1 00:00:08,717 --> 00:00:11,470 {\an8}Dinosaurs ruled the planet 2 00:00:11,470 --> 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 00:02:01,121 --> 00:02:04,625 [Attenborough] The vast swamplands of northeast Asia. 27 00:02:08,211 --> 00:02:13,425 Within this low-lying flooded territory, there are countless islands. 28 00:02:19,348 --> 00:02:23,101 Each of them is surrounded by slow-moving waters... 29 00:02:26,522 --> 00:02:31,068 and that makes them potential sanctuaries for new life. 30 00:02:34,446 --> 00:02:36,657 [squawking] 31 00:02:36,657 --> 00:02:42,788 A young pterosaur, an azhdarchid. Just a few hours old. 32 00:02:51,547 --> 00:02:53,298 Being on an island 33 00:02:53,298 --> 00:02:57,511 means that she's able to take her first tentative steps in safety. 34 00:03:05,519 --> 00:03:08,355 [squawking] 35 00:03:09,690 --> 00:03:15,487 Having found her feet, it's time to try out her wings. 36 00:03:17,114 --> 00:03:18,365 [squawks] 37 00:03:18,365 --> 00:03:22,286 Getting them to work properly will take some practice. 38 00:03:25,998 --> 00:03:28,166 Although she's only 1-foot tall, 39 00:03:28,166 --> 00:03:32,504 she will grow into a giant with a 30-foot wingspan. 40 00:03:33,630 --> 00:03:36,967 And to do that will require plenty of food... 41 00:03:40,095 --> 00:03:43,807 something this tiny island can't provide. 42 00:03:48,979 --> 00:03:50,522 She will have to leave 43 00:03:51,190 --> 00:03:55,360 to feed in the swampy forests that surround her island. 44 00:04:04,494 --> 00:04:09,291 Maiden flights are always tricky, especially when they're over open water. 45 00:04:12,461 --> 00:04:14,546 Today there is a light breeze. 46 00:04:15,047 --> 00:04:17,925 That will help by giving some extra lift. 47 00:04:36,109 --> 00:04:39,363 But this youngster is not yet strong enough. 48 00:04:41,073 --> 00:04:42,366 [squawks] 49 00:04:57,464 --> 00:04:58,590 [roaring] 50 00:05:01,301 --> 00:05:05,097 Shamosuchus. Fifteen-feet-long predators. 51 00:05:07,891 --> 00:05:10,018 This island might offer safety, 52 00:05:10,519 --> 00:05:13,856 but the surrounding waters certainly do not. 53 00:05:19,236 --> 00:05:23,323 If the takeoff isn't perfect, it's difficult to gain height. 54 00:05:29,580 --> 00:05:32,249 And this is not high enough. 55 00:05:33,709 --> 00:05:34,710 [chirps] 56 00:05:43,552 --> 00:05:45,304 Some of the stronger flyers 57 00:05:45,304 --> 00:05:48,432 have almost reached the safety of the forest. 58 00:05:51,018 --> 00:05:53,687 Others have still to make their attempt. 59 00:05:57,482 --> 00:05:59,318 [squawking] 60 00:06:27,471 --> 00:06:28,472 [chirps] 61 00:06:54,248 --> 00:06:56,625 A near-miraculous escape. 62 00:06:58,293 --> 00:07:01,672 And now the chance to collect her rewards. 63 00:07:14,184 --> 00:07:18,647 In these rich swamp forests, there's all the food she needs. 64 00:07:32,244 --> 00:07:34,872 Here in the wetlands of South America, 65 00:07:34,872 --> 00:07:39,334 long summer days are fueling a greater feast. 66 00:07:40,961 --> 00:07:44,673 These swamps are teeming with animals of all kinds. 67 00:07:53,724 --> 00:07:55,642 And hunters are gathering. 68 00:08:04,943 --> 00:08:08,238 The ferocious three-foot-long garfish. 