WEBVTT - Life Uh Finds A Way?! (Evolution's Best Mistakes) 0:00:07.240 --> 0:00:10.879 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, 0:00:15.440 --> 0:00:21.120 and today on the show, they're not dinosaurs, mon they're 0:00:21.160 --> 0:00:29.240 really Oh my god, what's that thing? That's right, folks, 0:00:29.240 --> 0:00:33.640 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 --> 0:00:45.280 the sordid history of pre dinosaur animals. We should have 0:00:45.360 --> 0:00:48.760 had a movie about these guys, take it over a 0:00:48.880 --> 0:00:53.320 park and making people question, you know, whether or not 0:00:53.400 --> 0:00:58.280 science has gone too far. So joining me today is paleontologists, 0:00:58.280 --> 0:01:02.720 science communicator, museum educator, and perhaps most importantly of all, 0:01:03.240 --> 0:01:05.119 a metal guitarist, Dane pa. 0:01:05.160 --> 0:01:08.080 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 --> 0:01:17.399 in these sorts of animals, the pre dinosaur guys. In fact, 0:01:17.440 --> 0:01:21.680 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 --> 0:01:29.800 still alive, given that it's the easiest to observe their behavior. 0:01:30.280 --> 0:01:33.520 But I think what is so fascinating to me about 0:01:33.640 --> 0:01:37.880 paleontology is the lack of direct observation that you can 0:01:37.920 --> 0:01:40.360 do and how you guys are kind of like almost 0:01:40.360 --> 0:01:43.960 like forensic detectives piecing together these animals. 0:01:45.080 --> 0:01:48.080 Yeah. Absolutely, So there's various different branches of how we 0:01:48.080 --> 0:01:50.760 can do this. We can kind of pass together the 0:01:50.840 --> 0:01:53.320 sort of most likely conclusions about Yeah, if you want 0:01:53.360 --> 0:01:56.480 to all about animal behavior specifically, we can use comparative anatomy. 0:01:56.880 --> 0:02:00.120 So you have this phenomenon evolution. You may know that 0:02:00.360 --> 0:02:04.600 of a convergent evolution, where different organisms will evolve similar 0:02:04.640 --> 0:02:07.200 features to solve similar problems in their environments. So you 0:02:07.200 --> 0:02:09.000 can look at the fossil record and you say, this 0:02:09.080 --> 0:02:12.840 animal has this particular shaped arm bone that means it 0:02:12.880 --> 0:02:15.359 was probably digging, or it has this feature in the 0:02:15.440 --> 0:02:19.520 spine which means it ran a certain media. So we 0:02:19.600 --> 0:02:21.680 can piece together. But yeah, it is very much like 0:02:21.720 --> 0:02:24.960 detective work taking these very sparse pieces of evidence, and 0:02:25.280 --> 0:02:29.919 the fossil record is notoriously sparse. I think there's sort 0:02:29.919 --> 0:02:32.800 of a ballpark estimation that only one in a million 0:02:32.840 --> 0:02:35.840 animals that has ever existed actually becomes a fossil. All 0:02:35.840 --> 0:02:39.880 the rest just die and rot away or are eaten, 0:02:40.200 --> 0:02:42.680 or are just completely lost to the winds of time. 0:02:42.960 --> 0:02:46.760 Yeah, because fossilization. I mean, there's a few ways in 0:02:46.800 --> 0:02:49.480 which something becomes a fossil, but it is certainly not 0:02:49.720 --> 0:02:53.320 a common thing to happen to an animal's carcass. It's 0:02:53.360 --> 0:02:55.840 not as if you have just every dinosaur who has 0:02:55.919 --> 0:03:02.200 dyed is perfectly encased in stone. The conditions, yeah, the 0:03:02.240 --> 0:03:05.880 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 0:03:13.960 --> 0:03:15.239 represented in one piece. 0:03:16.360 --> 0:03:19.720 Yeah, so there's the classic. It's the classic. One is 0:03:19.760 --> 0:03:22.760 the opening the early scene in the original Jurassic Park 0:03:22.760 --> 0:03:25.040 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 --> 0:03:32.359 with every bone exactly where it is. That almost never happens. 