1 00:00:15,682 --> 00:00:17,767 In the depths of space, 2 00:00:18,727 --> 00:00:20,603 a threat is looming. 3 00:00:22,647 --> 00:00:26,526 Trapped between the orbits of Jupiter and Mars… 4 00:00:28,778 --> 00:00:30,947 the asteroid belt. 5 00:00:33,324 --> 00:00:37,454 One and a half million chunks of ancient rock, 6 00:00:38,329 --> 00:00:40,206 circling the sun. 7 00:00:43,626 --> 00:00:46,129 Drifting endlessly. 8 00:00:55,680 --> 00:00:59,768 But, in a single moment of pure chance… 9 00:01:04,731 --> 00:01:08,943 …one asteroid is thrown out of its orbit. 10 00:01:11,029 --> 00:01:12,864 A fleeting instant, 11 00:01:13,615 --> 00:01:16,451 millions of kilometers from Earth, 12 00:01:17,077 --> 00:01:19,913 sends it on a new trajectory 13 00:01:20,830 --> 00:01:25,001 towards the very center of our solar system. 14 00:01:35,553 --> 00:01:40,433 But its journey will come to a sudden and violent end, 15 00:01:42,268 --> 00:01:48,066 in one of the most catastrophic events in Earth's history. 16 00:01:51,277 --> 00:01:53,154 And the final chapter 17 00:01:54,405 --> 00:01:56,282 in the epic story 18 00:01:57,492 --> 00:01:59,536 of the dinosaurs. 19 00:03:23,661 --> 00:03:25,246 It's three million years 20 00:03:25,330 --> 00:03:29,042 since the asteroid started its journey towards Earth. 21 00:03:31,169 --> 00:03:34,631 And the dinosaurs rule the planet. 22 00:03:35,715 --> 00:03:41,512 They dominate the land and are now entering the ocean as well. 23 00:03:44,599 --> 00:03:49,979 The high sea levels have split North America in two… 24 00:03:54,609 --> 00:03:56,653 creating endless coastlines… 25 00:04:00,573 --> 00:04:03,534 hundreds of tropical islands… 26 00:04:05,828 --> 00:04:08,039 and opportunity. 27 00:04:20,551 --> 00:04:23,304 But these islands are no paradise. 28 00:04:27,016 --> 00:04:30,019 They are home to a formidable predator. 29 00:04:34,983 --> 00:04:40,571 One of the fastest, most agile dinosaurs of its kind. 30 00:04:44,075 --> 00:04:48,413 North America's answer to the Spinosaurus. 31 00:04:59,716 --> 00:05:03,052 Just not in the way you would think. 32 00:05:04,512 --> 00:05:06,681 Not even remotely. 33 00:05:09,183 --> 00:05:12,061 This is Hesperornis. 34 00:05:13,396 --> 00:05:17,900 He is formidable, and he is fast. 35 00:05:20,570 --> 00:05:26,284 But he's pretty much the opposite of his giant, terrifying cousins. 36 00:05:36,294 --> 00:05:37,337 He's awkward… 37 00:05:38,504 --> 00:05:39,630 …and clumsy. 38 00:05:42,050 --> 00:05:43,634 And has tiny teeth. 39 00:05:44,802 --> 00:05:48,431 Not exactly the traits of a ferocious hunter. 40 00:05:50,183 --> 00:05:53,519 But what he does share with Spinosaurus 41 00:05:54,187 --> 00:05:57,732 is that he's not confined to dry land. 42 00:06:05,281 --> 00:06:10,995 In fact, he's the most advanced aquatic dinosaur in history. 43 00:06:17,794 --> 00:06:21,422 Like some sort of prehistoric penguin, 44 00:06:22,465 --> 00:06:27,804 he's able to swim far out to sea to access feeding grounds 45 00:06:28,429 --> 00:06:31,849 that were previously out of reach. 46 00:06:51,953 --> 00:06:56,541 This is the bounty of his new blue realm. 47 00:07:05,842 --> 00:07:11,305 Down here, his big clumsy feet become powerful propellers. 48 00:07:15,309 --> 00:07:21,315 And his 94 needle-sharp teeth snatch fish with ease. 49 00:07:38,082 --> 00:07:40,376 But as an air-breather, 50 00:07:41,294 --> 00:07:44,213 he's still tied to the surface. 51 00:07:56,350 --> 00:08:00,813 And the surface is not a safe place to linger. 52 00:08:04,275 --> 00:08:05,610 Because below, 53 00:08:06,944 --> 00:08:09,155 there are beasts 54 00:08:09,822 --> 00:08:13,159 twice the size of a killer whale. 