The Mystery Behind the Biggest Bears of All Time

  • Published on: 23 April 2019
  • Our new shirt!

    The short-faced bears turned out to be remarkably adaptable, undergoing radical changes to meet the demands of two changing continents. And yet, for reasons we don’t quite understand, their adaptability wasn’t enough to keep them from going extinct.   

    Thanks to Fabrizio De Rossi and Studio 252mya for the Arctodus and Arctotherium illustrations. You can find more of their work here:

    And thanks to Ceri Thomas for the Plionarctos and Arctotherium reconstructions! Check out more of Ceri's paleoart at and

    Produced in collaboration with PBS Digital Studios:

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    Katie Fichtner, Anthony Callaghan, Robert Amling, Po Foon Kwong, Larry Wilson, Merri Snaidman, Renzo Caimi Ordenes, John Vanek, Neil H. Gray, Marilyn Wolmart, Esmeralda Rupp-Spangle, Gregory Donovan, Ehit Dinesh Agarwal, الخليفي سلطان, Gabriel Cortez, Marcus Lejon, Robert Arévalo, Robert Hill, Kelby Reid, Todd Dittman, Betsy Radley, PS, Philip Slingerland, Jose Garcia, Eric Vonk, Tony Wamsley, Henrik Peteri, Jonathan Wright, Jon Monteiro, James Bording, Brad Nicholls, Miles Chaston, Michael McClellan, Jeff Graham, Maria Humphrey, Nathan Paskett, Connor Jensen, Daisuke Goto, Hubert Rady, Gregory Kintz, Tyson Cleary, Chandler Bass, Maly Lor, Joao Ascensao, Tsee Lee, Sarah Fritts, Ron Harvey Jr, Jacob Gerke, Alex Yan

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  • Runtime : 11:16
  • dinosaurs dinos paleo paleontology scishow eons pbs pbs digital studios hank green john green complexly fossils natural history Bears spectacled bear Arctodus simus short-faced bears Pleistocene Epoch Arctotherium angustidens Arctotherium Arctodus North America South America Great American Biotic Interchange Smilodon Prey jaguar cougar dire wolf hypercarnivore kleptoparasitism


  • Juan Lopez
    Juan Lopez   1 weeks ago

    What about the man-bear-pig the most deadly bear in the world lol but i love your channel

  • Cristobal Perez
    Cristobal Perez   1 weeks ago

    Only 10 feet tall?? The bears in Kodiak island are 11 feet plus right now

  • Alex Rolon
    Alex Rolon   2 weeks ago

    Da. This chick is sexy, she has sum nice thick legs Mmmmmmm she so fine .

  • Stan TheObserver
    Stan TheObserver   2 weeks ago

    MAN,MAN,MAN,MAN,MAN,MAN,MAN,MAN..Thats your answer to why they all went extinct.

  • SoulRippster
    SoulRippster   2 weeks ago

    The t-shirt is really weak honestly. Could have some cool dinosaurs and whatnot, maybe a stylized Anomalocaris.

  • jeff coulter
    jeff coulter   2 weeks ago

    lmao "and Steve" sounds like Steve is the guy at work no one likes

  • V Ling
    V Ling   2 weeks ago

    Btw, the "Ursus maritimus tyrannus" giant prehistoric polar bear sounds cool but probably never existed.The fossil was probably a brown bear.

  • sharkfinbite
    sharkfinbite   2 weeks ago

    Spectical bear is not plant eating. It is omnivorous.

  • Thebest Colin
    Thebest Colin   2 weeks ago

    Maybe it was humans that also hunted them. Idk?

  • Kyle
    Kyle   2 weeks ago

    Prehistoric animals are way more interesting than dinosaurs. They should make a version of Jurassic Park with them. Epoch Park?

  • Wo-man Ha-ter
    Wo-man Ha-ter   3 weeks ago

    would be better if a competent man was narrating

  • Christopher Conkright

    I have asked this before. If animals evolve along the same lines in different areas could be their DNA is more prone to say be wingless bird or big body. It’s DNA found it easier to go along the same lines since the original base dna was similar

  • Hambone3773
    Hambone3773   3 weeks ago

    Payton, Butkis, Singletary, Urlacher, Dent, Bortz, Thayer, Krutz, Hampton, McMichals, Sayers....

  • Lasse9591
    Lasse9591   3 weeks ago

    What kind of music are you guys using in your Videos?Keep up the good work

  • Hanky Pants
    Hanky Pants   3 weeks ago

    Come on guys, fix that chromakey bleeding, it's not that hard.

  • Deep Dish
    Deep Dish   4 weeks ago

    Da 85' Super Bowl Champions, Da Chicago Bears?

  • thedwightguy
    thedwightguy   4 weeks ago

    IN BC's Queen Charlotte's a research team found a 7,500 year old brown bear lower mandible that is almost 18 inches long. That means if you're in a second story window the bear would be looking at you eyeball to eyeball. The mandible is now in the Victoria, BC Museum. The QC were grasslands then, not cedar treed like today. Bears love grass and eat LOTS of it. !!

  • TovChapaev
    TovChapaev   4 weeks ago

    Too bad it wasn't Hank Green hosting this episode; the puns would have been unbearable!

  • James Waber
    James Waber   1 months ago

    Maybe they were hunted by others, extinguished by humans competition, disease or any combination - the reason doesn't need to make "sense" always, it can be multiple simultaneous reasons

  • Azi Poor
    Azi Poor   1 months ago

    Could you put a video about giant panda evolution please? Thanks

  • JafuetTheSame
    JafuetTheSame   1 months ago

    According to kamchatka native legends Arctodus Simus was there very recently, they called the creature "Irkuiem"

  • KageNoTenshi
    KageNoTenshi   1 months ago

    Ten thousands years ago, human is already a factor

  • feh meh
    feh meh   1 months ago

    I dislike that they put the animal's name behind the time stamp that appears when you pause the video.

  • Nicki nurse
    Nicki nurse   1 months ago

    Such a pleasant voice....great content. Why did they's ALWAYS climate change n the way that effects their food.

  • stan shaud
    stan shaud   1 months ago

    We killed em off just like the dire wolf

  • Stefan Babij
    Stefan Babij   1 months ago

    Very informative and well made! despite looking at the same pictures over and over again ;p

  • birocsabal
    birocsabal   1 months ago

    A. sinus's legbones: they were weak for rapid changes of angle during high speed!!!!!!!!!!!!!!!!!!!! Not for long distance running. Please, be accurate :) And why did they die out?