WEBVTT - Fossil Action Scenes: Dino Birth and Prehistoric Combat 0:00:03.040 --> 0:00:05.840 Welcome to stuff to blow your mind from house up 0:00:05.920 --> 0:00:30.240 works dot com. The allosaurus attacks, his teeth plunge like knives. 0:00:30.960 --> 0:00:36.519 The Diplodocus's skin turns ragged and red. The allosaurus bites deeper, 0:00:37.360 --> 0:00:41.519 his claws gripped her belly. A frightened diplodocus roars to 0:00:41.600 --> 0:00:46.720 the herd. Another diplodocus swings his rump sideways. His bony 0:00:46.760 --> 0:00:50.479 tail snaps like a whip through the air. The allosaurus 0:00:50.560 --> 0:00:55.400 falls back, his eyes sting like fire. The mother quetsoco 0:00:55.480 --> 0:00:59.640 Atlas jerks backwards in fear. She hears her maid calling 0:00:59.720 --> 0:01:04.560 as he flies overhead. Too late. The dromeo Saurus attack. 0:01:05.080 --> 0:01:10.120 They swallow eggs hole, they rip leathery wings. The quetso 0:01:10.200 --> 0:01:13.800 co Atlas swoops down as near he dares he sees 0:01:13.880 --> 0:01:20.080 and understands. He turned sharply away. I am quetzo co Atlas. 0:01:20.120 --> 0:01:23.680 The ground trembles below me. I glide over the rock 0:01:23.800 --> 0:01:28.880 ledge and soar into the sky. Hey, you welcome to 0:01:28.880 --> 0:01:30.960 stuff to blow your mind. My name is Robert Lamb, 0:01:31.000 --> 0:01:33.759 and I'm Joe McCormick. And Robert I gotta ask, when 0:01:33.880 --> 0:01:36.880 you are at home reading dinosaur books with your son, 0:01:37.120 --> 0:01:39.720 do you read them out loud in that Tulsa Doom 0:01:39.800 --> 0:01:41.759 voice you just did. Yes, if I can get away 0:01:41.800 --> 0:01:45.520 with it, I use voices, but sometimes he just says, 0:01:45.640 --> 0:01:48.680 use your regular voice, dad, and I I have to 0:01:48.720 --> 0:01:52.920 oblige or he could just grow up thinking that Fulsa 0:01:52.920 --> 0:01:58.160 Doom is his dad. Well, these books in particular really 0:01:58.200 --> 0:02:02.080 really encourage a very dramatic reading. Now who wrote these 0:02:02.080 --> 0:02:04.680 two we were looking at it was two different books. Yes, 0:02:04.720 --> 0:02:08.320 now these are. One book is called I Am Quetzalcoatlas 0:02:08.480 --> 0:02:11.240 and the other one is I Am Diplodocus. These were 0:02:11.240 --> 0:02:15.399 written by Karen Wallace and illustrated by Mike Bostock. Now, 0:02:15.560 --> 0:02:17.919 you sent me a link to these on Amazon, and 0:02:17.960 --> 0:02:19.880 I went and looked it up, and it is so 0:02:19.960 --> 0:02:23.480 funny because there is just one star review is coming 0:02:23.520 --> 0:02:28.040 out the eye sockets. People are mad about these books. Yeah, 0:02:28.120 --> 0:02:29.920 the first of all, I want to get out there. 0:02:29.919 --> 0:02:32.320 These are great books. I highly recommend. These are five 0:02:32.320 --> 0:02:34.600 star books in my opinions. These are these are dinosaur 0:02:34.680 --> 0:02:37.680 children's but dinosaur children's books. And uh. And when I 0:02:37.720 --> 0:02:39.840 say I love them, I'm not being like ironic, like, 0:02:39.880 --> 0:02:41.919 oh it's a horrible book, and you know it's but 0:02:42.280 --> 0:02:44.320 I but I find something weird about them. Now, these 0:02:44.360 --> 0:02:47.840 are these are great dinosaur books, but they are a 0:02:47.880 --> 0:02:51.120 bit dark, or at least they're a bit realistic. You know, 0:02:51.440 --> 0:02:54.000 so many dinosaur books are like kids having adventures with 0:02:54.040 --> 0:02:58.240 dinosaurs or things are kind of whitewashed. No, these these 0:02:58.240 --> 0:03:01.959 books encourage the child to look through the eyes of 0:03:01.960 --> 0:03:06.920 of of an animal living in an in an ancient time, uh, 0:03:07.160 --> 0:03:11.560 competing for resources, having to deal with the relentless predators, 0:03:12.160 --> 0:03:15.800 encountering death and injury, and and I think all the 0:03:15.800 --> 0:03:19.919 ones I've read end in death. Uh. But and it's 0:03:19.960 --> 0:03:22.760 weird because when I read the first one to my son, 0:03:22.840 --> 0:03:26.040 which I think was the quets solco Atlas one, I 