0:03:32.520 --> 0:03:35.880 Most fossil animals are known from a handful of bits 0:03:35.880 --> 0:03:39.720 of frag like maybe not even complete bones. Teeth are 0:03:39.840 --> 0:03:42.320 very very common because a lot of ret load. Before 0:03:42.320 --> 0:03:44.040 we want to talk reptiles in particular, a lot of 0:03:44.080 --> 0:03:48.760 reptiles shed and regrow their teeth, so teeth are quite common. Sharks. 0:03:48.880 --> 0:03:52.680 Sharks teeth are very common. Shells if you're looking in 0:03:52.960 --> 0:03:57.200 marine and aquatic environments are aquatic water based environments are 0:03:57.760 --> 0:04:01.120 generally speaking more productive for fossil because you have movements 0:04:01.120 --> 0:04:03.200 of the sediments, which is more likely to bury things. 0:04:03.560 --> 0:04:06.120 So a lot of the most productive sites for fossils 0:04:06.120 --> 0:04:09.160 in the world tend to be lakes and lagoons and 0:04:09.840 --> 0:04:14.080 slow flowing rivers where things can be easily buried not 0:04:14.120 --> 0:04:17.560 necessarily destroyed by strong currents or floods and things like that. 0:04:18.960 --> 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 0:04:27.880 --> 0:04:30.240 fossils from this period of time where you had this 0:04:31.320 --> 0:04:37.320 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 --> 0:04:45.159 is it is. It's so interesting too because it was 0:04:45.200 --> 0:04:50.880 discovered so early, well relatively early. The trials and airs 0:04:50.960 --> 0:04:54.680 of trying to put together these fossils that were so 0:04:55.279 --> 0:04:56.360 strange looking. 0:04:57.800 --> 0:05:01.040 Yeah. So the Burger Shale, it's what call the lagostatn, 0:05:01.440 --> 0:05:03.320 which is a German word and it's basically it's a 0:05:03.440 --> 0:05:06.440 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 0:05:09.360 --> 0:05:13.160 very deep water environment and possibly an oxic. So there 0:05:13.160 --> 0:05:17.000 had been quite low oxygen in that environment, which means 0:05:17.040 --> 0:05:19.040 not a lot of fuel for like bacteria and things 0:05:19.080 --> 0:05:21.359 to break down the carcasses when they sink to the 0:05:21.400 --> 0:05:25.679 sea floor. And yeah, you've got creatures, which yeah, they 0:05:25.800 --> 0:05:29.880 are so because so the Burgers show represents a period 0:05:29.880 --> 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 --> 0:05:40.440 it's very famous phenomena called the Cambrian Explosion, wherein there'd 0:05:40.480 --> 0:05:43.400 been micro organisms and algae and things around for several 0:05:43.480 --> 0:05:45.960 or several tens and hundreds of millions of years beforehand, 0:05:46.240 --> 0:05:48.159 but at this particular point, it was sort of the 0:05:48.200 --> 0:05:51.560 stars aligned, sort of the temperature was just right, the 0:05:51.560 --> 0:05:54.760 atmospheric conditions were just right, Everything just kind of landed 0:05:54.960 --> 0:05:59.120 just right, and there's this huge explosion in diversity of 0:05:59.680 --> 0:06:03.000 tomp like multicellular life. And you have early representatives of 0:06:03.960 --> 0:06:08.640 the early ancestors of arthropods, sponges, worms, sort of very 0:06:08.760 --> 0:06:11.839 very early. Yeah, you can kind of sort of squint 0:06:11.960 --> 0:06:14.400 and see the resemblance to modern animals. 