WEBVTT - Did Dinosaurs Really Have Feathers? 0:00:01.880 --> 0:00:05.400 Hey, welcome to Sign Stuff, a production of iHeartRadio. I'm 0:00:05.400 --> 0:00:09.160 hoor hitchhim, and today we're answering the question did dinosaurs 0:00:09.560 --> 0:00:12.520 have feathers? You might think you know the answer to 0:00:12.560 --> 0:00:15.720 this question, but as we'll learn today, the real answer 0:00:15.960 --> 0:00:19.680 has changed significantly in the last few years. To get 0:00:19.680 --> 0:00:21.720 the full story, we're going to talk to a couple 0:00:21.760 --> 0:00:24.960 of paleontologies. We're going to tell us what we know 0:00:25.239 --> 0:00:29.080 about the origin of feathers, which dinosaurs had them, and 0:00:29.120 --> 0:00:32.879 why feathers evolved in the first place. I promise by 0:00:32.920 --> 0:00:36.000 the end you want to look at dinosaurs or feathers 0:00:36.360 --> 0:00:44.880 the same way again. Enjoy. Hey everyone, So I picked 0:00:44.880 --> 0:00:47.920 today's topic to celebrate the release of my news book, 0:00:48.280 --> 0:00:52.680 Oliver's Great Big Universe Evolution Changes Everything. It's all about 0:00:52.680 --> 0:00:55.280 the history of life on Earth, is told by a 0:00:55.360 --> 0:00:58.200 kid named Oliver. It's a great book for those smart 0:00:58.280 --> 0:01:02.800 kids in your life, your nieces or nephews, your friend's kids. 0:01:03.160 --> 0:01:05.720 I promise, if they like funny stories and you think 0:01:05.760 --> 0:01:08.160 they might like science, I think this might be their 0:01:08.280 --> 0:01:11.200 favorite new book series. So please check it out at 0:01:11.240 --> 0:01:15.040 Great Big Universe dot net or your favorite bookseller. All right, 0:01:15.160 --> 0:01:18.679 let's talk about dinosaurs and feathers. Now, I'm excited for 0:01:18.720 --> 0:01:22.680 today's episode because we're gonna hear from two paletologists, one 0:01:22.680 --> 0:01:26.320 of whom was involved in the landmark discovery that put 0:01:26.360 --> 0:01:29.920 the origin of feathers way further back in time than 0:01:30.040 --> 0:01:33.280 anyone expected. But before we get there, I thought it 0:01:33.319 --> 0:01:36.440 was important that we covered the basics first because that's 0:01:36.480 --> 0:01:38.840 going to help us later in the episode. And the 0:01:38.840 --> 0:01:41.800 first question we're going to ask is what exactly is 0:01:41.840 --> 0:01:45.720 a dinosaur? You probably think you know, but according to 0:01:45.760 --> 0:01:52.040 our first expert, the answer is not that simple. Well, 0:01:52.040 --> 0:01:54.000 thank you, doctor O'Connor for joining us today. 0:01:54.200 --> 0:01:56.560 It's absolutely my pleasure. I'm a big fan, so I'm 0:01:56.560 --> 0:01:57.400 happy to be here. 0:01:57.600 --> 0:01:59.760 Awesome. Can you please tell us who you are and 0:01:59.760 --> 0:02:00.160 what you do. 0:02:00.480 --> 0:02:04.720 My name is Jingme O'Connor, and I'm the associate curator 0:02:04.800 --> 0:02:08.200 of Fossil Reptiles at the Field Museum of National Street 0:02:08.240 --> 0:02:11.280 in Chicago. It's just a fancy complicated way of saying 0:02:11.320 --> 0:02:13.959 that I'm a nerdy dinosaur paleontologist. 0:02:14.080 --> 0:02:16.680 I guess maybe for people who are not super familiar. 0:02:16.960 --> 0:02:19.640 He tell us what exactly is a dinosaur? Like what 0:02:19.760 --> 0:02:21.240 makes a dinosaur a dinosaur. 0:02:21.520 --> 0:02:24.920 Well, okay, that's not an easy question to answer. So 0:02:25.040 --> 0:02:29.040 dinosaurs are basically a group of animals that have a 0:02:29.200 --> 0:02:33.079 common ancestor. So, for example, all living mammals have one 0:02:33.120 --> 0:02:37.040 common ancestor, that's why they form a true group. And 0:02:37.360 --> 0:02:40.560 mammals are characterized by a specific set of traits that 0:02:40.600 --> 0:02:42.840 you can then use to identify that they're mammals, like 0:02:42.919 --> 0:02:46.440 milk and fur. But if only it was so easy 0:02:46.560 --> 0:02:51.600 with dinosaurs. Unfortunately, dinosaurs are really weird and different, and 0:02:51.760 --> 0:02:54.840 until recently we would have said things like dinosaurs have 0:02:54.880 --> 