WEBVTT - Creature Classic: Evolution's Best Mistakes! 0:00:07.200 --> 0:00:10.880 Welcome to Creature feature production of iHeartRadio. I'm your host 0:00:10.920 --> 0:00:15.400 of Many Parasites, Katie Golden. I studied psychology and evolutionary biology, 0:00:15.400 --> 0:00:21.000 and today on the show, they're not dinosaurs, mon they're 0:00:21.120 --> 0:00:29.200 really Oh my god, what's that thing? That's right, folks, 0:00:29.240 --> 0:00:33.600 we are talking about pre dinosaur animals who are really cool, 0:00:34.080 --> 0:00:38.920 really wild, really really hard for paleontologists to put together 0:00:39.720 --> 0:00:45.240 the sordid history of pre dinosaur animals. We should have 0:00:45.320 --> 0:00:48.720 had a movie about these guys, take it over a 0:00:48.840 --> 0:00:53.319 park and making people question, you know, whether or not 0:00:53.360 --> 0:00:58.240 science has gone too far. So joining me today is paleontologists, 0:00:58.240 --> 0:01:02.800 science communicator, museum educator, and perhaps most importantly of all, 0:01:03.200 --> 0:01:05.160 a metal guitarist, Dane. 0:01:04.880 --> 0:01:08.039 Pa It Welcome, Hey, thanks for having me. 0:01:08.640 --> 0:01:12.640 I'm so excited. So I am not really an expert 0:01:12.720 --> 0:01:17.280 in these sorts of animals, the pre dinosaur guys. In fact, 0:01:17.400 --> 0:01:21.319 dinosaurs I'm not even that well versed in because I 0:01:21.720 --> 0:01:24.720 have most of what I know are animals that are 0:01:25.280 --> 0:01:29.759 still alive, given that it's the easiest to observe their behavior. 0:01:30.240 --> 0:01:33.560 But I think what is so fascinating to me about 0:01:33.600 --> 0:01:37.880 paleontology is the lack of direct observation that you can 0:01:37.920 --> 0:01:40.279 do and how you guys are kind of like almost 0:01:40.319 --> 0:01:43.920 like forensic detectives piecing together these animals. 0:01:45.040 --> 0:01:48.040 Yeah. Absolutely, So there's various different branches of how we 0:01:48.080 --> 0:01:50.720 can do this. We can kind of pass together the 0:01:50.800 --> 0:01:53.280 sort of most likely conclusions about Yeah, if you want 0:01:53.320 --> 0:01:56.480 to all about animal behavior specifically, we can use comparative anatomy. 0:01:56.880 --> 0:02:00.280 So you have this phenomenon evolution, you may not out 0:02:00.320 --> 0:02:04.560 of a convergent evolution where different organisms will evolve similar 0:02:04.600 --> 0:02:07.160 features to solve similar problems in their environments. So you 0:02:07.200 --> 0:02:08.960 can look at the fossil record and you say, this 0:02:09.040 --> 0:02:12.800 animal has this particular shaped arm bone that means it 0:02:12.880 --> 0:02:15.360 was probably digging, or it has this feature in the 0:02:15.440 --> 0:02:19.720 spine which means it ran a media, so we can 0:02:19.800 --> 0:02:22.120 piece together. But yeah, it is very much like detective 0:02:22.160 --> 0:02:25.360 work taking these very sparse pieces of evidence, and the 0:02:25.360 --> 0:02:29.959 fossil record is notoriously sparse. I think there's sort of 0:02:30.000 --> 0:02:33.240 a ballpark estimation that only one in a million animals 0:02:33.240 --> 0:02:35.920 that has ever existed actually becomes a fossil. All the 0:02:35.919 --> 0:02:40.240 rest just die and rot away or are eaten, or 0:02:40.320 --> 0:02:42.680 are just completely lost to the winds of time. 0:02:42.919 --> 0:02:46.760 Yeah, because fossilization. I mean, there's a few ways in 0:02:46.760 --> 0:02:49.440 which something becomes a fossil, but it is certainly not 0:02:49.680 --> 0:02:53.320 a common thing to happen to an animal's carcass. It's 0:02:53.360 --> 0:02:55.800 not as if you have just every dinosaur who has 0:02:55.880 --> 0:03:02.200 dyed is perfectly encased in stone. The conditions, yeah, the 0:03:02.200 --> 0:03:05.840 conditions in which fossil actually form is quite rare. And 0:03:05.960 --> 0:03:08.840 it's even more rare for a fossil, like a complete 0:03:08.880 --> 0:03:13.880 fossil to form where you get the entire animal perfectly 0:03:13.919 --> 0:03:15.200 represented in one piece. 