How Did Dinosaurs Get So Huge?

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  • ℹ️ Published 4 years ago

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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.

Produced for PBS Digital Studios.

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💬 Comments

Maybe with VR/AR we would soon be able to imagine these giants. I am fascinated by this thought. 🙂

Author — Pragmatic Trespasser


yeah but when they lived, they lived for millions upon millions of years, much more than the amount of time humans have existed, so it WAS a very successful adaptation

Author — ThePhilosorpheus



ANSWER: they ate their vegetables.

Author — Matt Purvis


I’m gonna use the evolutionary argument of “bigger isn’t always better” when people ask about my chest size.

Author — Linden Shepherd


04:50 --> I've heard that one possible explanation for that is the higher levels of hoxygen in the atmosphere of that era.
When there is more oxygen, a bigger volume of muscle mass can be served by the same lungs, thus opening the possibility of increasing the size.
Size is always an advantage: for herbivores it permits to reach higher trees and to defend from carnivores more effectively. For carnivores it permits to climb towards the apex of the food chain (the bigger you are, the more food you can find).
So, basically, the natural selection tends always to increase the size.
The growth stops always due to some limiting factor(s).

Author — Federico Riggio


I find it amazing the same adaptations enabled both the existence of super-massive dinos and for _tiny_ birds to be light enough to fly.

Author — Crispy Bacon


I saw the Patagotitan skeleton. My god! I still cannot get over the size of these things. You need to see this in real life. You can see this at American Museum of Natural History in New York. I also got to see the T-Rex Skull in Missoula Montana at the University there. The T-Rex Skull also blew my mind when I saw how large it actually was!

Author — radwizard


Can we all just say life is both scary and beautiful. To know that these miraculous creatures once roamed this very earth we step on. Just insane. ❤️

Author — Firstname Lastname


Are we gonna ignore the fact Hank Green is 6'6"

Author — CupcakeofEmotions


Did they answer the question? That they grew so large because there was more oxygen in the atmosphere and they never stopped growing.

Author — Stahlflower Animation 'n Art


The extreme range of growth of dinosaurs means they actually occupied different ecological niches as they grew up, while smaller animals including other reptiles, birds, and mammals really occupy the same niche lifelone. I think this helped to drive them to extinction during the K-T event. If momentary changes were bad enough for any of their niches during growth, there'd be enough pressure to end such species.

Author — Jacke e-is-silent


Very nice and informative presentation! Hard to believe that dinosaurs may be still with us in the form of birds, unless you look closely at, especially the flightless birds, such as the Emu and Ostrich!! Anatomical similarities between them, such as air sacs, are also striking!! I also recall seeing some presentations that show, speculatively, some predatory dinosaurs with and of course there was Archaeopteryx!!! Good stuff on you tube!!

Author — Ron Schlorff


Hm, I'm sure you weren't implying that, but the ending sort of sounded like you assume that large dinosaurs weren't successful because they're extinct. I mean, the sauropods (just the most stereotypical group of large dinosaurs) existed for roughly 140 million years and it took one of the largest extinction events in earth's history to change that. That's pretty successful in my book.

Author — Muspell


You forgot another factor that I think is worth mentioning -- time. The dinosaurs had 165 million years to reach their size and it took them about 65 million years to get so big. Terrestrial mammals have had about an equal amount of time (65 million years) to reach such a massive size and we haven't attained it as your video does a great job of expressing; however it is worth noting that, if given another 100 million years, a lot can happen.

Author — Savage3OO6


I'm surprised you didn't mention anything about the oxygen content in the atmosphere. At times it was up to 35%, and it seems to me that oxygenating large mucles and bodies would have been easier because of this. Also, temperatures were frequently higher, and if dinosaurs were coldblooded, large bodies would enable them to retain the heat of the days, so much so that they didn't lose that heat at night. This would have allowed them to be more active and find more food.

Author — Tue Sorensen


That was super interesting!! Thank you!
I’d love to know more about ancient mammals! Why do we know/talk so much about dinosaurs but so seldom do we talk about entelodonts or all those -theriums?
We talk about ice age mammals lots, we lived with them. What about 10 million or 30 million years ago?

Author — Anthony PC


I would like to hear alternative theories to those now widely accepted ones on various subjects such as space, plants, animal development. Thank you.

Author — ANCHOR440


It would be absolutely great to have a time-and-space map of how life on Earth evolved. We see some videos describe animals, other describe fungi or plants, others describe the environment etc etc. But if there was a timelapse of the world map - and where different types of organisms lived on the ever-changing continents, it's would be awesome. Things like average temperature or air composition could be added. I know it's an ambitious request, but it would help so, so much to connect all the information we hear, which, for now, seems more like a myriad of non-connected dots rather than a comprehensive (hi)story.

Author — Elbi Adajew


At the end of the eons video I thought we don’t really know. I presume the huge size of dinosaures had been evolutionary selected until the 65 million years ago massive extinction.
Dinos might have some specific sequences of growth factor genes that play a role in morphology. While human grow in their childhood a mechanism may finally stop the height uptake. Dino might not have such mechanism. In addition, is it known what was their life expectancy ? The huge dinos might have been very old ones.
I agree the bigger is not the better. What matters is to fit with environment.

Author — Electrum


Remember back in high school, we were doing a group project for biology.
I brought this question up and everyone laughed at me.
I was confused and they kept laughed at me and I never got an explenation.
I still don't get it, I thought it was the most interesting and obvious question about Dinosaurs but it are very rare explained properly.
So I love this video because of it.

Author — DarkZtorm