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These are the user uploaded subtitles that are being translated: 1 00:00:01,070 --> 00:00:03,244 Viewers like you make this program possible. 2 00:00:03,279 --> 00:00:05,315 Support your local PBS station. 3 00:00:15,705 --> 00:00:17,017 The Arctic Circle, 4 00:00:17,051 --> 00:00:19,605 Northern Alaska. 5 00:00:19,640 --> 00:00:24,990 In one of the most inhospitable places on Earth, 6 00:00:25,025 --> 00:00:26,819 scientists search for clues to a mystery 7 00:00:26,854 --> 00:00:31,134 70 million years in the making. 8 00:00:32,687 --> 00:00:37,520 They're on the hunt for a lost world of polar dinosaurs. 9 00:00:39,073 --> 00:00:40,454 This is not the paleontology 10 00:00:40,488 --> 00:00:42,180 you normally see in books. 11 00:00:42,214 --> 00:00:43,526 What we're learning about dinosaurs 12 00:00:43,560 --> 00:00:45,252 from these discoveries, 13 00:00:45,286 --> 00:00:48,186 it's just really unparalleled and unprecedented. 14 00:00:51,085 --> 00:00:53,191 Alaska is the last place on Earth 15 00:00:53,225 --> 00:00:58,817 one might expect to find large reptiles. 16 00:00:58,851 --> 00:01:04,029 But the discovery of fossils has revealed dinosaurs could live 17 00:01:04,064 --> 00:01:09,310 farther north than what was once thought possible. 18 00:01:12,624 --> 00:01:14,108 Oh, we got a sweet layer right here. 19 00:01:15,661 --> 00:01:18,354 Now this team hopes to 20 00:01:18,388 --> 00:01:21,805 answer some fundamental questions. 21 00:01:21,840 --> 00:01:23,255 What kind of animals lived here? 22 00:01:23,290 --> 00:01:28,122 How did they survive the Arctic winters? 23 00:01:28,157 --> 00:01:30,435 How were they able to endure the cold? 24 00:01:30,469 --> 00:01:31,884 How were they able to endure the darkness? 25 00:01:31,919 --> 00:01:33,748 Where do they get their food? 26 00:01:33,783 --> 00:01:35,750 If they were up here year-round, 27 00:01:35,785 --> 00:01:37,166 were they really warm-blooded animals? 28 00:01:38,443 --> 00:01:39,651 Their journey will take them 29 00:01:39,685 --> 00:01:44,759 from the frozen wilderness of Northern Alaska 30 00:01:44,794 --> 00:01:45,933 to the mountaintops 31 00:01:45,967 --> 00:01:48,004 of Denali National Park and Preserve 32 00:01:48,038 --> 00:01:49,005 to the south. 33 00:01:49,039 --> 00:01:51,145 If we can understand 34 00:01:51,180 --> 00:01:52,388 how they survived here, 35 00:01:52,422 --> 00:01:53,837 we might be able to understand 36 00:01:53,872 --> 00:01:57,324 why they dominated the planet for over 100 million years. 37 00:01:59,291 --> 00:02:01,259 A surprising story... 38 00:02:02,294 --> 00:02:06,022 of adaptation and survival... 39 00:02:07,057 --> 00:02:10,889 against the odds. 40 00:02:10,923 --> 00:02:12,477 "Alaskan Dinosaurs." 41 00:02:12,511 --> 00:02:15,169 Right now, on "NOVA." 42 00:02:32,324 --> 00:02:35,120 Late March, 43 00:02:35,155 --> 00:02:37,364 Alaska's North Slope. 44 00:02:37,398 --> 00:02:39,814 28 miles south of the Arctic Ocean, 45 00:02:39,849 --> 00:02:42,886 a team of paleontologists 46 00:02:42,921 --> 00:02:46,545 is on the final leg of a 600-mile journey 47 00:02:46,580 --> 00:02:50,549 from Fairbanks to one of the northernmost reaches 48 00:02:50,584 --> 00:02:52,793 of North America. 49 00:02:54,381 --> 00:02:56,866 They're part of a long-term 50 00:02:56,900 --> 00:03:01,215 joint research project studying polar dinosaurs. 51 00:03:01,250 --> 00:03:03,390 Their plan is to 52 00:03:03,424 --> 00:03:06,220 spend the next several days searching for dino bones. 53 00:03:06,255 --> 00:03:09,810 What makes these dinosaurs amazing is the fact that 54 00:03:09,844 --> 00:03:11,950 they lived in an extreme environment. 55 00:03:11,984 --> 00:03:13,400 This isn't the sort of thing 56 00:03:13,434 --> 00:03:15,988 we typically associate with dinosaurs. 57 00:03:16,023 --> 00:03:18,612 So the fact that they lived at these latitudes 58 00:03:18,646 --> 00:03:21,891 tells us a lot about what dinosaurs were capable of doing. 59 00:03:21,925 --> 00:03:23,824 It shows them at their extremes. 60 00:03:25,274 --> 00:03:27,310 Over the past 13 years, 61 00:03:27,345 --> 00:03:30,624 paleontologist Pat Druckenmiller has made 62 00:03:30,658 --> 00:03:32,764 11 expeditions to the North Slope 63 00:03:32,798 --> 00:03:36,768 in search of fossils. 64 00:03:36,802 --> 00:03:40,323 He's joined by paleobiologist Gregory Erickson, 65 00:03:40,358 --> 00:03:42,187 also a veteran of this field work. 66 00:03:46,191 --> 00:03:50,851 Alaska is really paleontology's last frontier. 67 00:03:54,303 --> 00:03:55,890 Dinosaurs were living in the coldest environment 68 00:03:55,925 --> 00:03:58,203 in the Cretaceous, and it's a mystery as to, 69 00:03:58,238 --> 00:03:59,446 you know, how they were making it up there. 70 00:03:59,480 --> 00:04:02,483 How did they survive? 71 00:04:04,105 --> 00:04:07,764 Here, temperatures drop to 50 below at night, 72 00:04:07,799 --> 00:04:11,043 with wind chills plunging even lower. 73 00:04:13,183 --> 00:04:15,151 But despite these challenges, 74 00:04:15,185 --> 00:04:18,741 this is the ideal time to go fossil hunting 75 00:04:18,775 --> 00:04:21,295 on the North Slope. 76 00:04:21,330 --> 00:04:23,021 The hillside we're trying to dig out 77 00:04:23,055 --> 00:04:25,126 likes to slump on us in the summer. 78 00:04:25,161 --> 00:04:27,094 But in the wintertime, it's frozen solid 79 00:04:27,128 --> 00:04:30,200 and we can safely excavate into the layer. 