How Did Dinosaurs Get So Huge?

  • Publicado el 2 oct 2017
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    Part of why we’re so fascinated with extinct dinosaurs it’s just hard for us to believe that animals that huge actually existed. And yet, they existed! From the Jurassic to the Cretaceous Periods, creatures as tall as a five-story building were shaking the Earth.
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  • Ciencia y tecnologíaCiencia y tecnología

Comentarios • 2 074

  • Theseus Rahl
    Theseus Rahl Hace 19 horas

    Dang I see a lot of dinos/animals covered in this series so far that are featured in Ark: Survival Evolved. I think the reason is that they used the most extreme/big/scary/mesmerizing creatures they could to make the game more interesting. It's pretty cool. The Lystrosaurus is a boss!

  • Алмаз Загитов

    Common mistake made by people is perceiving the dinosaurs and birds as single thing. You can not call the humans as a rodents, but the apes, including humans have a common ancestor with the rodents

  • Volgen Productions
    Volgen Productions Hace 2 días +1

    Size is not determined by mass. I can name several dinosaurs bigger than the blue whale.

  • Haven Tran
    Haven Tran Hace 3 días

    Big dinosaurs and birds are designed to cover more grounds. Dinosaur are big is because of that reason and birds can fly. They are constantly on the move like elephants and whales.

  • Rachel Thompson
    Rachel Thompson Hace 5 días

    Oxygen density was greater, more oxygenated air, more methane and less CO2. Today's air quality would kill the dinosaurs off.

  • Sam P
    Sam P Hace 6 días

    So you don't know the answer

  • peter truncale
    peter truncale Hace 6 días

    "To grow so large was it really an advantage, after all the dinosaurs are all gone?" Dude a meteor took them out, your question is totally irrelevant whether it was an advantage being so large. They could of still be here now if it was not for the meteor.

  • Danie, Wilna Brits
    Danie, Wilna Brits Hace 8 días

    Was earts gravity the same as today? Maybe gravity was less. An elephant can only walk when three legs is on the ground, and this is with the gravity on earth today. How were those animals be able to walk with such heavy bodies?

    LORDBADASS Hace 8 días

    To be fair, the largest dinosaurs were all sauropods. I'm sure many dinosaurs weren't anywhere near as large.

  • Seven Nielsen
    Seven Nielsen Hace 9 días

    Convert meters to feet, please. This is the USA. Thank you. You deserve twelve Korliks of jb.

  • David Patterson
    David Patterson Hace 9 días

    I didn't even need to watch the video, I know the answer:
    They we're muscle Bois.

  • Mesozoic Studios
    Mesozoic Studios Hace 11 días

    The largest dino was barosaurus lentus ( BYU 9024 )

  • richard jugao
    richard jugao Hace 15 días

    Lolololol blue whale only 30m

  • Black Jay
    Black Jay Hace 15 días

    Considering how long dinosaurs remained at that size, I would say the evolutionary advantage was pretty clear. It took the entire food chain to collapse, climate change, and an asteroid. You'd be hard pressed to find animal lineages that were s successful as the sauropods. So no, the size clearly was very much an advantage, and they were pretty robust o the most part.

  • John Augsburger
    John Augsburger Hace 16 días


  • Tim Allen
    Tim Allen Hace 17 días

    I guess they were here for a long, long time, and about all they did was eat, so that got huge.

  • Đình Bảo Nguyễn
    Đình Bảo Nguyễn Hace 18 días

    But but but they survived for millions of years, doesnt that answer the question of survival at the end?

  • Jack Harpe 3rd
    Jack Harpe 3rd Hace 20 días

    My Goddess that Ceratops at 2:46 looked just like Sarah from The Land Before Time exept has Green Skin and Green Eyes when she actually had Tan Skin and Green Eyes but man that's Adorable!!!ídeo.html
    You just gotta love Dinosaurs! But I think I'm still more pro Long-Neck than Three-Horns. Sauropods FTW.

  • merle ackeret
    merle ackeret Hace 22 días

    Perhaps they stayed warmer by being large - gigantothermy

  • Kai Hill
    Kai Hill Hace 22 días

    blue whales are mammals, so i think its fair to say we came close in size...

