How big could the dinosaurs of Jurassic Park actually be?

[Traab]

I was pondering the many ways in which the movie makes no sense and that popped into my head. When talking about kaiju and such, the square cube law gets tossed around a lot to explain why king kong, for example, couldnt survive, because his monkey bones would shatter under the weight of his own frame. So I wondered, lets ignore all the bad science for a moment and assume that we can in fact clone dinosaurs. Is there a limit in this modern time on what species could actually survive? Like, could a brontosaurus actually function weighing in at 5x as much as an elephant? Could the pterodactyls still fly? If not, what would the rough cutoff point be? Would ANY be able to survive since they were evolved for a different atmosphere?

[Melayl]

They existed once at that size, so they could again. The square-cube "law" allowed it before.

That said, I don't know that they could survive. From what I remember learning, the oxygen concentration was much higher back then, allowing such large creatures to survive easier. Then again, whales are pretty darned large, too...

[Peelee]

I was pondering the many ways in which the movie makes no sense and that popped into my head. When talking about kaiju and such, the square cube law gets tossed around a lot to explain why king kong, for example, couldnt survive, because his monkey bones would shatter under the weight of his own frame.

The largest known animal that has ever lived is alive right now. You can go out and see them. The blue whale dwarfs all other known creatures. It is so large that you, as a fully grown human, can fit in its arteries.

The square cube law waves goodbye.

[Rater202]

The largest known animal that has ever lived is alive right now. You can go out and see them. The blue whale dwarfs all other known creatures. It is so large that you, as a fully grown human, can fit in its arteries.

The square cube law waves goodbye.

That is both interesting and horrifying and salute you for sharing that knowledge, kind sir.

[Peelee]

That is both interesting and horrifying and salute you for sharing that knowledge, kind sir.

Blue whales are crazy. The more you learn about them, the more unreal they sound. You can swim through their arteries. They can take in over 200 tons of water at once when feeding, which is even more insane when you consider that that's just a hair over what they weigh. But that's fair, they have a lot of empty space with a lung capacity of over 5,000 liters of air. The babies drink over 600 liters of milk a day, and they can hear each other communicate from 1,600 kilometers apart. Their tongue is the size of a freaking elephant.

If we didn't exist at the same time they do, they would sound too incredible to be real. Blue whales are crazy, man. Super neat.

ETA: Discovered another neat thing while fact checking myself. Blue whales are so colossally big that their newborn calfs are already among the largest animals in the modern world.

Blue whales are crazy.

[Manga Shoggoth]

The largest known animal that has ever lived is alive right now. You can go out and see them. The blue whale dwarfs all other known creatures. It is so large that you, as a fully grown human, can fit in its arteries.

The square cube law waves goodbye.

The Blue Whale gets away with it because it is in the sea and its weight is supported by its buoyancy. If it is beached then it can't support its own weight and suffocates - the square/cube law only waives in the absence of waves...

There were several dinosaurs simillar in size to the Blue Whale, and they had much the same advantage - The supports life in more than one way...

On the land side, the largest known dinosaur from a complete skeleton is the Giraffatitan, which clocks in around 12 meters (39 ft) - according to the size comparison you could literally walk underneath it. There are larger species, but we don't have complete skeletons for them.

This Vsauce video discusses the size question (starting with humans)

[Peelee]

The Blue Whale gets away with it because it is in the sea and its weight is supported by its buoyancy. If it is beached then it can't support its own weight and suffocates - the square/cube law only waives in the absence of waves...

There were several dinosaurs simillar in size to the Blue Whale, and they had much the same advantage - The supports life in more than one way...

On the land side, the largest known dinosaur from a complete skeleton is the Giraffatitan, which clocks in around 12 meters (39 ft) - according to the size comparison you could literally walk underneath it. There are larger species, but we don't have complete skeletons for them.

This Vsauce video discusses the size question (starting with humans)

Sure, but the question was asking about animals 5 times larger than an elephant when we can go to the ocean see an animal 33 times the size. Their tongue alone is as big as an elephant. This was partly done to show how insanely big blue whales are, but also to show how elephants are not the be-all, end-all of animal sizes. Heck, if anything, Jurassic Park actually undershot several dino sizes (notably the T-Rex, which is slightly larger than in the movies, and the dilophosaur, which is significantly larger than in the movies). The velociraptor was famously oversized but is likely just a deinonychus (or maybe utahraptor) under a wrong name.