80 00:04:38,174 --> 00:04:40,176 Along with excavation equipment, 81 00:04:40,210 --> 00:04:42,765 they'll be carrying everything they need to survive, 82 00:04:42,799 --> 00:04:48,357 including 100 gallons of gasoline to run generators, 83 00:04:48,391 --> 00:04:53,154 one ton of wood for fire stoves, 84 00:04:53,189 --> 00:04:58,298 and enough food to last for over a week. 85 00:05:00,921 --> 00:05:04,165 It's been three days of travel just to reach this point, 86 00:05:04,200 --> 00:05:06,823 and we're not over yet, because we now have to travel 87 00:05:06,858 --> 00:05:10,793 about 30 miles by snow machine to get out to the Colville River 88 00:05:10,827 --> 00:05:11,966 and reach our actual dig site. 89 00:05:27,499 --> 00:05:29,605 The team is heading to a fossil site 90 00:05:29,639 --> 00:05:31,917 in the Prince Creek Formation 91 00:05:31,952 --> 00:05:35,818 on the North Slope of Alaska. 92 00:05:35,852 --> 00:05:39,546 Through this remote, awe-inspiring landscape 93 00:05:39,580 --> 00:05:43,308 winds the Colville River, flowing north from 94 00:05:43,343 --> 00:05:46,760 the slopes of the Brooks Range to the Beaufort Sea. 95 00:05:50,039 --> 00:05:52,524 Along the bank of the frozen river, 96 00:05:52,559 --> 00:05:57,149 steep cliffs rise 100 feet. 97 00:05:57,184 --> 00:06:00,705 This is where geologist Robert Liscomb 98 00:06:00,739 --> 00:06:02,465 came across mysterious bones 99 00:06:02,500 --> 00:06:04,778 while working for an oil company 100 00:06:04,812 --> 00:06:07,712 in 1961. 101 00:06:07,746 --> 00:06:09,679 Later identified as dinosaur bones, 102 00:06:09,714 --> 00:06:12,855 the find was a surprise. 103 00:06:12,889 --> 00:06:15,478 Dinos, thought to be cold-blooded, 104 00:06:15,513 --> 00:06:18,585 shouldn't be able to survive in the cold and dark. 105 00:06:18,619 --> 00:06:22,105 Polar dinosaurs weren't really on paleontologists' radar 106 00:06:22,140 --> 00:06:24,245 for most of the 20th century. 107 00:06:24,280 --> 00:06:25,419 When you had a picture of 108 00:06:25,454 --> 00:06:26,834 what a dinosaur was and where they lived, 109 00:06:26,869 --> 00:06:29,458 it was often thought to be an equatorial sort of creature, 110 00:06:29,492 --> 00:06:30,907 a creature of warm environments, 111 00:06:30,942 --> 00:06:34,290 of these swampy sort of lowland environments. 112 00:06:34,324 --> 00:06:36,741 Thinking of dinosaurs living in the polar north, 113 00:06:36,775 --> 00:06:38,743 that wasn't something that was even considered. 114 00:06:44,162 --> 00:06:46,820 The discovery of Alaskan dinosaurs 115 00:06:46,854 --> 00:06:49,685 astonishes the scientific community... 116 00:06:52,412 --> 00:06:54,310 and puts the Prince Creek Formation 117 00:06:54,344 --> 00:06:57,555 on the map for paleontologists. 118 00:07:01,490 --> 00:07:04,562 To find them in a place like this, 119 00:07:04,596 --> 00:07:07,496 where the environment is so dramatically different, 120 00:07:07,530 --> 00:07:10,775 it really does challenge what we thought about these animals. 121 00:07:10,809 --> 00:07:14,330 So far, scientists have identified 122 00:07:14,364 --> 00:07:19,887 over a dozen species, both large and small: 123 00:07:19,922 --> 00:07:24,202 herbivorous beasts such as Pachyrhinosaurus, 124 00:07:24,236 --> 00:07:28,033 a formidable horned ceratopsid; 125 00:07:28,068 --> 00:07:33,936 and Ugrunaaluk, a duck-billed dinosaur over 25 feet long; 126 00:07:33,970 --> 00:07:37,629 as well as predators like Nanuqsaurus, 127 00:07:37,664 --> 00:07:42,669 a fearsome tyrannosaur and close cousin to T. rex; 128 00:07:42,703 --> 00:07:46,224 and a troodontid, a lightly built horse-sized 129 00:07:46,258 --> 00:07:50,746 dinosaur with deadly slasher claws. 130 00:07:56,234 --> 00:07:57,856 The team finally arrives 131 00:07:57,891 --> 00:08:00,652 at base camp, half a mile from the dig site. 132 00:08:00,687 --> 00:08:05,485 It's getting dark and the temperature is dropping, 133 00:08:05,519 --> 00:08:09,350 now down to minus-four degrees Fahrenheit. 134 00:08:09,385 --> 00:08:11,283 The site that we're interested in 135 00:08:11,318 --> 00:08:13,493 is at that point over there. 136 00:08:13,527 --> 00:08:15,356 But some of our crew is getting cold, 137 00:08:15,391 --> 00:08:17,945 and so it's important to get our tents up and, 138 00:08:17,980 --> 00:08:20,500 you know, get our stoves going. 139 00:08:22,502 --> 00:08:24,538 Working on the North Slope in the late winter 140 00:08:24,573 --> 00:08:28,853 means the days are still short and cold. 141 00:08:28,887 --> 00:08:33,754 Scientists agree, 70 million years ago, 142 00:08:33,789 --> 00:08:36,550 the Earth was generally much warmer. 143 00:08:36,585 --> 00:08:39,829 The dinosaurs living here, however, 144 00:08:39,864 --> 00:08:43,108 would have faced the same inescapable reality. 145 00:08:45,697 --> 00:08:51,254 As the Earth orbits the sun, it rotates on a tilted axis. 146 00:08:51,289 --> 00:08:54,292 During summer in the Northern Hemisphere, 147 00:08:54,326 --> 00:08:57,398 the North Pole is angled toward the sun. 148 00:08:57,433 --> 00:08:59,297 Areas above the Arctic Circle 149 00:08:59,331 --> 00:09:03,750 receive 24 hours of sunlight. 150 00:09:03,784 --> 00:09:08,133 But when Earth arrives at the opposite side of its orbit, 151 00:09:08,168 --> 00:09:10,860 the pattern reverses, and the north is tilted 152 00:09:10,895 --> 00:09:13,311 away from the sun. 153 00:09:13,345 --> 00:09:15,313 Because during the Cretaceous, 154 00:09:15,347 --> 00:09:18,592 Alaska was even farther north than today, 155 00:09:18,627 --> 00:09:23,079 the North Slope experienced four months of total darkness. 