Re: Life's scale reduction since the Dinosaurs

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

On Wed, 24 Jan 1996, JCMcL wrote:

> But why no mammals as large as large sauropods?

My own favorite theories include inferior limb structure for really large 
animals (dino limbs weren't all that flexible but were better than mammal 
limbs for really large animals); 

the presence of very tall gymnosperms 
(which often tend to have the leaves clustered near the top) in Jurassic 
environments;

the effect of higher fecundity (appears to be the case in most non-avian 
archosaurs) on population dynamics;

and a generally warmer, wetter, and more abundant environment in the 
Mosozoic.

(and I will personally shoot anyone who drags out the "largest ectotherm 
size vs. largest endotherm size" argument.  I am personally very strongly 
convinced that sauropods were as warm-blooded as you and I.)

> 
> How long after the first broad adaptive radiation of archosaurs did really 
> large sauropods (bigger than elephants) arise?

even the first good fossils from true sauropods are quite large.


Nick Pharris
Pacific Lutheran University
Tacoma, WA 98447
(206)535-8204
PharriNJ@PLU.edu

"If you can't convince them, confuse them." -- Harry S. Truman