0:02:58.440 a completely open hip socket and a bunch of traits 0:02:58.480 --> 0:03:01.800 that for a long time really did define dinosaurs. But 0:03:01.880 --> 0:03:05.480 then the more we find close relatives of dinosaurs, all 0:03:05.520 --> 0:03:08.960 those traits we used to use suddenly got blurred. We 0:03:09.000 --> 0:03:12.680 found that they were present in close non dinosaur animals, 0:03:12.840 --> 0:03:15.440 or they were absent in the oldest known dinosaurs that 0:03:15.480 --> 0:03:16.360 we started to find. 0:03:17.280 --> 0:03:20.080 All Right, what doctor O'Connor is saying is that the 0:03:20.120 --> 0:03:23.800 definition of a dinosaur is not an animal that looks 0:03:23.800 --> 0:03:27.720 a certain way or as a certain characteristic. It just 0:03:27.760 --> 0:03:33.560 means all the animals that came from one specific common ancestor. Because, 0:03:33.600 --> 0:03:38.600 as it turns, out, dinosaurs have cousins. Not every big, 0:03:38.760 --> 0:03:43.120 cool giant reptile is a dinosaur. For example, there are 0:03:43.160 --> 0:03:47.600 the big reptiles that eventually became crocodiles. Crogs did not 0:03:47.680 --> 0:03:52.360 come from dinosaurs. Or those giant swimming reptiles like Ichiosaurus 0:03:52.560 --> 0:03:55.880 or plesiosaurs that you see swimming around in the Jurassic 0:03:55.920 --> 0:04:02.119 Part movies. Those are not dinosaurs. There's a big one Terosaurus. 0:04:02.720 --> 0:04:06.000 These are the giant flying reptiles that you also see 0:04:06.000 --> 0:04:11.080 in movies, like pterodactyls or Terranodon. But the giant wings 0:04:11.160 --> 0:04:15.360 and the long deaks dose are not dinosaurs either. They're 0:04:15.360 --> 0:04:19.080 more like cousins of dinosaurs. So when you're talking about dinosaurs, 0:04:19.320 --> 0:04:23.320 you're really talking about a specific family of animals that 0:04:23.440 --> 0:04:26.280 came from one specific ancestor. 0:04:27.600 --> 0:04:31.480 Let's just say that the ancestral dinosaur was probably a small, 0:04:31.720 --> 0:04:36.320 warm blooded bipedal, probably carnivorous or omnivorous animal. 0:04:37.320 --> 0:04:41.279 So scientists think the first dinosaur, the ancestor of the 0:04:41.360 --> 0:04:45.920 animals we call dinosaurs, probably walked on two legs, kind 0:04:45.920 --> 0:04:49.440 of like Terrannosaurus REGs or the veloscy raptors that again 0:04:49.880 --> 0:04:52.400 you see in the Jurassic part movies. But here's a 0:04:52.440 --> 0:04:56.760 confusing part. Some dinosaurs branched out and went back to 0:04:56.880 --> 0:04:59.560 walking on four legs, and that's where you get some 0:04:59.600 --> 0:05:03.840 of the they're famous dinosaurs like Triceratops or the one 0:05:03.839 --> 0:05:07.680 with the really long neck, Brachiosaurus. All Right, I promise 0:05:07.760 --> 0:05:10.279 this will all be useful later. Now let's get to 0:05:10.320 --> 0:05:14.000 the other basic which is what exactly is a feather. 0:05:15.800 --> 0:05:19.320 So my name is Maria McNamara and I am professor 0:05:19.360 --> 0:05:22.760 of paleontology at University College Cork in Ireland. 0:05:23.080 --> 0:05:25.120 Can you tell us what a feather is? 0:05:25.480 --> 0:05:29.000 Ah, that's an interesting one. So a feather is basically 0:05:29.120 --> 0:05:33.360 an integumentary appendage, to give it its scientific term. It's 0:05:33.400 --> 0:05:37.640 basically made of protein, a protein called keratin. It's the 0:05:37.680 --> 0:05:41.159 same protein that makes up our hair and nails, and 0:05:41.480 --> 0:05:46.040 it is actually the most complex sort of tissue structure 0:05:46.360 --> 0:05:50.479 that is known in vertebrate animals. Each feather has a 0:05:50.560 --> 0:05:56.280 central sheaft with lateral side branches, and those branches have branches, 0:05:56.680 --> 0:06:01.280 and actually the branches are organized in a spiral around 0:06:01.320 --> 0:06:05.080 the shaft. So a feather is really the most complex 0:06:05.120 --> 0:06:06.640 tissue structure that is known. 