55 00:08:20,500 --> 00:08:22,502 Mosasaurs. 56 00:08:29,342 --> 00:08:33,429 The apex predators of these seas. 57 00:08:41,771 --> 00:08:45,399 Hesperornis must get back to the shore. 58 00:08:50,530 --> 00:08:54,033 But the mosasaur moves with frightening speed. 59 00:08:57,036 --> 00:09:01,582 Luckily, Hesperornis is much more agile. 60 00:09:08,297 --> 00:09:09,840 But he's exhausted. 61 00:09:13,219 --> 00:09:18,224 Which gives the mosasaur one last shot. 62 00:09:36,492 --> 00:09:39,954 Hesperornis is a true survivor, 63 00:09:41,122 --> 00:09:46,627 venturing further into the ocean than any dinosaur ever has. 64 00:09:49,589 --> 00:09:55,052 But these waters are treacherous, even for the best swimmers. 65 00:10:03,311 --> 00:10:07,106 Despite the dinosaurs' success in the shallows, 66 00:10:07,690 --> 00:10:09,734 the mosasaurs 67 00:10:09,817 --> 00:10:11,736 rule the waves. 68 00:10:19,910 --> 00:10:23,831 Eight hundred miles north, on land, 69 00:10:24,332 --> 00:10:26,250 it's a different story. 70 00:10:38,095 --> 00:10:41,641 Fueled by a warm, stable climate, 71 00:10:41,724 --> 00:10:46,145 the dinosaurs' dominance here is unrivaled. 72 00:10:53,944 --> 00:10:58,699 The great sauropods are thriving among the tall trees, 73 00:10:58,783 --> 00:11:02,119 as they have since the dawn of the Jurassic. 74 00:11:08,626 --> 00:11:12,380 But down below, there has been a revolution. 75 00:11:18,969 --> 00:11:22,306 A female hadrosaur. 76 00:11:25,434 --> 00:11:29,605 While she may be dwarfed in present company, 77 00:11:29,689 --> 00:11:33,526 she's actually larger than an elephant. 78 00:11:34,568 --> 00:11:38,155 And she won't be held up by these giants, 79 00:11:39,532 --> 00:11:43,452 because nothing can stop a mother on a mission. 80 00:11:45,871 --> 00:11:47,707 And that mission 81 00:11:48,207 --> 00:11:50,751 is to feed her family… 82 00:11:52,920 --> 00:11:54,588 who are somewhere 83 00:11:56,132 --> 00:11:57,466 down there. 84 00:12:07,893 --> 00:12:14,108 Long ago, their cheek-stuffing ancestors were scarce and scattered. 85 00:12:16,986 --> 00:12:23,701 But hadrosaurs are now so successful, their herds are thousands strong. 86 00:12:26,245 --> 00:12:31,751 The greatest gatherings of dinosaurs the world has ever known. 87 00:12:34,128 --> 00:12:38,549 But this female's family isn't traveling with the herd. 88 00:12:40,342 --> 00:12:43,637 There, in the safety of the crèche, 89 00:12:44,138 --> 00:12:48,434 a sprawling nursery for hundreds of young hadrosaurs… 90 00:12:51,187 --> 00:12:54,106 …including her own. 91 00:12:58,986 --> 00:13:03,699 At six months old, they have insatiable appetites, 92 00:13:04,492 --> 00:13:08,412 and will eat almost anything she brings them. 93 00:13:11,457 --> 00:13:12,708 Anything. 94 00:13:24,929 --> 00:13:29,475 Feeding in this bird-like way takes a lot of refills, 95 00:13:30,142 --> 00:13:34,688 so she's constantly leaving to go find food. 96 00:13:36,816 --> 00:13:39,193 And when moms are away, 97 00:13:39,276 --> 00:13:42,196 little ones will play. 98 00:14:06,053 --> 00:14:08,931 With the wingspan of a fighter jet, 99 00:14:09,473 --> 00:14:13,310 pterosaurs are now bigger than ever. 100 00:14:15,938 --> 00:14:19,567 And crèches are the perfect hunting grounds, 101 00:14:20,067 --> 00:14:24,405 where unguarded nests are the easiest pickings. 102 00:14:44,216 --> 00:14:46,886 Despite the threat from this towering monster, 103 00:14:46,969 --> 00:14:50,347 the mothers will defend their babies at all costs. 