0:03:16.320 --> 0:03:19.720 Yeah, So there's the classic. It's the classic. One is 0:03:19.720 --> 0:03:22.720 the opening the early scene in the original Jurassic Park 0:03:22.720 --> 0:03:25.000 where they're in the desert and they brush the sand 0:03:25.040 --> 0:03:28.600 away and there is a complete dinosaur skeleton perfectly formed, 0:03:28.600 --> 0:03:32.320 with every bone exactly where it is. That almost never happens. 0:03:32.480 --> 0:03:35.840 Most fossil animals are known from a handful of bits 0:03:35.880 --> 0:03:39.680 of frag like maybe not even complete bones. Teeth are 0:03:39.800 --> 0:03:42.280 very very common because a lot of ret load. Before 0:03:42.280 --> 0:03:44.040 we want to talk reptiles in particular, a lot of 0:03:44.040 --> 0:03:48.720 reptiles shed and regrow their teeth, so teeth are quite common. Sharks. 0:03:48.840 --> 0:03:52.640 Sharks teeth are very common. Shells if you're looking in 0:03:52.960 --> 0:03:57.160 marine and aquatic environments. Are aquatic water based environments are 0:03:57.720 --> 0:04:01.080 generally speaking more productive for fossils because you have movements 0:04:01.080 --> 0:04:03.160 of the sediments, which is more likely to bury things. 0:04:03.560 --> 0:04:06.040 So a lot of the most productive sites for fossils 0:04:06.080 --> 0:04:09.160 in the world tend to be lakes and lagoons and 0:04:09.800 --> 0:04:14.040 slow flowing rivers where things can be easily buried not 0:04:14.080 --> 0:04:17.520 necessarily destroyed by strong currents or floods and things like that. 0:04:18.920 --> 0:04:23.680 There's that beautiful Burgess Shale which was discovered in the 0:04:23.720 --> 0:04:27.720 early nineteen hundreds that had just an incredible wealth of 0:04:27.839 --> 0:04:30.200 fossils from this period of time where you had this 0:04:31.279 --> 0:04:37.279 almost doctor Seussian diversity of animals that seemed like some 0:04:37.400 --> 0:04:41.840 kind of awful fever dream, which oh yeah, yeah, which 0:04:41.880 --> 0:04:45.120 is it is. It's so interesting too because it was 0:04:45.160 --> 0:04:50.840 discovered so early, well relatively early. The trials and airs 0:04:50.920 --> 0:04:54.680 of trying to put together these fossils that were so 0:04:55.279 --> 0:04:56.320 strange looking. 0:04:57.800 --> 0:05:01.040 Yeah. So the Burger Shale, it's what we called a lagostatn, 0:05:01.400 --> 0:05:03.279 which is a German word and it's basically it's a 0:05:03.440 --> 0:05:06.400 it's the sort of blanket term for sites of exceptional 0:05:06.440 --> 0:05:09.240 preservation and the Burgess Shale seems to have been a 0:05:09.320 --> 0:05:13.120 very deep water environment and possibly an oxic. So there 0:05:13.120 --> 0:05:16.960 had been quite low oxygen in that environment, which means 0:05:17.000 --> 0:05:19.039 not a lot of fuel for like bacteria and things 0:05:19.040 --> 0:05:21.359 to break down the carcasses when they sink to the 0:05:21.360 --> 0:05:25.680 sea floor. And yeah, you've got creatures, which yeah, they 0:05:25.760 --> 0:05:29.839 are so because so the Burger Show represents a period 0:05:29.839 --> 0:05:32.800 of time called the Cambrian which is around two hundred 0:05:32.839 --> 0:05:35.720 and forty odd million years ago, and it's very you know, 0:05:35.760 --> 0:05:40.400 it's very famous phenomena called the Cambrian Explosion, wherein there'd 0:05:40.440 --> 0:05:43.480 been microorganisms and algae and things around for several or 0:05:43.520 --> 0:05:46.279 several tens and hundreds of millions of years beforehand, but 0:05:46.360 --> 0:05:49.000 at this particular point, it was sort of the stars aligned, 0:05:49.080 --> 0:05:52.640 sort of the temperature was just right, the atmospheric conditions 0:05:52.640 --> 0:05:55.400 were just right. Everything just kind of landed just right, 0:05:55.839 --> 0:06:01.320 and there's this huge explosion in diversity of comp multicellular life. 0:06:01.360 --> 0:06:07.839 And you have early representatives of early ancestors of arthropods, sponges, worms, 0:06:07.960 --> 0:06:10.840 sort of very very early. You know, you can kind 0:06:10.880 --> 0:06:14.400 of sort of squint and see the resemblance to modern animals. 