  • Stumpy Dlugi
    Stumpy Dlugi Hace 25 días

    There’s too many internet Einsteins here 😂

  • Rudi Hendricks
    Rudi Hendricks Hace 27 días

    Aren't reptiles direct decedents of dinosaurs

  • Marco Pizzi
    Marco Pizzi Hace 28 días

    Could their big size be the result of a runaway Fisher process? In other word the size give them an advantage in sexual selection and not in natural selection

  • Gary Panter
    Gary Panter Hace 28 días

    An incredibly Rich environment. Lots of oxygen and unlimited food. An animal will grow as large as the environment will support it

  • Marisa Bisping
    Marisa Bisping Hace un mes

    I thought it was understood that the biggest reason dinosaurs were so large is because the oxygen levels were higher.....?

  • Elijah Hua
    Elijah Hua Hace un mes

    Man, they’ve been at the top of the food chain for 160 million years, we mammals only thrives for 65 million years. Also the oxygen level is dropping due to human activity. So I guess we have no chance of winning unless we go to mars.

  • TheOtherWhiteBread0
    TheOtherWhiteBread0 Hace un mes


  • Clarence Jr
    Clarence Jr Hace un mes

    Fun fact: Most dinosaurs weren't even as tall as a regular fully grown human, so don't say "Get so big". Do some research.

  • Viktor Zakuchemkov
    Viktor Zakuchemkov Hace un mes

    Because the high level of oxygen at that time could help an organism to get this size, including they weren't have a major predator like human !

  • Justin Campbell
    Justin Campbell Hace un mes

    Here's a theory... Earth was once the size of Mars. The pangea was actually solid ground that enveloped the entire globe. As the Earth gained mass from the sun and outer space, it expanded and formed oceans. So, the Earth used to be less massive and have lower gravity. Also, the oxygen content was higher. This would allow dinosaurs to not be crushed by their own weight. I do believe the expanding Earth theory, but as for it having a large effect on dinosaurs a few million years ago, I'm not so sure it could have made the biggest difference

  • Phillip Lamoureux
    Phillip Lamoureux Hace un mes

    Some comment on higher atmospheric oxygen content and the herbivorous habits of the big tetrapods in an abundant plant environment would have rounded this piece out.

  • C. H. Choo
    C. H. Choo Hace un mes

    Maybe the earth at that time had more oxygen

  • Harold Camping
    Harold Camping Hace un mes

    They ate Mc Donalds.

  • Emily page
    Emily page Hace un mes

    How, why and where did mammals come from.

  • Brian Battles
    Brian Battles Hace un mes

    So....we don't know...

  • Merlyn Schutterle
    Merlyn Schutterle Hace un mes

    Maybe the earth spun faster and centrifugal forces allowed them to get that big.

  • forest leopard
    forest leopard Hace un mes


  • Mastermind Cow
    Mastermind Cow Hace un mes

    Maybe the sauropods got so big because the more food that they could eat, the less food there would be left for everyone else, thereby reducing competition for mates by leaving would-be rivals to starve.

  • Combat King 0
    Combat King 0 Hace un mes

    Tyrannosaurus vs Elephant.
    I imagine the dinosaur would win.

  • Mr Damnation
    Mr Damnation Hace un mes

    or rather why humans are so small

    and also why cant u just shut up for 1 second continously rambling .... smh

  • Robert R
    Robert R Hace un mes

    Easy: when they were a lad they ate four dozen eggs / Every morning to help them get large

  • shaymus crow
    shaymus crow Hace un mes

    If it was possible to clone a dinosaur it would not be able to survive in today's atmosphere you would have to keep it in a hyperbaric chamber I really big one

  • shaymus crow
    shaymus crow Hace un mes

    Think of a thick heavy atmosphere with lots of moisture think of an ocean above us in the atmosphere the reason whales or are able to get so large is because their weight is offset by the medium that they're in which is water which is heavy if you have a very heavy thick moist atmosphere you're able to get much larger and plus the atmosphere was much more rich in oxygen so think of a hyperbaric oxygen chamber that's very humid and then you get really big Critters

  • shaymus crow
    shaymus crow Hace un mes

    The main reasons that dinosaurs and insects from those times or so large was because he atmosphere was much heavier and thicker offsetting much of the weight of these animals and allowing for more efficient oxygen transport to the tissues as the gravitational effects was offset through buoyancy of a thicker atmosphere

  • AkuNoHana
    AkuNoHana Hace un mes

    How did it get so huge? Watch our video to the end and we won't tell you!