104 00:15:07,781 --> 00:15:13,078 But the giant pterosaur is determined to feed. 105 00:15:20,044 --> 00:15:25,090 The screams from the nest are like a dinner bell to the predator. 106 00:15:41,190 --> 00:15:44,485 But the little ones aren't just crying in fear. 107 00:15:45,611 --> 00:15:47,905 They're calling for help. 108 00:16:07,216 --> 00:16:11,136 This fierce instinct to protect their young 109 00:16:12,179 --> 00:16:17,017 is central to the hadrosaurs' remarkable success. 110 00:16:19,186 --> 00:16:24,692 {\an8}But other dinosaurs are taking defense to a whole new level 111 00:16:26,151 --> 00:16:31,490 {\an8}because the arms race between predator and prey is escalating. 112 00:16:33,993 --> 00:16:39,748 {\an8}And this will give rise to the most iconic dinosaurs of all time. 113 00:16:45,879 --> 00:16:48,132 {\an8}This will take so long 114 00:16:48,632 --> 00:16:52,803 {\an8}that the continent of North America will shift, 115 00:16:54,013 --> 00:16:57,433 {\an8}the land buckling up into the sky. 116 00:17:06,900 --> 00:17:09,028 The Rocky Mountains. 117 00:17:11,488 --> 00:17:15,034 It's here, in the foothills below, 118 00:17:16,744 --> 00:17:19,997 that the dinosaurs are making an impact. 119 00:17:28,797 --> 00:17:30,883 Pachycephalosaurus. 120 00:17:32,384 --> 00:17:35,804 Using their outrageously thick skulls… 121 00:17:38,640 --> 00:17:41,602 to duel for supremacy. 122 00:17:47,024 --> 00:17:48,776 And alongside them, 123 00:17:49,985 --> 00:17:53,906 a dinosaur with even more impressive headgear. 124 00:18:00,120 --> 00:18:02,331 Triceratops. 125 00:18:10,631 --> 00:18:13,092 She may look like a rhinoceros, 126 00:18:13,926 --> 00:18:16,637 but she's twice the size of one. 127 00:18:20,057 --> 00:18:25,104 And armed with spear-like horns over one meter in length. 128 00:18:32,778 --> 00:18:38,283 Triceratops and Pachycephalosaurus have impressive weapons. 129 00:18:40,661 --> 00:18:43,205 Yet there are some here 130 00:18:43,288 --> 00:18:47,126 that are even more armed and dangerous. 131 00:18:58,303 --> 00:19:00,639 Under the cover of darkness, 132 00:19:01,348 --> 00:19:04,893 the latest and greatest of the armored warriors. 133 00:19:07,437 --> 00:19:11,775 Six meters long and highly territorial. 134 00:19:15,070 --> 00:19:18,782 Ankylosaurus magniventris. 135 00:19:27,082 --> 00:19:29,626 He's on patrol for intruders 136 00:19:31,461 --> 00:19:35,174 bold enough to breach his borders. 137 00:19:43,265 --> 00:19:48,812 His tank-like torso is covered in dozens of thick, bony plates. 138 00:19:55,235 --> 00:19:56,862 And what's more, 139 00:19:57,696 --> 00:20:00,532 he has a powerful new weapon. 140 00:20:05,037 --> 00:20:08,957 A club-like tail, weighing half a ton, 141 00:20:09,750 --> 00:20:14,338 that he can use to take on whatever stalks these forests. 142 00:20:20,469 --> 00:20:22,804 He senses something. 143 00:20:52,000 --> 00:20:54,253 His borders have been breached… 144 00:20:56,463 --> 00:20:59,716 by the worst possible intruder of all. 145 00:21:12,604 --> 00:21:14,648 A Tyrannosaurus rex. 146 00:22:39,483 --> 00:22:41,443 Ankylosaurus 147 00:22:42,402 --> 00:22:43,653 versus T. rex. 148 00:22:53,538 --> 00:22:55,874 An evolutionary stalemate, 149 00:22:56,875 --> 00:22:59,378 millions of years in the making. 150 00:23:20,232 --> 00:23:22,234 But in this arms race, 151 00:23:24,069 --> 00:23:28,198 there's one thing that does set these dinosaurs apart. 152 00:23:31,410 --> 00:23:33,161 Intelligence. 