0:06:15.600 --> 0:06:18.400 Yeah, that's what's so interesting to me is when I 0:06:18.440 --> 0:06:22.640 see kind of these these animals from the more wormy ones, 0:06:22.680 --> 0:06:25.760 like the soft bodied ones, which I mean, it's incredible 0:06:25.800 --> 0:06:29.359 that we have fossils of these soft bodied animals, because 0:06:29.480 --> 0:06:32.839 we generally think of fossils as like hey, bones or shells, 0:06:32.880 --> 0:06:34.960 something hard, because those are more likely to be able 0:06:34.960 --> 0:06:37.880 to be preserved. But yeah, these soft bodied, like worm 0:06:38.040 --> 0:06:44.520 like animals that don't have many I think analogs in 0:06:44.920 --> 0:06:48.000 modern times, but you can you can kind of find like, actually, 0:06:48.000 --> 0:06:50.440 you know, we'll talk about one in a little bit 0:06:50.520 --> 0:06:52.640 that is very interesting, one of my favorite ones. But 0:06:52.880 --> 0:06:57.360 first let's talk about the Anomalocras, which I think is 0:06:57.440 --> 0:07:02.680 sort of one of the most famous examples of this 0:07:02.680 --> 0:07:09.080 this period. The name being Latin Greco for abnormal shrimp, 0:07:09.160 --> 0:07:10.760 which is very funny to me. 0:07:11.720 --> 0:07:15.440 Yeah, very very abnormal shrimp. Anomala carus is sort of 0:07:15.880 --> 0:07:19.040 it's famous for being kind of characterized as one of 0:07:19.080 --> 0:07:22.000 the first eight lot, one of the first large apex predators. 0:07:22.680 --> 0:07:24.320 It was so as far as we said, it was 0:07:24.440 --> 0:07:27.840 a free swimming animal, which is quite a big innovation. 0:07:27.960 --> 0:07:29.360 There were you know, a lot of the critters that 0:07:29.360 --> 0:07:32.880 were around at the time were sort of sediment based 0:07:33.000 --> 0:07:35.800 either fixed to the sea floor or burrowing or crawling 0:07:35.800 --> 0:07:38.040 around the sea floor. But anomal Carus was free swimming, 0:07:38.480 --> 0:07:41.720 had these sort of mobile tendrils on its face for 0:07:42.280 --> 0:07:45.360 gathering at prey, and we think it was probably most 0:07:45.440 --> 0:07:48.520 likely eating sort of the small Yeah, the small, soft 0:07:48.520 --> 0:07:52.080 body crystal floor trilobites would have been very abundant food source. 0:07:52.160 --> 0:07:55.520 So these are the famous sort of sort of woodlousey, 0:07:55.560 --> 0:07:57.600 beatlely looking critters. 0:07:57.160 --> 0:07:59.960 That likes or isopods of today. 0:08:00.320 --> 0:08:04.480 Yeah, yeah, very much. So. Unfortunately they went extinct at 0:08:04.520 --> 0:08:07.320 the end of the Permian period, which is the end 0:08:07.320 --> 0:08:10.080 of this sort of we say pre dinosaur is this 0:08:10.760 --> 0:08:13.880 larger period of time called the Paleozoic, So this is 0:08:13.880 --> 0:08:17.640 the sort of first of three major eons or chapters 0:08:17.640 --> 0:08:19.240 if you like, in the history of life on Earth. 0:08:19.520 --> 0:08:23.240 Paleozoic is from the Cambrian explosion five hundred and forty 0:08:23.240 --> 0:08:26.640 million years ago up to two hundred and fifty million 0:08:26.720 --> 0:08:30.440 years ago, which ends with the Permian extinction event, which 0:08:30.480 --> 0:08:35.720 took out huge, huge numbers of these amazing animals, some 0:08:35.800 --> 0:08:37.480 of which had made it all the way from the 0:08:37.559 --> 0:08:40.520 Cambrian explosion, like the trilobites. 0:08:41.760 --> 0:08:45.319 And what was the precipitating event do we think for 0:08:45.400 --> 0:08:48.600 that mouse extinction was a change in the climate. 0:08:49.679 --> 0:08:53.080 So well, ultimately, all mass extinction events are some form 0:08:53.080 --> 0:08:55.360 of climate change. It just depends on what the triggering 0:08:55.480 --> 0:08:58.480 event is and what we believe this one is. Was 0:08:58.520 --> 0:09:03.040 a massive spike in volcanic activity at this site in Siberia. 