0:06:06.680 --> 0:06:10.360 From the skin all right, you probably already knew what 0:06:10.440 --> 0:06:13.599 a feather was. But here's the thing. That description of 0:06:13.640 --> 0:06:19.039 feathers only applies to modern feathers. Early feathers, scientists think 0:06:19.400 --> 0:06:23.520 we're a lot simpler. They look more like hairs, except 0:06:23.640 --> 0:06:27.640 they're not hairs. How are they related to hairs? 0:06:28.480 --> 0:06:30.880 What feathers and hair have in common is that they're 0:06:30.920 --> 0:06:34.280 both outgroots from the skin, and they're both made of 0:06:34.360 --> 0:06:40.080 keroten protein. But that's where the similarity ends because hairs, 0:06:40.360 --> 0:06:44.719 unlike feathers, they don't branch, and hairs are solid. If 0:06:44.760 --> 0:06:47.000 you slice through a hair and look at us onto 0:06:47.040 --> 0:06:52.200 the microscope, you'll see a solid cylinder of keroten protein, 0:06:52.560 --> 0:06:55.520 whereas if you slice through a feather, it's hollow in 0:06:55.560 --> 0:06:59.919 the middle. So that's one major difference. And also in hairs, 0:07:00.120 --> 0:07:03.080 we have a form of keratin called alpha keratin. Alpha 0:07:03.120 --> 0:07:07.720 kerosin forms a helix, but the kerosion that's in feathers 0:07:08.040 --> 0:07:11.400 has traditionally been called beta keratin, and that looks like 0:07:11.480 --> 0:07:14.840 a corrugated tin roof, so it has an up and 0:07:14.880 --> 0:07:19.160 down zigzag corrugated pattern. So the structure of the proteins 0:07:19.280 --> 0:07:20.120 is very different. 0:07:20.600 --> 0:07:22.760 It makes hair sound a lot more boring. 0:07:23.040 --> 0:07:27.600 Hair is still a very interesting structure, but structurally it 0:07:27.640 --> 0:07:29.160 is simpler than feathers. 0:07:29.760 --> 0:07:32.720 So when we talk about dinosaurs, now you know what 0:07:32.720 --> 0:07:35.920 we mean. And when we talk about feathers, you also 0:07:35.960 --> 0:07:37.800 know what we mean. And now we get to the 0:07:37.880 --> 0:07:42.400 question did dinosaurs have feathers? And I'll just tell you 0:07:42.440 --> 0:07:46.320 the answer to this question is kind of shocking. At least, 0:07:46.400 --> 0:07:51.080 it really took me by surprise. Where did feathers come from? 0:07:51.240 --> 0:07:55.160 Ha? If I could answer that question, I would get 0:07:55.360 --> 0:07:57.800 I don't know, a normal prize or something. 0:07:58.800 --> 0:08:00.600 Yeah, that's good, let's get you noble price. 0:08:00.840 --> 0:08:03.320 Yeah. Yeah, Well, look that question, where haven't you feathers 0:08:03.320 --> 0:08:06.640 come from? That's the question that's been driving our research 0:08:07.120 --> 0:08:09.160 over the last fifteen years. 0:08:10.000 --> 0:08:12.800 All right. According to doctor McNamara, the answer to the 0:08:12.920 --> 0:08:16.760 question did dinosaurs have feathers? Or where did feathers come from? 0:08:16.960 --> 0:08:20.800 Has changed several times over the last thirty years, And 0:08:20.840 --> 0:08:24.600 it's changed because we keep finding fossils that totally rewrite 0:08:24.720 --> 0:08:27.360 what we think we know. So I'm going to take 0:08:27.400 --> 0:08:30.240 you back starting in the nineteen nineties. 0:08:31.680 --> 0:08:34.040 So you know, if we were to go back, let's 0:08:34.080 --> 0:08:36.839 say to nineteen ninety, right, and if you would ask 0:08:36.920 --> 0:08:39.440 me where the feathers come from, I would have told you, well, 0:08:39.520 --> 0:08:43.920 that's easy. Birds evolved feathers. Feathers are a feature that 0:08:44.000 --> 0:08:45.200 are unique to birds. 0:08:45.480 --> 0:08:46.320 Why do you think that is? 0:08:46.520 --> 0:08:49.960 Because before the nineties, you know, they were the only 0:08:50.240 --> 0:08:53.280 modern animals for which we had feathers. We hadn't discovered 0:08:53.320 --> 0:08:56.200 any fossils at that point that preserved feathers. 0:08:55.920 --> 0:08:59.000 And so the idea is that when birds evolved, part 0:08:59.040 --> 0:09:02.320 of what made them birds was that they developed feathers exactly. 