153 00:24:15,078 --> 00:24:20,667 T. rex is one of the most fearsome predators of all time. 154 00:24:23,211 --> 00:24:25,922 And to remain at the top of her game… 155 00:24:27,466 --> 00:24:33,138 …she must eat the equivalent of 200 steaks every day. 156 00:24:35,307 --> 00:24:40,562 And yet, so far, she hasn't eaten a single bite. 157 00:24:43,565 --> 00:24:49,154 That's because she has special plans for this take-out meal. 158 00:24:54,326 --> 00:24:58,955 But Ankylosaurus is no light snack. 159 00:25:05,712 --> 00:25:08,423 Six tons of muscle and bone, 160 00:25:08,924 --> 00:25:13,178 with an assortment of lumps and bumps. 161 00:25:25,398 --> 00:25:27,359 Even for T. rex, 162 00:25:28,109 --> 00:25:29,986 it's quite a drag. 163 00:26:04,312 --> 00:26:05,564 Finally, 164 00:26:06,690 --> 00:26:08,358 her journey's end. 165 00:26:17,659 --> 00:26:22,122 And the reason she's gone to all this effort. 166 00:26:35,176 --> 00:26:37,887 Five hungry hatchlings. 167 00:26:51,610 --> 00:26:53,445 A ferocious killer, 168 00:26:54,112 --> 00:26:55,238 yes. 169 00:26:56,364 --> 00:26:57,824 But also, 170 00:26:58,366 --> 00:27:00,076 a devoted mother. 171 00:27:16,468 --> 00:27:18,219 She will ensure 172 00:27:19,304 --> 00:27:21,723 her little ones are well-fed… 173 00:27:25,644 --> 00:27:29,564 to give them the very best start in life. 174 00:27:34,235 --> 00:27:36,905 Something their distant ancestors 175 00:27:37,405 --> 00:27:39,324 could only dream of. 176 00:27:42,661 --> 00:27:48,667 Far back in the Triassic, tiny Marasuchus hatched into hell. 177 00:27:50,168 --> 00:27:53,046 These dinosaurs-in-the-making, 178 00:27:54,172 --> 00:27:56,925 forced to live in the shadows. 179 00:27:57,926 --> 00:28:01,012 Hiding from the ruling reptiles. 180 00:28:03,890 --> 00:28:06,184 But when fate intervened… 181 00:28:08,311 --> 00:28:10,230 they turned catastrophe 182 00:28:11,523 --> 00:28:13,817 into opportunity… 183 00:28:16,403 --> 00:28:19,197 and began their monumental rise. 184 00:28:22,659 --> 00:28:26,955 Growing bigger, stronger, and ever more formidable. 185 00:28:34,212 --> 00:28:35,463 In time, 186 00:28:36,840 --> 00:28:40,135 they would triumph, not just on land, 187 00:28:41,636 --> 00:28:42,721 but in the sea 188 00:28:44,472 --> 00:28:45,974 and the sky. 189 00:28:47,976 --> 00:28:51,020 After 160 million years, 190 00:28:52,605 --> 00:28:55,316 the dinosaurs are now so dominant… 191 00:28:56,818 --> 00:29:00,321 …nothing on Earth can stand in their way. 192 00:29:06,828 --> 00:29:09,539 But something not of this Earth 193 00:29:10,123 --> 00:29:11,332 will. 194 00:29:13,209 --> 00:29:17,922 Because as this family's journey is just getting started, 195 00:29:19,215 --> 00:29:20,675 another journey 196 00:29:21,176 --> 00:29:23,344 is approaching its end. 197 00:29:27,932 --> 00:29:34,522 The asteroid, now hurtling towards Earth at 50 times the speed of sound, 198 00:29:36,024 --> 00:29:40,028 will finally have its date with destiny. 199 00:30:13,561 --> 00:30:18,483 It smashes into the ocean off the coast of Mexico, 200 00:30:19,234 --> 00:30:23,613 with the power of a billion atomic bombs. 201 00:30:24,823 --> 00:30:27,951 Temperatures are hot enough to vaporize the seabed… 202 00:30:30,995 --> 00:30:35,667 along with every living thing for hundreds of kilometers. 203 00:30:44,676 --> 00:30:48,096 Far away, in the foothills of the Rockies, 204 00:30:49,055 --> 00:30:55,144 these great dinosaurs have no idea what's about to hit them. 205 00:31:17,125 --> 00:31:20,795 The largest earthquakes in history. 206 00:31:29,596 --> 00:31:32,307 But the worst is yet to come. 207 00:31:35,602 --> 00:31:41,065 An enormous wall of superheated debris explodes outward. 208 00:31:58,499 --> 00:32:03,254 The dinosaurs caught beneath this death cloud 209 00:32:03,338 --> 00:32:05,465 are entombed. 