  • Evan Burns
    Evan Burns Hace un mes +1

    Its funny, being BIGGER is better in the SHORT term but SMALLER works out in the LONG run.

  • Humble Evidence Accepter

    Obviously, Sauropod Dinosaurs were quite small. Their sponge-like skeletons simply _swelled up_ with swamp water after death.

  • Corranhorn122
    Corranhorn122 Hace un mes

    Its blows my mind to think that, mass-wise, the tyrannosaurus rex was only half the size of paraceratherium, and yet its considered one of the largest land predators ever. Could it have taken one out?

  • Fernando Barros
    Fernando Barros Hace un mes

    You're finally great

  • philou425
    philou425 Hace un mes

    If they got blasted by a large comet, I don't see how bigger is not always better... Women know bigger is always better.

  • David LS
    David LS Hace un mes

    I don't like the narrative that non avian dinosaur adaptations were not optimal ''because if they were, why are they not around anymore?''. That is terribly outdated and goes back to the time when we didn't understand dinos and just thought they were sloppy beasts waiting on their extinction.
    Dude, they dominated the planet for almost 200 million years and survived 2 mass extinctions. No group of land amniotes has been more successful. The domain of mammals is on its way to last a lot shorter than that.

  • likira111
    likira111 Hace un mes

    I have never heard anyone say "speaking as a mammal" before.
    It makes me uncomfortable.

  • Chris Koay
    Chris Koay Hace un mes

    Higher oxygen concentration in early earth day

  • wcdeich4
    wcdeich4 Hace 2 meses

    Thank you! I did not know air sacks helped some dinosaurs get huge. But I'm surprised you did not mention being meso-thermic. Mammals waste a lot of energy just keeping 1 constant body temperature. Sure, generating heat internally is great when it is snowing outside. But when it is 85 degrees F outside, burning calories to raise our body temperature to 98.6 degrees F is kind of a waste.

    • Humble Evidence Accepter
      Humble Evidence Accepter Hace un mes

      I once heard of a speculation that they stayed warm just from sheer size. I think they called it _gigantothermy._

  • Music
    Music Hace 2 meses

    No mention of higher oxygen content.

  • C Brieeze
    C Brieeze Hace 2 meses

    Were there any filter feeder aquatic reptiles? Why hasn't there been any reptiles the size of whales in the same environment? There were dolphin shaped ones

    • Isaac Zelinski
      Isaac Zelinski Hace 2 meses

      C Brieeze stomatosuchus, the filter feeding crocodile

  • Marc T
    Marc T Hace 2 meses

    Yeah let's not mention the whole ice age thing, because that obviously had nothing to do with it. I mean living in a world with high rainfall, mild winters and pole to pole rainforests is completely overrated when it comes to size competitions.

  • Jwrazmo
    Jwrazmo Hace 2 meses

    Hi PBS Eons, I had a question about this video. If you are under the belief that dinosaurs were able to grow to much larger proportions than mammals due to laying eggs then why don't we see fish that are bigger than whales, as fish lay eggs?

  • The Sapien
    The Sapien Hace 2 meses +2

    But even birds today are small and the biggest of them can't fly like they once did.
    My guess is that gravity was less back then.

  • Paul Birsan
    Paul Birsan Hace 2 meses

    Dinos still beat us, they lived millions of years with this size, not the several thousand years we puny monkeys did.

  • Therapist Gus
    Therapist Gus Hace 2 meses +1

    I instantly like PBS videos, even before watching them.. Why? Because they’re that important and should be supported

  • Melvin Shine
    Melvin Shine Hace 2 meses +1

    There were large sauropods from the late Triassic up till the end of the Mesozoic and lived throughout the world. Mammals as a group have been the dominant land vertebrates for only around 50 million years. Being big clearly wasn't a detriment if that one group lived that long. Something else to keep in mind is that baleen whales consume a lot of protein while plant materiel isn't that nutritious by comparison.

  • craig daub
    craig daub Hace 2 meses

    Couldn't it also be because the atmosphere was different then?

  • Bogwedgle
    Bogwedgle Hace 2 meses

    Bigger is generally better in a stable environment, but as we saw 10000 years ago when the ice sheets retreated, large animals just suck at rapidly changing environments. They're relatively few in number and reproduce extremely slowly which makes adaptation almost impossible and means bad years where a lot of the population die take decades or centuries to fully recover from, and they require so much food that if that food source is interrupted, they can't cope, if you cut a herd of 500 deer by 80% you still have a genetically viable breeding population, if you cut a herd of 50 mammoths by 80% you just don't.

