1 00:00:01,840 --> 00:00:07,880 Speaker 1: Welcome to brainsty a production of iHeartRadio, Hey Brainstuff Laura 2 00:00:07,920 --> 00:00:14,280 Speaker 1: voleban here. According to the prevailing scientific theory, non avian 3 00:00:14,320 --> 00:00:18,320 Speaker 1: dinosaurs met their dramatic end after an enormous asteroid hit 4 00:00:18,360 --> 00:00:21,600 Speaker 1: the Earth near what's now Mexico about sixty six million 5 00:00:21,680 --> 00:00:26,480 Speaker 1: years ago, give or take. This mass extinction, known today 6 00:00:26,560 --> 00:00:30,680 Speaker 1: as the Cretaceous paleagen or the Cretaceous Tertiary extinction, event, 7 00:00:31,320 --> 00:00:34,680 Speaker 1: caused a huge amount of debris like dust and ash 8 00:00:34,720 --> 00:00:39,000 Speaker 1: to fill the atmosphere. This in turn created what's called 9 00:00:39,040 --> 00:00:42,159 Speaker 1: an impact winter, in which life giving light from the 10 00:00:42,200 --> 00:00:45,440 Speaker 1: sun was blocked. A plant life couldn't photosynthesize and thus 11 00:00:45,520 --> 00:00:48,960 Speaker 1: died off. The oceans acidified, the food chain was disrupted, 12 00:00:49,280 --> 00:00:52,159 Speaker 1: and some seventy to eighty percent of all life on 13 00:00:52,200 --> 00:00:55,720 Speaker 1: the planet was wiped out. It was the literal end 14 00:00:55,720 --> 00:01:01,040 Speaker 1: of an era, the Mesozoic to be specific. The mighty 15 00:01:01,120 --> 00:01:03,960 Speaker 1: non avian dinosaurs were perhaps the most famous of the 16 00:01:04,000 --> 00:01:07,319 Speaker 1: life forms that died out post asteroid, but many others 17 00:01:07,360 --> 00:01:12,000 Speaker 1: became extinct as well. These included aquatic reptiles like plesiosaurs, 18 00:01:12,480 --> 00:01:14,960 Speaker 1: the first vertebrate animals to fly by flapping their wings. 19 00:01:15,040 --> 00:01:19,000 Speaker 1: The pterosaurs, the vast numbers of oceanic invertebrates, and some 20 00:01:19,160 --> 00:01:23,119 Speaker 1: ninety percent of algae species. Life was never the same, 21 00:01:25,040 --> 00:01:28,040 Speaker 1: but some types of animals weren't hit nearly as hard. 22 00:01:28,720 --> 00:01:31,559 Speaker 1: At least a few members of about eighty four percent 23 00:01:31,560 --> 00:01:34,480 Speaker 1: of marine families and eighty two percent of land vertebrate 24 00:01:34,560 --> 00:01:38,480 Speaker 1: families made it through. So many life forms survived the 25 00:01:38,520 --> 00:01:40,880 Speaker 1: event that it would take way more than a podcast 26 00:01:40,920 --> 00:01:44,200 Speaker 1: episode to describe them all, and many of the animals 27 00:01:44,200 --> 00:01:48,840 Speaker 1: have descendants that still live today. Some of these species 28 00:01:48,880 --> 00:01:52,160 Speaker 1: look a lot like their Mesozoic counterparts. Others have changed 29 00:01:52,280 --> 00:01:55,480 Speaker 1: quite a bit, including birds, which are the descendants of 30 00:01:55,480 --> 00:02:01,240 Speaker 1: avian dinosaurs that managed to survive the extinction event. So 31 00:02:01,520 --> 00:02:05,400 Speaker 1: aside from birds, which of today's animals walked, crawled, slithered, 32 00:02:05,480 --> 00:02:11,000 Speaker 1: or swam alongside dinosaurs. Dinos lived on Earth during the 33 00:02:11,000 --> 00:02:14,280 Speaker 1: Mesozoic Era, which lasted from two hundred and forty eight 34 00:02:14,360 --> 00:02:18,720 Speaker 1: to sixty six million years ago. Geologists divide the Mesozoic 35 00:02:18,760 --> 00:02:22,440 Speaker 1: Era into three periods, from longest ago to most recent 36 00:02:22,600 --> 00:02:28,000 