0:09:02.440 --> 0:09:06.480 We thought that feathers were one of the defining characteristics 0:09:06.480 --> 0:09:10.160 of birds. And I mean, there's other features that define birds, 0:09:10.200 --> 0:09:14.920 having a really enlarge, exaggerated sternum, to have big, huge 0:09:15.160 --> 0:09:19.560 chest muscles for powering flight. Birds have special little bones 0:09:19.559 --> 0:09:22.240 in the shoulder girdle, they have special shape of their 0:09:22.280 --> 0:09:26.880 clavical These were all thought to be defining characteristics of birds, 0:09:27.080 --> 0:09:29.680 and feathers were thought to be one of those features. 0:09:29.720 --> 0:09:34.960 We simply hadn't found any fossils that had evidence of feathers. 0:09:34.920 --> 0:09:38.319 So before the nineteen nineties, we just thought feathers were 0:09:38.640 --> 0:09:41.720 a birth thing. Modern birds were the only animals we 0:09:41.760 --> 0:09:44.679 had ever seen with feathers, so we thought birds were 0:09:44.679 --> 0:09:48.880 the ones that evolved them. That basically feathers started with birds, 0:09:49.200 --> 0:09:52.640 which was a totally reasonable thing to assume. But then 0:09:52.720 --> 0:09:55.160 something happened in the mid nineteen nineties. 0:09:56.640 --> 0:09:59.199 But then in the mid nineteen nineties, the world was 0:09:59.280 --> 0:10:03.320 literally turned up side down with the dramatic discovery that 0:10:03.760 --> 0:10:06.360 some dinosaurs also had feathers. 0:10:07.320 --> 0:10:12.920 Yes, the nineties didn't just give us grunch rock. The 0:10:13.000 --> 0:10:16.840 nineties gave us one of the most significant dinosaur discoveries 0:10:17.200 --> 0:10:20.760 in history. We're gonna talk about this discovery and how 0:10:20.840 --> 0:10:25.679 it and other discoveries changed when we think feathers evolved. 0:10:26.120 --> 0:10:38.080 Stay with us. We'll be right back, and we're back Okay. 0:10:38.200 --> 0:10:41.559 Before the nineteen nineties, we thought feathers were just a 0:10:41.600 --> 0:10:44.640 bird thing, and the story everyone agreed to was that 0:10:44.760 --> 0:10:47.920 birds were the ones that evolved feathers. But then in 0:10:47.960 --> 0:10:51.080 the mid nineteen nineties there was a discovery that rocked 0:10:51.320 --> 0:10:53.280 everything we thought was true. 0:10:55.120 --> 0:10:58.480 So in the nineteen nineties there was the discovery of 0:10:58.800 --> 0:11:03.520 dinosaurs preserved soft tissues from the early Cretaceous je Hall 0:11:03.640 --> 0:11:08.280 biota of China, and the Jehall biota is now recognized 0:11:08.320 --> 0:11:12.439 as one of the most important fossil localities in the world. 0:11:12.840 --> 0:11:16.360 So these fossils are found in northeast China, and they 0:11:16.400 --> 0:11:21.479 preserve lots of different types of animals, with everything from plants, insects, turtles, 0:11:21.679 --> 0:11:26.119 some early mammals, and lots of dinosaurs. What was discovered 0:11:26.360 --> 0:11:30.840 was a dinosaur called sinosrouptrics. So Sinus ruptrics is a 0:11:30.880 --> 0:11:35.840 small little therapod dinosaur and it's only about thirty centimeters tall, 0:11:36.320 --> 0:11:41.160 and it preserves dark organic matter, dark remains of its 0:11:41.240 --> 0:11:44.680 soft tissues around the head, down the back of the neck, 0:11:44.760 --> 0:11:48.320 along the body, and along the tail. And when the 0:11:48.640 --> 0:11:52.720 Chinese research team looked at these fossils under the microscope, 0:11:52.960 --> 0:11:57.360 they could say that that brown material it actually had structure, 0:11:57.760 --> 0:12:01.479 and that structure was that it was posed of thousands 0:12:01.480 --> 0:12:05.959 of tiny filaments, and the Chinese team surmised that these 0:12:06.120 --> 0:12:09.880 filaments were in fact a very simple sort of feather. 0:12:10.960 --> 0:12:16.319 Basically, researchers in China discovered a dinosaur with feathers. It's 0:12:16.320 --> 0:12:19.280 a tiny dinosaur, only about a foot tall, and what 0:12:19.320 --> 0:12:21.840 the fossil showed was that it had kind of a 0:12:22.000 --> 0:12:25.400 mohawk running down its back and a fuzzy tail with 0:12:25.520 --> 0:12:29.360 stripes that looks sort of like the tail of a raccoon. Now, 0:12:29.440 --> 0:12:32.360 I know what you're thinking, that doesn't quite sound like feathers, 0:12:32.920 --> 0:12:36.080 and that's why this fossil was a little controversial. 