0:09:03.760 --> 0:09:07.400 So we're talking in an area hundreds of you know, 0:09:07.440 --> 0:09:09.880 tens of possibly tens of thousands of square kilometers of 0:09:10.000 --> 0:09:15.120 land in Russia basically fractured into a constantly erupting supervolcano, 0:09:15.559 --> 0:09:18.240 and I'm talking on the scale of thousands and thousands 0:09:18.240 --> 0:09:20.360 of years. And over the course of that time, it 0:09:20.480 --> 0:09:23.559 released you know, trillions of tons of toxic fumes and 0:09:23.600 --> 0:09:28.760 greenhouse gases. It caused a runaway greenhouse effect. It acidified 0:09:28.800 --> 0:09:35.680 the oceans huge amounts of acid rain. As sea temperatures rise, 0:09:36.400 --> 0:09:39.840 water is less able to hold gas at high temperatures, 0:09:39.880 --> 0:09:42.800 so A that means less oxygen for the life living 0:09:42.840 --> 0:09:45.360 in the ocean, and b it means less CO two 0:09:45.520 --> 0:09:48.360 is being absorbed into the ocean, which causes even more heating. 0:09:49.240 --> 0:09:52.440 Some estimates put it as high as eighty percent of 0:09:52.520 --> 0:09:55.000 all life on Earth was wiped out at the end 0:09:55.000 --> 0:09:56.000 of this extinction event. 0:09:56.320 --> 0:09:59.120 That's incredible. I mean, maybe this is the optimist in me, 0:09:59.200 --> 0:10:01.520 but I feel like it's so really impressive that we 0:10:01.640 --> 0:10:04.800 bounced back from that. You know, it's it's kind of 0:10:04.840 --> 0:10:08.679 amazing that you can have such a mass extinction. Obviously 0:10:08.920 --> 0:10:12.280 very bad for the current trialbides just trying to live 0:10:12.320 --> 0:10:16.480 their lives, but still the life somehow, you know, was 0:10:16.520 --> 0:10:17.679 able to recover from that. 0:10:18.559 --> 0:10:21.719 Yeah, well, among the survivors were well, obviously everything that's 0:10:21.720 --> 0:10:25.280 alive today is descended from that, you know, relatively small 0:10:25.280 --> 0:10:27.439 handful of life that made it through this extinction event, 0:10:28.000 --> 0:10:31.640 but it caused this huge kind of restructuring of the 0:10:31.679 --> 0:10:36.360 food chain. So there's this really interesting event sort of 0:10:36.400 --> 0:10:39.559 immediately following this extinction. We're still pre dinosaur. By the way, 0:10:39.559 --> 0:10:42.439 the dinosaurs don't really the dinosaurs don't really come into 0:10:42.440 --> 0:10:45.560 their own until the sort of middle to late Triassic period, 0:10:45.600 --> 0:10:47.360 which is sort of two hundred and twenty two hundred 0:10:47.400 --> 0:10:49.679 and thirty million years, So there's a good thirty million 0:10:49.760 --> 0:10:53.000 year block between that extinction and the dinosaurs really starting 0:10:53.000 --> 0:10:55.520 to come into their own, and there's this phenomenon known 0:10:55.559 --> 0:11:00.440 as the Mesozoic marine revolution, which is really interesting kind 0:11:00.440 --> 0:11:04.040 of upheaval in the oceans. So one major part of 0:11:04.080 --> 0:11:09.800 it is the diversification of secondarily aquatic tetrapods. So there's 0:11:09.800 --> 0:11:11.440 a few technical terms here. I want to make sure 0:11:11.480 --> 0:11:14.560 the audience are fully on board here. So secondarily aquatic 0:11:14.880 --> 0:11:17.680 is basically any animal that has evolved from a land 0:11:17.720 --> 0:11:19.960 based ancestor and has gone back into the water. 0:11:20.320 --> 0:11:23.679 So we've got whales. Whales would count as the right. 0:11:23.880 --> 0:11:29.280 Whales absolutely, yet sea turtles, crocodiles, sea lions, penguins, anything 0:11:29.280 --> 0:11:31.840 that has come from a land based ancestor into the ocean. 0:11:32.760 --> 0:11:35.640 During the Paleozoic before the Permian extinction event, they didn't 0:11:35.679 --> 0:11:39.000 really there weren't really any of them because throughout that 0:11:39.080 --> 0:11:43.120 time the large ocean niches, the sort of big spaces 0:11:43.120 --> 0:11:47.800 in the ecosystem were dominated by fish and arthropods, So 0:11:48.160 --> 0:11:51.640 the big predators in the ocean were giant fish and 0:11:51.840 --> 0:11:55.760 giants arthropods, So there were things like Dunkleostius is probably 0:11:55.760 --> 0:11:58.240 the most famous one, which is this it's part of 0:11:58.280 --> 0:12:00.800 a group of fish that doesn't exist anymore, called placoderms, 0:12:01.320 --> 0:12:04.640 and rather than having teeth, they just have extended bones 0:12:04.679 --> 0:12:07.400 of the skull that would sheer against each other like 0:12:07.400 --> 0:12:11.640 scissor blades. That is, there's been some recent studies on 0:12:11.679 --> 0:12:14.440 dontriosis as to exactly how big it was. It was 0:12:14.480 --> 0:12:17.360 believed to be like a sort of school bus sized monster. 