69 00:08:16,163 --> 00:08:19,875 Lunch for a giant Austroraptor. 70 00:08:25,714 --> 00:08:30,677 They are relatives of Velociraptors but much, much bigger. 71 00:08:37,226 --> 00:08:42,147 Twenty feet from head to tail and weighing over 800 pounds. 72 00:08:42,856 --> 00:08:44,274 [bellows] 73 00:08:56,036 --> 00:08:59,540 And with teeth not unlike those of a crocodile, 74 00:08:59,540 --> 00:09:03,794 these dinosaurs are very skilled at catching fish. 75 00:09:12,302 --> 00:09:15,556 For most of the year, they're solitary hunters. 76 00:09:17,307 --> 00:09:20,352 But as the number of fish increases during summer, 77 00:09:21,728 --> 00:09:24,815 so does the number of Austroraptors. 78 00:09:32,489 --> 00:09:36,785 The biggest try to keep the best fishing spots for themselves. 79 00:09:41,331 --> 00:09:43,125 They won't tolerate rivals. 80 00:09:43,125 --> 00:09:45,210 [bellowing] 81 00:09:47,045 --> 00:09:49,840 [hissing, roaring] 82 00:10:01,101 --> 00:10:05,480 For those not yet in their prime, it's a challenging time of year. 83 00:10:08,734 --> 00:10:12,821 This young male, still in his juvenile colors, 84 00:10:12,821 --> 00:10:16,366 has little hope of securing a good place to fish. 85 00:10:21,371 --> 00:10:25,042 However, there are other ways of getting a meal here. 86 00:10:30,714 --> 00:10:35,344 With so much food around, the adults are very wasteful feeders. 87 00:10:38,847 --> 00:10:42,351 They often eat only the choicest parts of the fish. 88 00:10:49,399 --> 00:10:54,196 And for a youngster, any leftovers will do very nicely. 89 00:10:56,365 --> 00:10:57,950 But it's risky. 90 00:11:08,627 --> 00:11:11,547 To succeed, he will have to be sneaky. 91 00:11:21,932 --> 00:11:24,852 - [bellowing] - [whines] 92 00:11:26,353 --> 00:11:27,813 [roaring] 93 00:11:34,319 --> 00:11:37,281 Bruised and empty-handed. 94 00:11:40,033 --> 00:11:43,036 But with the adults still feasting around him, 95 00:11:43,036 --> 00:11:44,955 there might be another opportunity. 96 00:11:46,206 --> 00:11:47,833 [roaring] 97 00:11:54,298 --> 00:11:56,300 [bellowing] 98 00:12:02,389 --> 00:12:05,893 Two adults fighting over the best fishing spot. 99 00:12:13,692 --> 00:12:15,903 [grunting, growling] 100 00:12:18,113 --> 00:12:20,115 [roaring] 101 00:12:28,332 --> 00:12:31,168 Time for the youngster to make a move... 102 00:12:32,461 --> 00:12:33,629 [predator roaring] 103 00:12:33,629 --> 00:12:35,923 ...and time to leave. 104 00:12:35,923 --> 00:12:37,841 [bellowing] 105 00:12:40,135 --> 00:12:41,136 Success. 106 00:12:42,012 --> 00:12:44,515 And more than just scraps. 107 00:12:47,267 --> 00:12:48,519 A lesson learnt. 108 00:12:49,436 --> 00:12:52,231 And when the good conditions return next year, 109 00:12:52,231 --> 00:12:56,652 perhaps he'll be able to challenge for a fishing spot of his own. 110 00:13:01,782 --> 00:13:03,784 [thunder rumbling] 111 00:13:05,744 --> 00:13:10,541 In northern Madagascar, conditions are already changing. 112 00:13:12,292 --> 00:13:17,422 The first rain in months is reviving the parched land. 113 00:13:25,597 --> 00:13:30,185 As pools and channels refill, the animals return. 114 00:13:53,333 --> 00:13:55,586 And they're not all dinosaurs. 115 00:14:04,094 --> 00:14:06,430 Lurking in these muddy pools... 