156 00:09:24,805 --> 00:09:26,151 The best indications 157 00:09:26,186 --> 00:09:29,396 from all of the geological and fossil evidence 158 00:09:29,430 --> 00:09:32,192 is that during that darkest, coldest winter months, 159 00:09:32,226 --> 00:09:35,160 it would have gotten below freezing. 160 00:09:35,195 --> 00:09:38,854 It would have been much colder 161 00:09:38,888 --> 00:09:41,546 than almost anywhere else 162 00:09:41,581 --> 00:09:44,169 dinosaurs would have been living. 163 00:09:58,321 --> 00:10:00,496 Early the next morning, 164 00:10:00,530 --> 00:10:02,256 Pat and Greg visit the site 165 00:10:02,291 --> 00:10:06,502 where the first Alaskan dinosaurs were discovered: 166 00:10:06,536 --> 00:10:09,470 the Liscomb Bone Bed. 167 00:10:13,820 --> 00:10:16,029 We have somewhere around 168 00:10:16,063 --> 00:10:17,996 6,000 catalogued bones in our collection 169 00:10:18,031 --> 00:10:20,516 from this one layer alone. 170 00:10:20,550 --> 00:10:22,173 And it's also the same layer 171 00:10:22,207 --> 00:10:24,589 that provided most of the material 172 00:10:24,624 --> 00:10:26,487 from which we named a new species 173 00:10:26,522 --> 00:10:28,248 of duck-billed dinosaur 174 00:10:28,282 --> 00:10:31,423 called Ugrunaaluk kuukpikensis. 175 00:10:31,458 --> 00:10:32,770 The areas that we work in 176 00:10:32,804 --> 00:10:35,082 have been long occupied by Indigenous peoples, 177 00:10:35,117 --> 00:10:36,325 and we think it's only fitting 178 00:10:36,359 --> 00:10:39,777 that when we construct a new scientific name, 179 00:10:39,811 --> 00:10:43,988 that we incorporate words from those languages 180 00:10:44,022 --> 00:10:45,990 from the areas in which we work. 181 00:10:48,440 --> 00:10:51,823 Ugrunaaluk kuukpikensis has its origin 182 00:10:51,858 --> 00:10:54,826 in Inupiaq words that mean, roughly, 183 00:10:54,861 --> 00:10:58,899 "ancient chewer of the Colville River." 184 00:10:58,934 --> 00:11:01,971 Close cousin to Edmontosaurus found to the south, 185 00:11:02,006 --> 00:11:06,010 Ugrunaaluk kuukpikensis 186 00:11:06,044 --> 00:11:09,047 is a four-ton herbivore. 187 00:11:09,082 --> 00:11:11,532 Its discovery in Alaska's North Slope 188 00:11:11,567 --> 00:11:14,052 created a puzzle for scientists. 189 00:11:14,087 --> 00:11:19,955 How did these large animals manage to survive so far north? 190 00:11:22,095 --> 00:11:25,201 Did they migrate to and from lower latitudes each year... 191 00:11:28,032 --> 00:11:30,413 like caribou do today? 192 00:11:35,004 --> 00:11:36,281 If they weren't migrating, 193 00:11:36,316 --> 00:11:38,111 how did they make a living up here? 194 00:11:38,145 --> 00:11:39,733 You can't imagine there was enough to eat, 195 00:11:39,768 --> 00:11:41,390 so it's just, you know, a bit of a mystery. 196 00:11:48,949 --> 00:11:50,433 To find clues, 197 00:11:50,468 --> 00:11:53,574 the scientists hope to recover more bone material. 198 00:11:55,438 --> 00:12:00,581 During the Cretaceous, some 145 to 66 million years ago, 199 00:12:00,616 --> 00:12:04,171 the section they're planning to dig was a river floodplain. 200 00:12:06,449 --> 00:12:09,038 Over millennia, some remains of dinosaurs 201 00:12:09,073 --> 00:12:12,283 find their way into rivers. 202 00:12:12,317 --> 00:12:15,665 Bones and other material from different species 203 00:12:15,700 --> 00:12:18,738 pile up at the bottom of the river channel. 204 00:12:18,772 --> 00:12:21,464 Layers of sediment bury the remains. 205 00:12:22,811 --> 00:12:26,884 Millions of years later, a new river, the Colville, 206 00:12:26,918 --> 00:12:28,886 carves through these layers, 207 00:12:28,920 --> 00:12:32,027 exposing the edge of the fossil bone bed 208 00:12:32,061 --> 00:12:34,374 along these cliffs. 209 00:12:38,930 --> 00:12:43,038 Pat examines the spot where they found bones before. 210 00:12:44,694 --> 00:12:49,147 They've come back to continue the work, 211 00:12:49,182 --> 00:12:53,082 but the familiar landscape has changed. 212 00:12:54,843 --> 00:12:56,741 Huh. 213 00:12:56,776 --> 00:12:58,916 That's kind of scary. 214 00:12:58,950 --> 00:13:01,332 It might have gone bye-bye. 215 00:13:01,366 --> 00:13:04,991 On first inspection, things don't look promising. 216 00:13:07,821 --> 00:13:09,823 It's all slump. 217 00:13:09,858 --> 00:13:11,100 Yeah. 218 00:13:11,135 --> 00:13:12,067 The layer's gone. 219 00:13:16,830 --> 00:13:19,868 In the summer, the faces of these cliffs 220 00:13:19,902 --> 00:13:23,803 regularly slump or slide down into the river, 221 00:13:23,837 --> 00:13:26,633 making it dangerous to work here. 222 00:13:28,566 --> 00:13:31,845 That process can expose fossils that had been hidden. 223 00:13:33,571 --> 00:13:35,953 But it can also bury the bone layer... 224 00:13:35,987 --> 00:13:40,578 and paleontologists... under tons of rock and mud. 225 00:13:42,511 --> 00:13:46,411 The team fears its bone bed may have been washed away. 226 00:13:46,446 --> 00:13:48,517 The hills are ungluing themselves. 227 00:13:48,551 --> 00:13:49,794 Rack it up to 228 00:13:49,829 --> 00:13:52,762 climate change or whatever, but you never know. 229 00:13:52,797 --> 00:13:54,626 The slumps can randomly just 230 00:13:54,661 --> 00:13:57,422 take out your favorite dinosaur site. 231 00:13:57,457 --> 00:13:59,908 Yeah, that's not good. 232 00:14:01,116 --> 00:14:04,395 Then, after further exploration, 233 00:14:04,429 --> 00:14:07,916 they find a newly exposed outcrop. 