0:12:17.480 --> 0:12:19.560 That's been scaled down with it recently we think sort of. 0:12:21.160 --> 0:12:23.679 Doesn't it where we like it was the size of 0:12:23.720 --> 0:12:27.080 the Empire state building. Maybe actually just the size of 0:12:27.120 --> 0:12:28.000 a Volkswagen. 0:12:28.840 --> 0:12:30.880 Yeah, there's quite a bit of that. There's also the 0:12:31.360 --> 0:12:35.640 sea scorpions, which were another casualty of the Permian extinction events. 0:12:36.280 --> 0:12:39.280 Not technically scorpions, they are arthropods, so they are. 0:12:40.400 --> 0:12:42.680 They look like a flat scorpion, kind of like if 0:12:42.720 --> 0:12:45.640 you took rolling pin and just sort of like rolled 0:12:45.640 --> 0:12:46.319 out a scorpion. 0:12:46.400 --> 0:12:48.240 Yeah, yeah, very much. 0:12:48.280 --> 0:12:48.360 So. 0:12:48.440 --> 0:12:50.600 Yeah, they've got this great, big, grasping pincers. They've got 0:12:50.640 --> 0:12:53.760 this big, long, flat tail which some of the smaller 0:12:53.800 --> 0:12:55.560 ones may have swamed, but some of the big ones 0:12:55.600 --> 0:12:59.320 probably stuck to the seabed. Some of the really big 0:12:59.360 --> 0:13:03.880 ones were nightmarish, like the biggest arthropods of all time. Yes, 0:13:04.840 --> 0:13:07.120 two meters long, possibly two and a half. For some 0:13:07.160 --> 0:13:09.280 of the really big ones. So these are the things 0:13:09.280 --> 0:13:13.120 that are occupying the big the big ocean niches at 0:13:13.120 --> 0:13:15.400 the time. And then the Permian extinction happens and it 0:13:15.480 --> 0:13:18.200 kind of opens up the food chain somewhe It opens 0:13:18.280 --> 0:13:20.840 up the ecosystem, and you have this big adaptive radiation 0:13:21.480 --> 0:13:24.080 where this happens a lot after extinction events. When you 0:13:24.120 --> 0:13:26.920 have when you've got the slate white clean, that leaves 0:13:26.960 --> 0:13:30.760 a lot of space for innovation and sort of evolutionary experimentation. 0:13:31.240 --> 0:13:34.280 So you start to get reptiles moving into the ocean. 0:13:34.320 --> 0:13:37.880 You get early sort of crocodile and turtle relatives. You 0:13:37.960 --> 0:13:41.480 have lots of very strange things that don't really exist anymore, 0:13:41.520 --> 0:13:45.360 like the placar donts. Placoderms is the armored fish, and 0:13:45.400 --> 0:13:48.160 then you have placardonts, which are these weird swimming reptiles 0:13:48.200 --> 0:13:51.480 that are not turtles, but they have very wide, flat 0:13:51.520 --> 0:13:54.079 bodies and armor across them. They sort of look like 0:13:54.280 --> 0:13:59.760 fake turtles. They're very strange armadillo things, yeah, very odd looking, 0:14:00.200 --> 0:14:02.320 but some of them have some of them are derived ones. 0:14:02.320 --> 0:14:05.440 They've got these forward facing teeth at the front of 0:14:05.440 --> 0:14:08.040 the jaw, and then they have these very flat plate 0:14:08.240 --> 0:14:10.320 like teeth at the back of the jaw and the 0:14:10.400 --> 0:14:14.199 roof of the mouth, and that's interpreted as being adaptations 0:14:14.240 --> 0:14:17.560 for prising apart and crushing shellfish. And that's the other 0:14:17.600 --> 0:14:21.200 big part of the mesozoat marine revolution is that it 0:14:21.360 --> 0:14:25.520 forced this big change in ocean invertebrates through the evolution 0:14:25.680 --> 0:14:30.600 of new creatures that can crack open and ingest shells 0:14:30.920 --> 0:14:34.680 and exoskeletons. Because you know, if you're like a limpet 0:14:34.960 --> 0:14:37.040 or a barnacle or something attached to a rock or 0:14:37.040 --> 0:14:39.160 attached to the sea floor, and there's nothing that can 0:14:39.160 --> 0:14:41.720 break you, basically fine, But if something pulls you off 0:14:41.760 --> 0:14:45.480 the rock and you can't reattach yourself or swim away 0:14:45.720 --> 0:14:48.680 or crawl into a hole and hide, you're basically doomed. 