116 00:14:08,807 --> 00:14:11,560 is a monster. 117 00:14:11,560 --> 00:14:12,811 [rumbling] 118 00:14:20,527 --> 00:14:21,737 [squawking] 119 00:14:22,529 --> 00:14:23,947 [croaks] 120 00:14:25,032 --> 00:14:29,119 - Beelzebufo, the devil toad. - [croaks] 121 00:14:32,122 --> 00:14:37,044 It's so big it can swallow a small dinosaur whole. 122 00:14:39,880 --> 00:14:41,965 But this male isn't here to hunt. 123 00:14:44,218 --> 00:14:46,762 He is looking for a mate. 124 00:14:49,890 --> 00:14:55,729 Female devil toads are fussy, so he needs to find a good spot. 125 00:14:58,190 --> 00:15:00,817 Only then will he be able to entice them in. 126 00:15:05,072 --> 00:15:07,074 [croaking] 127 00:15:12,913 --> 00:15:15,123 [croaking continues] 128 00:15:15,123 --> 00:15:18,544 His deep croaks travel far and wide. 129 00:15:31,640 --> 00:15:33,642 [predators roaring] 130 00:15:41,275 --> 00:15:43,277 [roaring continues] 131 00:15:45,612 --> 00:15:48,657 This isn't quite what he was hoping for. 132 00:15:53,871 --> 00:15:56,957 Fifty-foot-long rapetosaurs. 133 00:16:05,591 --> 00:16:10,137 They have been attracted here by the promise of a mud bath. 134 00:16:14,099 --> 00:16:18,103 For Beelzebufo, their timing couldn't be much worse. 135 00:16:34,286 --> 00:16:39,458 His pools now lie beneath 70 tons of sauropod. 136 00:16:47,174 --> 00:16:49,343 Time is short. 137 00:16:51,678 --> 00:16:56,266 Female devil toads will only mate at the start of the rainy season. 138 00:17:01,271 --> 00:17:03,023 He needs a new pool. 139 00:17:08,362 --> 00:17:09,363 There's one. 140 00:17:21,165 --> 00:17:23,085 Reaching it will be dangerous. 141 00:17:23,669 --> 00:17:26,630 [bellowing, grunting] 142 00:18:05,085 --> 00:18:07,337 Finally he's got there... 143 00:18:09,923 --> 00:18:12,259 but he's been noticed. 144 00:18:21,476 --> 00:18:23,145 [croaks] 145 00:18:23,729 --> 00:18:27,274 He's not known as a devil toad for nothing. 146 00:18:27,274 --> 00:18:29,026 [croaking] 147 00:18:32,279 --> 00:18:34,656 Time to try more singing... 148 00:18:35,657 --> 00:18:38,327 - [croaking] - [bellowing, grunting] 149 00:18:38,327 --> 00:18:45,167 ...but he can't make himself heard above the sound of satisfied sauropods. 150 00:18:45,167 --> 00:18:47,252 [sauropods bellowing] 151 00:18:54,635 --> 00:18:55,719 Luckily for him, 152 00:18:55,719 --> 00:19:00,849 there's one thing that rapetosaurs enjoy even more than wallowing in mud... 153 00:19:03,810 --> 00:19:06,271 and that is food. 154 00:19:10,734 --> 00:19:12,778 The hungry herd moves on... 155 00:19:14,988 --> 00:19:19,409 although, not without leaving something useful behind. 156 00:19:23,539 --> 00:19:28,544 Dozens of giant footprints, full of water. 157 00:19:37,886 --> 00:19:42,599 Perfect for a Beelzebufo to continue his quest for a mate. 158 00:19:45,352 --> 00:19:47,354 [croaking] 159 00:20:04,830 --> 00:20:07,666 A devil toad can only survive here 160 00:20:07,666 --> 00:20:12,462 because every year the land is flooded by seasonal rains. 161 00:20:15,048 --> 00:20:18,552 However, there are places where changing climate 162 00:20:18,552 --> 00:20:20,888 means the rains are less certain. 