0:03:26.080 --> 0:03:28.639 was reading it for the first time allowed to him, 0:03:28.680 --> 0:03:31.840 and we were getting to the violence, and then we 0:03:31.840 --> 0:03:36.200 were getting to the part where the male Quetsoco Atlas 0:03:36.200 --> 0:03:39.120 flies over and sees his family consumed by predators, and 0:03:39.120 --> 0:03:41.560 I was like, oh my god, my kid's gonna lose it. 0:03:41.600 --> 0:03:44.520 This is too dark, this is too violent. He doesn't 0:03:44.760 --> 0:03:48.200 he makes a skip over predation and documentaries. He's not 0:03:48.240 --> 0:03:52.960 crazy about super dramatic scenes in children's movies, so I 0:03:53.000 --> 0:03:54.760 didn't think he'd be able to handle this, but he did. 0:03:54.800 --> 0:03:57.720 He loved it, and and he has this, I don't know, 0:03:57.720 --> 0:04:00.880 an interesting disconnect where if it's dying a saur violence, 0:04:01.240 --> 0:04:03.600 it's okay. If he has a whole book about like 0:04:03.640 --> 0:04:06.200 it's called The Death of the Dinosaurs, it's a kid's 0:04:06.240 --> 0:04:09.520 book in which it's just it's basically Corman McCarthy's The 0:04:09.600 --> 0:04:13.600 Road with Dinosaurs, Death after Death after Death. And he 0:04:13.800 --> 0:04:15.200 and after we read it, he was like, oh, that's 0:04:15.200 --> 0:04:16.960 a great book. I love that. Yeah, there is no 0:04:17.080 --> 0:04:21.240 God and we are his dinosaur prophets. Uh. And indeed, 0:04:21.279 --> 0:04:24.320 one of the reviews for the uh for the book 0:04:24.480 --> 0:04:27.200 by Karen Wallace, I am a t rex Ryan Toronto 0:04:27.279 --> 0:04:30.800 Tyronosaurs Rex. Uh. One of the one star reviews, someone said, 0:04:30.839 --> 0:04:33.240 this reads like a Cormy McCarthy novel. They did, and 0:04:33.279 --> 0:04:35.040 I agree with them, but in a good way, in 0:04:35.080 --> 0:04:37.320 a five star way. A lot of these one star 0:04:37.360 --> 0:04:40.440 reviews featured lots of direct quotes from the books, like 0:04:40.600 --> 0:04:47.880 lists of words ripping, slicing, slashing, tearing, and thieving. I'm sorry, whoever, 0:04:47.920 --> 0:04:51.800 I just quoted from the internet, but uh, yeah, yeah, yeah, 0:04:51.839 --> 0:04:54.000 I mean there there is a certain way in which 0:04:54.040 --> 0:04:59.839 I understand how dinosaur violence can seem different than violence 0:04:59.880 --> 0:05:02.279 the it's taking place in the present. I mean, for 0:05:02.400 --> 0:05:08.840 one thing, we definitely do have a time desensitization mechanism 0:05:08.960 --> 0:05:11.680 in our brains. And in the same way that if 0:05:11.720 --> 0:05:16.240 you hear about how yesterday a thousand people were massacred, 0:05:16.279 --> 0:05:20.120 that is a heartbreaking tragedy. But if you hear about 0:05:20.520 --> 0:05:23.560 how a thousand years ago a thousand people were massacred, 0:05:23.600 --> 0:05:27.680 it's fodder for jokes. It just doesn't it just doesn't 0:05:27.720 --> 0:05:29.719 resonate in the same way. I guess it was no 0:05:29.839 --> 0:05:32.440 less tragic then, but it just really doesn't hit you. 0:05:33.560 --> 0:05:36.360 And dinosaurs may suffer from that, but I think they 0:05:36.480 --> 0:05:40.800 also are subject to a kind of conditioning in the 0:05:40.880 --> 0:05:44.359 brain that comes from dinosaur illustrations, which is that, at 0:05:44.440 --> 0:05:46.600 least in my mind. Maybe maybe this is not true 0:05:46.640 --> 0:05:49.400 across the board, but when I scan my memory of 0:05:49.480 --> 0:05:54.599 dinosaur illustrations from my childhood, they're always action scenes. Something 0:05:54.680 --> 0:05:57.680 violent is happening or is about to happen. It's not 0:05:57.720 --> 0:06:01.120 just lots of pictures of you know, some herbivore standing 0:06:01.160 --> 0:06:05.240 around in the water, drinking water, eating leaves, maybe a 0:06:05.320 --> 0:06:10.000 carnivore just basking in the sun. There's always feeding imminent 0:06:10.320 --> 0:06:14.120 or or fighting taking place. Something's leaping at something else, 0:06:14.279 --> 0:06:19.280 mouth open, claws extended, they're wrestling. I think of that, Uh, well, 0:06:19.320 --> 0:06:22.000 this wouldn't be dinosaurs, but it would be prehistoric animals. 