0:06:15.640 --> 0:06:18.440 Yeah, that's what's so interesting to me is when I 0:06:18.480 --> 0:06:22.640 see kind of these these animals from the more wormy ones, 0:06:22.720 --> 0:06:25.799 like the soft bodied ones, which I mean, it's incredible 0:06:25.800 --> 0:06:29.360 that we have fossils of these soft bodied animals, because 0:06:29.520 --> 0:06:32.880 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 0:06:35.000 --> 0:06:37.920 to be preserved. But yeah, these soft bodied, like worm 0:06:38.080 --> 0:06:44.560 like animals that don't have many I think analogs in 0:06:44.920 --> 0:06:47.960 modern times, but you can you can kind of find like, actually, 0:06:48.040 --> 0:06:50.280 you know, well, we'll talk about one in a little 0:06:50.320 --> 0:06:52.520 bit that is very interesting, one of my favorite ones. 0:06:52.520 --> 0:06:56.680 But first let's talk about the Anomalocras, which I think 0:06:56.760 --> 0:07:02.200 is sort of one of the most famous examples of 0:07:02.279 --> 0:07:09.120 this this period. The name being Latin Greco for abnormal shrimp, 0:07:09.200 --> 0:07:10.800 which is very funny to me. 0:07:11.760 --> 0:07:15.480 Yeah, very very abnormal shrimp. Anomalo carus is sort of 0:07:15.920 --> 0:07:19.080 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 --> 0:07:24.360 It was so as far as we said, it was 0:07:24.480 --> 0:07:27.880 a free swimming animal, which is quite a big innovation. 0:07:28.000 --> 0:07:29.360 There were, you know, a lot of the critters that 0:07:29.400 --> 0:07:32.880 were around at the time were sort of sediment based, 0:07:33.000 --> 0:07:35.840 either fixed to the sea floor or burrowing or crawling 0:07:35.840 --> 0:07:38.640 around sea floor. But Anomala carus was free swimming, had 0:07:38.640 --> 0:07:42.720 these sort of mobile tendrils on its face for gathering 0:07:42.720 --> 0:07:45.720 at prey, and we think it was probably most likely 0:07:45.800 --> 0:07:48.760 eating sort of the small Yeah, the small, soft body 0:07:48.800 --> 0:07:52.160 crystal floor trilobites would have been very abundant food source. 0:07:52.160 --> 0:07:55.560 So these are the famous sort of sort of woodlousey, 0:07:55.560 --> 0:07:57.360 beatley looking critters that. 0:07:57.880 --> 0:07:59.960 Like polls 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 0:08:07.360 --> 0:08:10.120 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 0:08:13.920 --> 0:08:17.640 the sort of first of three major eons or chapters 0:08:17.680 --> 0:08:19.240 if you like, in the history of life on Earth. 0:08:19.560 --> 0:08:23.280 Paleozoic is from the Cambrian explosion five hundred and forty 0:08:23.280 --> 0:08:26.680 million years ago up to two hundred and fifty million 0:08:26.760 --> 0:08:30.440 years ago, which ends with the Permian extinction event, which 0:08:30.480 --> 0:08:35.760 took out huge, huge numbers of these amazing animals, some 0:08:35.840 --> 0:08:37.560 of which had made it all the way from the 0:08:37.559 --> 0:08:40.559 Cambrian explosion, like the trilobites. 0:08:41.800 --> 0:08:45.240 And what was the precipitating event do we think for 0:08:45.400 --> 0:08:48.640 that mause extinction was a change in the climate. 0:08:49.720 --> 0:08:53.079 So well, ultimately, all mass extinction events are some form 0:08:53.120 --> 0:08:55.400 of climate change. It just depends on what the triggering 0:08:55.480 --> 0:08:58.719 event is and what we believe. This one was a 0:08:58.880 --> 0:09:03.080 massive spike in volcanic activity at this site in Siberia. 0:09:03.760 --> 0:09:07.720 So we're talking an area hundreds of you know, tens 0:09:07.720 --> 0:09:10.240 of possibly tens of thousands of square kilometers of land 0:09:10.280 --> 0:09:15.719 in Russia basically fractured into a constantly erupting supervolcano, and 0:09:15.760 --> 0:09:18.760 I'm talking on the scale of thousands and thousands of years. 