Hank gives a quick run-down of the reasons scientists think the land mammals of today are nowhere near the size of the largest sauropods. Some of them might surprise you!
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Well I don’t think sauropods were exactly cold blooded, personally I think all Dino’s were warm blooded. I just think the sauropods produced less heat as they got bigger, gradually re-evolving a slower metabolism, and lower natural body heat.
Saying "Erbivores" instead of "Herivores." Come on. I realise you might want to use the French pronunciation when talking about cooking, but other than that, these dinosaurs were not eating rosemary and thyme.
So there are no large land MAMMALS but why arent there giant land REPTILES in the equatorial regions of the planet where vegetation is plentiful and so is the heat? We know the catastrophe that caused the mass extinction of just about all land creatures 64 m yrs ago. but the survivors were mostly of the reptilian sort, crocks, komodos stuff like that so why didnt they re-evolve to giants?
I'm a little confused. Most of the reasons stated in this video would also have applied to the giant mammals of the past, who DIDN'T cook themselves, or crush themselves under their own weight, or die out immediately due to low birth rates. So the reasons are rather severely flawed. The only one that appears to hold up is the reduction in food supply.
There is something that fit! Oxygen level! And warmth!
Cretaceous period have up to 4000ppm of CO2 and 30% of oxygen!
It was also longer and warmer than next period, by 4 °C than modern temperature!
But there were giant Wombats (the size roughly of At-At) in Australia fairly recently geologically speaking (within the last 100,000 years) and Australia has one of the warmest environments in the modern world... :s
ACKSHUALLY Amphicoelias fragillimus is of doubtful existance since "it's bones were lost" and only drawings remain...simply put there's no proof that it's the largest -and before you try to prove me wrong just google the history of why that is the case.
So the confirmed largest species are the patagotitans.
Dinosaurs cold blooded....? The small ones could be similar to modern reptiles but the really big ones probably had some amount of body heat I would imagine.....
And Big Mammels could like Elephants adapt and produce less heat... why is body heat such a problem?
Dinosaurs were definitely warm-blooded, as were crocodiles. Look at the physiology of modern crocs and birds and the fact that birds are warm-blooded? And of course that other archosaur, pterosaurs, which were fuzzy, flying animals that could not possibly have functioned on reptilian-level metabolisms.
I say the reason why there's no giant insects is due to the oxygen level going down...down... really! You got the internet here...look it up! If I went in a time machine and bring a giant dragon fly back...it wouldn't survived our low oxygen levels.....
The only issue I have is that Amphicoelis fragillimus was only speculated to be that big from a single fossil. However, a better example to say was the largest dinosaur would be an argentinasaurus, patagotitan or even bruhathkayakosaurus. Which grew to an estimated 37m long, not nearly as long as Amphicoelis. This is why many palaeontologist doubt the legitimacy of the fossil, as all we have that remains are sketches from it and sizes as given by the palaeontologist at the site.
That's great, but what was NOT answered was: how do blue whales manage to be so big? I can get behind "they don't need the light bones because they're in the water" but what about long pregnancy and cooking themselves?
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