0:06:22.040 --> 0:06:25.680 I think of that iconic image of the saber tooth cat, 0:06:25.800 --> 0:06:28.120 and it's some other scavenger I don't remember what, maybe 0:06:28.160 --> 0:06:31.919 a dire wolf fighting over a mammoth carcass. Yeah, I 0:06:31.920 --> 0:06:35.640 mean paleo art is rich. There's there are a lot 0:06:35.680 --> 0:06:37.800 of just wonderful works there. I mean, especially when you're 0:06:37.839 --> 0:06:40.919 dealing with with actual painted paleo art and and not 0:06:41.120 --> 0:06:43.720 some of the c g I stuff. You find a 0:06:43.720 --> 0:06:46.840 lot of the times now and you do have scenes 0:06:46.880 --> 0:06:49.839 of like peaceful duck built dinosaurs out in the water. 0:06:49.960 --> 0:06:51.719 But the ones that stick with us, and the certainly 0:06:51.760 --> 0:06:53.880 the ones that I remember from dinosaur books to chin 0:06:54.200 --> 0:06:57.360 and then I'm rediscovering now with my almost five year old, 0:06:58.200 --> 0:07:01.880 are these scenes, like you say, I'm drum attic encounters 0:07:01.920 --> 0:07:06.800 of a one dinosaur battling another herbivore versus predator duking 0:07:06.880 --> 0:07:10.320 it out in a prehistoric landscape. I mean, that's the 0:07:10.320 --> 0:07:12.440 stuff that draws us in usually also there's like a 0:07:12.520 --> 0:07:16.200 volcano or roughing in the background. Why is that, Well, 0:07:17.080 --> 0:07:19.600 you know, I guess tying in like the whole extinct, 0:07:19.720 --> 0:07:21.800 like the the extinction of the dinosaurs is wrapped up 0:07:21.800 --> 0:07:25.000 in them. They're like the Norse gods, of of of 0:07:25.080 --> 0:07:28.680 prehistoric creatures. True, yeah, they existed for like tens of 0:07:28.760 --> 0:07:31.480 millions of years, and yet in our minds they're constantly 0:07:31.520 --> 0:07:35.560 going extinct. But but you're right, there's almost always a volcano. 0:07:35.640 --> 0:07:39.960 It's like two animals fighting volcano in the background. Crazy 0:07:40.040 --> 0:07:43.280 like the fight scenes you see for dinosaurs, Like how 0:07:43.320 --> 0:07:46.440 often do you encounter something that climactic even in our 0:07:46.480 --> 0:07:51.760 biggest blockbusters, like two to combatants battling killing each other 0:07:51.760 --> 0:07:55.720 as a volcano erupts in the background. Um, it's crazy stuff. 0:07:55.960 --> 0:07:57.720 I guess that's how it's got to be. And you 0:07:57.720 --> 0:08:00.760 know what, it's probably not the fact or not the 0:08:00.800 --> 0:08:03.320 case that that's really what the dominant art is is. 0:08:03.360 --> 0:08:05.680 Just that's what I remember. I think you it makes 0:08:05.680 --> 0:08:07.960 an impact. You know, you've probably called that out right. 0:08:08.600 --> 0:08:12.280 But one thing that's kind of cool is that you 0:08:12.400 --> 0:08:15.520 don't have to go to fiction to find a few 0:08:15.560 --> 0:08:18.920 of these crazy action scenes from the prehistoric world, and 0:08:18.960 --> 0:08:22.400 this brings us to our topic today. Robert, you suggested 0:08:22.440 --> 0:08:27.160 this episode and the idea is fossil action scenes. Now, 0:08:27.200 --> 0:08:28.840 what made you want to do this? Was it just 0:08:28.880 --> 0:08:32.200 reading these books? Yeah? It was really um. I mean 0:08:32.240 --> 0:08:34.600 I encountered stories about some of the some of these 0:08:34.640 --> 0:08:37.079 major finds before. But when I read to my son 0:08:37.080 --> 0:08:39.800 about dinosaurs, I I read some of these kids books. 