  • cyberpunkspike
    cyberpunkspike Hace 2 meses

    The largeness appears to be an adaptation advantageous in the following particular conditions.
    1. Ample amount of foliage that could be easily eaten, assuming your head was literally above all other potential grazers.
    2. Predators of limited intellectual capabilities, thus no planned or organized actions could tip the scales against favoring your size.
    This would work great until predators grew, which then keep selecting for becoming larger prey. Thus becoming a cycle, stupid predators select for bigger prey, bigger prey selects for bigger stupid predators. Which does appear to be what occurred. Thus explaining why size was selected for in the Jurassic.(?)
    That is until predators acquired intellectual or social adaptations, then size would become a liability. More size needs much more food, and would still be taken down by smaller predators. This would favor selecting the smallest and smartest predators, the smarter the the predator the smaller they could become. Being a smaller predator becomes possible, if you were smart enough to avoid being a bigger predator's lunch, which I'm assuming you could do... because you are capable of an organized take down of giant prey. Thus explaining why size wasn't selected for in the Cretaceous.(?)

  • Gabriel Blas
    Gabriel Blas Hace 3 meses

    This makes me wonder if there's actually an extinct ancient marine reptile that could be bigger than the Blue Whale? Fingers crossed!

  • Oak synia
    Oak synia Hace 3 meses

    They eat, alot

  • snappy452
    snappy452 Hace 3 meses

    I love this channel so much. Also, I would like to send a fruit basket to the parents of Hank and John Green as a thank you for having, um, relations, at least twice. You both did the world a great service.,

  • Stephen Tudor
    Stephen Tudor Hace 3 meses +2

    This is cool and we get different narrators too. all perfect in how they tell the story 👍🏻

  • Nachuak
    Nachuak Hace 3 meses

    Didn't mass amounts of extra oxygen that existed in the atmosphere back then contribute to their size?

  • Frank Dvorak
    Frank Dvorak Hace 3 meses +1

    Humans have lived for such a short time compared to sauropods. Just because we came after them doesn't mean our body plan is better. Human race is likely to go extinct soon, the way we over reproduce and act like locust on this planet will be our end

  • JulieBishop
    JulieBishop Hace 3 meses

    dinosaurs lived for millions of years that big. It seems that having a bigger brain to be smart enough to build the atomic bomb and think ourselves into depression is more of a disadvantage.

  • Dione Esteban
    Dione Esteban Hace 3 meses

    Probobly bezcuse the earth is warmer

  • Bethanie Petitpas
    Bethanie Petitpas Hace 3 meses

    Did the sauropods have feathers?

  • Clyde Cessna
    Clyde Cessna Hace 3 meses

    You implied that the size of the dinosaur was an evolutionary dead end. It was my understanding that these animals were destroyed because of an external event: the Chicxulub meteor. That was not the dinosaur's fault and so their size irrelevant to their extinction.

  • Dark Pariah
    Dark Pariah Hace 3 meses

    You answered "how," but not "why."

  • Uncle Phil
    Uncle Phil Hace 3 meses

    Why aint platypuses huge?

  • james corvett
    james corvett Hace 3 meses

    more O2 on Earth and possibly less gravity. the rock that killed them could have changed Earth gravity. And from what you read on the internet humans too were bigger.

    • Humble Evidence Accepter
      Humble Evidence Accepter Hace un mes

      Humans and our ancestors were actually smaller as you go back in time. An asteroid would not have any appreciable effect on gravity (how could it?). Not sure what the consensus is on oxygen levels, but I think you're right that more could've helped them grow bigger

  • Edward Foehring
    Edward Foehring Hace 3 meses

    More 02

  • MrFrontenginedragste
    MrFrontenginedragste Hace 3 meses

    I've always wondered if the earth was smaller or had less gravity.

  • instalite14
    instalite14 Hace 3 meses

    I always heard that the oxygen levels were so high during that time was why they got so large.

  • Christopher Neely
    Christopher Neely Hace 3 meses

    Convergent Evolution: EYES.
    and The Tail Club club. All the different species that formed a club as a tail, with or without spikes.

  • kanishq ruhil
    kanishq ruhil Hace 3 meses

    Nobody beats the blue whale

  • M Lourson
    M Lourson Hace 3 meses

    I bet that they got so big, because they lived long and longer they lived, more offspring they had. Sharks, lizards and snakes grow all their lives.