Speaker 1: the Triassic, Jurassic, and Cretaceous. Dinosaurs became more diverse as 37 00:02:28,040 --> 00:02:31,000 Speaker 1: time went by, and at the same time, other life 38 00:02:31,000 --> 00:02:36,080 Speaker 1: forms developed and became extinct. If the Mesozoic era was 39 00:02:36,120 --> 00:02:39,119 Speaker 1: the age of the dinosaurs, the next era, the Cenozoic era, 40 00:02:39,520 --> 00:02:43,520 Speaker 1: was the age of mammals. The first mammals were monotremes, 41 00:02:43,760 --> 00:02:47,760 Speaker 1: or mammals that reproduce by laying eggs. Mammals in general 42 00:02:47,800 --> 00:02:51,640 Speaker 1: are common today, but only three monotrem species still exist. 43 00:02:51,880 --> 00:02:54,799 Speaker 1: These are the duckbilled platypus and a couple of echidnas, 44 00:02:55,000 --> 00:02:57,280 Speaker 1: and you can see our past episodes on both of those. 45 00:02:58,800 --> 00:03:01,960 Speaker 1: Many types of reptiles species die during the extinction event, 46 00:03:02,240 --> 00:03:06,720 Speaker 1: but some snakes, lizards, and crocodilians persevered. Crocodilians have been 47 00:03:06,760 --> 00:03:09,560 Speaker 1: on the planet for about two hundred and forty million years. 48 00:03:10,200 --> 00:03:14,880 Speaker 1: There are twenty three crocodilian species today, including alligators, crocodiles, 49 00:03:14,919 --> 00:03:21,919 Speaker 1: and caymans. Mesozoic crocodilians were generally larger. Another prehistoric order 50 00:03:21,919 --> 00:03:26,880 Speaker 1: of reptiles is the Saphenodontians. Today there is one living sphenodon, 51 00:03:27,200 --> 00:03:31,359 Speaker 1: the Tuitara, a small, spiky, gray green reptile that lives 52 00:03:31,400 --> 00:03:37,280 Speaker 1: in New Zealand. The most likely evolutionary origin for these 53 00:03:37,280 --> 00:03:41,480 Speaker 1: reptiles is that in the distant past they arose from amphibians. 54 00:03:42,480 --> 00:03:46,000 Speaker 1: Very large amphibian species lived before and during the Mesozoic. 55 00:03:46,840 --> 00:03:50,160 Speaker 1: These are gone today, but in their place three primary 56 00:03:50,200 --> 00:03:54,280 Speaker 1: types of amphibians survived, frogs and toads, nuts and salamanders, 57 00:03:54,280 --> 00:03:58,160 Speaker 1: and celions, which are animals that mostly look like worms 58 00:03:58,200 --> 00:04:04,440 Speaker 1: but have skeletons. But not. Every family that lived during 59 00:04:04,440 --> 00:04:08,440 Speaker 1: the Mesozoic has only a few descendants left today. All 60 00:04:08,560 --> 00:04:12,520 Speaker 1: modern insect groups existed before or arose during the Mesozoic era, 61 00:04:13,360 --> 00:04:16,320 Speaker 1: and perhaps most notable of these is the usocial bee 62 00:04:16,520 --> 00:04:20,039 Speaker 1: of bees that live in colonies. Most likely these evolved 63 00:04:20,080 --> 00:04:23,039 Speaker 1: along with flowering plants, which started to develop in the 64 00:04:23,040 --> 00:04:27,080 Speaker 1: Cretaceous period. Without this code development, we humans wouldn't have 65 00:04:27,120 --> 00:04:30,520 Speaker 1: honey or a whole host of bee pollinated fruits, vegetables, nuts, 66 00:04:30,520 --> 00:04:36,200 Speaker 1: and grains today. Ferns and conifers were also widespread during 67 00:04:36,200 --> 00:04:40,080 Speaker 1: the Mesozoic era, and ferns actually experienced a huge population 68 00:04:40,240 --> 00:04:44,960 Speaker 1: spike after the extinction event. Then there's Gingo biloba. If 69 00:04:45,000 --> 00:04:47,040 Speaker 1: you see one of these trees but which has fan 70 00:04:47,120 --> 00:04:49,719 Speaker 