0:14:49.120 --> 0:14:53.280 So sessile animals, so things that attached to the sea 0:14:53.320 --> 0:14:55.520 floor and basically stay there the rest of their lives 0:14:55.800 --> 0:15:00.680 started to decline and animal and these sort of shellfish 0:15:00.680 --> 0:15:02.720 and invertebrates had to find all sorts of new ways 0:15:02.720 --> 0:15:06.160 to adapt. So creatures that lived on the surface declined, 0:15:06.400 --> 0:15:10.400 creatures that lived in burrows diversified. There was a lot 0:15:10.480 --> 0:15:14.520 more burrowing animals after this. A really good example is crinoids, 0:15:14.800 --> 0:15:17.960 which again making sure your audience caught up. Crynoids is 0:15:18.240 --> 0:15:23.000 really really weird creatures that evolved early on in the Paleozoic, 0:15:23.080 --> 0:15:28.160 not quite Cambrian. They have I think it's penta radial symmetry, 0:15:28.680 --> 0:15:31.960 So humans are bilaterally symmetrical. We've got a left side 0:15:31.960 --> 0:15:35.080 and the right side. Chronoids have five way symmetry. You 0:15:35.080 --> 0:15:36.680 can look you look down on them from the top, 0:15:36.720 --> 0:15:39.200 you can split them five ways as they've got the 0:15:39.240 --> 0:15:40.560 mouse in the middle. 0:15:40.800 --> 0:15:44.720 So like starf like kind of erms like starfish, and. 0:15:45.160 --> 0:15:47.520 There are yeah, there they are a kindoderms. Yeah, they're 0:15:47.520 --> 0:15:49.840 related to starfish and sea urchins. So they've got a 0:15:49.840 --> 0:15:51.640 mouth in the middle, and then they have all these 0:15:51.960 --> 0:15:56.600 big branching feathery arms that come outs and their suspension feeders. 0:15:56.600 --> 0:15:59.960 They gather organic material, they put their arms out, they 0:16:00.040 --> 0:16:02.800 collect food from the water, and then they draw their 0:16:02.880 --> 0:16:04.960 arms into the mouth in the middle. And there's two 0:16:05.000 --> 0:16:09.800 major varieties of them. There's the standard ones just as 0:16:09.800 --> 0:16:12.760 I've described, which can use their arms to swim around 0:16:12.800 --> 0:16:14.480 and crawl around on the sea floor, and we call 0:16:14.520 --> 0:16:17.880 them feather stars. And then there's the stalked variety, which 0:16:17.920 --> 0:16:20.800 have a great, big, long stalk that trails from underneath 0:16:20.800 --> 0:16:22.720 the body and attaches them to the seafloor. And they 0:16:22.840 --> 0:16:24.360 kind of makes them look like a flower, and we 0:16:24.440 --> 0:16:27.200 call them sea lilies, and they are all still around today. 0:16:27.200 --> 0:16:29.320 They've made it through all the extinctions, all the way 0:16:29.360 --> 0:16:32.760 into the present day. During the Massasoka marine Revolution, you 0:16:32.840 --> 0:16:37.080 have this explosion of creatures that can break through exoskeletons. 0:16:37.600 --> 0:16:41.680 The sea lilies, the ones fixed to the seafloor start 0:16:41.720 --> 0:16:44.520 to abandon the shallow water and move into the deeper ocean. 0:16:44.600 --> 0:16:46.480 So most of the sea lily species that we have 0:16:46.520 --> 0:16:50.560 today live in deep offshore waters, whereas the feather stars 0:16:50.560 --> 0:16:53.240 that can move around and swim and escape, they live 0:16:53.320 --> 0:16:57.040 on the reefs and coastal environments. So it is this 0:16:57.400 --> 0:17:02.120 complete restructuring of how in entire food chains and ecosystems 0:17:02.160 --> 0:17:04.119 work over this extinction boundary. 