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Re: Atomosphere (Last of the Pterosaurs

At 4:05 PM -0600 12/2/00, Steve Brusatte wrote:
>makes sense that the Earth is bleeding off atmosphere, but do we really have
Mesozoic air samples?

Keith Rigby claims that he does, although I don't know exactly what he has published on it. I interviewed him awhile back, and in my process of researching I came across some articles (including one in the Notre Dame Alumni Magazine, I believe) that described Rigby's research on some amber specimens that had 'Mesozoic air' trapped inside of them.

That's been around for quite a few years, but it's dubious at best. I think it was reported at the 1993 GSA Annual meeting. It's not clear what happens when air is trapped inside amber, but some chemical reactions are likely, and should change the composition. Remember that oxygen is inherently very reactive.

Furthermore, I believe that Rigby and Richard Hengst have done another study on Tyrannosaurus breathing, and much of it was on the difference between the atmosphere of today and the atmosphere of the Cretaceous. I know I have the paper lying around somewhere, and once (if) I find it I'll post the ref.

Part of the theory proposed at the GSA meeting was that the dinosaurs died from oxygen starvation when oxygen levels dropped.

-- Jeff Hecht