0:09:19.080 --> 0:09:21.240 And over the course of that time, it released you know, 0:09:21.320 --> 0:09:24.720 trillions of tons of toxic fumes and greenhouse gases. It 0:09:24.760 --> 0:09:30.680 caused a runaway greenhouse effect. It acidified the oceans matt 0:09:30.760 --> 0:09:36.680 huge amounts of acid rain. As sea temperatures rise, water 0:09:36.840 --> 0:09:40.079 is less able to hold gas at high temperatures, so 0:09:40.480 --> 0:09:42.960 A that means less oxygen for the life living in 0:09:42.960 --> 0:09:45.600 the ocean, and B it means less CO two is 0:09:45.640 --> 0:09:48.400 being absorbed into the ocean, which causes even more heating. 0:09:49.280 --> 0:09:52.480 Some estimates put it as high as eighty percent of 0:09:52.559 --> 0:09:55.000 all life on Earth was wiped out at the end 0:09:55.040 --> 0:09:56.000 of this extinction event. 0:09:56.360 --> 0:09:59.160 That's incredible. I mean, maybe this is the optimist in me, 0:09:59.200 --> 0:10:01.559 but I feel like that's so really impressive that we 0:10:01.679 --> 0:10:04.840 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 0:10:08.960 --> 0:10:12.160 very bad for the current trial bides just trying to 0:10:12.160 --> 0:10:15.720 live their lives, but still the life somehow, you know, 0:10:16.440 --> 0:10:17.720 was able to recover from that. 0:10:18.600 --> 0:10:21.760 Yeah, well, among the survivors were well, obviously everything that's 0:10:21.760 --> 0:10:25.280 alive today is descended from that, you know, relatively small 0:10:25.320 --> 0:10:27.440 handful of life that made it through this extinction event, 0:10:28.040 --> 0:10:31.680 but it caused this huge kind of restructuring of the 0:10:31.720 --> 0:10:36.400 food chain. So there's this really interesting event sort of 0:10:36.440 --> 0:10:39.600 immediately following that extinction. We're still pre dinosaur. By the way, 0:10:39.600 --> 0:10:42.480 the dinosaurs don't really the dinosaurs don't really come into 0:10:42.480 --> 0:10:45.559 their own until the sort of middle to late Triassic period, 0:10:45.640 --> 0:10:47.400 which is sort of two hundred and twenty two hundred 0:10:47.400 --> 0:10:49.680 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 0:10:53.040 --> 0:10:55.520 to come into their own, and there's this phenomenon known 0:10:55.559 --> 0:11:00.439 as the Mesozoic marine revolution, which is really interesting kind 0:11:00.480 --> 0:11:04.040 of upheaval in the oceans. So one major part of 0:11:04.080 --> 0:11:09.840 it is the diversification of secondarily aquatic tetrapods. So there's 0:11:09.840 --> 0:11:11.439 a few technical terms here. I want to make sure 0:11:11.480 --> 0:11:14.600 the audience are fully on board here. So secondarily aquatic 0:11:14.920 --> 0:11:17.720 is basically any animal that has evolved from a land 0:11:17.760 --> 0:11:20.000 based ancestor and has gone back into the water. 0:11:20.360 --> 0:11:23.720 So we've got whales. Whales would count as that, right. 0:11:23.920 --> 0:11:29.400 Whales absolutely, yet sturles, crocodiles, sea lions, penguins, anything that 0:11:29.600 --> 0:11:31.880 has come from a land based ancestor into the ocean. 0:11:32.760 --> 0:11:35.680 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 --> 0:11:47.839 in the ecosystem were dominated by fish and arthropods, So 0:11:48.200 --> 0:11:51.640 the big predators in the ocean were giant fish and 0:11:51.840 --> 0:11:55.800 giants arthropods, So there were things like Dunkleostius is probably 0:11:55.800 --> 0:11:58.280 the most famous one, which is this it's part of 0:11:58.280 --> 0:12:00.840 a group of fish that doesn't exist anymore, called the placoderms, 0:12:01.320 --> 0:12:04.679 and rather than having teeth they just have extended bones 0:12:04.720 --> 0:12:07.440 of the skull that would sheer against each other like 0:12:07.440 --> 0:12:11.680 scissor blades. That is, there's been some recent studies on 0:12:11.720 --> 0:12:14.480 Doncleosis as to exactly how big it was. It was 0:12:14.520 --> 0:12:17.400 believed to be like a sort of school bus sized monster. 