0:12:37.880 --> 0:12:42.319 Now this proved massively controversial because you know, the feathers 0:12:42.360 --> 0:12:45.520 that were all very familiar with, they have that clear 0:12:45.679 --> 0:12:48.199 pattern of branching. They have the central shaft and the 0:12:48.280 --> 0:12:52.080 lateral branches. But what not many people know is that 0:12:52.360 --> 0:12:56.640 some birds do have feathers that have a very simple structure. 0:12:56.880 --> 0:13:01.480 So some birds have feathers that are just simple filaments 0:13:01.520 --> 0:13:05.880 that don't have any branching. So turkeys, for instance, they 0:13:05.920 --> 0:13:09.240 have these weird, little spiky feathers that grow out of 0:13:09.280 --> 0:13:12.960 their chin and they are bristles. They are just a 0:13:13.080 --> 0:13:16.599 simple filament. And there's a bird called the black coucal, 0:13:17.320 --> 0:13:21.160 and the black coucal the juveniles they have feathers that 0:13:21.240 --> 0:13:25.360 don't branch. So there are modern examples of these sorts 0:13:25.360 --> 0:13:28.400 of feathers, and so the Chinese team said, these are 0:13:28.640 --> 0:13:33.040 so simple in structure, it's possible that these dinosaurs are 0:13:33.120 --> 0:13:37.640 showing us some of the very earliest types of feathers. 0:13:38.720 --> 0:13:42.439 Okay, so this wasn't a clear slam dug that dinosaurs 0:13:42.400 --> 0:13:48.439 said feathers. People thought, well, they could be hairs. Well, 0:13:48.440 --> 0:13:50.040 how do we know this are not just hairs. 0:13:50.240 --> 0:13:53.600 Yeah, so that's a very good question, and to be honest, 0:13:53.880 --> 0:13:58.040 that question wasn't answered for quite some time because really, 0:13:58.080 --> 0:13:59.680 if you want to prove that they're not hairs, you 0:13:59.679 --> 0:14:02.760 need to prove that they're hollow and not solid. So 0:14:02.920 --> 0:14:07.199 for a long time those structures were really controversial because 0:14:07.360 --> 0:14:10.679 the Chinese teams they weren't doing the sort of microscopic 0:14:10.800 --> 0:14:14.720 analyzes that were necessary to prove that they were feathers. 0:14:14.800 --> 0:14:18.600 And what was really exciting was when the dinosaur Microraptor 0:14:19.000 --> 0:14:23.000 was discovered. So this is a feathered dinosaur that preserves 0:14:23.120 --> 0:14:27.080 structures that are onlyquivocally feathers. You can't argue with them 0:14:27.360 --> 0:14:30.600 because they have the shaft, they have the lateral branches, 0:14:30.760 --> 0:14:33.520 and they even have the branches on the branches. They 0:14:33.600 --> 0:14:37.160 have the barbs and the barbules, and so those are 0:14:37.200 --> 0:14:41.920 effectively modern type feathers. They're identical to the feathers that 0:14:41.920 --> 0:14:45.720 we see in modern birds. So once Microraptor was discovered, 0:14:45.880 --> 0:14:48.760 when then there was no disputing the fact that at 0:14:48.840 --> 0:14:53.120 least some dinosaurs had true modern type feathers. 0:14:54.200 --> 0:14:56.840 All right, here's a little bit of context. We've known 0:14:56.880 --> 0:15:00.560 for a while that birds evolved from dinosaurs. If you've 0:15:00.560 --> 0:15:03.480 heard of archaep terics, if also the kind of looks 0:15:03.520 --> 0:15:06.920 halfway between a dinosaur and a bird that was discovered 0:15:07.080 --> 0:15:10.520 in eighteen sixty one. What the discoveries in China did 0:15:10.920 --> 0:15:15.120 was pushed the origin of feathers back to before archaep 0:15:15.200 --> 0:15:18.760 terics and into the kind of dinosaurs that directly evolved 0:15:19.080 --> 0:15:24.400 into birds. These dinosaurs are called therapods. So after these discoveries, 0:15:24.720 --> 0:15:28.720 people thought, wow, feathers didn't start with birds. They started 0:15:28.800 --> 0:15:33.160 right before birds, in the dinosaurs that evolved into birds. 0:15:34.920 --> 0:15:38.720 So then you know our concept of rock feathers were 0:15:38.760 --> 0:15:42.000 and where they came from. We felt, well, maybe feathers 0:15:42.040 --> 0:15:46.400 are something that evolved in birds and they're very close 0:15:46.560 --> 0:15:50.400 dinosaur relatives, that they were something that evolved just in 0:15:50.480 --> 0:15:54.840 the bird like dinosaurs the therapods, and that's what we 0:15:54.920 --> 0:15:57.320 thought for pretty much twenty years. 