Seriously Beorn?
I was pretty specific on the hurdles of larger organisms and the point that we have some living right now which means transport and dispersion are clearly managable, even with giant creatures.
So your other major hurdle is weight which I also covered along with the point that we don't really know what their weight was nor how their tissues were setup to manage it nor if they lived largely in water which would completely trivialize the "weight problem" all together.
I could understand if I had been generic or brought up some unrelated tripe and pretended it applied but for petesakes don't be a punk.
You say we that organisms living in extreme circumstances like heat, ph etc show that dinosaurs could live under extreme gravity. I say that these extreme environments are very different from an environment with a much lower gravity. Also, these organisms living under extreme circumstances are mostly bacteria. They are very far off from dinosaurs.
Then you come with giant squid and blue whales, which live in the water and are still smaller than the estimated size of some of the dinosaurs. And not all huge dinosaurs are long-necked plant eaters (take Spinosaurus for example).
Also, there is strong evidence from modern dinosaurs that the old dinosaurs were boat builders. Why would they mostly live in the water AND built boats?
I don't think that I'm being the punk here...
Yeah...because your entire intial response being a retorical question was constructive and fair?
And no. I say that examples of nature adapting to extreme conditions means it can not be safely assumed that dinosaurs required a large change in gravity/UA.
Most descriptions of spinosaurus suggest that it is related to crocodiles may have lived in and out of water. They also site it's estimated weight between 7 and 22 tons. The brontosauarus is estimated at over 25 tons. The largest acknowledged dinosaur remains found in Argentina suggest a possible size of over 100 tons. But you have to take that with a big grain of salt as they have only found some vertibrae and tibia and are making A LOT of speculation from there. By way of comparison, the african elephant can be a bit over 10 tons. The blue whale is up to around 200 tons.
There are (generally speaking) two hurdles for the size of an organism.
Transport and distribution internally (aka the volume vs. surface area efficiency issue, how do you circulate that much oxygen, blood, etc.)
Structural support (how do you deal with that much mass and the subsequent weight and kinetic momentum and pressure variences on tissues etc.)
You are correct that thermophiles etc. are mostly bacteria but that's really not the point. The point is that your average person would look at x situation and say "no way is something living there!" and yet nature seems to find ways to adapt.
But in regard to specifics. Obviously we have current living examples right now demonstrating the transport and distribution problem can be overcome as the size of a blue whale truly dwarfs most dinosaurs
In regard to the structural support issues. I specifically note that
A) we don't really know what they actually weighed
B) we have no clue how their connective and re-inforcing tissue structures worked
C) we don't really know how many of them lived on land and how much time they spent on it
D) we DO have organisms living at absolutely crushing pressures, even the afore mentioned whales can dive to depths well beyond what would crush you and I. They have quite a few adaptations that allow them to do so. So we do have living examples of complex organisms that can handle very high stresses on their tissues. It's not the exact same as the requirements of a land walking creature larger than an elephant but that's really not the point.
Thus my point that we can speculate about a lot of things but if we treat it beyond that and pretend we're talking about facts then we're kidding ourselves. This was said primarily in response to the assumptions that dinosaurs "must have required less gravity/UA".
Then you respond with the statement of where's the place on earth will less gravity? Which aside from being a purely abusive retorical question has jack all to do with anything I just said as my whole point was that the assumption of requiring different gravity is exactly that, an assumption.
Then when I call you out on the abusive statement...
You're response is that birds have built nests in water. I agree, they have and do.
http://birds.ecoport.org/Ecology/EBnests-aquatic.htmYou follow that with a statement questioning the validity of making a floating nest if you live in water. Never mind the point that all documented birds that make floating nests spend a good chunk of time swimming in the water...
Ignoring this you also make a statment than because modern birds (flyers) make floating nests, large ancient land creatures, are unlikely to have lived in water...
And you act like that isn't also a completely over the top abusive statement but is in fact a rational argument.
But to be even more specific...lets pretend that ancient flying dinosaurs also built nests on water, in fact lets pretend ALL of the ancient flyers did this and pretend we had some way to prove it. How exactly does that even start to apply to non flyer's habits and what does that have to do with the previous discussion at all?
So yes, I feel you simply ignored much of what is currently known about modern biology and life on the planet, ignored much of what is unknown about ancient life, and threw out some abusive statements.
Having said all of this, even ancient dinosaurs drove around in yachts...that would not tell us their actual mass or if they were not structurally sound enough that they would absolutely require lower gravity/UA.
Your assessment that birds
are dinosuars is messed up on so many levels I don't even know where to start let alone the point that you say modern dinos are all the flying type? What? So you'll count a bird as a dinosaur but hell no crocodiles?! And a parrot mimics what it hears so now we have "evidence" of racism in ancient times?
Do you understand the magnitude of the leaps in logic you're making?
Biologists and pretty much every text book on the planet call a bird a bird...because it is not cold blooded...among other aspects that dinosuars are assumed to have had. This is not to say there is not a historical link (which is the whole reasoning behind evolution) but it is to say there are enough critical differences established between what we call a bird and what we assume about dinosaurs.