gigantic. 566 00:50:32,550 --> 00:50:35,430 Here, in the south western United States, 567 00:50:35,510 --> 00:50:37,470 close to the Mexican border, 568 00:50:37,510 --> 00:50:41,680 evidence was found of the largest animal ever to fly. 569 00:50:46,270 --> 00:50:48,480 A pterosaur so gigantic, 570 00:50:48,560 --> 00:50:52,110 that for years, some scientists refused to believe 571 00:50:52,190 --> 00:50:53,860 that it could have existed. 572 00:51:00,830 --> 00:51:02,830 Seventy million years ago, 573 00:51:02,910 --> 00:51:06,620 the area was a hot, lush floodplain. 574 00:51:14,550 --> 00:51:18,220 I've come here to meet fossil hunter, Doug Lawson. 575 00:51:22,390 --> 00:51:25,890 And here, Doug made one of the most remarkable discoveries 576 00:51:25,980 --> 00:51:28,560 in the history of pterosaur research. 577 00:51:30,610 --> 00:51:35,280 On the side of the sandstone hill was this one isolated ball. 578 00:51:35,490 --> 00:51:39,200 And you might have thought, ''Well, it's just another dinosaur,'' 579 00:51:39,280 --> 00:51:43,200 except the material of this animal 580 00:51:43,290 --> 00:51:46,750 was very thin, very light individual. 581 00:51:47,580 --> 00:51:51,630 And, uh, it was difficult because, 582 00:51:51,710 --> 00:51:54,000 actually, if you thought it was pterosaur, 583 00:51:54,090 --> 00:51:57,170 then the bone that you were gonna be comparing it to 584 00:51:57,260 --> 00:52:00,720 was usually the size of a grain of rice. 585 00:52:01,050 --> 00:52:04,930 And this bone was bigger than a grapefruit. 586 00:52:05,350 --> 00:52:07,730 And it was covered with sandstone, 587 00:52:07,810 --> 00:52:09,810 so it was very difficult to see what it was. 588 00:52:09,900 --> 00:52:15,150 But I finally figured out that it was the wrist of the animal. 589 00:52:15,230 --> 00:52:17,070 And pterosaur wrists are unique. 590 00:52:17,530 --> 00:52:20,490 So, given that, when we had these other 591 00:52:21,870 --> 00:52:24,620 pieces of bone that we discovered in the location, 592 00:52:25,660 --> 00:52:27,830 you'd come to understand how big that was. 593 00:52:27,910 --> 00:52:31,330 This is just the upper arm bone of the specimen. 594 00:52:31,420 --> 00:52:33,210 -This... -Yeah, yeah. 595 00:52:33,380 --> 00:52:35,590 And looking at this you realise, 596 00:52:35,630 --> 00:52:39,630 ''Wow, we have something that's dinosaur sized. 597 00:52:39,680 --> 00:52:41,010 ''But it's a pterosaur.'' 598 00:52:41,590 --> 00:52:44,680 Now, you could not have prevented yourself from saying, 599 00:52:44,760 --> 00:52:46,270 ''How big is this?'' 600 00:52:46,350 --> 00:52:48,730 Oh, yeah, right. Then you'd say, ''Wow...'' 601 00:52:48,810 --> 00:52:50,440 Okay, we've... 602 00:52:50,520 --> 00:52:55,900 So, based on what we have, the estimate was about 50 feet. 603 00:52:56,230 --> 00:52:57,440 -Wingspan? -Yeah. 604 00:52:57,690 --> 00:52:59,190 Yeah, 50 foot wingspan. 605 00:52:59,280 --> 00:53:02,570 -I mean that... That is gigantic. -Oh, yeah, definitely. 606 00:53:02,660 --> 00:53:03,950 ATTENBOROUGH: Mind blowing. 607 00:53:04,030 --> 00:53:05,780 Did people believe it? 608 00:53:05,870 --> 00:53:07,540 LAWSON: Well, there was some question. 609 00:53:07,660 --> 00:53:11,620 No other pterosaur was even half the size of this one. 610 00:53:11,670 --> 00:53:16,710 And the fact that something so large that could fly, 611 00:53:16,750 --> 00:53:21,340 there was almost an aerodynamic question of whether this could even be. 612 00:53:23,680 --> 00:53:26,350 ATTENBOROUGH: It was a truly astounding discovery. 613 00:53:30,230 --> 00:53:33,150 His creature had wings that were so large, 614 00:53:33,230 --> 00:53:36,360 they could easily have spanned the width of this building. 615 00:53:42,740 --> 00:53:46,740 It lived 70 million years ago, during the Cretaceous period. 616 00:54:16,110 --> 00:54:18,440 (LOW GROWL) 617 00:54:29,030 --> 00:54:30,870 It stood 20 feet high. 618 00:54:31,120 --> 00:54:34,000 So tall it could look a giraffe in the eye. 619 00:54:35,710 --> 00:54:38,040 This was Quetzalcoatlus. 620 00:54:39,500 --> 00:54:42,550 Named after the Serpent God of the Aztecs. 