0:17:04.359 --> 0:17:06.000 Yeah, you have a mass when you have like a 0:17:06.040 --> 0:17:11.520 massive shock like that, you have for the remaining species 0:17:11.600 --> 0:17:14.720 that are now adapting to say the you know, the 0:17:14.840 --> 0:17:18.600 arms race that's happening as new species start to take 0:17:18.640 --> 0:17:21.480 over in the niches that have been abandoned by the 0:17:21.480 --> 0:17:26.000 species that have gone extinct. Everything is impacted right in 0:17:26.040 --> 0:17:29.200 a way that like they all have to readapt It 0:17:29.280 --> 0:17:31.240 kind of reminds me of one of the animals I 0:17:31.280 --> 0:17:35.280 was thinking of talking about today was Endocera's gigantium, which 0:17:35.320 --> 0:17:40.280 is sort of like that that big unicorn like cephalopod 0:17:40.600 --> 0:17:44.600 during the I'm gonna say a period as if I 0:17:44.680 --> 0:17:46.679 know what I'm talking about, even though I don't, the 0:17:46.800 --> 0:17:56.840 Ordovician period. So it was this like ancestor of modern 0:17:56.880 --> 0:18:01.600 day squid octopuses, not alloids, but unlike modern day squids 0:18:01.680 --> 0:18:06.320 and octopuses, it had this massive shell and unlike the nautilus, 0:18:06.359 --> 0:18:09.320 which still has that shell, it was this really straight, 0:18:09.720 --> 0:18:14.600 large conical shell that spanned from over nine up to 0:18:14.720 --> 0:18:19.240 possibly the larger estimates are eighteen feet, although that's not 0:18:19.320 --> 0:18:23.560 exactly confirmed, but it could be anywhere from like three 0:18:23.720 --> 0:18:27.479 to over five meters. And so it's thought it was 0:18:27.520 --> 0:18:31.800 like this ambush predator, right, because you're so big, you're 0:18:31.840 --> 0:18:34.000 not going to be very mobile, and you have this 0:18:34.119 --> 0:18:39.639 giant shell to defend itself. So that once, and similarly 0:18:39.680 --> 0:18:45.400 to other giant shelled cephalopods, thought that it went extinct 0:18:45.440 --> 0:18:48.960 because it could not outcompete with this new sort of 0:18:48.960 --> 0:18:53.879 wave of like the fish and more mobile, more agile, 0:18:54.320 --> 0:18:59.639 and swifter creatures that were evolving at the time. So 0:18:59.840 --> 0:19:01.919 it went from because you'd think, like a lot of 0:19:01.920 --> 0:19:04.479 people will often ask like, well, if you have something 0:19:04.520 --> 0:19:07.760 that has this amazing defense mechanism, like a giant shell, 0:19:08.000 --> 0:19:09.639 why would it get rid of it? Right, because like 0:19:09.840 --> 0:19:14.119 squid octopuses, they're very vulnerable, they're so squishy, But it 0:19:14.160 --> 0:19:17.959 doesn't matter necessarily if you're perfectly protected, if you're not 0:19:18.000 --> 0:19:20.919 getting any food, if you're unable to compete with the 0:19:21.000 --> 0:19:22.840 faster predators and the faster prey. 0:19:24.160 --> 0:19:26.880 Yeah, the the evolution of a spine was a big 0:19:26.920 --> 0:19:29.920 innovation because that that's you know, that provided the sort 0:19:29.960 --> 0:19:33.880 of propulsion for sort of early predatory fish to see, 0:19:33.960 --> 0:19:35.520 you know, be a lot faster and a lot more 0:19:35.560 --> 0:19:38.760 agile and maneuverable in the water. And yeah, so I 0:19:38.760 --> 0:19:41.840 think things like endoceras and you know, these giant autaloids 0:19:43.119 --> 0:19:45.840 would have would have had no predators, had had no 0:19:45.920 --> 0:19:49.440 competition until these larger, you know, the early ancestors of 0:19:49.480 --> 0:19:51.800 sharks and things like that, some of which would have 0:19:51.840 --> 0:19:58.399 been capable of cracking through these shells. Yeah, sharks were 0:19:58.400 --> 0:20:00.600 a big innovation at the time they used sort of 0:20:00.640 --> 0:20:02.719 started to occupy the ape experiens in each but they 0:20:02.720 --> 0:20:04.640 were kind of overtaken by the blackaderms, the big sort 0:20:04.640 --> 0:20:06.880 of sheer teeth fish. They were kind of your two 0:20:07.000 --> 0:20:10.800 main sort of apex predator bodies that came in at 0:20:10.840 --> 0:20:12.840 the time, and they were all kinds of bizarre as well. 0:20:13.560 --> 0:20:17.040 You have these really nice out groups, as they're called, 0:20:17.080 --> 0:20:19.040 So you have sort of you have your sort of 0:20:19.119 --> 