0:12:17.520 --> 0:12:19.560 That's been scaled down with it recently. We think sort of, 0:12:21.200 --> 0:12:21.600 doesn't it. 0:12:21.559 --> 0:12:24.240 Where we like it was the size of the Empire 0:12:24.280 --> 0:12:28.040 state building. Maybe actually just the size of a Volkswagen. 0:12:28.840 --> 0:12:30.920 Yeah, there's quite a bit of that. There's also the 0:12:31.400 --> 0:12:35.680 sea scorpions, which were another casualty of the Permian extinction events. 0:12:36.320 --> 0:12:39.559 Not technically scorpions, they are arthropods. 0:12:38.960 --> 0:12:42.600 So they look like a flat scorpion, kind of like 0:12:42.600 --> 0:12:44.640 if you took the rolling pin and just sort of 0:12:44.720 --> 0:12:46.360 like rolled out a scorpion. 0:12:46.440 --> 0:12:49.400 Yeah, yeah, very much so. Yeah, they've got this great, big, 0:12:49.440 --> 0:12:52.320 grasping pincers. They've got this big, long, flat tail, which 0:12:52.679 --> 0:12:54.960 some of the smaller ones may have swam, but some 0:12:55.000 --> 0:12:58.040 of the big ones probably stuck to the seabed. Some 0:12:58.120 --> 0:13:02.200 of the really big ones were nightmarish, like the biggest 0:13:02.320 --> 0:13:06.240 arthropods of all time. Yes, two meters long, possibly two 0:13:06.280 --> 0:13:08.040 and a half. For some of the really big ones. 0:13:08.440 --> 0:13:10.839 So these are the things that are occupying the big 0:13:11.480 --> 0:13:13.800 the big ocean niches at the time. And then the 0:13:13.800 --> 0:13:17.000 Permian extinction happens and it kind of opens up the 0:13:17.040 --> 0:13:19.200 food chain somewhe It opens up the ecosystem, and you 0:13:19.240 --> 0:13:22.760 have this big adaptive radiation where this happens a lot 0:13:22.800 --> 0:13:25.200 after extinction events. When you have when you've got the 0:13:25.240 --> 0:13:27.800 slate white clean, that leaves a lot of space for 0:13:28.160 --> 0:13:32.000 innovation and sort of evolutionary experimentation. So you start to 0:13:32.000 --> 0:13:35.360 get reptiles moving into the ocean. You get early sort 0:13:35.400 --> 0:13:38.679 of crocodile and turtle relatives. You have lots of very 0:13:38.679 --> 0:13:42.280 strange things that don't really exist anymore, like the placar 0:13:42.360 --> 0:13:46.480 donts Placoderms is the armored fish. And then you have plecardonts, 0:13:46.520 --> 0:13:50.000 which are these weird swimming reptiles that are not turtles, 0:13:50.000 --> 0:13:53.079 but they have very wide, flat bodies and armor across them. 0:13:53.080 --> 0:13:58.920 They sort of look like baked turtles. They're very strange things, yeah, 0:13:59.120 --> 0:14:01.480 very odd looking, but some of them have some of 0:14:01.480 --> 0:14:04.920 them are derived ones. They've got these forward facing teeth 0:14:04.960 --> 0:14:06.640 at the front of the jaw, and then they have 0:14:06.720 --> 0:14:09.640 these very flat plate like teeth at the back of 0:14:09.679 --> 0:14:12.360 the jaw and the roof of the mouth, and that's 0:14:12.400 --> 0:14:16.840 interpreted as being adaptations for prising apart and crushing shellfish. 0:14:16.880 --> 0:14:19.480 And that's the other big part of the mesozoat marine 0:14:19.520 --> 0:14:23.760 revolution is that it forced this big change in ocean 0:14:23.760 --> 0:14:27.720 invertebrates through the evolution of new creatures that can crack 0:14:27.800 --> 0:14:33.400 open and ingest shells and exoskeletons. Because if you think, 0:14:33.440 --> 0:14:35.600 you know, if you're like a limpet or a barnacle 0:14:35.680 --> 0:14:37.560 or something attached to a rock or attached to the 0:14:37.600 --> 0:14:40.400 sea floor, and there's nothing that can break you, basically fine, 0:14:40.440 --> 0:14:42.760 But if something pulls you off