  • squid din
    squid din Hace 3 meses

    0:38 we are bigger. cough cough blue whale and Paraceratherium. these mammals were truly dinosaur sized so technically we did come quite close to dinosaur sized.

  • Down Hill
    Down Hill Hace 3 meses

    along time ago, Earth, had greater oxygen quantity which was why everything was larger. Plants were larger thus herbivores = bigger which in turn carnivores = bigger as well. Even the insects were big compared to the ones of modern time. A professor from i forgot which university did an experiment where he grew fishes in a tank that had high oxygen content... after several generations the fishes' offspring grew to larger proportions. You can find it on youtube.

  • chestnut5602
    chestnut5602 Hace 3 meses

    How did they grow so large but have such small nostrils and mouths? Even with more oxygen they would not be able to breath without a substantial amount of air pressure to help with breathing.

  • CaramelLeek
    CaramelLeek Hace 3 meses

    For a second there I thought I was watching SciShow.

  • Ben VS Ben
    Ben VS Ben Hace 3 meses

    Airbag suspension? No wander they went extinct, the maintenance costs alone would be staggering for a lifeform that spent all of it's time off road.

  • Jae KiDd
    Jae KiDd Hace 3 meses +2

    imagine us being any where from 30-60 feet & 1 to maybe 50 tons that would be crazy we'd be like huge Giants I wonder if we'd still be as smart or even smarter cuz everyone in Hollywood makes it seem like really big people are naturally stupid?!?

    • Roy G Biv
      Roy G Biv Hace un mes

      You manage to fit the bill and you're just average-sized.

  • Nolan Schaeffer Jr.
    Nolan Schaeffer Jr. Hace 3 meses


  • SpiderEye_Golum
    SpiderEye_Golum Hace 3 meses

    Please do a video on which dinosaur was the most dangerous or deadly

    • SpiderEye_Golum
      SpiderEye_Golum Hace 3 meses

      I play this game called ark so if u can mention a few Dino’s that are the most deadly that would be great thanks

  • Peter M. Eggers
    Peter M. Eggers Hace 3 meses

    Since the dinosaurs ruled the earth over 100 times longer than humans have existed, I think it a bit smug to imply their size wasn't an asset. In fact, their descendants still exist as birds. I suspect that their size had more to do with high oxygen levels due to vigorous plant growth. I'm thinking that the asteroid that ended their reign, destroyed a dinosaur "Garden of Eden" allowing the dinosaurs' "cockroaches" (mammals) to evolve in the wasteland, culminating in human domination.

  • themutantlizard
    themutantlizard Hace 3 meses

    I would take pictures and film them

  • Sagan Worshipper
    Sagan Worshipper Hace 4 meses

    So basically we have no idea. Thanks!

  • David Draper
    David Draper Hace 4 meses

    Another reason for the size would be that it helps create a warmblooded state. Modern crocodiles become pseudo-warmblooded as they get larger which helps them be more active for longer periods of time.

  • Nerd With an Opinion
    Nerd With an Opinion Hace 4 meses

    does this mean we can have a titanosaur sized platapus

  • wade cooper
    wade cooper Hace 4 meses

    Damn! Stop calling birds dinosaurs. They are birds, they lived alongside dinosaurs and have beaks not teeth. Similar bone features do not qualify them as dinosaurs and terasaurs did not have feathers. This is theory manipulation to promote evolution over intelligent design. The Titanosaurs could not live in todays' gravity or thin air and low barometric pressure, their leg arteries would burst.

  • Cohors Praetoria
    Cohors Praetoria Hace 4 meses

    U haven't answered the most imoportant question: what kind of heart can allow those sizes?

  • Daniel Staal
    Daniel Staal Hace 4 meses

    I always wondered if part if it was because of the size disparity between eggs and the adults - what if they just kept growing? Even a moderate sized dinosaur has to grow quite a bit from a fairly small egg, so they've obviously got the gene setup to grow quite a bit - and with the size disparity, it makes sense for the adults to lay lots of eggs and see which reach a decent size. Even watching the eggs at some point would be kinda futile, as the parents wouldn't be able to deal with the threats to their eggs as the threats are too small.
    So the dinos were programmed to grow, and the larger they were the safer they were. There's no real reason for them to *stop* growing as they age, just to slow down.