0:15:57.920 --> 0:16:01.400 So for twenty years that was the story. Did dinosaurs 0:16:01.400 --> 0:16:05.920 of feathers? The answer was yes, a few dinosaurs, the 0:16:05.960 --> 0:16:09.600 ones that directly evolved into birds, had them, and that's 0:16:09.600 --> 0:16:14.280 when feathers started, but then that all changed in twenty thirteen. 0:16:15.880 --> 0:16:19.920 But then in twenty thirteen, we discovered a completely different 0:16:19.920 --> 0:16:22.360 type of dinosaur that's not related to the birds like 0:16:22.440 --> 0:16:24.760 dinosaurs at all, and each had feathers. 0:16:25.480 --> 0:16:28.480 Okay, let's get to the big twenty thirteen discovery. What 0:16:28.600 --> 0:16:33.240 doctor McNamara and her colleagues found was another dinosaur with feathers, 0:16:33.400 --> 0:16:35.160 but this one was different. 0:16:38.040 --> 0:16:41.880 It's an Ornithiskian dinosaur, so in the same family as 0:16:42.400 --> 0:16:47.880 viserah Thops and ankylosaurs, you know, these big, lumbering kind 0:16:47.920 --> 0:16:52.560 of beasts. So we found a quart repeated dinosaur, a herbivore. 0:16:53.160 --> 0:16:55.760 Each had feathers, and it didn't just have one type 0:16:55.760 --> 0:16:58.840 of feathers, it had three types of feathers, So that 0:16:59.080 --> 0:17:00.560 really rocked the world. 0:17:01.640 --> 0:17:05.639 What they found was a dinosaur they called Colinda dromuse, 0:17:05.880 --> 0:17:09.280 and it had hair like feathers on its head, chests, 0:17:09.320 --> 0:17:12.439 and legs. And what's significant about this dinosaur is that 0:17:12.480 --> 0:17:15.960 it's on a totally different branch of dinosaurs than the 0:17:16.040 --> 0:17:20.000 dinosaurs that evolved into birds. This one is more related 0:17:20.040 --> 0:17:23.359 to Triceratops, which is the big four legged dinosaur with 0:17:23.480 --> 0:17:27.120 the three horns, and this means feathers were even older 0:17:27.160 --> 0:17:28.080 than people. 0:17:27.840 --> 0:17:34.640 Thought by finding feathers in a more primitive dinosaur. If 0:17:34.680 --> 0:17:37.800 these two groups of dinosaurs had them, well, that kind 0:17:37.840 --> 0:17:42.120 of implies that the genetic machinery for making feathers may 0:17:42.200 --> 0:17:46.960 have actually evolved very early during dinosaur evolution, so that 0:17:47.080 --> 0:17:51.560 these distantly related types of dinosaurs had the ability to 0:17:51.600 --> 0:17:52.720 produce feathers. 0:17:53.119 --> 0:17:56.520 What doctor McNamara is saying is that the fact two 0:17:56.560 --> 0:18:01.679 distant dinosaur cousins had feathers implies that their ancestor also 0:18:01.720 --> 0:18:03.760 had feathers. It's sort of like if you and your 0:18:03.800 --> 0:18:07.280 cousin have the same gene, the gene probably didn't start 0:18:07.320 --> 0:18:10.320 with you. You both probably got it from your common 0:18:10.400 --> 0:18:14.280 grandmother or grandfather. This meant that feathers didn't start with 0:18:14.359 --> 0:18:17.840 the dinosaurs that became birds. They go back even further. 0:18:19.440 --> 0:18:22.479 There is also the option that maybe two groups of 0:18:22.520 --> 0:18:27.440 dinosaurs evolved feathers independently, but we actually considered it much 0:18:27.480 --> 0:18:33.680 more likely that this shared possession of feathers reflects common ancestry, 0:18:33.880 --> 0:18:37.080 that they were present in the common ancestor. So that 0:18:37.240 --> 0:18:41.080 was the stage of play for about six or seven years. 0:18:41.560 --> 0:18:45.399 That's right. That story only lasted about six years. And 0:18:45.440 --> 0:18:49.000 that's because in twenty nineteen, doctor McNamara and her colleagues 0:18:49.200 --> 0:18:53.359 found another fossil that totally threw that story out the window. 0:18:54.640 --> 0:18:57.000 When we come back, we'll talk about that discovery and 0:18:57.040 --> 0:19:01.720 we'll hear from our experts why scientists thinks evolved. Stay 0:19:01.760 --> 0:19:15.879 with us, you're listening to science stuff. Welcome back, all right. 