1 00:00:00,828 --> 00:00:03,150 (dramatic music) 2 00:00:03,150 --> 00:00:07,491 Earth is born out of chaos and catastrophe. 3 00:00:07,491 --> 00:00:08,340 (object banging) 4 00:00:08,340 --> 00:00:11,010 Despite such hostile conditions, 5 00:00:11,010 --> 00:00:13,563 life emerges on our planet. 6 00:00:14,487 --> 00:00:15,390 (water flowing) 7 00:00:15,390 --> 00:00:20,340 but it must withstand deadly disasters again and again. 8 00:00:20,340 --> 00:00:22,080 (wind whooshing) 9 00:00:22,080 --> 00:00:24,427 Planet Earth is a wild world 10 00:00:24,427 --> 00:00:28,053 shaken by unimaginable impacts, 11 00:00:30,330 --> 00:00:33,587 volcanic eruptions that flood the landscape 12 00:00:33,587 --> 00:00:38,520 and drastic climate changes that lead to ice ages 13 00:00:38,520 --> 00:00:41,793 that freeze the world from pole to pole. 14 00:00:43,260 --> 00:00:47,659 Yet each assault creates a path for something new. 15 00:00:47,659 --> 00:00:48,492 (birds chirping) 16 00:00:48,492 --> 00:00:51,240 Life always finds a way 17 00:00:51,240 --> 00:00:54,333 despite being constantly put to the test. 18 00:00:56,010 --> 00:00:59,490 Without these catastrophes, life as we know it 19 00:00:59,490 --> 00:01:03,873 would not exist on our fateful planet. 20 00:01:11,460 --> 00:01:14,830 Life evolved on earth four billion years ago 21 00:01:15,720 --> 00:01:19,167 when a series of severe ice ages froze our planet. 22 00:01:19,167 --> 00:01:22,950 They almost destroyed everything alive, 23 00:01:22,950 --> 00:01:25,980 but when the last glaciation ended, 24 00:01:25,980 --> 00:01:28,920 earth became a giant greenhouse. 25 00:01:28,920 --> 00:01:30,930 Oceans turned tropical 26 00:01:30,930 --> 00:01:34,773 and made way for an unprecedented explosion of life. 27 00:01:38,070 --> 00:01:40,830 This profound change marked the beginning 28 00:01:40,830 --> 00:01:45,663 of the Paleozoic era 541 million years ago. 29 00:01:46,762 --> 00:01:49,595 (water splashing) 30 00:01:50,490 --> 00:01:54,900 Life experienced significant evolutionary developments 31 00:01:54,900 --> 00:01:57,427 and took on much larger dimensions, 32 00:01:57,427 --> 00:02:02,427 thriving in new forms and conquering new habitats. 33 00:02:07,650 --> 00:02:10,710 But during this era, which lasted close 34 00:02:10,710 --> 00:02:14,580 to 300 million years, the planet was stuck 35 00:02:14,580 --> 00:02:16,533 by deadly catastrophes. 36 00:02:17,550 --> 00:02:21,030 The last and worst was a mass extinction 37 00:02:21,030 --> 00:02:23,973 that wiped out almost all life on earth. 38 00:02:25,051 --> 00:02:25,980 (animal growling) 39 00:02:25,980 --> 00:02:28,740 Scientists around the world are investigating 40 00:02:28,740 --> 00:02:31,590 how life in the Paleozoic evolved 41 00:02:31,590 --> 00:02:35,430 and which events ultimately resulted in the disaster 42 00:02:35,430 --> 00:02:37,833 known as the Great Dying. 43 00:02:39,180 --> 00:02:43,470 Morocco, in this dry, dusty north African landscape 44 00:02:43,470 --> 00:02:47,610 there is fossilized evidence of the biological revolution 45 00:02:47,610 --> 00:02:50,853 that became known as the Cambrian explosion. 46 00:02:52,290 --> 00:02:55,710 Paleontologist Philipe Havlik is here to find out more 47 00:02:55,710 --> 00:02:59,310 about how that complex life evolved. 48 00:02:59,310 --> 00:03:01,830 The story unfolded underwater 49 00:03:01,830 --> 00:03:04,083 and what was once a vast ocean. 50 00:03:06,117 --> 00:03:07,943 The Cambrian explosion being the beginning 51 00:03:07,943 --> 00:03:12,180 of the Cambrian period is the most exciting thing 52 00:03:12,180 --> 00:03:14,340 for any evolutionary researcher. 53 00:03:14,340 --> 00:03:17,910 It was the moment when almost all invertebrate animal groups 54 00:03:17,910 --> 00:03:21,090 suddenly appeared overnight, as if out of nowhere 55 00:03:21,090 --> 00:03:23,940 they started to divide into all kinds of species. 56 00:03:23,940 --> 00:03:25,470 We found hundreds of species 57 00:03:25,470 --> 00:03:27,810 within a very short period of time. 58 00:03:27,810 --> 00:03:30,990 We still require an enormous amount of research on this 59 00:03:30,990 --> 00:03:33,140 and still don't know exactly what happened. 60 00:03:33,990 --> 00:03:35,160 Philipe has arranged 61 00:03:35,160 --> 00:03:37,560 to meet with a local fossil trader 62 00:03:37,560 --> 00:03:40,470 who will help him decipher the story. 63 00:03:40,470 --> 00:03:42,630 Like many people in the area, 64 00:03:42,630 --> 00:03:46,833 Mohan Imati has traded in fossils his entire life. 65 00:03:47,923 --> 00:03:49,323 We can look at this layer. 66 00:03:50,757 --> 00:03:51,983 Maybe first some on the rocks, huh? 67 00:03:54,240 --> 00:03:57,093 Soon the experts find something interesting. 68 00:03:58,170 --> 00:03:59,790 What do you think about this one? 69 00:03:59,790 --> 00:04:02,350 Yeah, yeah, that is good fossil, it's trilobyte. 70 00:04:02,350 --> 00:04:05,097 It's almost complete, huh? 71 00:04:05,097 --> 00:04:06,452 Yes, it's complete, yeah. 72 00:04:06,452 --> 00:04:08,057 Trilobites 73 00:04:08,057 --> 00:04:09,303 are kind of like cockroaches among fossils. 74 00:04:09,303 --> 00:04:10,650 Their body is divided into three parts. 75 00:04:10,650 --> 00:04:13,380 We have the head, the cephalon, the thorax, 76 00:04:13,380 --> 00:04:15,180 the body, and the pyridium. 77 00:04:15,180 --> 00:04:17,280 Basically, the rear end of the Trilobites. 78 00:04:18,990 --> 00:04:20,490 Trilobites emerged 79 00:04:20,490 --> 00:04:22,203 at the beginning of the Cambrian. 80 00:04:25,260 --> 00:04:28,020 These arthropods are one of the earliest 81 00:04:28,020 --> 00:04:32,551 and most diverse groups of multicellular organisms on earth. 82 00:04:32,551 --> 00:04:34,800 (water flowing) 83 00:04:34,800 --> 00:04:36,810 Along with their unique body shape, 84 00:04:36,810 --> 00:04:41,610 Trilobites had a hard exoskeleton made of chitin. 85 00:04:41,610 --> 00:04:43,860 This protected their soft bodies 86 00:04:43,860 --> 00:04:46,803 and allowed their fossils to be well preserved. 87 00:04:49,080 --> 00:04:52,460 While Trilobites were a huge part of the marine ecosystem, 88 00:04:52,460 --> 00:04:55,233 they weren't the apex predators at the time. 89 00:04:56,900 --> 00:04:59,310 (water flowing) 90 00:04:59,310 --> 00:05:02,760 A terrifying giant shrimp like creature 91 00:05:02,760 --> 00:05:06,483 known as Anomalocaris claimed that honor. 92 00:05:10,877 --> 00:05:13,237 Anomalocaris was the fighting machine 93 00:05:13,237 --> 00:05:14,820 of the Cambria, four feet long 94 00:05:14,820 --> 00:05:16,440 equipped with long eye stalks, 95 00:05:16,440 --> 00:05:19,650 giving it 360 degree vision. 96 00:05:19,650 --> 00:05:23,040 It had large grappling arms at the very front. 97 00:05:23,040 --> 00:05:25,563 Anything that came close to it was eaten. 98 00:05:27,012 --> 00:05:31,636 (speaking in foreign language) 99 00:05:31,636 --> 00:05:33,178 (gentle music) 100 00:05:33,178 --> 00:05:34,427 (water flowing) 101 00:05:34,427 --> 00:05:35,674 Philipe sees the Cambrian 102 00:05:35,674 --> 00:05:37,890 as more of a revolution than an explosion 103 00:05:37,890 --> 00:05:41,040 because it marked the beginning of competition 104 00:05:41,040 --> 00:05:43,484 among living things. 105 00:05:43,484 --> 00:05:44,733 Some developed a shell 106 00:05:44,733 --> 00:05:48,030 and others developed weapons to crack this shell, 107 00:05:48,030 --> 00:05:50,580 and so it came to an extreme arms race. 108 00:05:50,580 --> 00:05:52,260 One had stronger tools. 109 00:05:52,260 --> 00:05:55,107 The next had spikes and used them to fight back, 110 00:05:55,107 --> 00:05:58,743 and in the end, the sea creatures we know today emerged. 111 00:06:00,180 --> 00:06:03,013 Life exploded in the oceans. 112 00:06:03,013 --> 00:06:06,960 Rising oxygen levels, genetic inventions 113 00:06:06,960 --> 00:06:11,190 and environmental changes created a complex cocktail 114 00:06:11,190 --> 00:06:14,340 that led to new and abundant diversity. 115 00:06:14,340 --> 00:06:16,383 Within just a few million years, 116 00:06:16,383 --> 00:06:19,620 mats of microbes covering the sea floor 117 00:06:19,620 --> 00:06:22,260 evolved into complex life. 118 00:06:22,260 --> 00:06:25,770 Simple unicellular organisms were replaced 119 00:06:25,770 --> 00:06:27,840 by highly mobile creatures 120 00:06:27,840 --> 00:06:30,840 that sported advanced anatomical features 121 00:06:30,840 --> 00:06:32,583 like legs and eyes. 122 00:06:33,690 --> 00:06:38,690 The Cambrian lasted until 485 million years ago. 123 00:06:38,760 --> 00:06:41,160 It was followed by the Ordovician, 124 00:06:41,160 --> 00:06:43,620 a second period of the Paleozoic, 125 00:06:43,620 --> 00:06:46,890 where life continued to diversify through the emergence 126 00:06:46,890 --> 00:06:50,580 of new marine species and ecosystems. 127 00:06:50,580 --> 00:06:53,070 Organisms that were dominant in the Cambrian 128 00:06:53,070 --> 00:06:55,080 were now replaced by a wide range 129 00:06:55,080 --> 00:06:57,720 of new marine invertebrates. 130 00:06:57,720 --> 00:07:00,420 The Moroccan rocks have an exquisitely preserved 131 00:07:00,420 --> 00:07:02,133 record of the Ordovician. 132 00:07:03,360 --> 00:07:05,730 Mohan takes Philipe to a site 133 00:07:05,730 --> 00:07:08,250 where he recently found a Cephalopod, 134 00:07:08,250 --> 00:07:09,720 a squid like creature 135 00:07:09,720 --> 00:07:12,483 that was even larger than Anomalocaris. 