234 00:14:07,950 --> 00:14:11,989 Oh, it's kinda got some slump on it. 235 00:14:12,023 --> 00:14:13,473 All right, I'm going up and have a look. 236 00:14:16,062 --> 00:14:17,270 Just when it looks like 237 00:14:17,304 --> 00:14:19,444 the trip may have been for nothing, 238 00:14:19,479 --> 00:14:23,276 the team has a stroke of luck. 239 00:14:23,310 --> 00:14:24,794 Look at that. 240 00:14:24,829 --> 00:14:27,556 Right there. 241 00:14:27,590 --> 00:14:29,869 Woo-hoo! 242 00:14:29,903 --> 00:14:30,904 Found the first bone! 243 00:14:34,666 --> 00:14:36,599 Oh, we got a sweet layer right here. 244 00:14:36,634 --> 00:14:37,911 That's good. 245 00:14:37,946 --> 00:14:41,156 Pieces of bone are clearly visible, 246 00:14:41,190 --> 00:14:44,918 sticking out of the frozen rock. 247 00:14:44,953 --> 00:14:47,127 - I - whacked right through one here. 248 00:14:47,162 --> 00:14:50,268 It's classic bone texture. 249 00:14:50,303 --> 00:14:53,444 For Pat, this layer is 250 00:14:53,478 --> 00:14:56,412 a paleontological gold mine. 251 00:14:56,447 --> 00:14:57,655 That's what this bone layer is all about. 252 00:14:57,689 --> 00:14:58,690 It's just dripping with bones. 253 00:15:02,867 --> 00:15:04,006 The challenge now 254 00:15:04,041 --> 00:15:07,423 is to safely extract the samples. 255 00:15:07,458 --> 00:15:11,220 No one's ever tried this up here before. 256 00:15:11,255 --> 00:15:12,739 Digging these animals up here, 257 00:15:12,773 --> 00:15:14,534 you know, basically the end of wintertime, 258 00:15:14,568 --> 00:15:15,811 we're gonna take the whole layer, 259 00:15:15,845 --> 00:15:17,537 rock and the bones, 260 00:15:17,571 --> 00:15:18,952 and try to extract it. 261 00:15:18,987 --> 00:15:20,126 Gotta find the sweet spot. 262 00:15:20,160 --> 00:15:21,127 Yep. There it is. 263 00:15:26,995 --> 00:15:28,997 They have just six days left to collect specimens 264 00:15:29,031 --> 00:15:31,931 before they need to return. 265 00:15:33,449 --> 00:15:36,625 The next steps are to break up the frozen mud and rock 266 00:15:36,659 --> 00:15:39,248 below the bone layer with jackhammers 267 00:15:39,283 --> 00:15:42,389 to create a working platform. 268 00:15:42,424 --> 00:15:44,771 Then carve out several blocks with chainsaws. 269 00:15:44,805 --> 00:15:49,845 Each chunk will be about three feet across 270 00:15:49,879 --> 00:15:52,296 and weigh up to 200 pounds. 271 00:15:58,129 --> 00:16:01,374 It's five days into a ten-day expedition. 272 00:16:01,408 --> 00:16:03,548 They still haven't extracted a single block. 273 00:16:03,583 --> 00:16:07,207 And then they suffer another setback. 274 00:16:09,451 --> 00:16:12,937 The chainsaws break down. 275 00:16:12,972 --> 00:16:17,907 It's up to head of operations Kevin May to fix the equipment. 276 00:16:17,942 --> 00:16:20,048 It is. 277 00:16:20,082 --> 00:16:22,567 We have been presented with 278 00:16:22,602 --> 00:16:24,776 some significant challenges here 279 00:16:24,811 --> 00:16:27,124 with the temperatures. 280 00:16:27,158 --> 00:16:31,542 If he can't get the chainsaws back up and running, 281 00:16:31,576 --> 00:16:33,613 the expedition could be over. 282 00:16:33,647 --> 00:16:34,924 Where's the other... 283 00:16:34,959 --> 00:16:36,961 Pal, you're too soon. 284 00:16:36,996 --> 00:16:39,929 How long do you need? 285 00:16:39,964 --> 00:16:41,345 I was really hoping to get over here 286 00:16:41,379 --> 00:16:44,141 and work on the chainsaws by myself, so... 287 00:16:46,798 --> 00:16:50,147 You get too many PhDs in a small area 288 00:16:50,181 --> 00:16:52,011 and nothing gets done. 289 00:16:54,737 --> 00:16:58,500 Kevin soon discovers a possible solution. 290 00:16:58,534 --> 00:17:01,192 Yep, that's what shut us down last night. 291 00:17:01,227 --> 00:17:02,711 Look at that. 292 00:17:02,745 --> 00:17:05,921 Can you thaw that, please? 293 00:17:08,820 --> 00:17:12,238 The friction from the chainsaws melts the permafrost, 294 00:17:12,272 --> 00:17:16,656 which seeps into the mechanics and immediately refreezes. 295 00:17:19,348 --> 00:17:20,315 Turns out that 296 00:17:20,349 --> 00:17:22,420 because of these temperatures, 297 00:17:22,455 --> 00:17:26,079 we're gonna have to repeatedly warm our chainsaws 298 00:17:26,114 --> 00:17:29,565 and get the chains thawed out a bit. 299 00:17:35,675 --> 00:17:36,952 After a thorough cleaning, 300 00:17:36,986 --> 00:17:40,335 the team tries again. 301 00:17:44,166 --> 00:17:45,926 Four more days in the biting cold 302 00:17:45,961 --> 00:17:48,101 digging, 303 00:17:48,136 --> 00:17:50,103 sawing, 304 00:17:50,138 --> 00:17:51,898 sleeping, 305 00:17:51,932 --> 00:17:54,659 and more sawing 306 00:17:54,694 --> 00:17:58,387 before the first block is finally freed. 307 00:17:58,422 --> 00:18:01,252 It's coming, it's coming. 308 00:18:07,569 --> 00:18:09,916 Well done, Pat. 309 00:18:09,950 --> 00:18:11,193 We have success! 310 00:18:11,228 --> 00:18:14,403 Yeah, that's a really nice, big chunk. 311 00:18:14,438 --> 00:18:16,267 There's a big one right there. 312 00:18:16,302 --> 00:18:19,615 Big, very dark, there's one right here. 313 00:18:19,650 --> 00:18:23,654 There's one there, there's one there. 314 00:18:23,688 --> 00:18:27,451 It's full of bones. 315 00:18:27,485 --> 00:18:30,488 After all that time... 316 00:18:30,523 --> 00:18:33,319 We've got it. 317 00:18:33,353 --> 00:18:36,149 We're hitting the jackpot right now. 318 00:18:36,184 --> 00:18:37,771 This is gonna pay off. 319 00:18:37,806 --> 00:18:39,048 Let's bring it in for a landing. 