Dinosaurs

[Harvin87]

Why were they so much bigger than any land and air animals we currently have?

How were 300 pound animals able to fly when the limit today is maybe 30-50 at the very maximum?

How could they lift 30 metre necks when the longest neck we have today requires extraordinary vascular systems to function at 2 metres?

How could animals 8-10 times the size of elephants exist in our gravity, let alone function as predators?

This is not a creationist thread. Dinosaurs existed. But what made it possible for them to exist? There is an inherent question to scientific orthodoxy here but it is not a religious/ creationist one.

Thanks in advance

 

[Crezth]

On the question of flying, it's really just because the animals were stronger.

Why were they stronger? I don't know.

 

[GoodSarmatian]

This is honestly just a guess, but I think Oxygen concentration in the atmosphere might have something to do with it.
The dinosaurs disappeared around 64 million years ago when the earth's atmosphere had an oxygen content of ~30% compared ~21% now.
Must have made it easier for organism to maintain proportionally larger muscles.

This is not a creationist thread. Dinosaurs existed. But what made it possible for them to exist? There is an inherent question to scientific orthodoxy here but it is not a religious/ creationist one.

The perceived necessity for this disclaimer makes me a sad ape .

 

[peter grimes]

The O2 was really that much higher??

I thought that if O2 went above something like 25% forest fires would rage out of control... but I'm not sure where I heard this, so for now I'm skeptical ape

 

[Cutlass]

Not all dinos were large. Most were similar in size to modern animals. We simply think of them as large because the best known ones were very large, and that's what is commonly discovered because it stands out so much.

How big animals can get is going to be dependent on their food supplies. So where there were huge animals, there was huge food supplies. It also matters what the other factors in survival are. Nature preserves that which can survive. If the larger animals don't exist now, it's because they can't survive now. Maybe because the food supply, maybe because of the predators they faced.

 

[Synobun]

They had much longer to evolve, the environment was MUCH more competitive, and, as said above, oxygen concentration in the atmosphere was higher and the world was much more wet and warm. The world was a massively different place back then, and the conditions for the evolution of the creatures back then was likely much different than after the extinction of dinosaurs and the ensuing ice ages.

 

[Puck Nutty]

In addition to the above posts, some theories suggest that herbivores needed to consume massive quantities of vegetation to maintain their massive bodies. This led to even bigger bodies, just to house their stomachs. Kind of a vicious circle of evolution, I guess.

Conversely, carnivores were generally smaller (velociraptors were the size of dogs for example) since meat eating was a more efficient way to gain energy. Now, you're probably thinking "But T-Rex and Allosaur were huge." True, they were. Their size may have been an evolutionary solution to the whole problem of trying to kill a 50 ton herbivore.

Now, not all carnivores grew big for hunting purposes. Some got smarter, such as the Velociraptors I mentioned earlier. They compensated for their size by hunting in packs and by staying away from the really big brutes.

Hope this answers some of your questions.

 

[peter grimes]

They had much longer to evolve,

??
What do you mean by this?
Every organism alive today has had 65,000,000 MORE years of ancestors' evolution than dinosaurs did.

How big animals can get is going to be dependent on their food supplies. So where there were huge animals, there was huge food supplies.

That's only part of the story, though. There's predation, for one. And I suspect that's a more powerful restriction. Consider the Island Effect.

 

[MrCynical]

This is honestly just a guess, but I think Oxygen concentration in the atmosphere might have something to do with it.
The dinosaurs disappeared around 64 million years ago when the earth's atmosphere had an oxygen content of ~30% compared ~21% now.
Must have made it easier for organism to maintain proportionally larger muscles.

What happened to this oxygen? Presumably would have to have been sequestered in some solid compound, but what exactly?

 

[madviking]

During the Carboniferous you also had dragonflies AND scorpions that were 30 effing inches wide.

 

[Yoda Power]

Mammoths would be alive today, had they not been killed by humans, right? They were pretty big too.

 

[Joecoolyo]

Mammoths would be alive today, had they not been killed by humans, right? They were pretty big too.

According to wiki, mammoths were usually around the size of the Asian elephant, so they weren't really as unusual in size compared to dinosaurs.

 

[gangleri2001]

The world was a wet and warm place back then, which meant a lot of food to eat.

 

[Traitorfish]

Maybe dinosaurs weren't big, we're just really tiny.

 

[Dachs]

During the Carboniferous you also had dragonflies AND scorpions that were 30 effing inches wide.

That periodization is unpopular now in this country. We usually use the Pennsylvanian and Mississippian epochs instead.

But yes.

 

[GoodGame]

This thread got me looking for answers for climate change (rather than meteors) and I came across this article. http://www.geo.umass.edu/climate/papers2/deconto_tectonics&climate.pdf

Perhaps plate tectonics played a big role in changing the suitability of land for the amount of vegetation needed for the size of the animals?

 

[Harvin87]

could human beings breathe the oxygen availiable to dinosaurs? , for example 65m. years ago?
thx guys.. interesting thread.

 

[Synobun]

could human beings breathe the oxygen availiable to dinosaurs? , for example 65m. years ago?
thx guys.. interesting thread.

Maybe if we adapted to it through generations, but if we were to suddenly get thrown back in time to that atmosphere, most of us would probably die. (just my guess, though it seems logical)

 

[madviking]

You might hyperventilate a bit, but over a long enough interval, humans would be become better at sports.

 

[Synobun]

You might hyperventilate a bit, but over a long enough interval, humans would be become better at sports.

Sports?! Well screw that then, everybody would die if we went back to that atmosphere

(that's a joke towards obese people)

[size=-2](don't worry I'm obese too)[/size]