163 00:20:26,643 --> 00:20:32,524 This inland basin in North America was, in the past, several feet deep in water. 164 00:20:36,361 --> 00:20:40,282 But after a decade of drought, it's now bone dry. 165 00:20:47,664 --> 00:20:51,460 Nonetheless, some dinosaurs still linger here. 166 00:21:02,137 --> 00:21:04,723 A herd of pachycephalosaurs, 167 00:21:06,058 --> 00:21:09,811 bizarre creatures with thick, dome-shaped skulls. 168 00:21:09,811 --> 00:21:10,896 [roars] 169 00:21:22,282 --> 00:21:25,369 They prefer to feed on fruit and leaves... 170 00:21:28,622 --> 00:21:33,961 but now they are forced to make do with roots and insects. 171 00:21:48,976 --> 00:21:51,937 The herd is led by a large male. 172 00:21:53,313 --> 00:21:54,439 [bellowing] 173 00:21:54,439 --> 00:22:00,445 He keeps order, so everyone is able to search for food in peace. 174 00:22:17,379 --> 00:22:21,300 But trouble is brewing within the herd. 175 00:22:24,386 --> 00:22:27,139 The young male is throwing his weight around. 176 00:22:35,689 --> 00:22:37,357 [bellowing] 177 00:22:40,027 --> 00:22:45,991 It's time for the dominant male to put him in his place or kick him out. 178 00:22:55,876 --> 00:22:58,128 He flaunts his colorful headgear... 179 00:23:05,385 --> 00:23:07,679 trying to intimidate the youngster. 180 00:23:14,978 --> 00:23:17,314 But he's not going to back down that easily. 181 00:23:23,946 --> 00:23:24,947 [bellowing] 182 00:24:02,985 --> 00:24:04,820 [bellowing, grunting] 183 00:24:07,155 --> 00:24:12,411 Ten-inch-thick skulls enable them to survive powerful, head-on collisions. 184 00:24:34,558 --> 00:24:36,518 The older male is heavier, 185 00:24:37,936 --> 00:24:41,732 but the younger is more agile and has more stamina, 186 00:24:42,733 --> 00:24:45,569 and that tips the balance in his favor. 187 00:24:57,164 --> 00:24:58,999 A bellow of victory. 188 00:24:58,999 --> 00:25:01,084 [bellowing] 189 00:25:08,675 --> 00:25:10,135 [whines] 190 00:25:10,135 --> 00:25:12,387 But too soon. 191 00:25:28,070 --> 00:25:31,073 The loser has to pay a heavy price. 192 00:25:38,622 --> 00:25:39,623 Exile. 193 00:25:45,045 --> 00:25:49,216 Alone, it will be a struggle to fend for himself. 194 00:25:55,097 --> 00:25:58,684 But life here will not be easy for the winner either 195 00:25:58,684 --> 00:26:03,772 unless the water returns to this land and soon. 196 00:26:12,072 --> 00:26:14,491 Across this vast continent, 197 00:26:14,491 --> 00:26:19,079 there are over 100,000 square miles of swamplands... 198 00:26:21,957 --> 00:26:25,794 and most of them remain flooded all year round. 199 00:26:33,051 --> 00:26:34,636 Here in spring, 200 00:26:34,636 --> 00:26:39,808 new plant growth creates excellent feeding grounds for the gathering herds. 201 00:26:45,397 --> 00:26:46,940 [roars] 202 00:26:55,324 --> 00:26:59,036 But where there are large numbers of plant eaters... 203 00:27:01,663 --> 00:27:03,707 there are great hunters. 204 00:27:15,260 --> 00:27:16,261 T. Rex... 205 00:27:18,847 --> 00:27:22,142 the most powerful land predators on the planet. 206 00:27:24,895 --> 00:27:27,105 They usually ambush their prey... 207 00:27:30,359 --> 00:27:32,736 but with so many watching eyes... 208 00:27:34,905 --> 00:27:37,908 this is not the right time to attack. 