320 00:18:40,602 --> 00:18:41,982 In total, 321 00:18:42,017 --> 00:18:46,677 the paleontologists manage to extract eight frozen blocks, 322 00:18:46,711 --> 00:18:49,266 1,000 pounds to haul home. 323 00:18:49,300 --> 00:18:50,370 And now it's just a matter of 324 00:18:50,405 --> 00:18:52,545 bringing home a bunch of rock, 325 00:18:52,579 --> 00:18:54,616 and we'll get that stuff back in the lab, 326 00:18:54,650 --> 00:18:58,067 and we can prepare it out and we'll see what we find. 327 00:19:00,587 --> 00:19:02,934 They hope the samples will 328 00:19:02,969 --> 00:19:05,730 contain fossils that can fill out their understanding 329 00:19:05,765 --> 00:19:10,942 of the animals that lived here and help answer the question 330 00:19:10,977 --> 00:19:15,326 at the heart of the Alaskan dinosaur mystery: 331 00:19:15,361 --> 00:19:18,571 how did they survive the dark polar winter? 332 00:19:18,605 --> 00:19:21,539 That's a tough place to make a living. 333 00:19:21,574 --> 00:19:23,162 How were dinosaurs able to do that? 334 00:19:23,196 --> 00:19:26,268 Did they have to leave, 335 00:19:26,303 --> 00:19:28,684 maybe migrate south? 336 00:19:28,719 --> 00:19:31,170 Or were they able to park themselves 337 00:19:31,204 --> 00:19:32,723 in the poles year-round? 338 00:19:32,757 --> 00:19:35,588 If we have evidence that they were staying year-round, 339 00:19:35,622 --> 00:19:39,247 it really has a powerful impact 340 00:19:39,281 --> 00:19:43,354 on what we expect of dinosaur physiology. 341 00:19:46,909 --> 00:19:49,912 Early July. 342 00:19:49,947 --> 00:19:51,880 At the University of Alaska 343 00:19:51,914 --> 00:19:53,916 Museum of the North in Fairbanks, 344 00:19:53,951 --> 00:19:56,816 the blocks from the Prince Creek Formation 345 00:19:56,850 --> 00:19:58,645 are in the prep lab. 346 00:20:00,682 --> 00:20:02,856 It's not just the big bones 347 00:20:02,891 --> 00:20:04,548 the scientists are after. 348 00:20:08,207 --> 00:20:11,348 Even the tiniest unassuming crumbs 349 00:20:11,382 --> 00:20:15,144 could hold vital pieces of the Alaskan dinosaur puzzle. 350 00:20:19,977 --> 00:20:24,878 To ensure the tiniest fragment isn't overlooked, 351 00:20:24,913 --> 00:20:28,779 the scientists scrutinize buckets of material 352 00:20:28,813 --> 00:20:30,436 grain by grain. 353 00:20:32,196 --> 00:20:34,129 It's a process of 354 00:20:34,163 --> 00:20:36,062 finding a needle in a haystack, or... 355 00:20:36,096 --> 00:20:38,167 I liken it more to panning for gold. 356 00:20:44,208 --> 00:20:45,658 Three years earlier, 357 00:20:45,692 --> 00:20:50,007 on their previous expedition to the Prince Creek Formation, 358 00:20:50,041 --> 00:20:53,735 Pat and Greg find something exceedingly rare 359 00:20:53,769 --> 00:20:56,531 and a potential clue to the mystery of the lifestyle 360 00:20:56,565 --> 00:21:00,569 of polar dinosaurs: 361 00:21:00,604 --> 00:21:06,541 very small bones they suspect are from a very young dinosaur. 362 00:21:06,575 --> 00:21:09,751 Some are no larger than the head of a pin. 363 00:21:12,823 --> 00:21:16,551 Small size alone doesn't necessarily mean that 364 00:21:16,585 --> 00:21:19,968 this is from a very young individual dinosaur. 365 00:21:20,002 --> 00:21:22,798 For that information, I look at other clues. 366 00:21:22,833 --> 00:21:24,386 And one of the best clues 367 00:21:24,421 --> 00:21:27,147 can be seen in the surface texture. 368 00:21:29,529 --> 00:21:32,152 What I'm seeing is a surface that's highly porous, 369 00:21:32,187 --> 00:21:34,741 as if somebody took a little pin and pricked the surface 370 00:21:34,776 --> 00:21:36,191 over and over and over again. 371 00:21:38,538 --> 00:21:41,265 And each of those holes represents places 372 00:21:41,300 --> 00:21:43,267 for little vascular canals 373 00:21:43,302 --> 00:21:46,063 where nutrients were flowing into a bone 374 00:21:46,097 --> 00:21:48,790 at a stage of rapid growth. 375 00:21:48,824 --> 00:21:52,897 That sort of surface texture is highly indicative of 376 00:21:52,932 --> 00:21:55,969 animals' very early stages of development. 377 00:21:56,004 --> 00:21:57,730 And by that we mean days, weeks, 378 00:21:57,764 --> 00:21:59,352 maybe as much as a couple of months, 379 00:21:59,387 --> 00:22:01,630 meaning that this is a great clue 380 00:22:01,665 --> 00:22:03,943 to help identify baby bones. 381 00:22:11,640 --> 00:22:15,264 It's an unprecedented find. 382 00:22:15,299 --> 00:22:19,268 Baby dinosaurs have never been found this far north before. 383 00:22:22,341 --> 00:22:25,067 This was a totally unexpected discovery. 384 00:22:25,102 --> 00:22:26,724 When we first started to see 385 00:22:26,759 --> 00:22:29,175 these, these small teeth and bones, 386 00:22:29,209 --> 00:22:34,491 it was, it was really a jaw-dropping experience. 387 00:22:34,525 --> 00:22:36,596 Further investigation reveals 388 00:22:36,631 --> 00:22:38,667 remains of the teeth and bones 389 00:22:38,702 --> 00:22:42,430 of seven different species of dinosaur, 390 00:22:42,464 --> 00:22:46,365 all in their very earliest stages of development. 391 00:22:46,399 --> 00:22:51,128 It's evidence that 70 million years ago, 392 00:22:51,162 --> 00:22:56,616 several species of dinosaurs nested in the Arctic, 393 00:22:56,651 --> 00:22:59,723 not only living in Alaska during the mild summer, 394 00:22:59,757 --> 00:23:01,759 but breeding here, as well. 395 00:23:05,901 --> 00:23:09,111 It raises a whole bunch of really interesting questions. 396 00:23:10,492 --> 00:23:12,114 One of the most important is, 397 00:23:12,149 --> 00:23:14,427 if they reproduced in the Arctic, 398 00:23:14,462 --> 00:23:17,257 is it actually possible for them to have also had time 399 00:23:17,292 --> 00:23:20,468 to migrate to lower latitudes? 