210 00:32:08,051 --> 00:32:13,222 Their world is so hot, it literally bursts into flames. 211 00:32:22,357 --> 00:32:24,442 Even the toughest armor 212 00:32:24,943 --> 00:32:26,778 is no protection. 213 00:32:36,162 --> 00:32:39,749 The cloud quickly engulfs the entire planet, 214 00:32:40,249 --> 00:32:42,418 suffocating it with ash. 215 00:32:44,504 --> 00:32:46,923 Shrouding it in darkness. 216 00:33:32,844 --> 00:33:37,890 The few still standing at the end of the day 217 00:33:39,642 --> 00:33:41,602 are in a nightmare. 218 00:33:43,104 --> 00:33:46,399 Choking in the gloom. 219 00:34:12,675 --> 00:34:14,218 By nightfall, 220 00:34:14,886 --> 00:34:20,475 the death toll for the dinosaurs is catastrophic. 221 00:34:47,668 --> 00:34:50,338 Starved of the sun's rays, 222 00:34:50,838 --> 00:34:54,759 an impact winter descends on the Earth. 223 00:35:01,140 --> 00:35:05,937 Global temperatures drop by 25 degrees Celsius. 224 00:35:09,148 --> 00:35:15,363 Conditions too cold for almost any dinosaur to withstand. 225 00:35:27,041 --> 00:35:29,460 Giant sauropods, 226 00:35:29,961 --> 00:35:31,671 laid to rest 227 00:35:32,171 --> 00:35:37,677 in the cinders of the very trees that made them so tall. 228 00:35:53,484 --> 00:35:55,778 In their crowded colonies, 229 00:35:56,529 --> 00:35:58,614 those who live together, 230 00:35:59,407 --> 00:36:00,950 die together. 231 00:36:08,708 --> 00:36:12,295 Protective mothers cannot shield their young 232 00:36:12,378 --> 00:36:14,505 from the freezing temperatures. 233 00:36:20,636 --> 00:36:24,765 The punishing cold has also taken its toll 234 00:36:25,391 --> 00:36:28,728 on the most famous dinosaur of all. 235 00:36:37,528 --> 00:36:39,530 The Tyrant King 236 00:36:40,448 --> 00:36:41,866 has fallen. 237 00:37:01,802 --> 00:37:05,223 Even the mighty Tyrannosaurus rex 238 00:37:05,848 --> 00:37:08,351 will not survive this. 239 00:37:40,007 --> 00:37:42,551 The reign of the dinosaurs 240 00:37:44,095 --> 00:37:45,721 has finally 241 00:37:46,514 --> 00:37:48,474 come to an end. 242 00:38:17,003 --> 00:38:20,298 But 66 million years later… 243 00:38:22,717 --> 00:38:26,262 the dinosaurs are rising again. 244 00:38:30,891 --> 00:38:32,268 This time, 245 00:38:32,351 --> 00:38:34,270 at our hands. 246 00:38:42,028 --> 00:38:47,908 Today, their fossils stand as monuments to a lost world. 247 00:38:49,076 --> 00:38:50,411 But more than that, 248 00:38:51,787 --> 00:38:58,210 they are the keys that unlock the secrets of the dinosaur story. 249 00:39:00,004 --> 00:39:04,884 Our understanding of their lives is now greater than ever. 250 00:39:06,302 --> 00:39:08,471 From their very first moments, 251 00:39:09,638 --> 00:39:11,265 to their very last. 252 00:39:15,019 --> 00:39:20,024 And the revelation that on Earth's darkest day, 253 00:39:20,608 --> 00:39:23,361 not all dinosaurs died. 254 00:39:25,363 --> 00:39:30,743 Some were small enough to find shelter from the apocalypse. 255 00:39:33,496 --> 00:39:35,373 And survive 256 00:39:36,040 --> 00:39:38,459 even to this day. 257 00:39:40,961 --> 00:39:46,384 The flying dinosaurs we now call the birds. 258 00:39:50,846 --> 00:39:56,936 And the clues to their past are hiding in plain sight. 259 00:40:18,416 --> 00:40:24,588 The remarkable journey that started 235 million years ago 260 00:40:25,798 --> 00:40:29,427 continues alongside us. 261 00:40:31,554 --> 00:40:33,722 They are the last remaining link… 262 00:40:36,016 --> 00:40:38,644 to a long-lost kingdom 263 00:40:40,646 --> 00:40:42,231 that was 264 00:40:43,232 --> 00:40:44,733 the age 265 00:40:45,526 --> 00:40:47,445 of the dinosaurs.