Yeah, but the age of the dinosaurs had more oxygen than now (hence the enormous trees, if nothing else), so they are fine in that respect.

Hadn't considered that. Quite right there. :)

Trees aren't a consequence of higher oxygen levels, but a cause :P

Mmmhmm I can't help thinking that since the atmosphere of Pandora was toxic for humans then the atmoshere on earth would be toxic for Na'vi, even more so in the jurassic period.

Depends on the breathing capabilities of the Na'vi I suppose.

I'd have to say though, I can't imagine Hammerheads living in Jurassic Earth. They're huge for one, and they'd need a lot of air. (not counting if it's toxic)

I'd like to see what dinosaurs (if they could breathe the air) could do on Pandora. :D

...and the saurapods didn't need lots of oxygen?

Did you know that during the Carboniferous era, (300 mil. years ago) plants and animals grew twice as large due to double oxygen levels? Kinda scream Pandora to anyone?

Yep it sure does, I just saw Jurassic Park and I was thinking the same thing. ;)

Of course they did. But once again, the air on Pandora is thicker, so Pandoran animals would require more of our air. And I can safely say that a Hammerhead would have more weight (and therefore more muscle mass, needing extra air) then the biggest sauropod.

On a side note, Jurassic Park 2 had a very Avatarish message.

Lower carbon dioxide levels - no.
Lower xenon levels - definitely no.
Lower hydrogen sulphide levels - again, definitely no.
The only problem would be the higher pollution level, but that wouldn't make it unbreathable, just unpleasant.

What about the oxygen levels?

^ Problem there.

This thread is making me want to get a Jurassic Park game. :P
You know, now that I think about it, the Turok's jaws are about the same size as a T-Rex's. Coincidence? I THINK NOT! :shoop:

If they're higher, it isn't a problem - humans can survive in an almost pure oxygen atmosphere (as long as there are no sources of ignition), as not even all of the oxygen breathed at normal levels is used - from ~21% atmospheric oxygen, there is ~15% in exhaled air.

No, no,no,no. I meant for Na'vi, not humans. Sorry Tsmukan. :P

I was using them as an example, since the biochemisty is similar between the two, so there is no obvious reason why not.