1: shaped green leaves that turn golden yellow in the fall, 71 00:04:50,200 --> 00:04:53,120 Speaker 1: you're looking at a plant that's almost identical in appearance 72 00:04:53,200 --> 00:04:59,120 Speaker 1: to its Mesozoic ancestors, but the oceans were particularly devastated 73 00:04:59,120 --> 00:05:03,000 Speaker 1: by the event. Dinosaurs were not particularly aquatic, but there 74 00:05:03,000 --> 00:05:06,680 Speaker 1: were lots of sea dwelling animals during the Mesozoic. The 75 00:05:06,760 --> 00:05:11,279 Speaker 1: aforementioned pleasyosaurs were long necked, finned reptiles. Think of the 76 00:05:11,360 --> 00:05:13,520 Speaker 1: Lochness monster and you've got a pretty good idea of 77 00:05:13,560 --> 00:05:16,680 Speaker 1: what one looked like, though as far as science knows, 78 00:05:16,920 --> 00:05:21,960 Speaker 1: they did not survive. Other marine life forms experienced heavy 79 00:05:21,960 --> 00:05:26,200 Speaker 1: losses but eventually recovered and went on to thrive and diversify. 80 00:05:27,880 --> 00:05:31,480 Speaker 1: Those include the echinoderms like sea stars, sea urchins, and 81 00:05:31,560 --> 00:05:36,040 Speaker 1: sea cucumbers, plus mollusks with their soft bodies and hard shells. 82 00:05:36,800 --> 00:05:40,240 Speaker 1: The clams, snails, lobsters, crabs, and shrimp that make their 83 00:05:40,240 --> 00:05:43,000 Speaker 1: way to the mouths of oceanic carnivores, and the plates 84 00:05:43,000 --> 00:05:46,640 Speaker 1: of hungry humans come from predecessors that, one way or another, 85 00:05:46,960 --> 00:05:51,040 Speaker 1: lived through the extinction event. Sharks also inhabited the world's 86 00:05:51,040 --> 00:05:54,159 Speaker 1: oceans long before the first dino made its way across land, 87 00:05:54,640 --> 00:05:59,680 Speaker 1: and they're among the most well known oceanic predators today, 88 00:06:00,120 --> 00:06:03,039 Speaker 1: but a few of today's species are the only remaining 89 00:06:03,080 --> 00:06:07,880 Speaker 1: examples of long extinct marine families. The most famous may 90 00:06:07,920 --> 00:06:11,880 Speaker 1: be the Sila camp, the last known marines sarcopterrigian, which 91 00:06:11,920 --> 00:06:16,640 Speaker 1: were lobe finned bony fish. There are plenty of other 92 00:06:16,680 --> 00:06:20,839 Speaker 1: Sarcopterygians in the world, though. All of the four limbed 93 00:06:20,920 --> 00:06:24,719 Speaker 1: vertebrates on the planet, from turtles to tucans to humans, 94 00:06:25,040 --> 00:06:29,760 Speaker 1: arose from common ancestors that diverged from the sarcoptigians long 95 00:06:29,800 --> 00:06:36,440 Speaker 1: before the Mesozoic era. Scientists thought selacanths were extinct until 96 00:06:36,440 --> 00:06:40,800 Speaker 1: the nineteen thirties, so hey, it's possible that researchers may 97 00:06:40,880 --> 00:06:43,919 Speaker 1: one day find other remnants of Mesoic life out there. 98 00:06:48,800 --> 00:06:51,320 Speaker 1: Today's episode is based on the article which of today's 99 00:06:51,320 --> 00:06:54,560 Speaker 1: animals lived alongside dinosaurs on how stuffworks dot Com, written 100 00:06:54,560 --> 00:06:57,320 Speaker 1: by Tracy V. Wilson. Brain Stuff is production of by 101 00:06:57,320 --> 00:07:00,320 Speaker 1: Heart Radio in partnership with how Stuffworks dot Com, produced 102 00:07:00,320 --> 00:07:03,360 Speaker 1: by Tyler Klang. For more podcasts from my Heart Radio, 103 00:07:03,600 --> 00:07:06,719 Speaker 1: visit the iHeartRadio app, Apple Podcasts, or wherever you listen 104 00:07:06,800 --> 00:07:07,799 Speaker 1: to your favorite shows.