0:08:39.840 --> 0:08:43.439 But we also go through the Macmillian Illustrated Encyclopedia of 0:08:43.480 --> 0:08:46.640 Dinosaurs and Prehistoric Animals, which is an older book, and 0:08:46.720 --> 0:08:48.720 certainly as we read through it, we have I have 0:08:48.800 --> 0:08:51.760 to remind myself that I'm not dealing with a recent text. 0:08:51.800 --> 0:08:55.040 It's like twenty or maybe thirty years old at this point, 0:08:55.240 --> 0:08:57.800 so it's probably got some outdated info. But man, those 0:08:57.840 --> 0:09:00.520 illustrations make up for that is gorgeous. Us. I'm looking 0:09:00.520 --> 0:09:02.880 at it right now. It's a gorgeous, gorgeous book. Imagine 0:09:02.880 --> 0:09:04.520 some of you listening and grew up with it as well. 0:09:04.679 --> 0:09:06.600 But it makes mention of some of these As we 0:09:06.600 --> 0:09:10.960 read the more in depth discussions on these these different 0:09:11.000 --> 0:09:14.160 fossil finds, it'll mention. Oh yeah, there is an encounter 0:09:14.280 --> 0:09:19.200 between protoceratops and this particular predator. Uh and and and 0:09:19.400 --> 0:09:22.920 we've learned a lot from what this creature consisted of 0:09:22.960 --> 0:09:26.440 based on this fossil find. Now you might be wondering, well, 0:09:26.480 --> 0:09:28.760 why why would that be such a special thing. I mean, 0:09:28.840 --> 0:09:32.600 these animals live for millions of years and they get fossilized. 0:09:32.640 --> 0:09:34.800 So why wouldn't we see all kinds of action scenes 0:09:34.800 --> 0:09:37.000 in the fossil record? Why is that a rare and 0:09:37.080 --> 0:09:40.160 wonderful thing to come across? Well, you have to think 0:09:40.200 --> 0:09:43.280 a little bit about the conditions under which fossils arise 0:09:43.360 --> 0:09:46.720 to understand why this really shouldn't happen all that often. Yeah, 0:09:46.800 --> 0:09:49.120 and really it makes it makes these encounters all the 0:09:49.160 --> 0:09:52.719 more amazing. So so yeah, stick stick with us here 0:09:52.720 --> 0:09:56.720 as we dive into just how fossilization occurs. Right, Okay, 0:09:57.400 --> 0:10:01.160 So when we think of fossils, were usually thinking of bones, 0:10:01.400 --> 0:10:04.240 But that's actually a little bit narrow because a fossil, 0:10:04.320 --> 0:10:06.959 in reality, as the term would be used by somebody 0:10:06.960 --> 0:10:11.400 who works in paleontology or biology, is a physical remnant 0:10:11.720 --> 0:10:15.120 of any kind left behind by an organism that lived 0:10:15.160 --> 0:10:18.800 in a previous geological age. So these could be things 0:10:18.840 --> 0:10:24.040 like preserved footprints or eggs or nest sites, burrows, things 0:10:24.040 --> 0:10:27.120 like that are sometimes fossilized. Or of course it could 0:10:27.120 --> 0:10:29.920 be the things were more familiar with body parts themselves. 0:10:29.960 --> 0:10:32.760 If it's more recent, it might even include maybe uh, 0:10:32.840 --> 0:10:36.559 soft tissue encased in ice or resin and stuff like that. 0:10:36.600 --> 0:10:40.199 But more often with the much longer extinct animals we're 0:10:40.240 --> 0:10:45.199 talking about, uh, fossilized bones, these geological entities that come 0:10:45.240 --> 0:10:49.560 up from the bedrock. Now, the vast majority of animals 0:10:49.600 --> 0:10:53.760 that die don't get fossilized. And you can probably figure 0:10:53.800 --> 0:10:55.760 this out if you just do a little mental math 0:10:55.800 --> 0:10:59.760 about how many organisms have ever existed and how you're 0:10:59.800 --> 0:11:04.440 not constantly wading through fossils on planet Earth. Um, there 0:11:04.440 --> 0:11:06.440 are a bunch of hurdles you have to pass through 0:11:06.679 --> 0:11:10.000 to turn from a regular dead animal into a fossil. 0:11:10.600 --> 0:11:13.360 First of all, fossilization is going to strongly prefer animals 0:11:13.360 --> 0:11:18.040 with hard body parts, right, you want to have bones, teeth, shells, 0:11:18.360 --> 0:11:21.520 animals that don't have hard body parts. If you're a 0:11:21.640 --> 0:11:25.440 jelly fish or a slug or something like that, you're 0:11:25.520 --> 0:11:30.959 almost always going to decompose entirely and just disappear into history. Also, 0:11:31.040 --> 0:11:35.120 fossilization depends very much on the environment. It's much more 0:11:35.160 --> 0:11:39.200 likely to happen in an environment that promotes rapid burial, 0:11:39.400 --> 0:11:41.880 because you can think about it, it's pretty intuitive. Actually, 0:11:41.920 --> 0:11:46.640 the longer a dead organism lies exposed to the open environment, 0:11:46.760 --> 0:11:48.880 the you know, the seafloor or the air or whatever 0:11:48.920 --> 0:11:51.520 it might be, the more vulnerable it is to all 0:11:51.600 --> 0:11:54.080 kinds of pressures that would destroy it. So this could 0:11:54.120 --> 0:12:01.040 be scavenging, scavenging by animals, decomposition by microbial life, erosion 0:12:01.280 --> 0:12:04.720 by forces like wind and tidal action and stuff like that, 0:12:04.800 --> 0:12:08.000 and just general destruction. If you're sitting out in the open, 0:12:08.679 --> 0:12:10.680 the parts of your body, even the hard parts of 0:12:10.679 --> 0:12:14.280 your body, you're gonna get worn down and destroyed over time. Yeah, 0:12:14.320 --> 0:12:16.440 I mean I always think that too. When I when 0:12:16.440 --> 0:12:18.640 I was a kid and I lived in a rural area, 0:12:19.080 --> 0:12:21.400 we'd go the same way to school every day or 0:12:21.440 --> 0:12:24.480 into town every day, and there was a dead fox 0:12:24.520 --> 0:12:26.679 at one point, and every maybe it was a coyote, 0:12:26.720 --> 0:12:29.040 I can't remember, but every time you pass, there'd be 0:12:29.080 --> 0:12:32.640 a little less of it, would be a little more scattered, because, yeah, 0:12:32.640 --> 0:12:35.280 a body is going in a natural environment, it's just 0:12:35.280 --> 0:12:38.240 gonna be scavenged and torn apart, and then it's going 0:12:38.280 --> 0:12:41.679 to break down like that. That coyote is never going 0:12:41.720 --> 0:12:44.000 to be a fossil. Uh. The route where I walk 0:12:44.120 --> 0:12:50.040 my dog Charlie has of late had a slowly settling 0:12:50.240 --> 0:12:53.720 pile of fur with a couple of visible jawbones and 0:12:53.800 --> 0:12:56.280 teeth and stuff. Not sure what that was. At some 0:12:56.360 --> 0:13:00.080 point it was something mammalian. Uh. And yeah, you you 0:13:00.160 --> 0:13:03.920 just watch it over time disappear. So, yeah, that's what 0:13:04.000 --> 0:13:05.960 happens out in the open. So for this reason, if 0:13:05.960 --> 0:13:07.640 you want to turn into a fossil, if you want 0:13:07.640 --> 0:13:09.720 to be preserved, you want to be in a sediment 0:13:09.880 --> 0:13:12.720 forming environment. That would be an area like the bottom 0:13:12.760 --> 0:13:15.360 of the sea floor, where there's a good deposition of 0:13:15.400 --> 0:13:18.200 sediment on top of you. And this is one reason 0:13:18.280 --> 0:13:20.840 you're going to see way more fossils of water dwelling 0:13:20.880 --> 0:13:24.400 animals than you do of land dwelling animals. But rapid 0:13:24.400 --> 0:13:27.680 burial can also happen in some other situations, for example, 0:13:27.800 --> 0:13:30.560 on land where there are sand dunes and the desert 0:13:30.640 --> 0:13:33.680 that might quickly bury an animal body that you know, 0:13:33.720 --> 0:13:36.200 if a sand dune collapses or gets blown by wind 0:13:36.280 --> 0:13:38.760 over the body or in an area where some kind 0:13:38.760 --> 0:13:42.720 of moving water flow. Alluvial areas can wash sediment over 0:13:42.720 --> 0:13:46.040 the body and bury it that way. Of course, over time, 0:13:46.080 --> 0:13:48.640 we know what happens to sediment under pressure. It gets 0:13:48.679 --> 0:13:53.720 turned into rocks and solidified in various ways. But even 0:13:53.800 --> 0:13:56.880 if an organism is quickly buried, that doesn't necessarily mean 0:13:56.960 --> 0:13:58.880 it's going to turn into a fossil. Then you you've 0:13:58.920 --> 0:14:01.280 still got a few hurdles, one of which is that 0:14:01.360 --> 0:14:05.719 it has to undergo some geological transformation. When you come 0:14:05.760 --> 0:14:11.400 across dinosaur bones in the museum, they're not really the 0:14:11.440 --> 0:14:14.679 bones of the dinosaur that you're looking at. What what 0:14:14.760 --> 0:14:18.800 you're looking at as a kind of geological photocopy in 0:14:18.840 --> 0:14:22.160 a sense. Uh So. One of the processes by which 0:14:22.200 --> 0:14:25.760 this happens is known as per mineralization. And this is 0:14:25.800 --> 0:14:31.080 when you've got groundwater that trickles around and through a dead, 0:14:31.200 --> 0:14:34.800 buried organism, and as it trickles through the organism, it 0:14:34.840 --> 