136 00:07:13,380 --> 00:07:15,360 That's what we found. 137 00:07:15,360 --> 00:07:16,440 Oh, whoa, whoa, whoa, whoa, whoa. 138 00:07:16,440 --> 00:07:17,940 It's actually a pretty nice piece. 139 00:07:17,940 --> 00:07:20,100 And do you know the biggest of this one? 140 00:07:20,100 --> 00:07:21,960 They reached up to nine meters 141 00:07:21,960 --> 00:07:25,620 and just to shell its Camarasaurus, it was found in Russia. 142 00:07:25,620 --> 00:07:28,260 Camarasaurus was the largest predator 143 00:07:28,260 --> 00:07:29,640 in the Ordovician. 144 00:07:29,640 --> 00:07:32,640 10 tentacles projected from its cone like body, 145 00:07:32,640 --> 00:07:34,350 allowing it to catch and feed 146 00:07:34,350 --> 00:07:37,183 on Trilobites and other creatures. 147 00:07:37,183 --> 00:07:38,433 (water whooshing) 148 00:07:38,433 --> 00:07:39,660 (dramatic music) 149 00:07:39,660 --> 00:07:41,760 The tentacles grabbed the prey, 150 00:07:41,760 --> 00:07:44,283 then sucked it inwards to be devoured. 151 00:07:45,180 --> 00:07:47,520 This massive increase in size 152 00:07:47,520 --> 00:07:50,430 is attributed to the evolutionary pressures 153 00:07:50,430 --> 00:07:53,523 that develop in predator, prey dynamics. 154 00:07:54,780 --> 00:07:57,872 Being big can help creatures avoid predators 155 00:07:57,872 --> 00:08:01,443 or become more effective predators themselves. 156 00:08:02,550 --> 00:08:04,890 Scientists believe the environment 157 00:08:04,890 --> 00:08:06,903 also affected this growth. 158 00:08:08,220 --> 00:08:10,057 In the Ordovician, 159 00:08:10,057 --> 00:08:11,580 the first plants emerged on land, 160 00:08:11,580 --> 00:08:13,260 which increased the oxygen levels 161 00:08:13,260 --> 00:08:15,900 and thereby led to climate fluctuations. 162 00:08:15,900 --> 00:08:17,280 This, of course, is a trigger 163 00:08:17,280 --> 00:08:19,890 that significantly advances evolution. 164 00:08:19,890 --> 00:08:23,864 Life must deal with new situations time and time again. 165 00:08:23,864 --> 00:08:25,110 (gentle music) 166 00:08:25,110 --> 00:08:26,670 The Moroccan fossil record 167 00:08:26,670 --> 00:08:28,850 reveals a bustling Ordovician world 168 00:08:28,850 --> 00:08:32,493 full of increasingly complex creatures. 169 00:08:34,170 --> 00:08:36,977 But about 444 million years ago, 170 00:08:36,977 --> 00:08:39,393 things suddenly changed. 171 00:08:42,540 --> 00:08:45,753 The fossils show that there was a massive die off. 172 00:08:47,250 --> 00:08:51,180 Even with their new adaptations, more than 85% 173 00:08:51,180 --> 00:08:54,189 of marine life was wiped out. 174 00:08:54,189 --> 00:08:57,106 (vehicle whirring) 175 00:08:57,960 --> 00:09:00,870 Philipe is searching for clues about what happened 176 00:09:00,870 --> 00:09:03,483 on the northern edge of the Sahara desert. 177 00:09:06,300 --> 00:09:07,530 Here we have a seabed 178 00:09:07,530 --> 00:09:10,530 in which numerous different fossils are preserved. 179 00:09:10,530 --> 00:09:12,150 They indicate that we are exactly 180 00:09:12,150 --> 00:09:13,983 at the right point in time. 181 00:09:13,983 --> 00:09:17,310 (object banging) 182 00:09:17,310 --> 00:09:20,823 But then he finds something unusual. 183 00:09:22,110 --> 00:09:24,039 Here I have a stone within a stone, 184 00:09:24,039 --> 00:09:27,390 and that shouldn't happen in this marine deposit. 185 00:09:27,390 --> 00:09:29,760 We are relatively far out at sea here, 186 00:09:29,760 --> 00:09:32,190 so there simply shouldn't be any pebbles, 187 00:09:32,190 --> 00:09:34,170 especially not angular ones. 188 00:09:34,170 --> 00:09:37,530 There's only one way to get them so far into the sea. 189 00:09:37,530 --> 00:09:39,963 A small iceberg must have drifted out here. 190 00:09:42,258 --> 00:09:43,091 (gentle music) 191 00:09:43,091 --> 00:09:46,830 When glaciers move over land, they grind rocks 192 00:09:46,830 --> 00:09:49,980 beneath them, picking up and transporting bits 193 00:09:49,980 --> 00:09:53,010 and pieces until the ice melts. 194 00:09:53,010 --> 00:09:55,410 Havlik believes that when an iceberg melted 195 00:09:55,410 --> 00:09:58,830 in the Ordovician ocean, it dropped this pedal here 196 00:09:58,830 --> 00:10:02,250 about 444 million years ago. 197 00:10:02,250 --> 00:10:05,790 A glaciation event seems to be the only explanation 198 00:10:05,790 --> 00:10:08,463 for the pebble trapped in older stone. 199 00:10:11,340 --> 00:10:13,950 We also find such evidence in other places 200 00:10:13,950 --> 00:10:16,410 around the world, not only in North Africa, 201 00:10:16,410 --> 00:10:18,123 it's also in South America. 202 00:10:19,000 --> 00:10:20,040 It's the same in Southern Europe. 203 00:10:20,040 --> 00:10:22,110 It's something that appears everywhere. 204 00:10:22,110 --> 00:10:24,680 That means the moment there is large scale cooling, 205 00:10:24,680 --> 00:10:28,110 most creatures, at that time only sea creatures, 206 00:10:28,110 --> 00:10:30,000 have no chance of survival. 207 00:10:30,000 --> 00:10:32,613 In other words, most of them simply go extinct. 208 00:10:34,320 --> 00:10:36,360 Complex life was flourishing 209 00:10:36,360 --> 00:10:39,693 until suddenly everything changed. 210 00:10:40,920 --> 00:10:44,193 Because the glacial deposits occurred at the same time 211 00:10:44,193 --> 00:10:46,500 as the mass extinction event, 212 00:10:46,500 --> 00:10:50,430 it seems plausible that an ice age was responsible 213 00:10:50,430 --> 00:10:53,384 for the death of so many new species. 214 00:10:53,384 --> 00:10:56,460 But how did the climate suddenly change 215 00:10:56,460 --> 00:10:58,852 from tropical to Arctic? 216 00:10:58,852 --> 00:11:02,370 Iceland, to uncover what could have caused 217 00:11:02,370 --> 00:11:04,530 such a huge glacial event, 218 00:11:04,530 --> 00:11:09,530 geologist Professor Colin Devey has come to a unique place. 219 00:11:09,660 --> 00:11:11,407 We're in the Silfra gap, 220 00:11:11,407 --> 00:11:13,080 and this is where you can really see 221 00:11:13,080 --> 00:11:14,340 plate tectonics in action. 222 00:11:14,340 --> 00:11:18,030 You can really see one side 223 00:11:18,030 --> 00:11:20,610 of the earth moving away from the other side of the earth. 224 00:11:20,610 --> 00:11:23,293 This is where tectonics really happens. 225 00:11:23,293 --> 00:11:26,250 Rocks here reveal how earth 226 00:11:26,250 --> 00:11:28,470 is shaped by internal forces 227 00:11:28,470 --> 00:11:32,823 deep below its crust, the thin outer shell of our planet. 228 00:11:33,690 --> 00:11:36,690 Collin believes these forces played a crucial role 229 00:11:36,690 --> 00:11:39,990 in the extinction event at the end of the Ordovician. 230 00:11:39,990 --> 00:11:42,150 Iceland is a place on the planet 231 00:11:42,150 --> 00:11:45,317 where you can see wet tectonic plates, where the surface 232 00:11:45,317 --> 00:11:47,658 of the earth actually splits apart. 233 00:11:47,658 --> 00:11:50,880 Tectonic plates provide clues 234 00:11:50,880 --> 00:11:54,750 about what's happening beneath the surface of earth. 235 00:11:54,750 --> 00:11:59,730 Today we have seven major plates and numerous smaller ones. 236 00:11:59,730 --> 00:12:02,932 They all rest on the molten rock of earth's mantle 237 00:12:02,932 --> 00:12:05,073 and fit closely together. 238 00:12:06,570 --> 00:12:09,000 The tectonic plates move due to heat 239 00:12:09,000 --> 00:12:12,600 from radioactive processes inside earth. 240 00:12:12,600 --> 00:12:15,510 At times, they move closer together 241 00:12:15,510 --> 00:12:17,793 and at others, farther apart. 242 00:12:18,646 --> 00:12:19,830 (dramatic music) 243 00:12:19,830 --> 00:12:21,630 This is the edge of a plate. 244 00:12:21,630 --> 00:12:26,460 This continental drift is what this is all about. 245 00:12:26,460 --> 00:12:29,760 This is the result of Europe going that way 246 00:12:29,760 --> 00:12:32,820 and America going that way, not very fast. 247 00:12:32,820 --> 00:12:35,193 It's about as fast as your fingernail grows. 248 00:12:35,193 --> 00:12:38,310 The gap is part of the Mid-Atlantic ridge 249 00:12:38,310 --> 00:12:42,543 between the North American and the Eurasian tectonic plates. 250 00:12:43,410 --> 00:12:45,090 Okay, that was the easiest 251 00:12:45,090 --> 00:12:46,857 transatlantic flight I've ever done 252 00:12:46,857 --> 00:12:50,940 and the quickest, probably not the warmest, 253 00:12:50,940 --> 00:12:53,416 but hey, you can't have everything. 254 00:12:53,416 --> 00:12:56,120 When the plates move apart from each other, 255 00:12:56,120 --> 00:12:59,643 the land between them suffers enormous tension. 256 00:13:01,560 --> 00:13:04,470 A major earthquake eventually rips through the rock 257 00:13:04,470 --> 00:13:08,160 to release pressure, creating enormous fissures 258 00:13:08,160 --> 00:13:09,573 like the Silfra gap. 259 00:13:13,500 --> 00:13:16,530 What's happening here normally happens on the sea floor 260 00:13:16,530 --> 00:13:18,960 at about 2,500 meters depth, 261 00:13:18,960 --> 00:13:22,200 in the Atlantic, even deeper, 4,000, 5,000 meters. 262 00:13:22,200 --> 00:13:25,380 This is how the earth has changed its face, 263 00:13:25,380 --> 00:13:27,060 has changed life on earth, 264 00:13:27,060 --> 00:13:30,300 has changed everything about the earth. 265 00:13:30,300 --> 00:13:32,010 Since they first formed, 266 00:13:32,010 --> 00:13:33,900 the tectonic plates have continued 267 00:13:33,900 --> 00:13:35,910 to move around the planet. 268 00:13:35,910 --> 00:13:40,230 Over time, the continents they create also change. 