400 00:23:20,502 --> 00:23:25,231 If migratory, dinosaurs would have to move north, 401 00:23:25,265 --> 00:23:27,923 incubate and hatch their eggs, 402 00:23:27,958 --> 00:23:30,236 and then return to the south, 403 00:23:30,270 --> 00:23:35,034 2,000 miles away, with baby dinosaurs in tow, 404 00:23:35,068 --> 00:23:39,176 in order to escape the depth of the polar winter shadow... 405 00:23:39,210 --> 00:23:42,731 and all between spring and early fall. 406 00:23:42,766 --> 00:23:45,389 Could the hatchlings have managed it? 407 00:23:48,772 --> 00:23:53,328 One important clue can be found inside specimens like this, 408 00:23:53,362 --> 00:23:57,505 less than an eighth of an inch long. 409 00:23:57,539 --> 00:23:59,610 It looks like a drill bit, 410 00:23:59,645 --> 00:24:03,442 but it's actually a tooth from a baby dinosaur. 411 00:24:05,927 --> 00:24:10,828 When teeth form, daily growth lines are laid down. 412 00:24:10,863 --> 00:24:12,589 And by counting those up, one can figure out 413 00:24:12,623 --> 00:24:15,661 how long it took dinosaurs to incubate their eggs. 414 00:24:15,695 --> 00:24:17,663 So we looked at really small embryos, 415 00:24:17,697 --> 00:24:20,251 animals that were just about to hatch out, 416 00:24:20,286 --> 00:24:23,462 and we were able to figure out really large dinosaur eggs 417 00:24:23,496 --> 00:24:25,809 took six months to incubate. 418 00:24:29,433 --> 00:24:33,782 If it took large animals such as Ugrunaaluk 419 00:24:33,817 --> 00:24:35,404 six months to hatch, 420 00:24:35,439 --> 00:24:38,062 and eggs were laid during the spring, 421 00:24:38,097 --> 00:24:41,721 the dinosaurs would have only one month to move south 422 00:24:41,756 --> 00:24:47,037 before the onset of polar winter. 423 00:24:47,071 --> 00:24:48,797 There's no way that those dinosaurs 424 00:24:48,832 --> 00:24:51,973 could have hatched out and made a 2,000-mile trek 425 00:24:52,007 --> 00:24:55,839 all the way down to Alberta to warmer climatic conditions. 426 00:24:55,873 --> 00:24:57,875 It just wasn't possible. 427 00:24:57,910 --> 00:25:00,188 It's just unavoidable... they were up there year-round. 428 00:25:02,466 --> 00:25:05,262 The idea that dinosaurs lived in cold darkness 429 00:25:05,296 --> 00:25:09,818 challenges previous assumptions about dinosaur biology 430 00:25:09,853 --> 00:25:11,855 and the traditional view that they were 431 00:25:11,889 --> 00:25:16,376 giant cold-blooded animals like today's reptiles, 432 00:25:16,411 --> 00:25:20,829 relying on ambient temperature to warm their bodies. 433 00:25:20,864 --> 00:25:23,694 What we don't find in the Prince Creek Formation 434 00:25:23,729 --> 00:25:26,594 is evidence for cold-blooded animals 435 00:25:26,628 --> 00:25:31,944 such as crocodiles and turtles, lizards, amphibians. 436 00:25:31,978 --> 00:25:36,017 It's almost like they were physiologically limited. 437 00:25:36,051 --> 00:25:38,157 What we do find up there are birds 438 00:25:38,191 --> 00:25:40,884 and mammals 439 00:25:40,918 --> 00:25:43,403 and dinosaurs. 440 00:25:43,438 --> 00:25:46,096 That alone suggested that they were warm-blooded. 441 00:25:50,169 --> 00:25:52,102 Even if they weren't cold-blooded, 442 00:25:52,136 --> 00:25:56,934 how did herbivores like Ugrunaaluk find enough food? 443 00:26:00,282 --> 00:26:03,562 Without sunlight, many trees shed their leaves. 444 00:26:03,596 --> 00:26:08,877 During these winter months, food for the plant-eaters 445 00:26:08,912 --> 00:26:10,845 would have withered or died. 446 00:26:18,646 --> 00:26:21,269 If we think about those Alaskan ecosystems, 447 00:26:21,303 --> 00:26:24,997 we have to address the fact... 448 00:26:26,032 --> 00:26:27,413 Where do they get their food? 449 00:26:29,104 --> 00:26:32,211 Karen Chin is one of the world's leading experts 450 00:26:32,245 --> 00:26:35,663 in dinosaur dung. 451 00:26:35,697 --> 00:26:39,011 She's been investigating hadrosaur diet 452 00:26:39,045 --> 00:26:41,530 by studying the fossilized remains of their feces, 453 00:26:41,565 --> 00:26:45,224 known as coprolites. 454 00:26:49,331 --> 00:26:51,644 At 100 times magnification, 455 00:26:51,679 --> 00:26:54,647 even the individual fossilized cells 456 00:26:54,682 --> 00:26:57,616 of the dinosaur's last meal are visible. 457 00:27:00,895 --> 00:27:04,312 Investigating coprolites from non-polar dinosaurs 458 00:27:04,346 --> 00:27:06,555 living in Southern Utah and Montana, 459 00:27:06,590 --> 00:27:09,075 Karen finds something intriguing. 460 00:27:09,110 --> 00:27:12,216 We can see chunks of intact wood, 461 00:27:12,251 --> 00:27:15,150 and that's where you see all of the cells 462 00:27:15,185 --> 00:27:17,497 are almost glued together. 463 00:27:17,532 --> 00:27:19,603 They're glued together with lignin. 464 00:27:19,638 --> 00:27:24,125 But then you can also see all of these loose cells 465 00:27:24,159 --> 00:27:27,542 all over the place, in no particular order, 466 00:27:27,576 --> 00:27:31,132 scattered all around. 467 00:27:35,136 --> 00:27:38,933 And that indicates rotting wood. 468 00:27:38,967 --> 00:27:43,662 To break down lignin, it requires oxygen, 469 00:27:43,696 --> 00:27:46,872 so that can't happen in an animal's gut. 470 00:27:46,906 --> 00:27:51,186 It has to happen outside, where there's access to oxygen. 471 00:27:51,221 --> 00:27:55,604 So we know that the wood was degraded, decomposed, 472 00:27:55,639 --> 00:27:58,573 before it was ingested by the dinosaur. 473 00:28:00,748 --> 00:28:01,956 I was quite surprised... 