From the Cambrian Explosion to the Great Dying

  • Published on: 20 February 2018
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    The first era of our current eon, the Paleozoic Era, is probably the most deceptively fascinating time in Earth’s history. With near constant revolutions in life, punctuated by catastrophic extinctions, it is also one of the most chaotic.

    Correction! At 9:19, we erroneously refer to Dimetrodon as an herbivore. It was definitely a carnivore. We even made a whole video about Dimetrodon and their carnivorous ways in a previous episode: Thanks to everyone who pointed out our error!

    Thanks to Studio 252mya for their illustrations. You can find more of their work here:

    Produced in collaboration with PBS Digital Studios:

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  • Runtime : 11:58
  • dinosaurs dinos paleo paleontology scishow eons pbs pbs digital studios hank green john green complexly fossils natural history Paleozoic Era Cambrian Cambrian Explosion Anomalocaris Ordovician The Great Ordovician Biodiversification Event Cameroceras Pikaia ostracoderms Ordovician-Silurian Extinction Event Silurian Devonian placoderms Late Devonian Extinctions Carboniferous Pangea Carboniferous Rainforest Collapse Dimetrodon Permian-Triassic Extinction Event Great Dying


  • PBS Eons
    PBS Eons   1 years ago

    Correction! At 9:19, we erroneously refer to Dimetrodon as an herbivore. It was definitely a carnivore. We even made a whole video about Dimetrodon and their carnivorous ways in a previous episode: Thanks to everyone who pointed out our error!

  • Patrick
    Patrick   1 days ago

    Does it ever seem like she just makes up names? I could be like... "The Clackladoris emerged and shared a convergent evolutionary track...", and you wouldn't suspect a thing.

  • Craig Carmichael
    Craig Carmichael   2 days ago

    All these "end of period" "mass extinctions" except that ending the Permian were doubtless caused simply by the newer, more highly evolved life forms out-competing the earlier ones. (Even the dinosaurs seem to have withered away after the placental mammals appeared.) More important than oxygen levels were carbon dioxide levels, which started very high and gradually lowered until virtually all of the carbon in the air was converted to coal in the Carboniferous. Before the late Carboniferous, the atmosphere was pretty much unbreathable to higher life forms. Insects managed it somewhat earlier, but when amphibians crawled ashore, the giant insects disappeared. More recent evidence would indicate that there were no reptiles and almost no amniotes until the end of the Permian and the great dying, and that things long identified as "reptiles" were actually amphibians. The so-called "stem mammals" were actually amphibians or pre-reptiles that hadn't evolved enough for their skeletons to look distinctively like reptiles yet. (Why do I watch these things with so much seemingly outdated, erroneous info, anyway? But then paleontology has always been about finding wondrous things of the distant past, making educated guesses about them, and then having those guesses corrected or refined later as more is learned.)

  • Fathazard
    Fathazard   6 days ago

    @PBSeons Where do you get your music from?

  • doug marcus
    doug marcus   6 days ago

    i thought dimetrodon was a carnivore. eradsomosaurus was the herbivorous sail back.

  • Thomas Dykstra
    Thomas Dykstra   6 days ago

    The "Cambrian Explosion" was a "Great Dying", evidencing the decimation of lifeforms present at the time of the Great Flood judgment... The sediments containing this prodigious range of creatures is obviously a death collection, gathered fairly quickly under catastrophic circumstances. The fossilization processes depended upon these unique circumstances, and owe their efficacy to the one-off chemistries brought about by a globe in wholesale turmoil.

  • chris smook
    chris smook   6 days ago

    so when did the freshavocadoes took over the planet??

  • Qlipphoth
    Qlipphoth   1 weeks ago

    "Carnivorous sea scorpions" that sounds so metal.

  • puncheex2
    puncheex2   1 weeks ago

    4:50 I find it odd that the video seems to say that the begins and ends of the periods brought on radical changes, whereas in truth it is the other way around. Early geologists saw the changes happen in the rocks and named the periods after the locations they found the rocks in.6:56 What? "No skeletons of these ancient pioneers (early tetrapods) are known..."? What of Eusteropteron? Ichthyeostega? Acanthostega? Tiktaalik?