621 00:54:46,760 --> 00:54:48,600 It was probably a scavenger. 622 00:54:49,220 --> 00:54:52,890 Using its long neck to probe deep into the carcasses 623 00:54:52,980 --> 00:54:54,640 of dead dinosaurs. 624 00:55:28,300 --> 00:55:31,850 Any small animal foolish enough to get in its way 625 00:55:31,930 --> 00:55:34,480 was likely to meet a grizzly end. 626 00:55:34,770 --> 00:55:36,140 (LIZARD SQUEALING) 627 00:55:51,700 --> 00:55:55,330 But how did the giant Quetzalcoatlus get off the ground? 628 00:55:57,250 --> 00:56:01,630 The answer may be found inside the pterosaur arm bones. 629 00:56:05,800 --> 00:56:08,590 There are two things you have to get right, 630 00:56:08,680 --> 00:56:12,720 if an animal the size of a giraffe, like Quetzalcoatlus, 631 00:56:12,810 --> 00:56:14,220 is to get into the air. 632 00:56:14,850 --> 00:56:17,230 Weight and power. 633 00:56:17,810 --> 00:56:20,560 And a close examination of the bones, 634 00:56:20,650 --> 00:56:23,320 show how the pterosaurs did that. 635 00:56:33,280 --> 00:56:36,620 A scan of the arm bone of Quetzalcoatlus 636 00:56:36,700 --> 00:56:40,120 shows that just like those of other pterosaurs, 637 00:56:40,210 --> 00:56:41,380 it was hollow. 638 00:56:46,670 --> 00:56:49,550 This animal was very lightweight. 639 00:56:51,640 --> 00:56:53,970 It may have been the size of a giraffe, 640 00:56:54,050 --> 00:56:57,060 but it was no heavier than two human beings. 641 00:57:06,400 --> 00:57:10,490 But at the very top of the arm, the bone is very different. 642 00:57:11,700 --> 00:57:16,120 All these supporting struts line up in one direction. 643 00:57:17,660 --> 00:57:21,370 And that gives us a clue as to how the animal got airborne. 644 00:57:36,060 --> 00:57:38,600 The upper arms were reinforced 645 00:57:38,680 --> 00:57:41,980 so that they could withstand the sudden burst of great power 646 00:57:42,060 --> 00:57:43,730 without breaking. 647 00:57:46,730 --> 00:57:48,980 The animal used all four of its limbs 648 00:57:49,070 --> 00:57:50,690 as a giant catapult. 649 00:57:51,150 --> 00:57:55,030 To launch its body skyward at 35 miles an hour. 650 00:58:00,080 --> 00:58:02,670 It used a quadrupedal launch. 651 00:58:12,170 --> 00:58:14,300 But how did it actually fly? 652 00:58:22,560 --> 00:58:25,770 There is a practical way of finding out. 653 00:58:35,110 --> 00:58:39,910 A modern glider is about the same size as that giant pterosaur. 654 00:58:40,540 --> 00:58:43,370 It too, has long slender wings. 655 00:58:43,460 --> 00:58:46,460 And it too, is extremely light. 656 00:58:48,590 --> 00:58:51,710 This flying machine is so lightweight, 657 00:58:51,800 --> 00:58:54,010 it doesn't even need an engine. 658 00:58:54,340 --> 00:58:58,390 All it requires is a tow to get it into the air. 659 00:59:19,240 --> 00:59:23,580 This is the nearest I will ever get to experiencing the magic 660 00:59:23,660 --> 00:59:26,250 of Quetzalcoatlus in flight. 661 00:59:52,860 --> 00:59:54,530 (CALLING) 662 01:00:11,420 --> 01:00:13,380 With its giant wingspan, 663 01:00:13,460 --> 01:00:16,170 this was the largest animal ever to fly. 664 01:00:22,300 --> 01:00:25,890 Quetzalcoatlus kept its wing beats to a minimum. 665 01:00:28,310 --> 01:00:30,150 It was a living glider. 666 01:00:46,160 --> 01:00:48,660 And it had much more detailed control 667 01:00:48,750 --> 01:00:52,960 that even the most advanced and sophisticated of modern aircraft. 668 01:00:55,050 --> 01:00:57,670 (OVER RADIO) We are controlling our flight, 669 01:00:57,760 --> 01:01:00,760 using at least in part, our tail. 670 01:01:01,220 --> 01:01:02,970 However, 671 01:01:03,050 --> 01:01:07,060 whereas powered aeroplanes have tails and birds have tails, 672 01:01:07,140 --> 01:01:11,150 advanced pterosaurs like Quetzalcoatlus 673 01:01:11,190 --> 01:01:12,730 didn't have a tail. 674 01:01:12,810 --> 01:01:15,900 So, steering must have been much more difficult, 675 01:01:15,980 --> 01:01:19,450 and would have required very considerable brain power. 