474 00:28:01,990 --> 00:28:05,684 why were they eating so much wood? 475 00:28:05,718 --> 00:28:07,996 The incredible new evidence 476 00:28:08,031 --> 00:28:11,897 suggests the southern hadrosaurs could diversify their diets, 477 00:28:11,931 --> 00:28:16,764 feeding on rotting wood to survive. 478 00:28:16,798 --> 00:28:19,628 Where are you going to get protein if you're an herbivore? 479 00:28:19,663 --> 00:28:21,838 You can go to a rotting log 480 00:28:21,872 --> 00:28:25,186 where there's lots of creepy crawlers 481 00:28:25,220 --> 00:28:27,844 like beetles and millipedes and pill bugs. 482 00:28:30,985 --> 00:28:33,401 It raises the tantalizing possibility 483 00:28:33,435 --> 00:28:35,748 that this could have been a winter food source 484 00:28:35,783 --> 00:28:40,166 for Alaskan dinosaurs, as well. 485 00:28:40,201 --> 00:28:43,411 Herbivorous dinosaurs like Ugrunaaluk 486 00:28:43,445 --> 00:28:45,931 might also have been feeding on rotting wood 487 00:28:45,965 --> 00:28:48,899 during the four months of the year or so when 488 00:28:48,934 --> 00:28:51,281 they had the polar winter. 489 00:28:54,318 --> 00:28:56,769 With the arrival of winter, 490 00:28:56,804 --> 00:29:00,566 darkness is one problem for the Alaskan dinosaurs. 491 00:29:02,188 --> 00:29:06,434 They also face much colder temperatures. 492 00:29:08,470 --> 00:29:11,232 What in their physiology allowed them 493 00:29:11,266 --> 00:29:13,406 to remain in Alaska, shielding them 494 00:29:13,441 --> 00:29:15,615 from the elements? 495 00:29:18,342 --> 00:29:21,656 So for a long time, the image of a traditional, classic dinosaur 496 00:29:21,690 --> 00:29:24,141 was of a very scaly, very reptilian, 497 00:29:24,176 --> 00:29:26,799 almost a monstrous sort of creature. 498 00:29:26,834 --> 00:29:28,732 But lately, dinosaurs have been getting softer, 499 00:29:28,767 --> 00:29:30,009 they've been getting fuzzier. 500 00:29:30,044 --> 00:29:32,874 Like, dare I say it, they're getting cute. 501 00:29:32,909 --> 00:29:34,531 There was a early tyrannosaur 502 00:29:34,565 --> 00:29:38,569 that lived about 125 million years ago named Yutyrannus 503 00:29:38,604 --> 00:29:40,330 covered almost head to tail 504 00:29:40,364 --> 00:29:42,573 in fluffy feathers, and this was not a small animal. 505 00:29:42,608 --> 00:29:43,989 This animal was about 30 feet long. 506 00:29:44,023 --> 00:29:49,408 Intriguingly, Yutyrannus lived in a part of China 507 00:29:49,442 --> 00:29:52,791 during the early Cretaceous that had a cool climate 508 00:29:52,825 --> 00:29:58,244 similar to Alaska 70 million years ago. 509 00:29:58,279 --> 00:30:03,146 Most dinosaurs had simple feathers that looked like hair. 510 00:30:03,180 --> 00:30:04,906 Our hair keeps us warm, 511 00:30:04,941 --> 00:30:06,321 that's what hair does in mammals, 512 00:30:06,356 --> 00:30:09,808 and for many dinosaurs, they had these simple feathers 513 00:30:09,842 --> 00:30:12,811 probably to keep their bodies warm. 514 00:30:14,813 --> 00:30:16,953 If dinosaurs that were living in an area 515 00:30:16,987 --> 00:30:20,163 of similar temperatures earlier in the Cretaceous 516 00:30:20,197 --> 00:30:23,373 had all of these thick coats of feathers, 517 00:30:23,407 --> 00:30:26,376 then probably a lot of the Alaskan dinosaurs did, too. 518 00:30:28,102 --> 00:30:29,344 In addition to feathers, 519 00:30:29,379 --> 00:30:33,107 Alaskan dinosaurs may have had other adaptations 520 00:30:33,141 --> 00:30:36,248 for surviving colder temperatures. 521 00:30:36,282 --> 00:30:38,975 One of the interesting groups of dinosaurs 522 00:30:39,009 --> 00:30:41,770 that we have represented in our fauna 523 00:30:41,805 --> 00:30:44,256 in the Prince Creek Formation are thescelosaurids. 524 00:30:46,465 --> 00:30:48,950 Thescelosaurids are dwarves 525 00:30:48,985 --> 00:30:51,677 in a land of Alaskan giants. 526 00:30:51,711 --> 00:30:54,714 The smaller of two Arctic species 527 00:30:54,749 --> 00:30:58,339 is just 18 inches tall at the hip. 528 00:30:58,373 --> 00:31:01,790 Small creatures lose heat more rapidly, 529 00:31:01,825 --> 00:31:05,311 and they freeze a lot faster. 530 00:31:05,346 --> 00:31:09,074 So how did these small dinos survive the cold? 531 00:31:12,940 --> 00:31:15,011 A clue can be found 532 00:31:15,045 --> 00:31:16,944 in their Montana cousins. 533 00:31:20,948 --> 00:31:22,708 Some species of thescelosaurs 534 00:31:22,742 --> 00:31:27,506 were found actually preserved in a burrow. 535 00:31:29,128 --> 00:31:30,716 Up until about 20 years ago, 536 00:31:30,750 --> 00:31:32,960 that's not something that we thought dinosaurs did. 537 00:31:35,134 --> 00:31:37,585 That raises the exciting possibility that 538 00:31:37,619 --> 00:31:41,175 perhaps the species of thescelosaurid in Alaska 539 00:31:41,209 --> 00:31:43,453 might also have been capable of burrowing, 540 00:31:43,487 --> 00:31:46,490 and potentially over-wintering by hibernating. 541 00:31:48,699 --> 00:31:52,393 Feathers and the ability to burrow 542 00:31:52,427 --> 00:31:54,774 aren't the only adaptations that may have helped polar dinosaurs 543 00:31:54,809 --> 00:31:57,467 survive the cold temperatures. 544 00:32:00,401 --> 00:32:02,748 We're finding a very exciting 545 00:32:02,782 --> 00:32:06,648 number of bones from troodontids in the bone bed layer 546 00:32:06,683 --> 00:32:08,616 we excavated this winter. 