269 00:13:40,230 --> 00:13:42,577 About 444 million years ago, 270 00:13:42,577 --> 00:13:46,920 our world looked very different, which could be important 271 00:13:46,920 --> 00:13:49,153 to the Ordovician mass extinction 272 00:13:49,153 --> 00:13:52,260 Plate tectonics is the thing that drives the puzzle. 273 00:13:52,260 --> 00:13:54,250 It moves the continents around. 274 00:13:54,250 --> 00:13:55,620 At the end of the Ordovician, 275 00:13:55,620 --> 00:13:58,380 plate tectonics had pushed the continents together 276 00:13:58,380 --> 00:13:59,850 into a big lump, 277 00:13:59,850 --> 00:14:02,910 into a big mass of continent called Gondwana. 278 00:14:02,910 --> 00:14:05,460 Gondwana was a super continent 279 00:14:05,460 --> 00:14:09,210 covering almost 1/3 of the earth's surface. 280 00:14:09,210 --> 00:14:12,720 The giant landmass almost stretched from the equator 281 00:14:12,720 --> 00:14:14,280 to the south pole, 282 00:14:14,280 --> 00:14:18,360 and included the modern continents of South America, Africa, 283 00:14:18,360 --> 00:14:23,125 most of Antarctica and Australia and some of India. 284 00:14:23,125 --> 00:14:24,300 And life in the Ordovician 285 00:14:24,300 --> 00:14:29,200 was mainly on the shelves around the Gondwanan continent. 286 00:14:29,200 --> 00:14:31,050 Gondwana had moved quite a long way down south, 287 00:14:31,050 --> 00:14:32,310 so it was at the South Pole, 288 00:14:32,310 --> 00:14:34,170 or part of it was at the South Pole, 289 00:14:34,170 --> 00:14:36,370 and that seems to have set the world up 290 00:14:36,370 --> 00:14:39,870 for very bad environmental conditions 291 00:14:39,870 --> 00:14:41,963 for life in the oceans. 292 00:14:41,963 --> 00:14:43,080 (dramatic music) 293 00:14:43,080 --> 00:14:45,630 Life thrived on the super continent. 294 00:14:45,630 --> 00:14:49,713 Sea animals like Conodonts and Trilobites flourished. 295 00:14:50,640 --> 00:14:52,080 But as the continent began 296 00:14:52,080 --> 00:14:54,690 to move farther towards the South Pole, 297 00:14:54,690 --> 00:14:58,143 it had a catastrophic effect on living things. 298 00:14:59,550 --> 00:15:02,550 And if the ice builds up, sea level drops, 299 00:15:02,550 --> 00:15:04,560 then those shallow water regions 300 00:15:04,560 --> 00:15:07,170 around the continent are all of a sudden dry land 301 00:15:07,170 --> 00:15:08,940 and there's no place to live. 302 00:15:08,940 --> 00:15:11,340 And it seems like that is probably one of the pressures 303 00:15:11,340 --> 00:15:14,973 that really hurt life in the Ordovician earth. 304 00:15:16,530 --> 00:15:18,330 Major glaciation at the end 305 00:15:18,330 --> 00:15:20,973 of the Ordovician caused sea levels to drop. 306 00:15:22,500 --> 00:15:24,414 The consequences were dire. 307 00:15:24,414 --> 00:15:28,263 85% of marine species were wiped out. 308 00:15:30,390 --> 00:15:32,673 It was a colossal loss of life. 309 00:15:33,789 --> 00:15:34,740 (water whirring) 310 00:15:34,740 --> 00:15:38,323 The Ordovician mass extinction led to the Silurian period 311 00:15:38,323 --> 00:15:42,690 that began 443 million years ago. 312 00:15:42,690 --> 00:15:45,030 It is characterized by the recovery 313 00:15:45,030 --> 00:15:47,550 and triumphant reemergence of life 314 00:15:47,550 --> 00:15:50,340 after just a few million years, 315 00:15:50,340 --> 00:15:52,440 creatures were rapidly evolving 316 00:15:52,440 --> 00:15:54,810 and becoming even more complex. 317 00:15:54,810 --> 00:15:58,920 They exploited new habitats, found new sources of food, 318 00:15:58,920 --> 00:16:00,990 and moved in new ways. 319 00:16:00,990 --> 00:16:04,800 The Silurian ended 419 million years ago 320 00:16:04,800 --> 00:16:07,770 and gave rise to the Devonian period. 321 00:16:07,770 --> 00:16:09,090 Back in Morocco, 322 00:16:09,090 --> 00:16:12,780 Philipe Havlik has rejoined fossil trader, Mohan Imati 323 00:16:12,780 --> 00:16:14,930 to investigate how life evolved 324 00:16:14,930 --> 00:16:18,180 in this important chapter in Earth's history. 325 00:16:18,180 --> 00:16:22,110 The Devonian is also well preserved in Moroccan rocks. 326 00:16:22,110 --> 00:16:25,170 Over the years, Mohan has collected many fossils 327 00:16:25,170 --> 00:16:28,560 from this period, especially Trilobites. 328 00:16:28,560 --> 00:16:32,269 It is my Devonian stuff I collect long time ago. 329 00:16:32,269 --> 00:16:33,360 (person laughing) 330 00:16:33,360 --> 00:16:35,760 So this is 20 years of collecting or how much? 331 00:16:36,965 --> 00:16:38,214 More, yes. 332 00:16:38,214 --> 00:16:41,400 The Trilobites in the Devonian in particular, 333 00:16:41,400 --> 00:16:43,530 show an incredible diversity. 334 00:16:43,530 --> 00:16:45,330 There are some that have huge eyes 335 00:16:45,330 --> 00:16:47,700 with many complex facets on them. 336 00:16:47,700 --> 00:16:49,890 They can basically see everything. 337 00:16:49,890 --> 00:16:52,260 Some even have appendages on their heads 338 00:16:52,260 --> 00:16:54,510 so that they can swim through open water. 339 00:16:54,510 --> 00:16:56,503 There is really everything you can imagine, 340 00:16:56,503 --> 00:17:00,240 a biodiversity that we have never seen before, 341 00:17:00,240 --> 00:17:03,963 and probably the greatest variety of trilobite species ever. 342 00:17:06,810 --> 00:17:10,140 But other animal groups also evolved rapidly 343 00:17:10,140 --> 00:17:12,963 during the Devonian to become more dominant. 344 00:17:14,400 --> 00:17:16,860 You could call it the age of the fish. 345 00:17:16,860 --> 00:17:20,310 These had an exoskeleton that consisted of a certain number 346 00:17:20,310 --> 00:17:22,713 of plates, and so did the chewing tools. 347 00:17:24,270 --> 00:17:25,875 Dunkleosteus 348 00:17:25,875 --> 00:17:28,770 was one of the largest of these armored fish. 349 00:17:28,770 --> 00:17:31,050 It was a colossal sea creature 350 00:17:31,050 --> 00:17:34,080 that may have reached 26 feet in length 351 00:17:34,080 --> 00:17:35,550 while ruling the oceans 352 00:17:35,550 --> 00:17:38,103 and devouring everything in its path. 353 00:17:39,720 --> 00:17:41,550 Dunkleosteus had a huge pair 354 00:17:41,550 --> 00:17:43,500 of crushing shears at the front, 355 00:17:43,500 --> 00:17:45,840 which it could consistently resharpen. 356 00:17:45,840 --> 00:17:47,940 They simply crushed on top of each other. 357 00:17:47,940 --> 00:17:51,444 It cut through everything that got in its way. 358 00:17:51,444 --> 00:17:53,850 (water whooshing) 359 00:17:53,850 --> 00:17:56,880 As the oceans grew busier during the Devonian, 360 00:17:56,880 --> 00:17:58,560 some creatures began looking 361 00:17:58,560 --> 00:18:01,533 for alternative, less crowded environments. 362 00:18:02,790 --> 00:18:05,337 A fish known as Tiktaalik 363 00:18:05,337 --> 00:18:08,223 attempted a revolutionary strategy. 364 00:18:09,240 --> 00:18:13,440 It tried to transition out of the water, onto land. 365 00:18:16,950 --> 00:18:18,930 For a vertebrate, life in the water 366 00:18:18,930 --> 00:18:21,450 cannot be compared with life on land. 367 00:18:21,450 --> 00:18:23,220 If you make a swimming movement, 368 00:18:23,220 --> 00:18:24,960 you can have wobbly fins, 369 00:18:24,960 --> 00:18:27,750 but on land, it's a completely different situation. 370 00:18:27,750 --> 00:18:30,900 You need a rigid frame so that you can move around. 371 00:18:30,900 --> 00:18:32,970 That's exactly what Tiktaalik had. 372 00:18:32,970 --> 00:18:35,550 It had fingers, it had arm bones. 373 00:18:35,550 --> 00:18:38,790 It had an internal skeleton, a spine that allowed it 374 00:18:38,790 --> 00:18:42,027 to use its four legs to move around perfectly. 375 00:18:42,027 --> 00:18:46,620 (speaking in foreign language) 376 00:18:46,620 --> 00:18:47,520 Tiktaalik was challenged 377 00:18:47,520 --> 00:18:50,190 to develop the ability to breathe air, 378 00:18:50,190 --> 00:18:53,160 but was successful becoming the first vertebra 379 00:18:53,160 --> 00:18:54,870 to conquer land. 380 00:18:54,870 --> 00:18:56,100 But just as animals 381 00:18:56,100 --> 00:18:58,650 and plants were gaining a foothold on land, 382 00:18:58,650 --> 00:19:01,463 a new threat emerged once again. 383 00:19:01,463 --> 00:19:04,080 (tense music) 384 00:19:04,080 --> 00:19:05,373 Effenberg, Germany. 385 00:19:07,530 --> 00:19:10,260 Geology professor David De Vleeschouwer 386 00:19:10,260 --> 00:19:13,440 and a team of students are searching a quarry 387 00:19:13,440 --> 00:19:15,783 for clues about the fateful events 388 00:19:15,783 --> 00:19:18,813 that took shape at the end of the Devonian. 389 00:19:20,451 --> 00:19:22,807 (gentle music) 390 00:19:22,807 --> 00:19:24,540 This is the wall that we're going to sample, 391 00:19:24,540 --> 00:19:25,770 today, as you can see, 392 00:19:25,770 --> 00:19:29,140 there are two very pronounced black shale layers 393 00:19:29,140 --> 00:19:31,320 that you can readily see. 394 00:19:31,320 --> 00:19:34,087 So when we find a black shale like this one 395 00:19:34,087 --> 00:19:35,490 in the geological record, it's a clear indication 396 00:19:35,490 --> 00:19:37,890 that we had low oxygen 397 00:19:37,890 --> 00:19:41,456 or even no oxygen condition in the sea water. 398 00:19:41,456 --> 00:19:44,520 And of course, that means that all the life 399 00:19:44,520 --> 00:19:47,940 that was living in the water column had a difficult time 400 00:19:47,940 --> 00:19:49,650 because all Devonian life, 401 00:19:49,650 --> 00:19:51,480 late Devonian life in the water column 402 00:19:51,480 --> 00:19:53,568 was dependent on oxygen. 