676 01:01:20,240 --> 01:01:24,620 But there was, people think, a payoff to that. 677 01:01:24,990 --> 01:01:26,700 Because without a tail, 678 01:01:26,790 --> 01:01:30,000 Quetzalcoatlus was even more manoeuvrable, 679 01:01:30,080 --> 01:01:31,870 than we are in this. 680 01:01:42,340 --> 01:01:45,470 Quetzalcoatlus doubtless used many of the techniques 681 01:01:45,550 --> 01:01:47,810 employed by human glider pilots. 682 01:01:47,890 --> 01:01:49,020 (SCREECHES) 683 01:01:53,810 --> 01:01:57,820 To maintain our height, we need to find a thermal. 684 01:01:57,900 --> 01:02:02,990 That's those columns of warm air that rise from patches of the landscape, 685 01:02:03,070 --> 01:02:06,870 that heat well in the sun, like patches of rock. 686 01:02:07,410 --> 01:02:09,080 You can tell where they are, 687 01:02:09,200 --> 01:02:13,000 because white fluffy clouds form at the top of them. 688 01:02:13,750 --> 01:02:17,210 And there's one over there, and we're going to have to get to it 689 01:02:17,250 --> 01:02:19,590 if we're going to maintain our height. 690 01:02:34,100 --> 01:02:37,610 It's been estimated that by exploiting thermals, 691 01:02:37,690 --> 01:02:43,240 Quetzalcoatlus could travel some 1 0,000 miles in a single flight. 692 01:02:43,280 --> 01:02:47,240 And that is almost half the circumference of the entire planet. 693 01:03:06,220 --> 01:03:09,390 It might even be that like some eagles today, 694 01:03:09,510 --> 01:03:14,060 these flying giants undertook long migratory journeys every year. 695 01:03:57,900 --> 01:04:03,110 And so, a 1 50 million years after they had first appeared, 696 01:04:03,190 --> 01:04:06,650 the pterosaurs were at their most spectacular. 697 01:04:22,540 --> 01:04:23,960 (SCREECHING) 698 01:04:53,450 --> 01:04:57,540 And then, suddenly, they vanished. 699 01:05:25,900 --> 01:05:30,200 A meteor that crashed into Earth 65 million years ago 700 01:05:30,280 --> 01:05:35,200 is often blamed for the extinction of the dinosaurs and the pterosaurs. 701 01:05:37,620 --> 01:05:41,120 But the truth is that their fate was already sealed 702 01:05:41,210 --> 01:05:43,250 millions of years before that moment, 703 01:05:44,380 --> 01:05:48,050 by the early birds that had been evolving in their shadow. 704 01:05:53,090 --> 01:05:56,930 It was the birds that rose from the ashes of that meteor. 705 01:06:00,980 --> 01:06:04,520 They occupy all the niches that the pterosaurs once did. 706 01:06:06,480 --> 01:06:10,780 So, why did birds survive and the pterosaurs die? 707 01:06:12,740 --> 01:06:16,370 Birds had one great advantage over the pterosaurs. 708 01:06:18,370 --> 01:06:20,080 Their rigid flight feathers 709 01:06:20,160 --> 01:06:22,790 meant that their wings had no need to be anchored to either 710 01:06:22,870 --> 01:06:25,330 their flanks or their legs. 711 01:06:34,470 --> 01:06:36,890 So, birds could run, 712 01:06:36,970 --> 01:06:39,350 and walk, and pounce, 713 01:06:39,470 --> 01:06:41,270 whatever they needed to do, 714 01:06:41,390 --> 01:06:45,230 to collect their food in almost any of the land's environments. 715 01:06:48,650 --> 01:06:52,440 No pterosaurs, encumbered by their skinny wings, 716 01:06:52,530 --> 01:06:54,530 could wade like flamingos. 717 01:07:00,200 --> 01:07:01,750 Birds today 718 01:07:01,830 --> 01:07:05,250 have evolved into thousands of different species, 719 01:07:05,330 --> 01:07:07,670 flying with many different techniques. 720 01:07:08,460 --> 01:07:10,420 But it was the pterosaurs 721 01:07:10,500 --> 01:07:12,380 that were first into the air. 722 01:07:12,970 --> 01:07:16,800 It was they that solved the fundamental problems of flight. 723 01:07:17,850 --> 01:07:19,390 And in their prime, 724 01:07:19,470 --> 01:07:21,140 they reached a grandeur, 725 01:07:21,220 --> 01:07:24,060 that the birds still can't match. 726 01:07:35,240 --> 01:07:37,110 (SQUAWKING) 727 01:07:41,370 --> 01:07:46,620 The dynasty of the pterosaurs lasted over a 1 50 million years. 728 01:07:47,750 --> 01:07:52,130 We human beings have only been around for about two. 729 01:07:53,590 --> 01:07:57,890 But only now, are we beginning to appreciate to the full 730 01:07:57,970 --> 01:08:02,720 the wonders and the splendours of those pioneers of flight, 731 01:08:02,810 --> 01:08:04,350 the pterosaurs.