0:14:38.000 carries these minerals with it, dissolved minerals in the water 0:14:38.960 --> 0:14:41.800 and leave some of them behind. So the mineral laden 0:14:41.800 --> 0:14:45.280 water fills all these little microscopic gaps and pores in 0:14:45.360 --> 0:14:48.520 your bones, and it deposits some of those minerals that 0:14:48.560 --> 0:14:51.800 it carries in those empty spaces, and then over time 0:14:51.880 --> 0:14:55.520 these minerals accumulate and crystallize throughout the structure of the bone, 0:14:55.840 --> 0:14:59.600 essentially turning the bone into a rock in the shape 0:14:59.600 --> 0:15:03.120 of the original bone. I have to admit, like looking 0:15:03.200 --> 0:15:05.640 back on my own history of dinosaurs, I think I 0:15:05.680 --> 0:15:08.520 had a sense of sadness when I learned for the 0:15:08.560 --> 0:15:12.880 first time that dinosaur bones are not actual dinosaur bones, 0:15:12.880 --> 0:15:16.360 that they are their fossils. Of course, it's it's still amazing, 0:15:16.560 --> 0:15:19.120 but but I think I feel like there's there's a 0:15:19.120 --> 0:15:21.600 certain sadness that can sink in when you when you 0:15:21.640 --> 0:15:23.720 first have to realize, oh, this is it's not as 0:15:23.800 --> 0:15:27.600 simple as the bones of the creature that I'm trying 0:15:27.600 --> 0:15:30.520 to imagine. Well, while these processes do go on, I 0:15:30.560 --> 0:15:33.120 can't say for sure that it's like none of the 0:15:33.160 --> 0:15:35.800 original bone is left. I'm not actually sure about that. 0:15:36.080 --> 0:15:38.400 You know, some part of it may remain in in 0:15:38.400 --> 0:15:41.280 the process like per mineralization. Of course, I also have 0:15:41.320 --> 0:15:43.600 to add that when you're at the museum, you're also 0:15:44.120 --> 0:15:45.960 looking at you might be looking at a specimen for 0:15:46.000 --> 0:15:49.200 which and there there is no complete skeleton, and they're like, 0:15:49.720 --> 0:15:52.920 you know, casts created based on projections. And in some 0:15:53.120 --> 0:15:56.240 museums you might go to, especially smaller museums, you might 0:15:56.280 --> 0:16:00.800 be looking at an entire replica as opposed to actual fossls, 0:16:00.920 --> 0:16:03.160 and a good museum will tell you the difference. I mean, 0:16:03.400 --> 0:16:06.000 for example, the American Museum of Natural History in New York. 0:16:06.040 --> 0:16:09.680 I remember going through their big fossil exhibits. They would 0:16:09.680 --> 0:16:14.880 have illustrations alongside the reconstructions that would show you sometimes 0:16:14.880 --> 0:16:18.080 like what part was original and what part was recast. 0:16:18.840 --> 0:16:21.400 So you have this per mineralization process, but then you've 0:16:21.400 --> 0:16:24.440 also got this process known as replacement, and this is 0:16:24.680 --> 0:16:28.280 similar but sort of more more total, more holistic, and 0:16:28.440 --> 0:16:32.040 organism's body is buried and then it disappears because it 0:16:32.040 --> 0:16:36.400 gets decomposed, maybe my microbial life or gets dissolved through 0:16:36.480 --> 0:16:40.280 chemical reactions with the soil or the groundwater gets washed 0:16:40.320 --> 0:16:43.120 away and eroded, and what you're left with is a 0:16:43.160 --> 0:16:47.000 cavity in the ground in the shape of the original structure. 0:16:47.040 --> 0:16:49.120 So you might have like a cavity in the shape 0:16:49.440 --> 0:16:52.040 of a skeleton or a shell or a bone, and 0:16:52.080 --> 0:16:55.440 then this cavity gets filled in with some other mineral, 0:16:55.800 --> 0:16:58.960 creating a sort of mineral cast in the same shape 0:16:58.960 --> 0:17:03.000 as the original organ in structure. Then, of course there 0:17:03.000 --> 0:17:07.400 are other ways. There is for example, carbonization where organisms 0:17:07.440 --> 0:17:10.320 get squeezed between layers of sediment and leave this carbon 0:17:10.440 --> 0:17:14.600 imprint that sometimes happens to like plants and insects. Then 0:17:14.640 --> 0:17:17.000 there would also be resin in casing, which we all 0:17:17.040 --> 0:17:19.840 know from Jurassic Parks seeing the mosquito and the amber. 