403 00:19:53,568 --> 00:19:54,450 (gentle music) 404 00:19:54,450 --> 00:19:57,690 David and his team must collect rock samples 405 00:19:57,690 --> 00:20:02,160 to understand how the Devonian climate changed over time. 406 00:20:02,160 --> 00:20:05,883 They are time capsules of an ancient apocalypse. 407 00:20:07,093 --> 00:20:09,720 (gentle music) 408 00:20:09,720 --> 00:20:12,990 Back at the University of Münster in Germany, David 409 00:20:12,990 --> 00:20:17,990 and PhD student Nina Visan use a special x-ray device 410 00:20:18,090 --> 00:20:21,060 that allows them to analyze the rocks 411 00:20:21,060 --> 00:20:24,543 and draw conclusions about the prehistoric climate. 412 00:20:25,560 --> 00:20:29,490 So the sample we just analyzed came from a rock layer 413 00:20:29,490 --> 00:20:32,880 just below the black shale level. 414 00:20:32,880 --> 00:20:36,330 And what we've seen is very sharp transitions 415 00:20:36,330 --> 00:20:38,790 between humid phases and arid phases. 416 00:20:38,790 --> 00:20:42,270 So climate change was certainly going on 417 00:20:42,270 --> 00:20:45,570 and playing its role in the dynamics 418 00:20:45,570 --> 00:20:48,592 just prior to the anoxic event. 419 00:20:48,592 --> 00:20:50,850 (gentle music) 420 00:20:50,850 --> 00:20:52,080 David suspects 421 00:20:52,080 --> 00:20:55,500 that the alternating phases of wet and dry climates 422 00:20:55,500 --> 00:20:59,190 and the black layers of death follow a certain pattern, 423 00:20:59,190 --> 00:21:02,313 a rhythm that can be linked to a cosmic event. 424 00:21:04,380 --> 00:21:07,740 By the 17th century, scientists already realized 425 00:21:07,740 --> 00:21:09,480 that earth doesn't follow 426 00:21:09,480 --> 00:21:12,960 a perfectly stable orbit around the sun. 427 00:21:12,960 --> 00:21:16,577 And Serbian mathematician Milutin Milanković 428 00:21:16,577 --> 00:21:19,897 later calculated how the Earth's astronomical position 429 00:21:19,897 --> 00:21:23,880 relative to the sun changes over time, 430 00:21:23,880 --> 00:21:26,550 including the shape of its orbit. 431 00:21:26,550 --> 00:21:28,830 That's what we call eccentricity, 432 00:21:28,830 --> 00:21:30,423 and it's changing from a perfect circle 433 00:21:30,423 --> 00:21:33,360 towards a more elliptical form 434 00:21:33,360 --> 00:21:37,470 every 100,000 and every 400,000 years. 435 00:21:37,470 --> 00:21:39,660 This leads to fluctuations 436 00:21:39,660 --> 00:21:44,100 in how the sun's energy gets distributed on the planet, 437 00:21:44,100 --> 00:21:46,533 which in turn triggers climate changes. 438 00:21:46,533 --> 00:21:49,530 In addition, the elliptical orbit 439 00:21:49,530 --> 00:21:52,563 coincided with an evolutionary development. 440 00:21:54,690 --> 00:21:58,560 During the late Devonian vegetation on land flourished, 441 00:21:58,560 --> 00:22:02,580 and some trees grew to heights of more than 100 feet. 442 00:22:02,580 --> 00:22:06,240 Over time, ancient forest became established, 443 00:22:06,240 --> 00:22:07,770 transforming land 444 00:22:07,770 --> 00:22:11,520 that was once barren into a lush landscape. 445 00:22:11,520 --> 00:22:15,210 Our planet gradually emerged as the familiar green 446 00:22:15,210 --> 00:22:18,570 and blue earth we recognize today. 447 00:22:18,570 --> 00:22:22,230 So during the Devonian, land plants really evolved widely 448 00:22:22,230 --> 00:22:23,910 and developed deep root systems. 449 00:22:23,910 --> 00:22:25,260 And that is important 450 00:22:25,260 --> 00:22:28,320 because deep roots, they create a lot of area 451 00:22:28,320 --> 00:22:31,170 where weathering and erosion can take place, 452 00:22:31,170 --> 00:22:32,880 and a lot of weathering and erosion, 453 00:22:32,880 --> 00:22:34,920 that means that a lot of nutrients 454 00:22:34,920 --> 00:22:38,040 and detrital material can be transported, for example, 455 00:22:38,040 --> 00:22:41,400 by rivers from the continent towards the ocean, 456 00:22:41,400 --> 00:22:42,865 towards the seas. 457 00:22:42,865 --> 00:22:44,250 (tense music) 458 00:22:44,250 --> 00:22:46,080 At the same time, 459 00:22:46,080 --> 00:22:49,095 Earth's orbit was becoming more elliptical, 460 00:22:49,095 --> 00:22:51,753 which led to climate chaos. 461 00:22:53,550 --> 00:22:58,550 The combination triggered a catastrophic chain of events. 462 00:23:00,780 --> 00:23:03,750 And that is what we think is going on. 463 00:23:03,750 --> 00:23:07,440 An enhanced hydrological cycle, much stronger monsoons 464 00:23:07,440 --> 00:23:11,340 during those high eccentricity orbits, 465 00:23:11,340 --> 00:23:14,010 bringing those extreme precipitation events 466 00:23:14,010 --> 00:23:16,710 and flushing those nutrients towards the ocean, 467 00:23:16,710 --> 00:23:20,100 they're acting as food for everything 468 00:23:20,100 --> 00:23:22,017 that was alive in the water column. 469 00:23:22,017 --> 00:23:25,560 When that life decomposed, when it was sinking 470 00:23:25,560 --> 00:23:28,650 to the sea floor, it was consuming oxygen. 471 00:23:28,650 --> 00:23:31,440 Thereby the oxygen levels in the oceans 472 00:23:31,440 --> 00:23:35,310 were going down and suffocating life in the oceans. 473 00:23:35,310 --> 00:23:37,590 Ironically, it was the evolution 474 00:23:37,590 --> 00:23:38,850 of life on land 475 00:23:38,850 --> 00:23:43,230 that was responsible for the demise of life in the oceans. 476 00:23:43,230 --> 00:23:47,520 The astronomically forced climate change acted as a trigger, 477 00:23:47,520 --> 00:23:52,520 pushing the system past a tipping point and into chaos. 478 00:23:52,650 --> 00:23:56,266 Every animal in the intricate food web felt the impact 479 00:23:56,266 --> 00:24:00,930 as four extinction events took their toll. 480 00:24:00,930 --> 00:24:02,937 Ultimately, between 70 481 00:24:02,937 --> 00:24:06,586 and 80% of all Devonian species vanished. 482 00:24:06,586 --> 00:24:08,640 (gentle music) 483 00:24:08,640 --> 00:24:11,730 Yet life was not to be defeated. 484 00:24:11,730 --> 00:24:14,340 Despite the devastating mass extinctions 485 00:24:14,340 --> 00:24:17,970 during the Devonian, these catastrophic events 486 00:24:17,970 --> 00:24:20,973 paved the way for new species to emerge. 487 00:24:22,020 --> 00:24:24,713 It was the start of an evolutionary pathway 488 00:24:24,713 --> 00:24:29,190 that would one day forge the beginning of our own species. 489 00:24:29,190 --> 00:24:31,050 A pathway Philipe Havlik 490 00:24:31,050 --> 00:24:33,873 is especially interested in exploring. 491 00:24:34,710 --> 00:24:37,380 Around 360 million years ago 492 00:24:37,380 --> 00:24:39,060 in the Carboniferous period, 493 00:24:39,060 --> 00:24:41,610 life had really arrived on land. 494 00:24:41,610 --> 00:24:43,530 There were extensive swamp forests 495 00:24:43,530 --> 00:24:46,050 and everything was lush and green. 496 00:24:46,050 --> 00:24:49,080 And in the undergrowth, there was a lot of life, 497 00:24:49,080 --> 00:24:50,883 including huge insects. 498 00:24:52,277 --> 00:24:55,170 One of the most impressive 499 00:24:55,170 --> 00:24:58,230 is this little dragonfly I am holding here. 500 00:24:58,230 --> 00:25:02,190 Meganeura, an animal that had a wingspan of 20 inches, 501 00:25:02,190 --> 00:25:06,120 so it was at least five times the size of today's dragonfly. 502 00:25:06,120 --> 00:25:07,323 They really got big. 503 00:25:11,250 --> 00:25:13,980 But while insects became supersized 504 00:25:13,980 --> 00:25:17,460 and amphibians ruled the ancient swamps, a new group 505 00:25:17,460 --> 00:25:20,690 of animals would make the most important evolutionary jump 506 00:25:20,690 --> 00:25:22,473 during this era. 507 00:25:23,723 --> 00:25:26,040 In the Carboniferous period, 508 00:25:26,040 --> 00:25:27,930 vertebrates had already conquered 509 00:25:27,930 --> 00:25:30,900 the entire coastal areas of the continent. 510 00:25:30,900 --> 00:25:33,660 However, a very important step was still missing 511 00:25:33,660 --> 00:25:36,337 in order to venture deeper onto land. 512 00:25:36,337 --> 00:25:38,640 (speaking in foreign language) 513 00:25:38,640 --> 00:25:41,460 Reptiles would make this leap. 514 00:25:41,460 --> 00:25:44,100 For the first time in the history of life, 515 00:25:44,100 --> 00:25:48,540 creatures would be able to fully live away from water. 516 00:25:48,540 --> 00:25:49,373 But how? 517 00:25:50,777 --> 00:25:54,480 The solution was as ingenious as it was simple, 518 00:25:54,480 --> 00:25:56,796 the vertebrates simply took the ocean with them. 519 00:25:56,796 --> 00:25:59,190 They packed it into a small bowl, 520 00:25:59,190 --> 00:26:02,550 and were able to put it down anywhere on the continent. 521 00:26:02,550 --> 00:26:06,180 We still recognize the shell and the small ocean today, 522 00:26:06,180 --> 00:26:08,959 it is the egg, the amniotic egg. 523 00:26:08,959 --> 00:26:10,335 (gentle music) 524 00:26:10,335 --> 00:26:11,587 (object banging) 525 00:26:11,587 --> 00:26:12,600 A key property of reptile eggs 526 00:26:12,600 --> 00:26:14,490 is an amniotic membrane. 527 00:26:14,490 --> 00:26:15,870 It's a protective envelope 528 00:26:15,870 --> 00:26:19,440 that surrounds the growing life from external influences. 529 00:26:19,440 --> 00:26:21,510 But another substance inside the egg 530 00:26:21,510 --> 00:26:25,134 is also critical to this evolutionary step. 531 00:26:25,134 --> 00:26:26,400 (speaking in foreign language) 532 00:26:26,400 --> 00:26:28,850 What's inside the egg is the ocean, 533 00:26:28,850 --> 00:26:30,750 what we call egg white. 