  • Smitty Smitty
    Smitty Smitty   2 weeks ago

    This is indoctrination...not education. Your theories change to fit the narrative 🤦‍♂️🤦‍♂️🤦‍♂️

  • gps999 sharma
    gps999 sharma   2 weeks ago

    i am from India and thank you for these amazing information

  • tanushree saha
    tanushree saha   2 weeks ago

    👍Great vedio and great for them hwo are studing about these things or great for archaeologist , sientist 👍. 😊 Thank you for making thses vedioes😊

  • jerrydinoballs
    jerrydinoballs   2 weeks ago

    Hello I love the videos and all the cool information. Y’all do a great job. The only thing I think would help is if every Th omg just slowed down a bit. It’s so much info that’s just coming at me at a break neck pace and I have a hard time keeping up. Thank you keep up the great work

  • Howard F
    Howard F   2 weeks ago

    Seriously, diatoms in the Cambrian? I think not (1:57)

  • Ren
    Ren   2 weeks ago

    Lol...could've been a BIG save had the pic been an Edaphosaurus. Oops, we all knew what you meant though. ;)

  • Dari Mellusco
    Dari Mellusco   2 weeks ago

    how has noone mentioned we're in the cenozoic era not palaeozoic, theyre thinking of the phanerozoic eon

  • john C
    john C   2 weeks ago

    “The great dying” lol when there’s so many extinction events you just get straight to the point 😂

  • Yingtheeevee
    Yingtheeevee   2 weeks ago

    so extinction is a depletion of oxygen levels....Mr Beast knows something we don't

  • The Phoenix Empyre
    The Phoenix Empyre   3 weeks ago

    Moral of the story:Plants have caused extinction more than humans could dare dream about

  • Tony Midyett
    Tony Midyett   3 weeks ago

    What do American Midwesterners and Kiwis eat for breakfast? "Eegs".

  • Mark Peterson
    Mark Peterson   3 weeks ago

    What an interesting story. I don't usually enjoy fairytales, but this one was pretty cool. I'm going to watch real science videos now that prove this has not and couldn't ever happen.

  • Worm-revolver
    Worm-revolver   3 weeks ago

    when do you think the first predator appeared? I mean, when did the first thing that didn't survive on just sunlight and oxygen, or whatever the atmosphere was during that time.

  • juanm227
    juanm227   1 months ago

    The music in the beginning along with the amazing writing made that intro to the episode much more epic. Love it.

  • Mark Clifford
    Mark Clifford   1 months ago

    I'd like to know more about the mega fauna that human's drove to extinction, either directly or indirectly, also thanks for an informative and engaging channel I love your videos.

  • Shimron Netia
    Shimron Netia   1 months ago

    who gave those names to all those creatures?

  • ErasmusPrime239
    ErasmusPrime239   1 months ago

    Earth: Earth has giveth, Earth hast taketh away.Asteroid: Hold my bear.

  • Fredrik Dunge
    Fredrik Dunge   1 months ago

    When a mass extinction happens to great number of individuals is detrimental, any useful mutation will be diluted in far to large a genepool to have an effect on the species as a whole, while less populous species may find itself with isolated populations that can evolve incredibly quickly. By the time enough individuals of a populous species have died of to allow for evolution other species have already evolved into the niches. Hence why so many of the fossils we find have no living descendants. In order for us to find them, they'd have to be numerous, in order to survive a rapid change in the environment they would have to not be.

  • Trev0r98
    Trev0r98   1 months ago

    The Cambrian explosion was likely triggered by a gamma ray burst from a distant star that went supernova (or hypernova) roughly 550 million years ago. The gamma rays struck the earth, penetrating down through the ancient oceans and induced radical changes in the DNA of countless organisms, causing countless mutations - mostly detrimental to the vast majority of genera, but beneficial to a few others. These few others were all that was needed to kick off the Cambrian explosion. Weird, nightmarish creatures like Anomalocaris and Opabinia quite possibly owed their very existence to some ancient, unnamed star that blew up way out in deep space, half a billion years ago.

  • GratifyingMyself
    GratifyingMyself   1 months ago

    At 11:55, given Tiktalik, what it means that no skeleton of them known? I am confused.Does it mean that Tiktalik was still a fish and her immediate descendents who were exclusively land dwellers haven't been found?Can someone clarify?

  • Mai Alkhubaizi
    Mai Alkhubaizi   1 months ago

    can I learn how will life be like without a moon and how life would be like without the sun and how life would be like with no gravity

  • Alberad08
    Alberad08   1 months ago

    Thanks for sharing! BTW Dimetrodon was a carnivore - probably just a slip of the tongue there.

  • Trueantitheist
    Trueantitheist   2 months ago

    Lots of triggred okay boomers bitching about your climate change mention, these people are in such denial it's pathetic.