547 00:32:08,650 --> 00:32:10,169 And because they're so rare, 548 00:32:10,204 --> 00:32:12,896 every single bone that we find is providing 549 00:32:12,931 --> 00:32:14,518 another new piece of the puzzle 550 00:32:14,553 --> 00:32:18,591 in understanding what this animal was. 551 00:32:20,731 --> 00:32:24,218 Troodontids were lightweight, fast-moving, 552 00:32:24,252 --> 00:32:27,290 and agile predators 553 00:32:27,324 --> 00:32:31,466 with eyes set towards the front, 554 00:32:31,501 --> 00:32:36,782 a common adaptation in predators giving them binocular vision 555 00:32:36,816 --> 00:32:40,820 to triangulate small, scurrying prey. 556 00:32:40,855 --> 00:32:42,443 They're raptors, so to speak, 557 00:32:42,477 --> 00:32:46,999 and had giant sickle claws on their second toe, 558 00:32:47,034 --> 00:32:51,590 and clawed hands, and menacing teeth. 559 00:32:51,624 --> 00:32:55,490 In many ways, this was a roadrunner from Hell. 560 00:32:58,493 --> 00:33:00,392 But the Alaskan troodontid 561 00:33:00,426 --> 00:33:04,016 has one noticeable aspect that sets it apart. 562 00:33:05,949 --> 00:33:07,261 So I'm looking at 563 00:33:07,295 --> 00:33:13,370 a adult troodon tooth from the Prince Creek Formation. 564 00:33:13,405 --> 00:33:15,510 And this is a monster, it's a big one. 565 00:33:18,824 --> 00:33:24,243 This tooth is probably 50% longer than we see in 566 00:33:24,278 --> 00:33:28,075 Troodon formosus, which is a species found down in Montana. 567 00:33:29,938 --> 00:33:32,527 That suggests this is a different species, 568 00:33:32,562 --> 00:33:35,082 or same species got larger up here. 569 00:33:38,947 --> 00:33:41,364 Troodontids that lived elsewhere 570 00:33:41,398 --> 00:33:44,263 stood three feet at the hip. 571 00:33:44,298 --> 00:33:48,716 But the Alaskan troodontid was twice as tall. 572 00:33:48,750 --> 00:33:51,236 Why would living in a harsher environment 573 00:33:51,270 --> 00:33:55,102 lead to a larger size? 574 00:33:55,136 --> 00:33:58,105 It's been shown with some mammals and few other birds 575 00:33:58,139 --> 00:34:00,107 and a few other creatures that they get larger 576 00:34:00,141 --> 00:34:02,350 when they live closer to the poles. 577 00:34:02,385 --> 00:34:05,319 It's a thermal advantage to be bigger in a cold environment. 578 00:34:05,353 --> 00:34:08,149 You're, you're less likely to cool down, so to speak. 579 00:34:08,184 --> 00:34:12,567 So far, from the Prince Creek Formation alone, 580 00:34:12,602 --> 00:34:15,605 scientists have identified 581 00:34:15,639 --> 00:34:19,643 at least 13 unique species of dinosaurs specially adapted 582 00:34:19,678 --> 00:34:21,611 to life in the Arctic. 583 00:34:21,645 --> 00:34:24,717 But among all the species found there, 584 00:34:24,752 --> 00:34:28,376 one is of particular interest to the team. 585 00:34:28,411 --> 00:34:30,896 It's an animal that was originally thought 586 00:34:30,930 --> 00:34:36,212 to have evolved to be smaller, not larger, like the troodontid. 587 00:34:36,246 --> 00:34:39,801 That animal came to light in 2014, 588 00:34:39,836 --> 00:34:41,424 when another team of scientists 589 00:34:41,458 --> 00:34:43,805 working at the Prince Creek Formation 590 00:34:43,840 --> 00:34:47,085 announced the discovery of Nanuqsaurus, 591 00:34:47,119 --> 00:34:49,535 the Arctic's apex predator. 592 00:34:49,570 --> 00:34:52,193 Ultimately, what this comes down to is this. 593 00:34:52,228 --> 00:34:55,576 T. rex, the most iconic dinosaur of all, 594 00:34:55,610 --> 00:34:58,682 how do you take that type of animal 595 00:34:58,717 --> 00:35:00,684 and move it into the Arctic? 596 00:35:00,719 --> 00:35:02,583 What does it become? 597 00:35:02,617 --> 00:35:07,035 Estimated to be half the size of an adult T. rex, 598 00:35:07,070 --> 00:35:10,522 it's labeled a dwarf species. 599 00:35:10,556 --> 00:35:14,491 Mysteriously, it comes from a lineage of giants, 600 00:35:14,526 --> 00:35:16,873 but when first discovered, 601 00:35:16,907 --> 00:35:19,703 it was thought to have bucked the evolutionary trend 602 00:35:19,738 --> 00:35:22,361 that suggested tyrannosaurs evolved 603 00:35:22,396 --> 00:35:25,813 to become larger over millions of years. 604 00:35:25,847 --> 00:35:27,780 If it's tough to survive there, 605 00:35:27,815 --> 00:35:29,782 animals often get smaller. 606 00:35:29,817 --> 00:35:31,784 It's easier to cope with limited resources 607 00:35:31,819 --> 00:35:34,477 if you're getting smaller, so maybe because the Arctic 608 00:35:34,511 --> 00:35:36,513 was a tough place to live... it was cold, it was dark... 609 00:35:36,548 --> 00:35:39,413 the tyrannosaurs could not get as big there. 610 00:35:42,070 --> 00:35:45,004 But these initial findings are made 611 00:35:45,039 --> 00:35:48,870 on just a handful of bone fragments. 612 00:35:48,905 --> 00:35:54,013 Leading them to wonder, was it really as small as it looked? 613 00:36:00,227 --> 00:36:03,161 Pat and the team haven't identified 614 00:36:03,195 --> 00:36:05,059 any new Nanuqsaurus bones 615 00:36:05,093 --> 00:36:07,648 from the Colville this time. 616 00:36:07,682 --> 00:36:09,443 But there is another place 617 00:36:09,477 --> 00:36:13,274 they hope to find evidence. 618 00:36:14,724 --> 00:36:19,384 Not with bones, teeth, or dinosaur droppings, however, 619 00:36:19,418 --> 00:36:22,352 but thanks to a different record of the past 620 00:36:22,387 --> 00:36:25,493 preserved in the very ground they walked on. 621 00:36:27,909 --> 00:36:29,877 Their footprints. 622 00:36:29,911 --> 00:36:33,225 It's not just finding new species. 623 00:36:33,260 --> 00:36:35,745 It's not just tracking these animals. 47948

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