0:19:15.960 --> 0:19:19.359 We're telling the story of what we know about dinosaurs 0:19:19.400 --> 0:19:24.119 and feathers. In twenty thirteen, palontologist doctor Maria McNamara was 0:19:24.200 --> 0:19:27.600 part of a team that made a remarkable discovery. The 0:19:27.720 --> 0:19:31.040 fund feathers is a distant cousin of the dinosaurs that 0:19:31.200 --> 0:19:34.919 eventually evolved into birds. And this meant that feathers didn't 0:19:34.960 --> 0:19:38.560 evolve with birds, nor did they evolve with the dinosaurs 0:19:38.560 --> 0:19:42.360 that became birds. Other dinosaurs had them, which meant the 0:19:42.359 --> 0:19:46.800 origin of feathers went back even further. But how far back, 0:19:47.080 --> 0:19:51.760 which dinosaur ancestor was it that first evolved feathers. The answer, 0:19:51.880 --> 0:19:55.760 it turned out, was even more surprising than anyone expected. 0:19:57.680 --> 0:20:01.440 That was the stage of play for about six seven years, 0:20:01.880 --> 0:20:06.119 and then in twenty nineteen we discovered feathers in a 0:20:06.240 --> 0:20:11.680 completely different group of animal. We discovered feathers in pterosaurs. 0:20:12.760 --> 0:20:16.159 That's right, Doctor McNamara and her colleagues found feathers in 0:20:16.280 --> 0:20:21.840 animals that aren't even dinosaurs. They found feathers in pterosaurs. Now, 0:20:21.920 --> 0:20:23.520 what are pterosaurs. 0:20:25.560 --> 0:20:29.440 These are the giant flying reptiles, the cousins of dinosaurs 0:20:29.640 --> 0:20:33.760 that roamed the skies during much of the Mesozoic. So 0:20:33.800 --> 0:20:38.440 we found these little baby pterosaurs, these two juveniles from 0:20:38.520 --> 0:20:44.160 China that literally had feathers covering their entire bodies, and 0:20:44.520 --> 0:20:47.800 they had four different types of feathers. They had some 0:20:48.119 --> 0:20:51.280 simple hair like feathers that we have found on lots 0:20:51.320 --> 0:20:54.680 of dinosaurs and that are also present in modern birds, 0:20:54.920 --> 0:20:58.560 and three types of branched feather feathers that branch at 0:20:58.560 --> 0:21:01.399 the base, feathers that branch and shaffway along the shaft, 0:21:01.640 --> 0:21:04.280 and even some feathers that branch at the tip. So 0:21:04.320 --> 0:21:07.200 we find these in these juvenile terosaurs. 0:21:08.080 --> 0:21:11.440 So they found feathers, real feathers in animals that are 0:21:11.480 --> 0:21:14.639 not dinosaurs. They're more like the cousins the whole group 0:21:14.760 --> 0:21:18.600 of dinosaurs. Now what does this mean, Well, there are 0:21:18.600 --> 0:21:23.920 two possibilities. Either pterosaurs, the flying cousins of dinosaurs, also 0:21:24.000 --> 0:21:28.480 evolved feathers, and the feathers look the same by sheer coincidents, 0:21:28.960 --> 0:21:32.320 or feathers evolved way in the past before these two 0:21:32.359 --> 0:21:36.719 groups of animals branched off. Now, the first possibility that 0:21:36.800 --> 0:21:39.720 both groups of animals involved feathers and they look the 0:21:39.760 --> 0:21:44.400 same by sheer coincidents does sometimes happen in nature. It's 0:21:44.400 --> 0:21:49.320 called convergent evolution. For example, birds evolved wings, but so 0:21:49.480 --> 0:21:53.520 that bats and sharks evolved fins and a streamlined body, 0:21:53.760 --> 0:21:56.400 but so that whales. But in the case of feathers, 0:21:56.560 --> 0:22:01.400 paleontologists argue this is very unlike likely. Here's how doctor 0:22:01.480 --> 0:22:03.280 Jingme O'Connor explains it. 0:22:04.720 --> 0:22:08.280 The one of the ways that paleontology makes hypotheses is 0:22:08.320 --> 0:22:10.920 based on the principle of parsimony. 0:22:11.800 --> 0:22:17.199 Okay, parsimony in general means being economical or cheap, but 0:22:17.400 --> 0:22:19.520 in the context of science, it means that if you 0:22:19.560 --> 0:22:23.159 have two possibilities, usually the one that's right is the 0:22:23.280 --> 0:22:26.879 simpler one. If you've heard of Alkham's razor, it's pretty 0:22:26.960 --> 0:22:27.920 much the same thing. 