0:17:20.240 --> 0:17:22.399 Things can be frozen and ice, of course, like we 0:17:22.440 --> 0:17:24.760 see from the previous ice age. You might see a 0:17:24.920 --> 0:17:28.679 mammoth frozen and ice. And then things can be for example, 0:17:28.720 --> 0:17:32.399 buried in tar, like in the tar pits. So there 0:17:32.400 --> 0:17:35.040 are a lot of ways things can be preserved across 0:17:35.080 --> 0:17:38.919 the geological eons. But despite all these different ways that 0:17:39.040 --> 0:17:41.760 it can happen, it doesn't happen that much. Only a 0:17:41.880 --> 0:17:46.000 very small portion of the animals that exist get preserved, 0:17:46.200 --> 0:17:48.240 and then only a small portion of those that get 0:17:48.280 --> 0:17:51.480 preserved actually get found by us. So we have a 0:17:51.720 --> 0:17:55.040 have a very limited sampling of what there once was 0:17:55.200 --> 0:17:57.840 on planet Earth. But another thing to think about is 0:17:58.480 --> 0:18:01.800 not just the scarcity of fossiles, but the process by 0:18:01.840 --> 0:18:07.080 which they're created. It doesn't tend to favor action. You know, 0:18:07.200 --> 0:18:10.239 you're you're not likely to catch a fossil of an 0:18:10.280 --> 0:18:14.000 animal in mid behavior where it's clear what was happening. 0:18:14.640 --> 0:18:18.760 Something was dead, was probably very very often moved around 0:18:18.880 --> 0:18:21.960 by some water currents or something like that, so you 0:18:22.000 --> 0:18:24.359 don't really necessarily get a sense of what was going 0:18:24.400 --> 0:18:28.280 on in this animal's life. Yeah, fossil evidence of feeding 0:18:28.280 --> 0:18:31.200 behavior or any kind of like really key life moments 0:18:31.200 --> 0:18:35.400 are exceedingly rare. And it's that it's always worth remembering 0:18:35.720 --> 0:18:39.119 that the fossil record itself is inherently incomplete. You're not 0:18:39.160 --> 0:18:42.880 gonna never gonna have a complete fossil record because, as 0:18:42.880 --> 0:18:46.720 we've discussed, like the limits of fossilization, that all the 0:18:46.720 --> 0:18:48.679 criteria that have to be met a stand in the 0:18:48.720 --> 0:18:51.040 way of that um And I don't mention this to 0:18:51.080 --> 0:18:53.119 cast doubt on what we have or the you know, 0:18:53.280 --> 0:18:55.720 the visions of the past that we derive from our fossils. 0:18:55.920 --> 0:18:57.720 It's just that we're left to figure out the shape 0:18:57.720 --> 0:19:01.320 of what came before with an in complete jigsaw puzzle 0:19:01.359 --> 0:19:04.600 that has no box right heart of the cover. And 0:19:04.600 --> 0:19:07.159 it's Joe discussed here to begin with, sediment has to 0:19:07.200 --> 0:19:10.000 cover in organisms remains in order for the long fossilization 0:19:10.040 --> 0:19:13.960 process to begin. Most organisms decomposed before this can happen. 0:19:14.359 --> 0:19:17.520 Fossilization odds increase if the organism happens to exist in 0:19:17.600 --> 0:19:20.560 large numbers or lived in and around a sediment. So, 0:19:20.600 --> 0:19:24.680 for instance, trilobytes meet both criteria. Tons of them, they're 0:19:24.720 --> 0:19:28.040 on the ocean floor, They're very well represented in the 0:19:28.080 --> 0:19:30.359 fossil record. Not so great for a lot of these 0:19:31.040 --> 0:19:34.000 great wonderful land predators you'd want to see, Yeah, like 0:19:34.040 --> 0:19:36.320 something like a t rex that that would have been 0:19:36.320 --> 0:19:39.520 an apex predator. I always think of a pyramid, a 0:19:39.560 --> 0:19:43.560 pyramid of bones, okay, and your apex predator is seated 0:19:43.640 --> 0:19:46.400 on a throne at the top of this pyramid. So 0:19:47.200 --> 0:19:49.399 you can only have so many pyramids based on the 0:19:50.400 --> 0:19:53.680 bones and the bodies and the life force of the creatures. 