534 00:26:30,750 --> 00:26:34,200 This transparent liquid enables the developing life 535 00:26:34,200 --> 00:26:36,350 to swim around in a small sea. 536 00:26:36,350 --> 00:26:39,256 Not only does this ocean contain the embryo, 537 00:26:39,256 --> 00:26:42,060 which is somewhere in the slippery stuff here, 538 00:26:42,060 --> 00:26:45,420 it also contains huge food storage. 539 00:26:45,420 --> 00:26:48,480 The egg yolk must be enough to feed the little one 540 00:26:48,480 --> 00:26:52,800 until it is big enough to go ashore, survive on its own, 541 00:26:52,800 --> 00:26:56,316 crack the shell, and start its own life. 542 00:26:56,316 --> 00:27:00,233 (speaking in foreign language) 543 00:27:05,182 --> 00:27:06,180 This key innovation 544 00:27:06,180 --> 00:27:08,755 represented a major transition in evolution, 545 00:27:08,755 --> 00:27:13,473 and because of it, reptiles were ready to conquer land. 546 00:27:15,240 --> 00:27:18,827 The continents aligned to form a new super continent 547 00:27:18,827 --> 00:27:23,133 known as Pangaea at the end of the Carboniferous period. 548 00:27:23,133 --> 00:27:25,633 (tense music) 549 00:27:26,910 --> 00:27:29,682 This heralded the beginning of the Permian 550 00:27:29,682 --> 00:27:32,457 299 million years ago, 551 00:27:32,457 --> 00:27:36,423 and would be the final chapter in the Paleozoic era. 552 00:27:38,318 --> 00:27:41,340 South Africa, 553 00:27:41,340 --> 00:27:44,400 the Karoo Basin is one of the best places in the world 554 00:27:44,400 --> 00:27:47,580 to search for remnants of the Permian Period. 555 00:27:47,580 --> 00:27:50,490 Paleontologist Professor Roger Smith 556 00:27:50,490 --> 00:27:52,230 is trying to piece together 557 00:27:52,230 --> 00:27:54,777 the evolution of terrestrial ecosystems 558 00:27:54,777 --> 00:27:58,980 by searching for fossils that illustrate changes. 559 00:27:58,980 --> 00:28:03,450 This level is at about 253 million years ago, 560 00:28:03,450 --> 00:28:06,030 you would've been standing on a vast flat, 561 00:28:06,030 --> 00:28:08,040 featureless alluvial plane, 562 00:28:08,040 --> 00:28:09,450 but way off in the distance 563 00:28:09,450 --> 00:28:11,670 you would've seen a mountain range. 564 00:28:11,670 --> 00:28:13,860 The Gondwanan mountains. 565 00:28:13,860 --> 00:28:15,990 The mountains were formed when the continent 566 00:28:15,990 --> 00:28:18,180 of Gondwana came together. 567 00:28:18,180 --> 00:28:19,883 Huge peaks were pushed up 568 00:28:19,883 --> 00:28:22,410 as the continental plates converged 569 00:28:22,410 --> 00:28:24,780 into a gigantic landmass. 570 00:28:24,780 --> 00:28:26,190 Millions of years later, 571 00:28:26,190 --> 00:28:29,910 when Gondwana began to break up into smaller continents, 572 00:28:29,910 --> 00:28:32,850 it created a huge rift valley. 573 00:28:32,850 --> 00:28:35,880 The rift widened and deepened over time, 574 00:28:35,880 --> 00:28:37,950 filling with sediments washed down 575 00:28:37,950 --> 00:28:39,840 from the surrounding mountains. 576 00:28:39,840 --> 00:28:43,443 What is left today is known as the Karoo Basin. 577 00:28:46,740 --> 00:28:50,640 In the late 1960s, near the town of Fraserburgh, 578 00:28:50,640 --> 00:28:53,529 an incredible fossil site was discovered by accident. 579 00:28:53,529 --> 00:28:58,529 It reveals a rare peak into the ancient past here. 580 00:28:59,070 --> 00:29:01,920 This is really an amazing paleo surface. 581 00:29:01,920 --> 00:29:05,520 It's a part of the ancient floodplain 582 00:29:05,520 --> 00:29:08,760 that has been captured and frozen in time. 583 00:29:08,760 --> 00:29:11,080 It's like a paleo Polaroid 584 00:29:11,080 --> 00:29:16,067 of the middle Permian period showing us everything 585 00:29:16,067 --> 00:29:18,809 that was happening on those ancient Karoo floodplains. 586 00:29:18,809 --> 00:29:22,440 Look at these ripples, they are just as fresh 587 00:29:22,440 --> 00:29:26,673 and as sharp as if they were made just the other day. 588 00:29:28,170 --> 00:29:30,510 And there's the other right hand there. 589 00:29:30,510 --> 00:29:34,350 So it would've been a movement like this, 590 00:29:34,350 --> 00:29:36,793 rotate this, rotate this, 591 00:29:36,793 --> 00:29:38,523 rotate this. 592 00:29:39,861 --> 00:29:40,740 (gentle music) 593 00:29:40,740 --> 00:29:43,293 The footprints may have been left by, 594 00:29:43,293 --> 00:29:47,190 an herbivore that weighed as much as two tons 595 00:29:47,190 --> 00:29:49,900 and reached 15 feet in length. 596 00:29:49,900 --> 00:29:54,600 This species belongs to the Therapsids, a group of animals 597 00:29:54,600 --> 00:29:58,293 that represents a crucial step in the evolution of mammals. 598 00:30:00,030 --> 00:30:03,240 While not fully erect, Therapsids already had 599 00:30:03,240 --> 00:30:08,070 a more upright posture and other mammal like features. 600 00:30:08,070 --> 00:30:09,690 There was an abundance 601 00:30:09,690 --> 00:30:13,169 of food in this area 260 million years ago 602 00:30:13,169 --> 00:30:16,860 and life thrived in the warm climate. 603 00:30:16,860 --> 00:30:19,080 Vegetation along the river banks 604 00:30:19,080 --> 00:30:22,290 fed the fast herds of grazing herbivores, 605 00:30:22,290 --> 00:30:24,453 which were dominated by moscops, 606 00:30:25,487 --> 00:30:29,490 but there were carnivorous Therapsids too. 607 00:30:29,490 --> 00:30:32,250 Towards the end of the Permian, a new type 608 00:30:32,250 --> 00:30:36,270 of predatory evolved, the gorgonopsians. 609 00:30:36,270 --> 00:30:39,330 They were large beasts with powerful jaws 610 00:30:39,330 --> 00:30:41,820 and distinct saber like teeth. 611 00:30:41,820 --> 00:30:46,140 The masses of herbivores were the perfect prey for them. 612 00:30:46,140 --> 00:30:48,367 This is a gorgonopsian. 613 00:30:48,367 --> 00:30:50,340 It's is a carnivore, clearly 614 00:30:50,340 --> 00:30:55,340 because of its sharp saber like tusk or canine. 615 00:30:56,400 --> 00:30:59,523 And these intermission sharp incisors. 616 00:31:01,417 --> 00:31:03,990 With predatory carnivores 617 00:31:03,990 --> 00:31:06,540 and a vast array of potential prey, 618 00:31:06,540 --> 00:31:09,510 a dynamic and diverse food chain thrived here 619 00:31:09,510 --> 00:31:11,387 for millions of years. 620 00:31:11,387 --> 00:31:14,220 (animal growling) 621 00:31:16,320 --> 00:31:20,700 But the Karoo Basin also reveals that something changed 622 00:31:20,700 --> 00:31:23,523 around 252 million years ago. 623 00:31:25,170 --> 00:31:29,360 A dramatic shift that can clearly be seen in the rocks. 624 00:31:29,360 --> 00:31:31,350 (gentle music) 625 00:31:31,350 --> 00:31:34,530 We're now up at this dramatic color change, 626 00:31:34,530 --> 00:31:36,510 which I could see from a distance. 627 00:31:36,510 --> 00:31:41,310 And you can now see that this blue, gray, 628 00:31:41,310 --> 00:31:43,567 wet floodplain mud rocks here 629 00:31:43,567 --> 00:31:46,880 have rapidly transitioned, rapidly at this point here 630 00:31:46,880 --> 00:31:51,880 into something very red, very semi arid if you like. 631 00:31:53,550 --> 00:31:56,010 And the most likely cause of that drying out 632 00:31:56,010 --> 00:32:00,240 is climate change, rapid climate change, 633 00:32:00,240 --> 00:32:04,110 and the effect that that rapid climate change had 634 00:32:04,110 --> 00:32:07,530 on the environment and then on the animals 635 00:32:07,530 --> 00:32:10,410 and plants is quite dramatic. 636 00:32:10,410 --> 00:32:12,780 We can see that it's abrupt. 637 00:32:12,780 --> 00:32:17,640 It's very fast, and it could be as little as 10,000 years 638 00:32:17,640 --> 00:32:19,680 or up to 100,000 years, 639 00:32:19,680 --> 00:32:21,543 but it's in that timeframe. 640 00:32:22,380 --> 00:32:23,790 The change in color 641 00:32:23,790 --> 00:32:26,220 not only marks a change in climate, 642 00:32:26,220 --> 00:32:29,373 it also marks a change in the amount of fossils. 643 00:32:30,930 --> 00:32:35,930 It's simple, below this line, there are abundant fossils 644 00:32:36,030 --> 00:32:38,700 and above it, almost none. 645 00:32:38,700 --> 00:32:41,010 This only mean one thing. 646 00:32:41,010 --> 00:32:44,760 The change in climate led to a mass extinction. 647 00:32:44,760 --> 00:32:48,360 The effect of that rapid climate change 648 00:32:48,360 --> 00:32:51,210 on the animals and plants was dramatic. 649 00:32:51,210 --> 00:32:53,910 So dramatic that 95% 650 00:32:53,910 --> 00:32:56,493 of species worldwide went extinct. 651 00:32:56,493 --> 00:33:01,493 The worst mass extinction that has been recorded on earth. 652 00:33:01,710 --> 00:33:04,440 The once lush Permian environment 653 00:33:04,440 --> 00:33:06,194 suddenly dried up. 654 00:33:06,194 --> 00:33:10,230 Something drastic happened that caused the extinction 655 00:33:10,230 --> 00:33:12,870 of most species on our planet. 656 00:33:12,870 --> 00:33:17,073 An event that became known as the Great Dying. 657 00:33:17,073 --> 00:33:19,233 (animal growling) 658 00:33:19,233 --> 00:33:21,270 (tense music) 659 00:33:21,270 --> 00:33:24,900 Iceland, the land of fire and ice 660 00:33:24,900 --> 00:33:27,510 offers scientists a firsthand glimpse 661 00:33:27,510 --> 00:33:31,950 of the tremendous forces our planet can unleash. 