As far as i know, there arent bigger animals around today due to the square-cube law, and yet their were dinosaurs the size of whales on land?
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Small correction: the blue whale is the largest animal ever on earth so there weren’t dinosaurs the size of whales when you talk about the extremes of both.
You actually can scale up an elephant somewhat. Your average African Elephant is something like 4 metric tons and 3 meters tall. The very biggest on record were 10 tons and 4.2 meters.
But some extinct elephants are thought to have reached 5 meters and 22 tons.
Not sure what happened with it, but there was a theory reported on that the very large dinosaurs would have necessarily been water-bound. See https://www.syfy.com/syfy-wire/hugest-dinosaurs-would-have-been-clumsy-on-land
This is not what the cube square law means.
It means that body plans can’t simply be scaled up or down.
It does not mean that mammals like the elephants can’t evolve to grow bigger than they do today, just that it would require them to look differently.
The largest animal to ever live is alive today and is a mammal. The blue whale is bigger than any fish, reptile or any other type of animal alive today or in the past.
As far as land animals are concerned there are some really massive ones around today and some even bigger one that were alive in the past.
Extinct relatives of elephants like mammoths could grow to quite a large size and other weird ones like the Paraceratherium which was a relative of modern rhinos and big enough to be mistaken for a dinosaur at first glance when you see its skeleton on display in a museum.
We can’t actually be sure what the maximum size for a land based mammal would be under ideal conditions and with the right evolutionary pressure o get as big as possible.
They would look less and less familiar the bigger they grow since the familiar form don’t scale up right thanks to cube square law.
Hyraces are the closest living relatives of elephants, they are small and furry and look nothing like elephants. If a modern mammal evolved to be as much bigger as the elephant is to the hyrax they would likely look similarly different.
The evolutionary pressure and right conditions simply isn’t there though and might never return.
What happened to the theory that they all spent eons in shallow seas? That some mammals returned to a aquatic environment and were able to grow larger and simultaneously lost their heavy fur, elephants, hippos, rhinos, humans…
Couldn’t T-Rex and their prey been splashing around in 6’ of water taking the strain off their joints? Hippos have a complex life style mostly in water. The giant beaver of North America probably weren’t running through the forest but mostly hanging around in streams.
It’s really hard to be 10-20 tons without external support.
A T-Rex breast plate looks like my row boat and they ran like a duck swims. To run on two legs requires an upright posture or you’ll be zig zagging!
The square cube law doesn’t limit size. It just says that the weight of something grows faster than its size.
That’s okay if an animal is built to handle that much weight. Elephants are bigger than humans because their bones are proportionally bigger. They can handle it.
But if I took a normal human, and scaled them up to be the size of an elephant, they’d die. Our human body plan doesn’t work at that size. It couldn’t handle the extra weight.
Tldr: The Square Cube law isn’t a limit, it’s a design principle. As things get bigger, they need more support.
I guess one of the main problem for elephant to grow is a cooling system. They are mammals, so they have high level metabolism that produce a lot of heat as a byproduct. In order to keep the temperature constant they need good cooling system, that why they grow huge ears filled with many blood vessels for cooling. They actually increase their body surface with their ears. Whales can grow bigger because water has much higher thermal conductivity, so they can regulate their temperature easier.
Dinosaurs were reptiles so their metabolism is slower they don’t produce that much energy/heat. Plus their body temperature is changing along with the temp of the environment. So cooling is not a problem for them.
If you think about it – you always see lizards, snakes and crocodiles lying on the sun in order to get warmer when all the mammals, like lions or antelopes trying to find a shadow.
The simple answer is they didn’t know. Math, as we know it, is only 2500 years old. Hell, the square-cube law only was put into effect around 500 years ago.
As Mark Twain said, “They did not know it was impossible, so they did it.”
The dinosaurs, having lived millions of years ago, were simply able to grow to such enormous sizes due to the simple fact that no one had yet come along to prove it is an impossible feat.
My understanding is that during the time that dinosaurs walked the earth, the amount of oxygen in the atmosphere was a lot higher when compared with the oxygen levels of today. The extra oxygen enabled animals to grow very large. I’m not entirely sure how or where I heard it, but I usually tend to think that’s the reason why.
Because the big guys died out due to a lack of food. Over the course of the ice ages and the other phenomena, resources became scarce. Only those creatures whose needs were more realistic to the changing world around them were able to survive.
It’s way more complicated than that, but on another level, it really isn’t.
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