209 00:27:48,752 --> 00:27:50,629 As darkness falls, 210 00:27:50,629 --> 00:27:54,758 some of the herds that had been grazing out in the open 211 00:27:54,758 --> 00:27:57,344 retreat into the forest for shelter. 212 00:28:01,557 --> 00:28:05,519 Now the odds switch in favor of the predators. 213 00:28:19,199 --> 00:28:23,245 Tyrannosaurs have the largest eyes of any dinosaur, 214 00:28:24,913 --> 00:28:27,958 which gives them superb low-light vision. 215 00:28:41,805 --> 00:28:43,807 [bellowing] 216 00:28:48,687 --> 00:28:53,025 And they're able to move through the forest in near silence, 217 00:28:53,692 --> 00:28:56,445 thanks to cushioned pads on their feet. 218 00:29:07,581 --> 00:29:09,917 A group of edmontosaurs. 219 00:29:21,220 --> 00:29:22,721 They lack armor, 220 00:29:22,721 --> 00:29:26,934 but they're as big as T. rex and twice as fast. 221 00:29:31,438 --> 00:29:33,899 To catch one needs cunning. 222 00:29:46,245 --> 00:29:50,457 Each of the hunters carefully moves into position. 223 00:30:00,634 --> 00:30:04,263 Then one deliberately makes a noise. 224 00:30:05,055 --> 00:30:06,557 [branches cracking] 225 00:30:06,557 --> 00:30:08,642 [rumbling] 226 00:30:16,692 --> 00:30:19,528 The edmontosaurs are alarmed. 227 00:30:28,829 --> 00:30:30,956 They now know hunters are close, 228 00:30:32,040 --> 00:30:34,543 but they don't know exactly where they are. 229 00:30:37,713 --> 00:30:39,631 Time to spring the trap. 230 00:30:43,218 --> 00:30:44,928 One T. Rex rushes out. 231 00:30:44,928 --> 00:30:46,972 [roaring] 232 00:30:52,269 --> 00:30:53,270 [roars] 233 00:30:55,272 --> 00:31:01,737 The herd panics and bolts to where the other T. rex is waiting in ambush. 234 00:31:05,032 --> 00:31:07,034 [roaring] 235 00:31:32,309 --> 00:31:34,311 [bellowing] 236 00:31:42,361 --> 00:31:44,947 A perfectly executed plan... 237 00:31:49,117 --> 00:31:53,330 by one of the greatest land predators that have ever lived... 238 00:31:58,794 --> 00:32:02,714 in the swamps of our prehistoric planet. 239 00:32:22,192 --> 00:32:26,363 This is the skull of a pachycephalosaur, 240 00:32:26,363 --> 00:32:28,824 a 16-foot-long plant eater. 241 00:32:29,950 --> 00:32:32,202 Despite years of research, 242 00:32:32,202 --> 00:32:37,374 we're still trying to understand why it had this bizarre-shaped head. 243 00:32:48,051 --> 00:32:50,512 {\an8}The most distinctive feature about the pachycephalosaurs, of course, 244 00:32:50,512 --> 00:32:53,515 {\an8}is this really weird dome that they have on their head. 245 00:32:56,768 --> 00:33:01,815 All around it is a series of very odd tubercles and nobbles and bobbles. 246 00:33:02,441 --> 00:33:04,484 They look quite dragonlike. 247 00:33:06,528 --> 00:33:08,947 {\an8}When they first saw these very thick, domed skulls, 248 00:33:08,947 --> 00:33:11,867 {\an8}and these domes could be up to 30 centimeters in thickness, 249 00:33:12,701 --> 00:33:14,536 they were thought to be very strong. 250 00:33:14,536 --> 00:33:17,664 It was thought that maybe they were using them for headbutting each other 251 00:33:17,664 --> 00:33:19,875 in contests over social hierarchy. 252 00:33:22,211 --> 00:33:26,757 [Attenborough] Today, animals like bighorn sheep butt heads in this way. 253 00:33:28,717 --> 00:33:32,137 A thickened skull helps protect their brain from impact. 