662 00:33:31,950 --> 00:33:34,170 In the barren landscape of Laki, 663 00:33:34,170 --> 00:33:37,380 geologist Colin Devey hopes to uncover remnants 664 00:33:37,380 --> 00:33:39,870 of a historic volcanic event. 665 00:33:39,870 --> 00:33:41,940 The great dying at the end of the Permian 666 00:33:41,940 --> 00:33:45,930 coincided with a huge volcanic eruption. 667 00:33:45,930 --> 00:33:48,930 And to get an idea of what might have happened then, 668 00:33:48,930 --> 00:33:52,923 I've come here to Laki on Iceland, where in 1783, 669 00:33:53,820 --> 00:33:56,070 a massive eruption covered the land here 670 00:33:56,070 --> 00:33:58,560 with lava affecting the local population, 671 00:33:58,560 --> 00:34:00,603 but actually affecting half the globe. 672 00:34:01,530 --> 00:34:03,030 That's Mount Laki. 673 00:34:03,030 --> 00:34:04,230 And I'm gonna go to the top 674 00:34:04,230 --> 00:34:07,263 so I can get an overview of what this looks like. 675 00:34:07,263 --> 00:34:08,547 (gentle music) 676 00:34:08,547 --> 00:34:11,197 The event was called a fissure eruption. 677 00:34:12,120 --> 00:34:15,287 It occurs when an elongated linear crack 678 00:34:15,287 --> 00:34:19,170 opens on the earth's surface, which allows magma 679 00:34:19,170 --> 00:34:21,723 to rise and erupt. 680 00:34:24,480 --> 00:34:27,000 Look at that, it's amazing. 681 00:34:27,000 --> 00:34:29,799 It's a row of volcanoes. 682 00:34:29,799 --> 00:34:32,300 They disappear into the horizon. 683 00:34:32,300 --> 00:34:34,350 I mean, that's got to be 20, 30 kilometers long. 684 00:34:34,350 --> 00:34:38,883 The whole countrysides just covered in lava. 685 00:34:39,810 --> 00:34:42,903 I presume the lava's come out of these volcanoes. 686 00:34:47,100 --> 00:34:50,210 The eruption lasted eight months 687 00:34:50,210 --> 00:34:52,050 and is thought to be one 688 00:34:52,050 --> 00:34:55,593 of the largest volcanic events ever recorded. 689 00:34:58,830 --> 00:35:01,050 I'm standing here right on the crack. 690 00:35:01,050 --> 00:35:03,510 This is where the magma came out. 691 00:35:03,510 --> 00:35:05,310 When the eruption was taking place, 692 00:35:05,310 --> 00:35:07,500 you couldn't be anywhere in here 693 00:35:07,500 --> 00:35:09,030 'cause it's all full of magma. 694 00:35:09,030 --> 00:35:11,370 This was a magma channel. 695 00:35:11,370 --> 00:35:14,085 This one obviously produced a lot of magma, a lot of lava 696 00:35:14,085 --> 00:35:17,010 that got out of this crack 697 00:35:17,010 --> 00:35:18,510 and covered the landscape around 698 00:35:18,510 --> 00:35:20,510 what we saw from the top of the volcano. 699 00:35:23,820 --> 00:35:25,710 The amount of lava produced 700 00:35:25,710 --> 00:35:30,450 by the Laki fissure volcano in 1783 over the course 701 00:35:30,450 --> 00:35:33,363 of eight months is staggering. 702 00:35:35,670 --> 00:35:39,300 It produced 14 cubic kilometers of magma, 703 00:35:39,300 --> 00:35:42,330 which is impossible to imagine. 704 00:35:42,330 --> 00:35:44,670 But if you were to actually spread that out over the whole 705 00:35:44,670 --> 00:35:48,720 of the USA, you'd have about like the icing on a cake, 706 00:35:48,720 --> 00:35:51,720 1.4 millimeters of lava over the whole USA. 707 00:35:51,720 --> 00:35:52,593 It's a lot. 708 00:35:53,850 --> 00:35:55,320 But it's nothing 709 00:35:55,320 --> 00:35:58,873 compared to what took place at the end of the Permian. 710 00:35:58,873 --> 00:36:00,270 (fire whirring) 711 00:36:00,270 --> 00:36:02,250 252 million years ago, 712 00:36:02,250 --> 00:36:05,220 a massive volcanic event created one 713 00:36:05,220 --> 00:36:09,000 of the most extensive volcanic landscapes in the world, 714 00:36:09,000 --> 00:36:11,763 known as the Siberian Traps. 715 00:36:13,290 --> 00:36:16,140 This is minuscule compared to the Siberian Traps. 716 00:36:16,140 --> 00:36:18,480 This was 14 cubic kilometers. 717 00:36:18,480 --> 00:36:22,410 The Siberian Traps were four million cubic kilometers. 718 00:36:22,410 --> 00:36:24,450 So if you were to spread 719 00:36:24,450 --> 00:36:27,136 the Siberian Traps all over the USA, 720 00:36:27,136 --> 00:36:32,136 you'd not have 1.4 millimeters like you have with Laki. 721 00:36:32,370 --> 00:36:35,954 You'd have 400 meters of lava. 722 00:36:35,954 --> 00:36:38,043 It's a different beast altogether. 723 00:36:39,007 --> 00:36:40,920 (gentle music) 724 00:36:40,920 --> 00:36:42,660 Colin is looking closely 725 00:36:42,660 --> 00:36:44,910 at data from the Laki eruption 726 00:36:44,910 --> 00:36:48,210 to better understand the monumental impact 727 00:36:48,210 --> 00:36:49,773 of the ancient eruption. 728 00:36:52,590 --> 00:36:54,900 I found it really interesting, 729 00:36:54,900 --> 00:36:56,940 but also very important document 730 00:36:56,940 --> 00:36:59,070 on what happened here at Laki. 731 00:36:59,070 --> 00:37:01,110 Normally, we geologists 732 00:37:01,110 --> 00:37:03,390 get to situations like this after the event. 733 00:37:03,390 --> 00:37:05,970 We can look at the rocks when everything's happened 734 00:37:05,970 --> 00:37:08,522 and try and find out what happened. 735 00:37:08,522 --> 00:37:13,522 But here, the pastor in a church 50 kilometers away 736 00:37:14,520 --> 00:37:16,440 from here, so near enough to be influenced 737 00:37:16,440 --> 00:37:19,470 by the eruption, wrote down what happened. 738 00:37:19,470 --> 00:37:23,010 He describes how the lava advances down the valley 739 00:37:23,010 --> 00:37:25,553 towards his church, towards his congregation, 740 00:37:25,553 --> 00:37:28,890 destroying farms, destroying people's livelihoods 741 00:37:28,890 --> 00:37:30,090 and actually killing those people 742 00:37:30,090 --> 00:37:31,560 'cause they just died of hunger. 743 00:37:31,560 --> 00:37:32,763 They died of starvation. 744 00:37:34,200 --> 00:37:35,033 (fire whirring) 745 00:37:35,033 --> 00:37:39,060 In the summer of 1783, the Earth shook 746 00:37:39,060 --> 00:37:42,783 with fury when Mount Laki erupted in Iceland, 747 00:37:43,800 --> 00:37:46,650 a 15 mile long fissure tore open, 748 00:37:46,650 --> 00:37:49,173 spewing molten lava into the air. 749 00:37:50,070 --> 00:37:52,770 Villages were engulfed by the flows. 750 00:37:52,770 --> 00:37:54,496 People ran for their lives 751 00:37:54,496 --> 00:37:57,510 as their surroundings went up in flames 752 00:37:57,510 --> 00:38:00,033 and the sky turned blood red. 753 00:38:01,530 --> 00:38:05,730 The pastor also describes how both the animals 754 00:38:05,730 --> 00:38:08,100 and the people at that time, at the same time, 755 00:38:08,100 --> 00:38:09,660 started to develop 756 00:38:09,660 --> 00:38:12,873 what appeared to be strange diseases. 757 00:38:12,873 --> 00:38:16,230 The animals had deformed claws 758 00:38:16,230 --> 00:38:18,505 or very deformed teeth. 759 00:38:18,505 --> 00:38:21,680 The people also had lumps under their skin, also problems 760 00:38:21,680 --> 00:38:24,450 with their mouths and their teeth and were dying. 761 00:38:24,450 --> 00:38:27,000 The animals were dying and the people were dying as well. 762 00:38:27,000 --> 00:38:30,540 And of course, for people at that time, 763 00:38:30,540 --> 00:38:33,960 this was like a visitation from God. 764 00:38:33,960 --> 00:38:35,760 This was something they'd never before. 765 00:38:35,760 --> 00:38:38,523 This was the wrath of God is what they thought. 766 00:38:39,930 --> 00:38:43,410 I really don't think that's the correct explanation. 767 00:38:43,410 --> 00:38:46,260 I think it's to do with how volcanoes work. 768 00:38:46,260 --> 00:38:49,020 Colin Devey examines the volcanic rocks 769 00:38:49,020 --> 00:38:51,150 for clues about why both humans 770 00:38:51,150 --> 00:38:55,113 and animals succumb to this strange, mysterious disease. 771 00:38:56,370 --> 00:38:58,872 What I can read in the rocks is that they're full 772 00:38:58,872 --> 00:39:01,530 of bubbles, and that's probably the most important thing 773 00:39:01,530 --> 00:39:05,430 'cause it says that these were very gas rich lavas. 774 00:39:05,430 --> 00:39:08,220 Obviously, the gas is no longer in these bubbles now, 775 00:39:08,220 --> 00:39:09,810 but people have been able to analyze 776 00:39:09,810 --> 00:39:12,150 what gases came out of there. 777 00:39:12,150 --> 00:39:14,130 Along with carbon dioxide, 778 00:39:14,130 --> 00:39:16,743 traces of two other gases were found. 779 00:39:18,180 --> 00:39:22,242 The first one was fluorine, it's a poison. 780 00:39:22,242 --> 00:39:25,530 And the symptoms of fluorine poison are exactly the things 781 00:39:25,530 --> 00:39:26,700 that the pastor wrote about. 782 00:39:26,700 --> 00:39:30,690 That's what caused those deformities of animals and humans. 783 00:39:30,690 --> 00:39:34,650 The second gas was sulfur, 784 00:39:34,650 --> 00:39:36,690 sulfur dioxide. 785 00:39:36,690 --> 00:39:40,560 Now, sulfur dioxide spread around half the globe 786 00:39:40,560 --> 00:39:44,460 and caused in Europe, for example, a year without summer. 787 00:39:44,460 --> 00:39:47,277 Now it does that because sulfur dioxide in the atmosphere 788 00:39:47,277 --> 00:39:50,250 connects to water, makes tiny, tiny droplets 789 00:39:50,250 --> 00:39:52,650 of sulfuric acid, which block the sunlight. 790 00:39:52,650 --> 00:39:55,320 So they reduce the temperature of the earth, 791 00:39:55,320 --> 00:39:59,100 a year without summer, the plants don't grow as well. 792 00:39:59,100 --> 00:40:01,173 Harvests fail, people starve. 