0:22:29.800 --> 0:22:34.840 It's basically assuming that instead of evolution evolving these feathers 0:22:34.920 --> 0:22:38.480 in pterosaurs and then also evolving them a different time 0:22:38.640 --> 0:22:42.480 in dinosaurs. Since these groups are so closely related, it 0:22:42.520 --> 0:22:46.840 would be most parsimonious that the common ancestor of these 0:22:46.880 --> 0:22:49.840 two groups already had these features. And the reason it's 0:22:49.880 --> 0:22:53.440 present in pterosaurs and dinosaurs is because they both inherited it. 0:22:54.000 --> 0:22:56.040 What doctor O'Connor is saying is that it would be 0:22:56.080 --> 0:23:00.600 a stretch for both dinosaurs and pterosaurs to evolve feathers 0:23:00.880 --> 0:23:04.720 independently out of the blue, especially because a the two 0:23:04.760 --> 0:23:08.080 groups of animals are closely related, so it's not a 0:23:08.119 --> 0:23:11.399 stretch to imagine their common ancestor had feathers, and b 0:23:11.880 --> 0:23:16.240 Feathers are complex, They're not easy to just suddenly evolve. 0:23:18.240 --> 0:23:24.119 Feathers are complex structures, complex poratinous outgrowths. So the more 0:23:24.119 --> 0:23:27.680 complex the structure is, like, the more unlikely it is 0:23:27.760 --> 0:23:31.439 to evolve, you know, rather than having these complex like 0:23:31.560 --> 0:23:35.600 caoratinous external structures evolving a bunch of different times and 0:23:35.720 --> 0:23:39.560 all these dinosaurs and also in pterosaurs, it makes more sense, 0:23:39.760 --> 0:23:43.720 or it's more parsimonious for it to evolve once in 0:23:43.760 --> 0:23:44.760 the common ancestor. 0:23:45.440 --> 0:23:49.000 And if you assume feathers evolved in a distant ancestor 0:23:49.080 --> 0:23:53.639 of dinosaurs and pterosaurs, it means that feathers evolved before 0:23:54.200 --> 0:23:55.560 dinosaurs existed. 0:23:57.240 --> 0:24:00.200 We favor the idea that the presence of feather is 0:24:00.320 --> 0:24:04.960 in terosaurs and dinosaurs. We feel that this implies that 0:24:05.040 --> 0:24:09.640 the genetic networks required to grow feathers must have evolved 0:24:09.680 --> 0:24:13.480 in the common ancestor of pterosaurs and dinosaurs, and that 0:24:13.600 --> 0:24:18.600 common ancestor we predicted would have lived seventeen million years 0:24:18.800 --> 0:24:20.240 earlier than both. 0:24:21.280 --> 0:24:24.520 And this leads to the shocking answer I promised. If 0:24:24.560 --> 0:24:28.560 feathers evolved before dinosaurs became their own branch of animals, 0:24:28.840 --> 0:24:32.800 it means the ancestor of all dinosaurs had feathers, which 0:24:32.840 --> 0:24:37.200 means all dinosaurs had feathers. It's not that a few 0:24:37.280 --> 0:24:41.120 dinosaurs and feathers, or that some dinosaurs had them. They 0:24:41.280 --> 0:24:44.439 all had feathers, or at least they all had the 0:24:44.560 --> 0:24:48.280 genes the ability to grow feathers. We'll get to what 0:24:48.320 --> 0:24:50.880 that means in a minute, but first it turns out 0:24:51.080 --> 0:24:55.520 that's not the end of the story. 0:24:54.560 --> 0:24:57.280 And that was the accepted state of play for the 0:24:57.400 --> 0:25:00.760 last few years and most of the community. You know, 0:25:00.880 --> 0:25:03.800 we're happy with the evidence that we put forward that 0:25:03.840 --> 0:25:08.280 these structures were feathers, because we had evidence from microscopic analyzes. 0:25:08.480 --> 0:25:12.600 We had evidence from chemical analyzes that they basically contained 0:25:12.680 --> 0:25:15.760 the same sorts of pigment granules as feathers, and they 0:25:15.800 --> 0:25:18.480 contained you know that we had chemical evidence for the 0:25:18.560 --> 0:25:22.000 kerot and protein. But this year we produced really a 0:25:22.040 --> 0:25:23.520 quite shocking discovery. 0:25:23.840 --> 0:25:26.199 What another shocking discovery. 0:25:26.920 --> 0:25:30.240 We were looking in some early Triassic rocks. We were 0:25:30.440 --> 0:25:35.840 looking at animals that really they are very distant relatives 0:25:35.880 --> 0:25:39.800 of dinosaurs and pterosaurs, and we found that some of 0:25:39.880 --> 0:25:46.600 these very early Triassic reptiles, they preserve this remarkable structure 0:25:47.000 --> 0:25:51.160 on their back that's made of these materials which look 0:25:51.560 --> 0:25:55.240