the rock and you 0:14:42.840 --> 0:14:46.560 can't reattach yourself or swim away or crawl into a 0:14:46.600 --> 0:14:51.480 hole and hide, you're basically doomed. So sessile animals, so 0:14:51.680 --> 0:14:54.480 things that attached to the sea floor and basically stay 0:14:54.520 --> 0:14:57.800 there the rest of their lives started to decline and 0:14:58.000 --> 0:15:01.520 animal and yeah, these sort of shellfish and invertebrates had 0:15:01.520 --> 0:15:03.280 to find all sorts of new ways to adapt. So 0:15:04.040 --> 0:15:07.480 creatures that lived on the surface declined, Creatures that lived 0:15:07.520 --> 0:15:11.440 in burrows diversified. There was a lot more burrowing animals 0:15:11.480 --> 0:15:15.720 after this. A really good example is crinoids, which, again 0:15:16.080 --> 0:15:19.040 making sure your audience caught up. Crinoids is really really 0:15:19.480 --> 0:15:23.200 weird creatures that evolved early on in the Paleozoic, not 0:15:23.280 --> 0:15:28.200 quite the Cambrian. They have I think it's penta radial symmetry. 0:15:28.680 --> 0:15:32.000 So humans are bilaterally symmetrical. We've got a left side 0:15:32.000 --> 0:15:35.080 and the right side. Chronoids have five way symmetry. You 0:15:35.120 --> 0:15:36.680 can look you look down on them from the top, 0:15:36.720 --> 0:15:39.240 you can split them five ways as they've got the 0:15:39.280 --> 0:15:40.520 mouse in the middle. 0:15:40.840 --> 0:15:44.560 So like starf like kind of terms like starfish and 0:15:45.200 --> 0:15:45.560 there are. 0:15:45.680 --> 0:15:48.400 Yeah, they are a kindoderms. Yeah, they're related to starfish 0:15:48.400 --> 0:15:50.600 and sea urchins. So they've got a mouth in the middle, 0:15:50.600 --> 0:15:53.680 and then they have all these big branching feathery arms 0:15:53.720 --> 0:15:59.000 that come outs and their suspension feeders. They gather organic material, 0:15:59.040 --> 0:16:01.800 they put their arms out, they collect food from the water, 0:16:01.840 --> 0:16:03.680 and then they draw their arms into the mouth in 0:16:03.680 --> 0:16:07.080 the middle. And there's two major varieties of them. There's 0:16:07.160 --> 0:16:11.440 the standard ones just as I've described, which can use 0:16:11.440 --> 0:16:13.680 their arms to swim around and crawl around on the 0:16:13.680 --> 0:16:16.200 sea floor, and we call them feather stars. And then 0:16:16.240 --> 0:16:18.680 there's the stalked variety, which have a great, big, long 0:16:18.720 --> 0:16:21.760 stalk that trails from underneath the body and attaches them 0:16:21.800 --> 0:16:23.600 to the seafloor. And they kind of makes them look 0:16:23.640 --> 0:16:25.840 like a flower, and we call them sea lilies, and 0:16:25.920 --> 0:16:28.120 they are all still around today. They've made it through 0:16:28.160 --> 0:16:30.160 all the extinctions, all the way into the present day. 0:16:30.840 --> 0:16:34.560 During the Massasoka marine Revolution, you have this explosion of 0:16:34.680 --> 0:16:39.440 creatures that can break through exo skeletons. The sea lilies, 0:16:39.520 --> 0:16:42.400 the ones fix to the sea floor, start to abandon 0:16:42.440 --> 0:16:44.720 the shallow water and move into the deeper ocean. So 0:16:44.840 --> 0:16:46.840 most of the sea lily species that we have today 0:16:46.880 --> 0:16:50.680 live in deep offshore waters, whereas the feather stars that 0:16:50.720 --> 0:16:53.480 can move around and swim and escape, they live on 0:16:53.760 --> 0:16:57.880 the reefs and coastal environments. So it is this complete 0:16:58.000 --> 0:17:02.680 restructuring of how entire food chains and ecosystems work over 0:17:02.720 --> 0:17:04.119 this extinction boundary. 