Re: Climate change

["Nicholas J. Pharris" <pharrinj@PLU.edu>]

On Thu, 4 Apr 1996, Christopher Nedin wrote:

> Then, day/night temperature fluctuations were fairly small over
> considerable areas of the globe, making gigantothermy a viable strategy.

We'll see.

> However, with the major climate shift towards the end of the Mesozoic (for
> whatever reasons), the broad, ameliorated, global climatic zonations
> collapsed, resulting in the expansion of the temperate zones - complete
> with their more varied day/night, summer/winter temperature range.

OK, what about the (reduced) temperate zones that *did* exist during the 
Mesozoic?  What of the dinosaurs there?  60 degrees is a ways up the 
earth, but it isn't all the way.  What of the dinos down there in 
Australia, where, someone recently posted, it may have gotten down to -4 
deg C?

> it is hard to re-heat
> - especially if metabolism is only partially aiding the heating process.
> The result would be that the big dinos would be forced into the narrower
> tropical/subtropical zones.  But the whole supporting ecosytem was in
> collape by then.

Bear in mind that this is all assuming the dinosaurs were gigantothermic, 
which has not been proven (although, alas, neither has endothermy).

> Chris
> 
> cnedin@geology.adelaide.edu.au                  nedin@ediacara.org
> -------------------------------------------------------------------

Nick Pharris
Pacific Lutheran University
Tacoma, WA 98447
(206)535-8206
PharriNJ@PLU.edu