Science
Related: About this forumIf dinosaurs suddenly magically appeared today, could they
breathe in today's atmosphere?
TexasProgresive
(12,157 posts)to support the great fern forests that supported the herbaceous dinos. Which gave big fat dino cows to the T-Rex and other predator dinos. This would be continuing the cycle as that giant bio-mass became the oil, gas and coal which we burn releasing more CO2 back in the the air. It's the cycle of life on a grand scale.
OffWithTheirHeads
(10,337 posts)Romeo.lima333
(1,127 posts)Erich Bloodaxe BSN
(14,733 posts)Is that some sort of in-joke? The earth's gravitational field hasn't changed in any significant way since it formed. Yeah, we pick up a tiny bit of mass from meteorites, and lose a bit when things like helium escape the atmosphere, but overall it's basically constant.
eppur_se_muova
(36,266 posts)... so, you see, all those big giant dinosaurs weren't all that heavy. Gravity is stronger now, so we don't have such big animals anymore.
Erich Bloodaxe BSN
(14,733 posts)rock
(13,218 posts)So running after prey is out of the question. They would probably have to learn to ride motorcycles.
Fumesucker
(45,851 posts)Thor_MN
(11,843 posts)If you are talking what most people mean, the really big ones, probably not.
The small ones would probably be OK.
AlbertCat
(17,505 posts)They are OK!
Thor_MN
(11,843 posts)The question, in my opinion, although not overtly stated, was about dinosaurs being able to survive in today's atmosphere. The atmosphere has changed over the years and oxygen content now is less than in some eras. Modern birds have had the chance to adapt as the atmosphere changed, but would a dinosaur suddenly thrust into our atmosphere have issues?
I think it is likely that the biggest dinosaurs were able to get so big because they had more oxygen to breathe. They would probably struggle like we do at higher elevations.
packman
(16,296 posts)way back when which helped the growth of the large beasties.
muriel_volestrangler
(101,321 posts)https://en.wikipedia.org/wiki/Mesozoic
We can adapt to the altitude at La Paz, which, at about 3500m, has about 2/3rds the oxygen (2/3rds of everything, of course) of sea level atmosphere. So even if they were used to more oxygen, they'd probably be able to breathe.
NickB79
(19,247 posts)Just as there are numerous species today that are adapted to living at high altitudes, I'm sure dinosaurs filled those niches as well, especially now that we're aware they were feathered and likely warm-blooded.
Even during the Cretaceous, when oxygen levels were highest, there would have been dinosaurs breathing much lower levels at high elevations, comparable to today's sea level content.
Johonny
(20,851 posts)The pattern on bones suggests that dinosaurs had air sacks like birds. Air sacks allow for better extraction of O2 from the air. It is what allows birds to breath in atmospheric conditions where mammals struggle. Since the bone patterns of birds and bird like dinosaurs are so similar it is assumed that birds (who are a type of dinosaur) and dinosaurs had very similar lung physiology. There is of course another whole branch of dinosaurs that do not have evidence of air sacks in their bones. It is unclear if they had any air sacks at all. Would these dinosaurs have trouble in todays atmosphere. Well, these dinosaurs were more abundant the closer to modern times.
Peter Ward probably does a better job describing this than me. So I'll just recommend his book.
http://www.amazon.com/Out-Thin-Air-Dinosaurs-Atmosphere/dp/0309100615