Speaker 1: Welcome to brainsty a production of iHeartRadio, Hey Brainstuff Laura
Speaker 1: voleban here. According to the prevailing scientific theory, non avian
Speaker 1: dinosaurs met their dramatic end after an enormous asteroid hit
Speaker 1: the Earth near what's now Mexico about sixty six million
Speaker 1: years ago, give or take. This mass extinction, known today
Speaker 1: as the Cretaceous paleagen or the Cretaceous Tertiary extinction, event,
Speaker 1: caused a huge amount of debris like dust and ash
Speaker 1: to fill the atmosphere. This in turn created what's called
Speaker 1: an impact winter, in which life giving light from the
Speaker 1: sun was blocked. A plant life couldn't photosynthesize and thus
Speaker 1: died off. The oceans acidified, the food chain was disrupted,
Speaker 1: and some seventy to eighty percent of all life on
Speaker 1: the planet was wiped out. It was the literal end
Speaker 1: of an era, the Mesozoic to be specific. The mighty
Speaker 1: non avian dinosaurs were perhaps the most famous of the
Speaker 1: life forms that died out post asteroid, but many others
Speaker 1: became extinct as well. These included aquatic reptiles like plesiosaurs,
Speaker 1: the first vertebrate animals to fly by flapping their wings.
Speaker 1: The pterosaurs, the vast numbers of oceanic invertebrates, and some
Speaker 1: ninety percent of algae species. Life was never the same,
Speaker 1: but some types of animals weren't hit nearly as hard.
Speaker 1: At least a few members of about eighty four percent
Speaker 1: of marine families and eighty two percent of land vertebrate
Speaker 1: families made it through. So many life forms survived the
Speaker 1: event that it would take way more than a podcast
Speaker 1: episode to describe them all, and many of the animals
Speaker 1: have descendants that still live today. Some of these species
Speaker 1: look a lot like their Mesozoic counterparts. Others have changed
Speaker 1: quite a bit, including birds, which are the descendants of
Speaker 1: avian dinosaurs that managed to survive the extinction event. So
Speaker 1: aside from birds, which of today's animals walked, crawled, slithered,
Speaker 1: or swam alongside dinosaurs. Dinos lived on Earth during the
Speaker 1: Mesozoic Era, which lasted from two hundred and forty eight
Speaker 1: to sixty six million years ago. Geologists divide the Mesozoic
Speaker 1: Era into three periods, from longest ago to most recent
Speaker 1: the Triassic, Jurassic, and Cretaceous. Dinosaurs became more diverse as
Speaker 1: time went by, and at the same time, other life
Speaker 1: forms developed and became extinct. If the Mesozoic era was
Speaker 1: the age of the dinosaurs, the next era, the Cenozoic era,
Speaker 1: was the age of mammals. The first mammals were monotremes,
Speaker 1: or mammals that reproduce by laying eggs. Mammals in general
Speaker 1: are common today, but only three monotrem species still exist.
Speaker 1: These are the duckbilled platypus and a couple of echidnas,
Speaker 1: and you can see our past episodes on both of those.
Speaker 1: Many types of reptiles species die during the extinction event,
Speaker 1: but some snakes, lizards, and crocodilians persevered. Crocodilians have been
Speaker 1: on the planet for about two hundred and forty million years.
Speaker 1: There are twenty three crocodilian species today, including alligators, crocodiles,
Speaker 1: and caymans. Mesozoic crocodilians were generally larger. Another prehistoric order
Speaker 1: of reptiles is the Saphenodontians. Today there is one living sphenodon,
Speaker 1: the Tuitara, a small, spiky, gray green reptile that lives
Speaker 1: in New Zealand. The most likely evolutionary origin for these
Speaker 1: reptiles is that in the distant past they arose from amphibians.
Speaker 1: Very large amphibian species lived before and during the Mesozoic.
Speaker 1: These are gone today, but in their place three primary
Speaker 1: types of amphibians survived, frogs and toads, nuts and salamanders,
Speaker 1: and celions, which are animals that mostly look like worms
Speaker 1: but have skeletons. But not. Every family that lived during
Speaker 1: the Mesozoic has only a few descendants left today. All
Speaker 1: modern insect groups existed before or arose during the Mesozoic era,
Speaker 1: and perhaps most notable of these is the usocial bee
Speaker 1: of bees that live in colonies. Most likely these evolved
Speaker 1: along with flowering plants, which started to develop in the
Speaker 1: Cretaceous period. Without this code development, we humans wouldn't have
Speaker 1: honey or a whole host of bee pollinated fruits, vegetables, nuts,
Speaker 1: and grains today. Ferns and conifers were also widespread during
Speaker 1: the Mesozoic era, and ferns actually experienced a huge population
Speaker 1: spike after the extinction event. Then there's Gingo biloba. If
Speaker 1: you see one of these trees but which has fan
Speaker 1: shaped green leaves that turn golden yellow in the fall,
Speaker 1: you're looking at a plant that's almost identical in appearance
Speaker 1: to its Mesozoic ancestors, but the oceans were particularly devastated
Speaker 1: by the event. Dinosaurs were not particularly aquatic, but there
Speaker 1: were lots of sea dwelling animals during the Mesozoic. The
Speaker 1: aforementioned pleasyosaurs were long necked, finned reptiles. Think of the
Speaker 1: Lochness monster and you've got a pretty good idea of
Speaker 1: what one looked like, though as far as science knows,
Speaker 1: they did not survive. Other marine life forms experienced heavy
Speaker 1: losses but eventually recovered and went on to thrive and diversify.
Speaker 1: Those include the echinoderms like sea stars, sea urchins, and
Speaker 1: sea cucumbers, plus mollusks with their soft bodies and hard shells.
Speaker 1: The clams, snails, lobsters, crabs, and shrimp that make their
Speaker 1: way to the mouths of oceanic carnivores, and the plates
Speaker 1: of hungry humans come from predecessors that, one way or another,
Speaker 1: lived through the extinction event. Sharks also inhabited the world's
Speaker 1: oceans long before the first dino made its way across land,
Speaker 1: and they're among the most well known oceanic predators today,
Speaker 1: but a few of today's species are the only remaining
Speaker 1: examples of long extinct marine families. The most famous may
Speaker 1: be the Sila camp, the last known marines sarcopterrigian, which
Speaker 1: were lobe finned bony fish. There are plenty of other
Speaker 1: Sarcopterygians in the world, though. All of the four limbed
Speaker 1: vertebrates on the planet, from turtles to tucans to humans,
Speaker 1: arose from common ancestors that diverged from the sarcoptigians long
Speaker 1: before the Mesozoic era. Scientists thought selacanths were extinct until
Speaker 1: the nineteen thirties, so hey, it's possible that researchers may
Speaker 1: one day find other remnants of Mesoic life out there.
Speaker 1: Today's episode is based on the article which of today's
Speaker 1: animals lived alongside dinosaurs on how stuffworks dot Com, written
Speaker 1: by Tracy V. Wilson. Brain Stuff is production of by
Speaker 1: Heart Radio in partnership with how Stuffworks dot Com, produced
Speaker 1: by Tyler Klang. For more podcasts from my Heart Radio,
Speaker 1: visit the iHeartRadio app, Apple Podcasts, or wherever you listen
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