0:20:22.040 evolutionary group of animals that we consider modern day sharks, 0:20:22.359 --> 0:20:23.960 and then you sort of go back a step on 0:20:24.000 --> 0:20:27.080 the family tree and off on a little weird side branch, 0:20:27.080 --> 0:20:30.080 and you find all these really odd creatures that aren't 0:20:30.200 --> 0:20:33.800 quite entirely sharks that that's sort of the closest thing 0:20:33.840 --> 0:20:37.560 we can relate in to things like one of the 0:20:37.560 --> 0:20:42.160 more famous one is Stepacanthus, which has got these like rays. 0:20:42.200 --> 0:20:44.920 It's rather than like the kind of triangular dorsalt thing. 0:20:45.040 --> 0:20:47.680 It's got this kind of flattened structure on its back 0:20:47.720 --> 0:20:49.640 with all these bristles and spines across it. We think 0:20:49.680 --> 0:20:52.720 it's a sexual display structure of some kind because we 0:20:52.760 --> 0:20:56.800 only find it in the males. There's a ah the 0:20:56.920 --> 0:20:58.760 names escaping me now there's all kinds of there's a oh, 0:20:58.760 --> 0:21:00.040 helicaprion as a real. 0:21:00.160 --> 0:21:05.399 Yeah yeah, so yeah, this this whole family group of 0:21:05.440 --> 0:21:09.159 sharks that, instead of having a jawline as conventional sharks do, 0:21:09.280 --> 0:21:10.920 all their teeth run down the middle of the jaw, 0:21:11.280 --> 0:21:13.760 and there's some that have them like scissor blades, one 0:21:13.800 --> 0:21:14.280 on top of the other. 0:21:14.320 --> 0:21:17.320 But helica prion has this big spiral of teeth which 0:21:17.359 --> 0:21:20.000 we now interpret as being new teeth growing in the 0:21:20.040 --> 0:21:23.800 center and kind of growing outwards towards the outer edge 0:21:23.800 --> 0:21:26.119 of the spiral, and then as they are replaced, they 0:21:26.200 --> 0:21:29.119 kind of fall out of the front. It's possible it 0:21:29.160 --> 0:21:31.879 may have been able to use that to cut through 0:21:32.040 --> 0:21:35.080 you know, shells and of things like the squid and 0:21:35.080 --> 0:21:37.640 the autoloids that were hanging around at the time. 0:21:39.800 --> 0:21:42.159 Yeah, no, it is. It is so weird because with 0:21:42.200 --> 0:21:45.200 a lot of these animals, when I mean, one thing 0:21:45.280 --> 0:21:48.120 is that I think that the reason these shapes look 0:21:48.160 --> 0:21:50.840 so bizarre to us is that we are we acclimate 0:21:50.880 --> 0:21:55.239 ourselves to the shapes of say, you know, we look 0:21:55.280 --> 0:21:58.359 at a hammerhead shark, right, and we're we're acclimatized to that. 0:21:58.440 --> 0:22:01.320 So we see that and we understand it. We see 0:22:01.320 --> 0:22:04.840 this this as a normal animal shape more or less, 0:22:05.080 --> 0:22:08.320 but that's really only because we have gotten used to 0:22:08.359 --> 0:22:10.679 it that when like the first people who probably saw 0:22:11.040 --> 0:22:13.800 a hammerhead shark was like, well, this is an incredibly 0:22:13.800 --> 0:22:17.199 weird shape for a shark head. So something like Stethacanthus 0:22:17.240 --> 0:22:21.560 that has this weird anvil on its head, which I'd 0:22:21.600 --> 0:22:23.320 be I'd love to see a hammerhead shark and as 0:22:23.400 --> 0:22:25.960 Deethacanthus get together and see what what what they would 0:22:26.040 --> 0:22:30.639 make us they can build, see what they can craft? Uh, 0:22:30.800 --> 0:22:32.760 But you know, yeah, I mean it's it is interesting 0:22:32.800 --> 0:22:35.120 because they're all especially when we're trying to piece together 0:22:35.200 --> 0:22:38.840 say the purpose like how how say the jaws work 0:22:38.840 --> 0:22:41.159 of this like weird spiraling saw two thing, how they 0:22:41.200 --> 0:22:44.919 would actually maneuver that? Or like this death of Canthus, 0:22:45.000 --> 0:22:47.640 what that that protrusion was? And the way we piece 0:22:47.680 --> 0:22:49.680 it together in terms of well, if it was only 0:22:49.720 --> 0:22:54.280 found on males, maybe it would be uh a sexual 0:22:54.400 --> 0:22:59.080 signaling uh device essentially. But it's also kind of odd 0:22:59.119 --> 0:23:01.840