0:19:53.760 --> 0:19:56.200 And so your apex predator that's gonna be a really 0:19:56.320 --> 0:19:59.320 rare fined. Yeah, I mean, the ecology can't support lots 0:19:59.400 --> 0:20:01.320 of them in the place, so there's not that many 0:20:01.359 --> 0:20:04.560 to choose from. And then it's also existing in circumstances 0:20:04.560 --> 0:20:07.160 that make it less likely to get fossilized when it dies, 0:20:07.560 --> 0:20:10.040 right and then you know, and that's why we have 0:20:10.359 --> 0:20:13.280 we have a number of species out there where we're 0:20:13.400 --> 0:20:16.320 basing the entire species on me maybe even just a 0:20:16.320 --> 0:20:19.200 few different bones, you know, or at least an incomplete skeleton. 0:20:19.720 --> 0:20:22.320 And then plus fossils might be set in stone, but 0:20:22.400 --> 0:20:25.400 they're far from impervious. Like all rocks, they can erode, 0:20:25.400 --> 0:20:28.480 they can melt, they can fragment. So even once fossilization occurs, 0:20:28.720 --> 0:20:31.120 that doesn't mean they're gonna last. It also doesn't mean 0:20:31.160 --> 0:20:33.679 that somebody didn't build a church over it at some point. 0:20:34.160 --> 0:20:36.240 And it's now and so you know, it's a UNESCO 0:20:36.320 --> 0:20:39.760 World Heritage Site now, and you'll never get that juicy 0:20:40.200 --> 0:20:45.000 like you know, three t rex of feeding fossil extravaganza 0:20:45.160 --> 0:20:48.239 that's trapped underneath it. You know, there's so even if 0:20:48.240 --> 0:20:52.280 fossilization happens, we might never see it. So even when 0:20:52.280 --> 0:20:55.240 you do wind up with the fossil jigsaw puzzle pieces 0:20:55.280 --> 0:20:57.280 you need, you still have to figure out how they 0:20:57.320 --> 0:21:00.000 fit together. You have to imagine the missing pieces. Uh, 0:21:00.000 --> 0:21:03.879 there's been a long process in which we've continually refined 0:21:03.880 --> 0:21:08.280 our understanding of the form of these dinosaurs. We're still 0:21:08.320 --> 0:21:11.119 continuing to refine our understanding of what they looked like, 0:21:11.160 --> 0:21:13.119 how they behaved. I mean, you look at something like 0:21:13.160 --> 0:21:18.600 the iguanadon the spike thumbed creature, one of the earliest 0:21:18.600 --> 0:21:21.960 dinosaur finds who's got two thumbs and got illustrated in 0:21:21.960 --> 0:21:26.440 a very weird way. Yeah, you look that guy, because 0:21:26.440 --> 0:21:30.200 if you look at those illustrations, the body just changes rapidly. 0:21:30.640 --> 0:21:32.720 T Rex is another one where we've we've had some 0:21:32.720 --> 0:21:36.360 some distinct changes over time and how we interpret its 0:21:36.680 --> 0:21:39.840 bodily positioning and uh, you know, so a lot of 0:21:39.880 --> 0:21:42.159 the time we can only guess at the shape. We 0:21:42.200 --> 0:21:44.720 can form theories about the shape, and the same goes. 0:21:45.080 --> 0:21:48.960 The same holds true for how different prehistoric species would 0:21:48.960 --> 0:21:51.879 have interacted with each other based on their forms and 0:21:51.880 --> 0:21:55.959 the behavior of existing animals. Evidence of dinosaurs feeding, as 0:21:55.960 --> 0:21:58.639 we said, is exceedingly rare, but every so often the 0:21:58.680 --> 0:22:01.959 fossil records record throws us a real hum dinger. They 0:22:02.000 --> 0:22:05.720 give us an action scene preserved in stone. So that 0:22:05.880 --> 0:22:07.400 is what we're gonna be looking at for the rest 0:22:07.440 --> 0:22:09.040 of the episode. But I think we should take a 0:22:09.119 --> 0:22:10.920 quick break first, and when we come back we will 0:22:10.960 --> 0:22:18.359 get into some of these amazing fossil action scenes. All right, 0:22:18.400 --> 0:22:21.320 we're back now, Robert. Before we actually take a look 0:22:21.320 --> 0:22:23.840 at these fossil action scenes, one thing we should keep 0:22:23.880 --> 0:22:27.600 in mind is that we should say again, you can't 0:22:27.680 --> 0:22:30.520 always look at a fossil and know how and where 0:22:30.560 --> 0:22:34.159 an organism died, right because a lot of remains are, 0:22:34.240 --> 0:22:37.200 for example, moved around by water currents before they get 0:22:37.200 --> 0:22:40.000 buried and fossilized. Uh, it might call to mind you 0:22:40.040 --> 0:22:45.600 can imagine like a big alluvial floodwater deposit where a 0:22:45.640 --> 0:22:49.000