793 00:40:02,400 --> 00:40:04,860 These gases were also emitted 794 00:40:04,860 --> 00:40:06,660 at the end of the Permian, 795 00:40:06,660 --> 00:40:09,480 but on a completely different scale. 796 00:40:09,480 --> 00:40:10,650 (gentle music) 797 00:40:10,650 --> 00:40:13,830 Now imagine that happening over a million years, 798 00:40:13,830 --> 00:40:14,970 over and over again. 799 00:40:14,970 --> 00:40:17,190 We know the Siberian Traps are a great big pile 800 00:40:17,190 --> 00:40:18,300 of huge lava flows. 801 00:40:18,300 --> 00:40:21,171 So maybe every 100 years, 1000 years, 802 00:40:21,171 --> 00:40:26,171 the world was faced with a global catastrophe of cooling, 803 00:40:26,610 --> 00:40:27,993 of no sunlight. 804 00:40:29,773 --> 00:40:31,035 (gentle music) 805 00:40:31,035 --> 00:40:32,285 Because of the simultaneous emission of CO2, 806 00:40:32,285 --> 00:40:36,930 a warm greenhouse climate was repeatedly established 807 00:40:36,930 --> 00:40:40,680 before it would give way to the next cold phase. 808 00:40:40,680 --> 00:40:43,170 And you've just got adapted to that. 809 00:40:43,170 --> 00:40:45,270 And then the world turns into a balmy paradise. 810 00:40:45,270 --> 00:40:47,220 I mean, how do you make that U-turn? 811 00:40:47,220 --> 00:40:48,930 It's like riding a rollercoaster. 812 00:40:48,930 --> 00:40:50,400 You're on the steep hill 813 00:40:50,400 --> 00:40:51,900 and all of a sudden you're going up the other side 814 00:40:51,900 --> 00:40:54,750 in terms of climate and your environment. 815 00:40:54,750 --> 00:40:59,100 And that's probably, it's probably like a heavyweight boxer. 816 00:40:59,100 --> 00:41:02,430 You know, the sulfur dioxide kind of pummeled you 817 00:41:02,430 --> 00:41:05,103 and then the carbon dioxide took your chin off. 818 00:41:06,330 --> 00:41:08,220 This could be one explanation 819 00:41:08,220 --> 00:41:11,340 for the global mass extinction on land. 820 00:41:11,340 --> 00:41:13,217 But the great dying 821 00:41:13,217 --> 00:41:15,780 had an even greater impact on marine life. 822 00:41:15,780 --> 00:41:19,297 So, were the volcanic eruptions truly responsible 823 00:41:19,297 --> 00:41:21,093 for the catastrophe? 824 00:41:22,860 --> 00:41:24,750 Kiel, Germany, 825 00:41:24,750 --> 00:41:28,020 at the GEOMAR Helmholtz Center for Ocean Research, 826 00:41:28,020 --> 00:41:30,577 geochemist, Dr Hana Jurikova 827 00:41:30,577 --> 00:41:33,270 takes a close look at certain marine animals 828 00:41:33,270 --> 00:41:36,933 for clues about what led to the disaster. 829 00:41:40,128 --> 00:41:41,437 So what we have here are Brachiopods. 830 00:41:41,437 --> 00:41:43,710 These are really unique animals 831 00:41:43,710 --> 00:41:46,410 that have been around on earth for more than 500 million 832 00:41:46,410 --> 00:41:48,510 of year since the beginning of Cambrian. 833 00:41:48,510 --> 00:41:50,510 And they have changed very little since. 834 00:41:52,050 --> 00:41:54,780 By analyzing the Brachiopods, 835 00:41:54,780 --> 00:41:56,490 Hana hopes to find out 836 00:41:56,490 --> 00:42:01,173 how the worst mass extinction in Earth's history unfolded. 837 00:42:04,050 --> 00:42:06,960 So these fossils that we have here were deposited 838 00:42:06,960 --> 00:42:11,550 at the bottom of the TEUs Ocean 252 million of years ago. 839 00:42:11,550 --> 00:42:15,540 And what is really important is that some of them deposited 840 00:42:15,540 --> 00:42:18,000 before the Permiandransic mass extinction, 841 00:42:18,000 --> 00:42:21,033 and some of them like this one right after. 842 00:42:22,140 --> 00:42:23,370 The fossil remains 843 00:42:23,370 --> 00:42:26,820 of organisms like Brachiopod contain clues 844 00:42:26,820 --> 00:42:29,733 about what happened on earth in the past. 845 00:42:31,230 --> 00:42:34,500 By comparing the chemical composition of Brachiopod shells 846 00:42:34,500 --> 00:42:36,507 that lived before the mass extinction 847 00:42:36,507 --> 00:42:39,600 and after the mass extinction, I hope to find out 848 00:42:39,600 --> 00:42:41,133 what caused a great dying. 849 00:42:42,750 --> 00:42:45,150 The Brachiopod record a history 850 00:42:45,150 --> 00:42:47,943 of the ocean's acidity in their shells, 851 00:42:48,900 --> 00:42:53,550 and the analysis reveals that it increased significantly 852 00:42:53,550 --> 00:42:58,500 at the end of the Permian, Hana can determine 853 00:42:58,500 --> 00:43:01,470 historic acidification in an experiment 854 00:43:01,470 --> 00:43:06,470 with living brachial pots, by measuring the pH levels. 855 00:43:06,503 --> 00:43:09,690 (water bubbling) 856 00:43:09,690 --> 00:43:12,344 Now I know that the ocean pH in the late Permian Ocean 857 00:43:12,344 --> 00:43:14,640 was around eight. 858 00:43:14,640 --> 00:43:18,180 In fact, very similar to what we have in the oceans today. 859 00:43:18,180 --> 00:43:19,860 Right after the mass extinction, 860 00:43:19,860 --> 00:43:21,803 the oceans have become very acidic 861 00:43:21,803 --> 00:43:24,860 and the pH have dropped values of 7.5. 862 00:43:25,740 --> 00:43:28,080 This has happened in a very short time, 863 00:43:28,080 --> 00:43:30,270 only maybe 10,000s of years. 864 00:43:30,270 --> 00:43:32,579 This is just a habit in the geological time. 865 00:43:32,579 --> 00:43:36,360 It's way too fast for any organisms to really adapt to it. 866 00:43:36,360 --> 00:43:39,373 This was way too swift, this was a death sentence. 867 00:43:39,373 --> 00:43:42,600 Acid has dire consequences for animals 868 00:43:42,600 --> 00:43:45,420 that build calcium carbonate shells. 869 00:43:45,420 --> 00:43:49,380 Many organisms living in the late Permian Ocean 870 00:43:49,380 --> 00:43:51,270 build calcium carbonate shells 871 00:43:51,270 --> 00:43:53,430 just like this coral over here. 872 00:43:53,430 --> 00:43:55,393 When the ocean becomes way too acidic, 873 00:43:55,393 --> 00:43:58,890 they can no longer build their shells or skeletons. 874 00:43:58,890 --> 00:44:01,233 Let's see what happens if we put some acid 875 00:44:01,233 --> 00:44:02,973 on this coral here. 876 00:44:05,040 --> 00:44:06,180 Hana wants to show 877 00:44:06,180 --> 00:44:09,123 how acidic waters impact marine life. 878 00:44:10,350 --> 00:44:13,500 The experiment reveals the devastating effects 879 00:44:13,500 --> 00:44:15,900 of acidification on organisms 880 00:44:15,900 --> 00:44:18,543 that rely on calcium carbonate shells, 881 00:44:19,740 --> 00:44:21,873 the coral dissolves. 882 00:44:23,850 --> 00:44:27,470 Countless animals were doomed to die in the acidic oceans 883 00:44:27,470 --> 00:44:28,833 of the late Permian. 884 00:44:29,997 --> 00:44:31,170 (tense music) 885 00:44:31,170 --> 00:44:33,510 Food chains began to collapse 886 00:44:33,510 --> 00:44:37,380 and one species after another died out. 887 00:44:37,380 --> 00:44:41,790 It was the last gasp for prehistoric life on earth 888 00:44:41,790 --> 00:44:44,824 and the deadliest time in our planet's history. 889 00:44:44,824 --> 00:44:48,873 But what caused this massive acidification? 890 00:44:49,830 --> 00:44:51,960 Increased levels of CO2 891 00:44:51,960 --> 00:44:55,920 in the atmosphere would certainly acidify the oceans. 892 00:44:55,920 --> 00:44:57,930 But was the CO2 released 893 00:44:57,930 --> 00:45:00,933 by the Siberian Traps significant enough? 894 00:45:02,250 --> 00:45:03,870 From research we know today 895 00:45:03,870 --> 00:45:07,500 that the Siberian Traps released more than 387 billion 896 00:45:07,500 --> 00:45:09,570 of tons CO2 to the atmosphere. 897 00:45:09,570 --> 00:45:10,710 For comparison, 898 00:45:10,710 --> 00:45:13,740 this is more than 40 times the amount of carbon 899 00:45:13,740 --> 00:45:16,953 if we were to fire up all the fossil fuels on earth today. 900 00:45:18,450 --> 00:45:22,230 Despite the huge amount of CO2, Hana knows 901 00:45:22,230 --> 00:45:24,110 that it wouldn't have been enough. 902 00:45:24,110 --> 00:45:26,673 Something else must have happened. 903 00:45:27,570 --> 00:45:30,480 Although this was unbelievably extreme, I do not think 904 00:45:30,480 --> 00:45:32,070 that the Siberian Traps were enough 905 00:45:32,070 --> 00:45:34,800 to acidify the oceans in such a short time. 906 00:45:34,800 --> 00:45:38,280 The huge amount of CO2 must have come from lava burning 907 00:45:38,280 --> 00:45:40,740 available fossil fuel reserves on Earth 908 00:45:40,740 --> 00:45:42,210 during that time, I think 909 00:45:42,210 --> 00:45:44,583 that the Lake Permian world was just burning. 910 00:45:45,510 --> 00:45:47,730 When ancient fuels ignite, 911 00:45:47,730 --> 00:45:50,108 they set off widespread wildfires 912 00:45:50,108 --> 00:45:53,853 that release even more carbon into the atmosphere. 913 00:45:54,900 --> 00:45:58,770 As the oceans acidified, the land burned. 914 00:45:58,770 --> 00:46:00,810 It was hell on earth. 915 00:46:00,810 --> 00:46:03,993 How could any life survive this inferno? 916 00:46:04,906 --> 00:46:06,030 (birds chirping) 917 00:46:06,030 --> 00:46:09,630 In South Africa, paleontologist Roger Smith 918 00:46:09,630 --> 00:46:12,507 is trying to answer this question. 919 00:46:12,507 --> 00:46:16,170 The famous South African fossil hunter James Kitching 920 00:46:16,170 --> 00:46:18,123 left notes about a Gorgonopsian 921 00:46:18,123 --> 00:46:21,407 that he found in a Triassic formation. 922 00:46:21,407 --> 00:46:24,240 The scientific community believes 923 00:46:24,240 --> 00:46:26,250 that this predatory species 924 00:46:26,250 --> 00:46:29,370 did not survive the Permian mass extinction. 