0:17:04.359 --> 0:17:06.040 Yeah, you have a mass when you have like a 0:17:06.080 --> 0:17:11.560 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 0:17:14.880 --> 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 0:17:21.520 --> 0:17:26.040 species that have gone extinct. Everything is impacted right in 0:17:26.080 --> 0:17:29.240 a way that like they all have to readapt It 0:17:29.280 --> 0:17:31.280 kind of reminds me of one of the animals I 0:17:31.320 --> 0:17:35.280 was thinking of talking about today was Endoceras Gigantium, which 0:17:35.320 --> 0:17:40.320 is sort of like that that big unicorn like cephalopod 0:17:40.640 --> 0:17:44.639 during the I'm gonna say a period as if I 0:17:44.720 --> 0:17:46.720 know what I'm talking about, even though I don't, the 0:17:46.840 --> 0:17:56.840 Ordovician period. So it was this like ancestor of modern 0:17:56.920 --> 0:18:01.639 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 --> 0:18:09.360 which still has that shell, it was this really straight, 0:18:09.760 --> 0:18:14.639 large conical shell that spanned from over nine up to 0:18:14.760 --> 0:18:19.240 possibly the larger estimates are eighteen feet, although that's not 0:18:19.359 --> 0:18:23.600 exactly confirmed, but it could be anywhere from like three 0:18:23.760 --> 0:18:27.480 to over five meters. And so it's thought it was 0:18:27.560 --> 0:18:31.840 like this ambush predator, right, because you're so big, you're 0:18:31.840 --> 0:18:34.040 not going to be very mobile, and you have this 0:18:34.160 --> 0:18:39.679 giant shell to defend itself. So that once, and similarly 0:18:39.720 --> 0:18:45.360 to other giant shelled cephalopods, thought that it went extinct 0:18:45.480 --> 0:18:48.880 because it could not out compete with this new sort 0:18:48.880 --> 0:18:53.919 of wave of like the fish and more mobile, more agile, 0:18:54.320 --> 0:18:59.680 and swifter creatures that were evolving at the time. So 0:18:59.880 --> 0:19:01.920 it went from because you'd think, like a lot of 0:19:01.920 --> 0:19:04.520 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, 0:19:08.040 --> 0:19:09.639 why would it get rid of it? Right, because like 0:19:09.880 --> 0:19:14.119 squid octopuses, they're very vulnerable, they're so squishy, But it 0:19:14.160 --> 0:19:18.000 doesn't matter necessarily if you're perfectly protected, if you're not 0:19:18.040 --> 0:19:20.960 getting any food, if you're unable to compete with the 0:19:21.000 --> 0:19:22.879 faster predators and the faster prey. 0:19:24.160 --> 0:19:26.920 Yeah, the the evolution of a spine was a big 0:19:26.920 --> 0:19:29.960 innovation because that that's you know, that provided the sort 0:19:29.960 --> 0:19:33.840 of propulsion for sort of early predatory fish to swe 0:19:34.000 --> 0:19:35.560 you know, be a lot faster and a lot more 0:19:35.600 --> 0:19:38.760 agile and maneuverable in the water. And yeah, so I 0:19:38.800 --> 0:19:41.880 think things like endoceras and you know, these giant autaloids 0:19:43.160 --> 0:19:45.879 would have would have had no predators, had had no 0:19:45.920 --> 0:19:49.480 competition until these larger, you know, the early ancestors of 0:19:49.520 --> 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 --> 0:20:00.639 a big innovation at the time they used sort of 0:20:00.680 --> 0:20:02.840 started to occupy the ape expression each but they were 0:20:02.920 --> 0:20:04.720 kind of overtaken by the placoderms, the big sort of 0:20:04.720 --> 0:20:07.280 sheer teeth fish. They were kind of your two main 0:20:08.840 --> 0:20:11.080 sort of apex predator bodies that came in at the time, 0:20:11.080 --> 0:20:13.679 and they were all kinds of bizarre as well. You 0:20:13.720 --> 0:20:17.159 have these really nice out groups, as they're called, So 0:20:17.240 --> 0:20:19.800 you have sort of we have your sort of evolutionary 0:20:19.840 --> 0:20:22.480 group of animals