254 00:33:35,307 --> 00:33:39,686 But does this fully explain pachycephalosaur's domed head? 255 00:33:39,686 --> 00:33:40,979 [squawks] 256 00:33:41,855 --> 00:33:43,148 [grunts] 257 00:33:43,148 --> 00:33:46,401 A number of paleontologists thought that they should look inside the skulls. 258 00:33:47,736 --> 00:33:50,864 They sliced up a number of pachycephalosaur domes, 259 00:33:50,864 --> 00:33:54,243 and when they did that, they found out that maybe it wasn't strong enough 260 00:33:54,243 --> 00:33:57,204 to withstand these direct head-on impacts. 261 00:33:58,372 --> 00:34:01,500 [Attenborough] However, they did discover something else, 262 00:34:01,500 --> 00:34:04,419 suggesting the dome had a different use. 263 00:34:05,629 --> 00:34:09,591 The surface was marked with a mesh of tiny fibers. 264 00:34:11,176 --> 00:34:14,137 Perhaps they supported brightly colored skin, 265 00:34:14,137 --> 00:34:16,139 used to attract a mate. 266 00:34:17,808 --> 00:34:24,147 This new theory seemed to be accepted until 2013, 267 00:34:24,857 --> 00:34:27,317 when a new discovery was made. 268 00:34:29,360 --> 00:34:31,237 A pachycephalosaur was found, 269 00:34:31,237 --> 00:34:37,034 with marks showing it had survived multiple injuries to the top of its head, 270 00:34:38,661 --> 00:34:40,956 and it wasn't a one-off. 271 00:34:41,998 --> 00:34:45,127 They went back and looked through historic museum collections 272 00:34:45,127 --> 00:34:48,172 and discovered that actually there was quite a lot of evidence for these lesions 273 00:34:48,172 --> 00:34:51,925 in a similar place across a whole bunch of different pachycephalosaurs. 274 00:34:53,802 --> 00:34:56,679 This is good evidence that they probably were headbutting. 275 00:35:02,394 --> 00:35:04,646 [Attenborough] So, were the skulls strong enough 276 00:35:04,646 --> 00:35:07,816 to protect pachycephalosaur's brain after all? 277 00:35:08,567 --> 00:35:09,776 [grunting] 278 00:35:11,153 --> 00:35:15,490 To find out, scientists turned to the latest scanning technology. 279 00:35:17,159 --> 00:35:20,996 We can use CT scans to build virtual models of the bones, 280 00:35:20,996 --> 00:35:24,124 and then we can subject those to various engineering tests 281 00:35:24,124 --> 00:35:28,337 in the same way that we'd do with an aeroplane part or an artificial hip. 282 00:35:29,588 --> 00:35:33,258 [Attenborough] This provided the final piece of evidence. 283 00:35:37,429 --> 00:35:39,181 [Maidment] What they've shown is that pachycephalosaur domes 284 00:35:39,181 --> 00:35:42,059 could actually have withstood an enormous amount of force. 285 00:35:44,311 --> 00:35:47,397 It's the sort of force that goes through American footballers 286 00:35:47,397 --> 00:35:49,066 when they hit each other. 287 00:35:54,780 --> 00:35:58,325 [Attenborough] We now believe pachycephalosaurs used their head 288 00:35:58,325 --> 00:35:59,952 both as a formidable weapon... 289 00:35:59,952 --> 00:36:02,204 [roaring] 290 00:36:02,204 --> 00:36:04,206 ...and as a colorful display. 291 00:36:07,292 --> 00:36:12,297 Two ways to demonstrate who was boss in their prehistoric world.