Regardless, though, of all the problems a "realistic" Jurassic Park would have, the largeness of the dinosaurs wouldn't be one of them.

[Mechalich]

It's worth noting that modern African Elephants are significantly below the size limit for the Proboscid body plan. [urlhttps://en.wikipedia.org/wiki/Palaeoloxodon_namadicus]Palaeoloxodon namadicus[/url] clocks in at over 5 meters at the shoulder and an estimated 22 tonnes, more than double the mass of the largest African Bush Elephant on record.

From what I remember learning, the oxygen concentration was much higher back then, allowing such large creatures to survive easier.

This is actually untrue. Oxygen concentration varied throughout the Mesozoic (not surprising, it was a really long time), but may have actually been significantly below current levels during much of the Triassic and Jurassic, while being somewhat higher during the Cretaceous. The period of time in Earth's history with notably high oxygen levels was the Carboniferous, famous for massive arthropods. However, Tetrapod life on land during that time had not yet developed the structural features necessary for truly massive size, so we don't know if that would have contributed.

It is worth noting that evidence strongly suggests that Sauropods, as the group containing the largest ever land animals, did possess a version of the highly efficient respiratory system with unidirectional flow seen in modern birds, which may have been a prerequisite for their massive sizes.

[hamishspence]

Heck, if anything, Jurassic Park actually undershot several dino sizes (notably the T-Rex, which is slightly larger than in the movies, and the dilophosaur, which is significantly larger than in the movies). The velociraptor was famously oversized but is likely just a deinonychus (or maybe utahraptor) under a wrong name.

The Dilophosaur, yes, but I don't know about the T. rex. I was under the impression that the prop was approximately the size of Sue, one of the largest and longest-lived T. rex specimens (adult T. rex varied quite a bit in size, with Sue and Scotty being the two largest, and several others being quite a bit smaller).

Spinosaurus is a better example of "noticeably larger than the movie specimen - albeit shorter-legged).


Deinonychus was a bit smaller than the movie raptor, Utahraptor both larger and more robustly built. Currently, the closest match to the movie raptors is Dakotaraptor, which is slightly larger but fits the "oversized Deinonychus" shape perfectly.

[Peelee]

The Dilophosaur, yes, but I don't know about the T. rex. I was under the impression that the prop was approximately the size of Sue, one of the largest and longest-lived T. rex specimens (adult T. rex varied quite a bit in size, with Sue and Scotty being the two largest, and several others being quite a bit smaller).

Sue was my basis as well, but that's because Sue is the most complete skeleton recovered to date. Sue is about 43 feet long and over 13 feet tall at the hips.

Jurassic Park's animatronic is 12 feet at the hips, and 40 feet long.

Also, Dr. Dave Hone (vertebrate palaeontologist specializing in theropods) claims that they could reach around 14 foot hip height and 50 foot lengths.

As such, while Jurassic Park's T-Rex was well within range for an actual one, I don't feel like I was off in saying that it was slightly smaller than what we have examples for. There's three feet in length and one foot for hip height that Sue had on Rexy. It's not a hill I'd die on, and it's certainly close enough to be accurate for any random Tyrannosaur DNA Hammond found, but if we're talking specifically about whether the size of Jurassic Park dinos was an issue concerning realism, JP did portray a T-Rex smaller than the most complete one we have record of (and smaller than Scotty, who as you note is the largest one we have record of), so I felt that tidbit of information was relevant.

[hamishspence]

Yup.

I recall reading that the JP2 Stegosaurus, at least, was much bigger than any real Stegosaurus discovered. And of course Jurassic World II's Mosasaurus (as opposed to JW I'd which is closer to size-accurate) is much bigger than real Mosasaurus were.

[Peelee]

Yup.

I recall reading that the JP2 Stegosaurus, at least, was much bigger than any real Stegosaurus discovered. And of course Jurassic World II's Mosasaurus (as opposed to JW I'd which is closer to size-accurate) is much bigger than real Mosasaurus were.

Apropos of nothing, but while I really like Camp Cretaceous, I have a major issue with how they treat dinosaurs. They're just like "oh that one's an herbivore, it's fine!"

Spoiler: This herbivore will straight up ****ing murder you.

Show

Meanwhile...

Spoiler: These carnivores are famously friendly and will even save humans in danger.

Show

Be more ecologically accurate, Camp Cretaceous!

[Azuresun]

They existed once at that size, so they could again. The square-cube "law" allowed it before.