that we consider modern day sharks, and 0:20:22.520 --> 0:20:24.119 then you sort of go back a step on the 0:20:24.119 --> 0:20:27.080 family tree and off on a little weird side branch, 0:20:27.119 --> 0:20:30.119 and you find all these really odd creatures that aren't 0:20:30.240 --> 0:20:33.840 quite entirely sharks that that's sort of the closest thing 0:20:33.840 --> 0:20:37.560 we can relate into the things like one of the 0:20:37.600 --> 0:20:42.200 more famous one is Stepacanthus, which has got these like rays. 0:20:42.240 --> 0:20:44.880 It's rather than like the kind of triangular dorsalt thing. 0:20:45.080 --> 0:20:47.720 It's got this kind of flattened structure on its back 0:20:47.760 --> 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 0:20:52.800 --> 0:20:56.840 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. There's a oh, 0:20:58.800 --> 0:20:59.760 helica prion. 0:20:59.520 --> 0:21:02.400 As a real yeah. 0:21:02.200 --> 0:21:05.960 Yeah, so yeah, this this whole family group of sharks that, 0:21:06.119 --> 0:21:09.440 instead of having a jawline as conventional sharks do, all 0:21:09.440 --> 0:21:11.399 their teeth run down the middle of the jaw, and 0:21:11.440 --> 0:21:13.879 there's some that have them like scissor blades, one on 0:21:13.920 --> 0:21:15.680 top of the other. But helica prion has this big 0:21:15.720 --> 0:21:19.120 spiral of teeth which we now interpret as being new 0:21:19.160 --> 0:21:22.520 teeth growing in the center and kind of growing outwards 0:21:22.920 --> 0:21:25.280 towards the outer edge of the spiral, and then as 0:21:25.280 --> 0:21:27.280 they are replaced, they kind of fall out of the front. 0:21:28.400 --> 0:21:30.280 It's possible it may have been able to use that 0:21:31.040 --> 0:21:34.479 to cut through, you know, shells and of things like 0:21:34.520 --> 0:21:37.320 the squid and the autoloids that were hanging around at 0:21:37.359 --> 0:21:37.640 the time. 0:21:39.840 --> 0:21:42.199 Yeah, no, it is. It is so weird because with 0:21:42.240 --> 0:21:45.240 a lot of these animals, when I mean, one thing 0:21:45.320 --> 0:21:48.120 is that I think that the reason these shapes look 0:21:48.200 --> 0:21:50.879 so bizarre to us is that we are we acclimate 0:21:50.880 --> 0:21:55.280 ourselves to the shapes of say, you know, we look 0:21:55.280 --> 0:21:58.159 at a hammerhead shark, right, and we're we're a climatized 0:21:58.200 --> 0:22:00.919 to that. So we see that and we understand it 0:22:00.960 --> 0:22:04.280 we see this sh this as a normal animal shape 0:22:04.320 --> 0:22:07.679 more or less, but that's really only because we have 0:22:07.760 --> 0:22:09.800 gotten used to it that when like the first people 0:22:09.800 --> 0:22:12.480 who probably saw a hammerhead shark was like, well, this 0:22:12.640 --> 0:22:15.560 is an incredibly weird shape for a shark head. So 0:22:15.600 --> 0:22:19.640 something like stephacanthus that has this weird anvil on its head, 0:22:20.720 --> 0:22:23.120 which I'd be I'd love to see a hammerhead shark 0:22:23.119 --> 0:22:25.600 and a deethacanthus get together and see what what what 0:22:25.640 --> 0:22:28.680 they would make us, what they can build, see what 0:22:29.040 --> 0:22:31.840 they can craft? Uh, but you know, yeah, I mean 0:22:31.880 --> 0:22:34.320 it's it is interesting because they're all especially when we're 0:22:34.320 --> 0:22:36.680 trying to piece together say that the purpose like how 0:22:36.760 --> 0:22:40.280 how say the jaws work of this like weird spiraling 0:22:40.359 --> 0:22:43.480 saw too thing, how they would actually maneuver that? Or 0:22:43.520 --> 0:22:46.520 like this death of canthus, what that that protrusion was, 0:22:46.560 --> 0:22:48.840 and the way we piece it together in terms of well, 0:22:49.080 --> 0:22:52.720