925 00:46:29,370 --> 00:46:34,347 So finding one in Triassic soil would be incredible. 926 00:46:34,347 --> 00:46:35,730 (gentle music) 927 00:46:35,730 --> 00:46:37,873 Here we are on Fairydale, 928 00:46:37,873 --> 00:46:40,230 and this is that point on the map on James Kitching's map 929 00:46:40,230 --> 00:46:42,030 where he put the pencil mark 930 00:46:42,030 --> 00:46:45,240 and he had marked where the Gorgonopsian had come from. 931 00:46:45,240 --> 00:46:47,760 And that mark is just down over there, 932 00:46:47,760 --> 00:46:49,530 that's the position of it. 933 00:46:49,530 --> 00:46:54,420 So our job now is to see whether we can find another one. 934 00:46:54,420 --> 00:46:57,840 So students, this is a Gorgonopsian. 935 00:46:57,840 --> 00:47:00,780 This was the apex predator. 936 00:47:00,780 --> 00:47:04,173 And your mission today is to find more of this, so let's go. 937 00:47:05,423 --> 00:47:07,440 (gentle music) 938 00:47:07,440 --> 00:47:10,352 Dr. Julian Benoit from the University of 939 00:47:10,352 --> 00:47:13,770 has done the research. 940 00:47:13,770 --> 00:47:16,740 His students have scanned the entire area, 941 00:47:16,740 --> 00:47:18,900 marked by James Kitching, 942 00:47:18,900 --> 00:47:23,610 but didn't find anything resembling a Gorgonopsian fossil. 943 00:47:23,610 --> 00:47:27,573 Roger and Julian decide to examine the area themselves. 944 00:47:29,910 --> 00:47:31,470 So what's this, Roger? 945 00:47:31,470 --> 00:47:32,670 Yes, look at this. 946 00:47:32,670 --> 00:47:36,390 This is a sandstone tube going down 947 00:47:36,390 --> 00:47:38,100 into the floodplain mud drops. 948 00:47:38,100 --> 00:47:39,840 You can see the levels of the floodplain, 949 00:47:39,840 --> 00:47:42,510 and this is definitely cutting down through it. 950 00:47:42,510 --> 00:47:45,810 It used to be an open hole, so it must have been dug 951 00:47:45,810 --> 00:47:46,950 by an animal. 952 00:47:46,950 --> 00:47:51,360 And if that animal was digging holes here, 953 00:47:51,360 --> 00:47:54,780 it must have been a survivor of the mass extinction. 954 00:47:54,780 --> 00:47:57,123 So we need to find this animal. 955 00:47:58,320 --> 00:48:01,170 The team hasn't found anything yet, 956 00:48:01,170 --> 00:48:03,660 but they are certain that the fossil remains 957 00:48:03,660 --> 00:48:05,160 of the tunnel building animal 958 00:48:05,160 --> 00:48:08,809 in the Triassic formation will be found nearby. 959 00:48:08,809 --> 00:48:11,392 (gentle music) 960 00:48:15,630 --> 00:48:17,677 Look this bone over there, Roger, 961 00:48:20,937 --> 00:48:21,780 here, some bone there. 962 00:48:21,780 --> 00:48:22,860 Look at that. 963 00:48:22,860 --> 00:48:26,070 Yeah, something exposed right here. 964 00:48:26,070 --> 00:48:26,903 Okay. 965 00:48:27,813 --> 00:48:29,063 What is that? 966 00:48:29,063 --> 00:48:30,310 I think that is a skull. 967 00:48:30,310 --> 00:48:35,310 Yes, this is the right orbit or the right eyeball. 968 00:48:35,640 --> 00:48:38,070 And that's the top of the skull. 969 00:48:38,070 --> 00:48:40,110 And this must then be the snout. 970 00:48:40,110 --> 00:48:43,130 Yeah, it's the mouth coming in here. 971 00:48:43,130 --> 00:48:45,203 You know, I think this is Lystrosaurus 972 00:48:45,203 --> 00:48:50,203 and it could well have been the animal 973 00:48:50,370 --> 00:48:52,113 that dug that burrow. 974 00:48:52,113 --> 00:48:54,696 (upbeat music) 975 00:48:56,433 --> 00:48:58,770 Like other Dicynodons, Lystrosaurus 976 00:48:58,770 --> 00:49:03,060 only had two tusk like teeth, which had used for defense 977 00:49:03,060 --> 00:49:05,490 and to tear apart small predators. 978 00:49:05,490 --> 00:49:07,743 Even though it was a herbivore, 979 00:49:09,420 --> 00:49:12,470 it had a horny beak for snipping off parts of plants 980 00:49:12,470 --> 00:49:16,773 and was about the size of a powerfully built pig. 981 00:49:18,030 --> 00:49:19,800 Its shoulders and hip structures 982 00:49:19,800 --> 00:49:23,373 indicate that it moved with a semi crawling gate. 983 00:49:24,810 --> 00:49:28,530 Its front legs were even more robust than the hind ones, 984 00:49:28,530 --> 00:49:30,570 and were used to create burrows 985 00:49:30,570 --> 00:49:32,313 where it sheltered and nested. 986 00:49:35,580 --> 00:49:37,740 Roger decides to bring the fossil 987 00:49:37,740 --> 00:49:40,110 to the University of Cape Town. 988 00:49:40,110 --> 00:49:43,883 Here, Poaleo biologist, Professor Anusuya Chinsamy-Turan 989 00:49:43,883 --> 00:49:47,130 will look at it to see if there are clues 990 00:49:47,130 --> 00:49:50,820 as to how the animal survived the mass extinction. 991 00:49:50,820 --> 00:49:51,930 Hey, Anusuya. 992 00:49:51,930 --> 00:49:54,003 Roger, wow, what have you got this? 993 00:49:54,003 --> 00:49:56,352 Yes, so I've just been out in the field 994 00:49:56,352 --> 00:49:59,250 and collected this for you. 995 00:49:59,250 --> 00:50:02,040 I haven't actually looked underneath it yet. 996 00:50:02,040 --> 00:50:03,573 It's all there, and lower jaw. 997 00:50:04,813 --> 00:50:05,646 Wow, that's amazing. 998 00:50:05,646 --> 00:50:09,720 While Lystrosaurus lived in the Permian, 999 00:50:09,720 --> 00:50:13,320 this one clearly survived the Great Dying. 1000 00:50:13,320 --> 00:50:17,430 By taking thin slices of its bone, Anusuya is able 1001 00:50:17,430 --> 00:50:19,950 to learn more about the animal. 1002 00:50:19,950 --> 00:50:24,390 So when we look at the bones of the Triassic Lystrosaurus, 1003 00:50:24,390 --> 00:50:25,920 it clearly indicates 1004 00:50:25,920 --> 00:50:27,960 that they had a faster growth rate 1005 00:50:27,960 --> 00:50:29,820 than the Permian relatives. 1006 00:50:29,820 --> 00:50:32,460 And this is an important adaptive strategy 1007 00:50:32,460 --> 00:50:34,620 because it means that they would be able 1008 00:50:34,620 --> 00:50:38,250 to grow more quickly, reach adulthood quicker, 1009 00:50:38,250 --> 00:50:40,260 and be able to reproduce quickly. 1010 00:50:40,260 --> 00:50:44,850 And this is a very classic strategy for survivors 1011 00:50:44,850 --> 00:50:47,970 of such a catastrophic event. 1012 00:50:47,970 --> 00:50:49,710 But Professor Chinsamy-Turan 1013 00:50:49,710 --> 00:50:52,170 can determine more about this Lystrosaurus 1014 00:50:52,170 --> 00:50:54,330 from the makeup of its head. 1015 00:50:54,330 --> 00:50:57,150 So one of the very distinctive characteristics 1016 00:50:57,150 --> 00:50:58,958 of Lystrosaurus 1017 00:50:58,958 --> 00:51:01,510 as compared to any other Dicynodons is the fact 1018 00:51:02,613 --> 00:51:03,810 that it's snout turns downward. 1019 00:51:03,810 --> 00:51:05,640 So if you look at the skull here, 1020 00:51:05,640 --> 00:51:07,020 these would've been the orbits 1021 00:51:07,020 --> 00:51:09,540 and the snout actually turns down. 1022 00:51:09,540 --> 00:51:12,900 So compared to the other Dicynodons where the skull, 1023 00:51:12,900 --> 00:51:15,720 where the snout actually projects forward, 1024 00:51:15,720 --> 00:51:17,580 this immediately tells us 1025 00:51:17,580 --> 00:51:20,280 that they were eating different food substances. 1026 00:51:20,280 --> 00:51:23,040 The paleo biologist is certain 1027 00:51:23,040 --> 00:51:27,003 that diet played a key role in the Lystrosaurus survival. 1028 00:51:28,350 --> 00:51:30,930 When we think about the end of the Permian, we know 1029 00:51:30,930 --> 00:51:33,390 that it was a very tough time 1030 00:51:33,390 --> 00:51:35,700 for both the plants and the animals. 1031 00:51:35,700 --> 00:51:37,920 And during the drying out times, 1032 00:51:37,920 --> 00:51:41,940 only the really tough vegetation probably would've survived. 1033 00:51:41,940 --> 00:51:44,220 So if Lystrosaurus survived, 1034 00:51:44,220 --> 00:51:46,530 we think that it probably survived 1035 00:51:46,530 --> 00:51:49,521 because it was able to eat the tough vegetation 1036 00:51:49,521 --> 00:51:52,623 that may also have survived at the end of the Permian. 1037 00:51:54,390 --> 00:51:56,130 The ability to dig tunnels 1038 00:51:56,130 --> 00:51:58,340 for shelter from harsh climate shifts, 1039 00:51:58,340 --> 00:52:00,690 along with the capacity to feed 1040 00:52:00,690 --> 00:52:05,340 on the few things that remained were essential for survival. 1041 00:52:05,340 --> 00:52:08,730 Lystrosaurus is a prime example of how life 1042 00:52:08,730 --> 00:52:11,400 always seems to find a way. 1043 00:52:11,400 --> 00:52:14,463 Even in the face of the worst catastrophes. 1044 00:52:15,720 --> 00:52:17,760 Throughout the Paleozoic era, 1045 00:52:17,760 --> 00:52:20,109 many fascinating animals emerged 1046 00:52:20,109 --> 00:52:23,280 and the three major extinction events 1047 00:52:23,280 --> 00:52:25,800 wiped out most of them. 1048 00:52:25,800 --> 00:52:27,350 But even the great dying, 1049 00:52:27,350 --> 00:52:30,480 the worst extinction in Earth's history 1050 00:52:30,480 --> 00:52:32,859 couldn't destroy all life. 1051 00:52:32,859 --> 00:52:37,859 The emerging Mesozoic era would see the rise of the largest 1052 00:52:38,880 --> 00:52:41,670 and most fearsome of all land creatures 1053 00:52:41,670 --> 00:52:44,190 that ever roamed our planet. 1054 00:52:44,190 --> 00:52:48,330 The dinosaurs, each catastrophe 1055 00:52:48,330 --> 00:52:53,250 and its extinction event drove evolution forward 1056 00:52:53,250 --> 00:52:57,603 and ultimately led to the life we know today. 1057 00:52:58,480 --> 00:53:01,230 (dramatic music) 1058 00:53:29,484 --> 00:53:32,234 (dramatic music)