That said, I don't know that they could survive. From what I remember learning, the oxygen concentration was much higher back then, allowing such large creatures to survive easier. Then again, whales are pretty darned large, too...

I read an interesting article a while back that suggested that the sauropod body plan could theoretically have gone up to animals weighing a thousand tons (the biggest known titanosaurs would have been about a hundred as adults). But there was never any need to, because theropods (their predators) hit their own size limit, and food wasn't plentiful enough to make getting that big viable.

(and yes, I know 10x heavier doesn't equal 10x bigger, but it's still pretty impressive)

[Rater202]

Spinosaurus is a better example of "noticeably larger than the movie specimen - albeit shorter-legged).

Interesting trivia: Supplementary materials hidden in the Jurrasic World Website in the leadup to Fallen Kingdom state that Wu and co were doing experiments with using dino DNA to make bioweapons and attack animals well before the park was reopened as Jurrasic World.

It also mentions that there's a hyper-aggressive prototype hybrid loose on Isle de Sorna, where the second and third movies of the original trilogy take place.

It's not stated outright, but the way the hybrid is described makes it very much seem like the "spinosaurus" is the prototype hybrid.

[Peelee]

Interesting trivia: Supplementary materials hidden in the Jurrasic World Website in the leadup to Fallen Kingdom state that Wu and co were doing experiments with using dino DNA to make bioweapons and attack animals well before the park was reopened as Jurrasic World.

It also mentions that there's a hyper-aggressive prototype hybrid loose on Isle de Sorna, where the second and third movies of the original trilogy take place.

It's not stated outright, but the way the hybrid is described makes it very much seem like the "spinosaurus" is the prototype hybrid.

Interesting trivia: you're literally describing the plot of Camp Cretaceous.

Also, you very much find out what the hybrid is. In season 2, I believe. Their latest season just dropped a month ago or so. It's on Netflix, if you're interested. It's much better than I expected it to be, except for my aforementioned complaint.

[Rater202]

Interesting trivia: you're literally describing the plot of Camp Cretaceous.

Also, you very much find out what the hybrid is. In season 2, I believe. Their latest season just dropped a month ago or so. It's on Netflix, if you're interested. It's much better than I expected it to be, except for my aforementioned complaint.

Okay then. Was not aware of that.

I was just going by what I did know... Ie: the implied retcon that the reason why the Spino's legs were wrong was becuase it wasn't actually a spino but a weaponized hybrid.

[Peelee]

Okay then. Was not aware of that.

I was just going by what I did know... Ie: the implied retcon that the reason why the Spino's legs were wrong was becuase it wasn't actually a spino but a weaponized hybrid.

Minor spoiler:

Spoiler

Show

It's not the Spinosaurus.

[Lord Torath]

I read an interesting article a while back that suggested that the sauropod body plan could theoretically have gone up to animals weighing a thousand tons (the biggest known titanosaurs would have been about a hundred as adults). But there was never any need to, because theropods (their predators) hit their own size limit, and food wasn't plentiful enough to make getting that big viable.

(and yes, I know 10x heavier doesn't equal 10x bigger, but it's still pretty impressive)

Do you by chance have a link to that article, or remember where you saw it? I've got a son who would be exceeding interested in reading it.

[Rater202]

Minor spoiler:

Spoiler

Show

It's not the Spinosaurus.

Spoiler

Show

So I'm looking it up, but so far I haven't found anything that says that the Spino wasn't a Hybrid, just that it's not the first hybrid.

Or even the first sucessful hybrid. Spino could have been made first but designated a failure.

the Spino is mentioned by name in hidden pages on the Jurassic World website refers to experiments.

Semi Related: I've also learned that Jurassic World: The Game gives you an achievement if you have a T-Rex, a Pterodactyl, a Triceratops, a Smilodon*, and a Mastadon in the same park.

*That is to say, the quote-unquote "sabretoothed tiger."

[Peelee]

I was referring to this:

It also mentions that there's a hyper-aggressive prototype hybrid loose on Isle de Sorna, where the second and third movies of the original trilogy take place.

It's not stated outright, but the way the hybrid is described makes it very much seem like the "spinosaurus" is the prototype hybrid.

Sorry, I could have been clearer, that's my fault.

[snowblizz]

you, as a fully grown human, can fit in its arteries.

What is the cholesterol count on that?
Imagine going to the doctor and he's like "I'm sorry your cholesterol count is: human males now fill your arteries. Time to cut back on saturated fats."

Meanwhile...

Spoiler: These carnivores are famously friendly and will even save humans in danger.

Show

I don't trust Dolphins. They are too friendly. They are up to something, I swear I heard o...*aaaugh*.

[Peelee]

What is the cholesterol count on that?
Imagine going to the doctor and he's like "I'm sorry your cholesterol count is: human males now fill your arteries. Time to cut back on saturated fats."


I don't trust Dolphins. They are too friendly. They are up to something, I swear I heard o...*aaaugh*.

Just don't trust hippos. The more you learn about hippos, the more absolutely terrifying they are. They take down apex predators whenever they damn well feel like it, for chrissake! LOOK HOW WIDE THEY CAN OPEN THEIR JAWS THEY CAN SNAP YOU IN HALF FOR THE LULZ

[Rater202]

Just don't trust hippos. The more you learn about hippos, the more absolutely terrifying they are. They take down apex predators whenever they damn well feel like it, for chrissake! LOOK HOW WIDE THEY CAN OPEN THEIR JAWS THEY CAN SNAP YOU IN HALF FOR THE LULZ

Steve Irwin, the man who made a career out of wrestling crocodiles, picking up venomous snakes, walking up and touching big cats, and so on was afraid of hippos.

To repeat: The Crocodile Hunter was afraid of hippos.

[Melayl]

This is actually untrue. Oxygen concentration varied throughout the Mesozoic (not surprising, it was a really long time), but may have actually been significantly below current levels during much of the Triassic and Jurassic, while being somewhat higher during the Cretaceous. The period of time in Earth's history with notably high oxygen levels was the Carboniferous, famous for massive arthropods. However, Tetrapod life on land during that time had not yet developed the structural features necessary for truly massive size, so we don't know if that would have contributed.

It is worth noting that evidence strongly suggests that Sauropods, as the group containing the largest ever land animals, did possess a version of the highly efficient respiratory system with unidirectional flow seen in modern birds, which may have been a prerequisite for their massive sizes.

Thank you for the correction. It was 4th or 5th grade when I last read up on that period. 4th grade was very, very long ago.

[Khedrac]

On the subject of territorial herbivores, also beware the Cape Buffalo which is also extremely aggressive and territorial.

And another thing on the hippo front - whilst they like to spend most of their time in water (not surprising at their size) they are a 1.5 tonne animal that can run (on land) at about 30mph (48 kph) - that's faster than an elephant, slightly slower than a rhino and faster than Usain Bolt's peak speed! At that speed and weight it doesn't need to bite you, it can just trample you!

[Tvtyrant]

Dinosaurs were bigger because of a few agreed on factors AFAIK.

The first part is easy to see the difference. An elephant has the longest gestation of any animal alive, and if they got any bigger it would make the gestation even longer. The energy resources to reproduce are too high in large mammals.

The second one is a major advantage for birds as well. Archosaurs all have a layer of cartilage added over the ribs and going down over what in mammals is the belly. In Dinosaurs (including birds) this ossified to create what is in essence a frontal spinal column, making the body much more rigid and able to maintain pressure more easily. The back and hip problems that face all large mammals are thus alleviated.

[Peelee]

The first part is easy to see the difference. An elephant has the longest gestation of any animal alive, and if they got any bigger it would make the gestation even longer. The energy resources to reproduce are too high in large mammals.

Blue Whale gestation period is half that of the elephant, with newborns being twice as large and about as massive as adult female elephants.

Blue whales are crazy.

[Tvtyrant]

Blue Whale gestation period is half that of the elephant, with newborns being twice as large and about as massive as adult female elephants.

Blue whales are crazy.

They are also in water. They have better food (plankton is more calorie efficient then grass), and don't have the physical problems gravity forces on the body.

Notably, the whale family didn't become giant rat-beasts on land.

[Peelee]

They are also in water. They have better food (plankton is more calorie efficient then grass), and don't have the physical problems gravity forces on the body.

Notably, the whale family didn't become giant rat-beasts on land.

I know, I'm pretty much just trotting them out at this point because regardless of the water helping them out a lot, blue whales are still crazy. Like, every aspect of them. They are marvels of nature.

[Tvtyrant]

I know, I'm pretty much just trotting them out at this point because regardless of the water helping them out a lot, blue whales are still crazy. Like, every aspect of them. They are marvels of nature.

They are fantastic animals for sure!