Re: Life's scale reduction since the Dinosaurs

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

On Wed, 24 Jan 1996, Stephen Hurrell wrote:

> We all know that the Dinosaurs were big. What is not so generally 
> realized is that life has been reducing in size over periods of 
> hundreds of millions of years. 
> 
> There can be no doubt that this size reduction has taken place. 
> After the extinction of the Dinosaurs a range of Supergiant Mammals 
> approaching the size of the smaller Dinosaurs evolved. These Supergiant 
> Mammals were superseded by Giant Mammals which were larger 
> versions of the Mammals alive today. These Giant Mammals have in 
> their turn died out to be replaced by a smaller scale of life.

Odd.  You do realize, of course, that the largest dinosaurs came at the 
*middle* of the Mesozoic, and that the therapsids who preceeded the 
dinosaurs were not larger than they.  There were plenty of animals around 
before the dinos; you can't start the history of life on earth with the 
Dinosauria.  All in all, I see no particular trend in animal size in 
*any* particular direction, nor can I think of a model which would 
dictate such a trend.  There are always animals around of many different 
size ranges.

> 
> Stephen Hurrell 
> 11 Farmers Heath
> Great Sutton
> South Wirral
> L66 2GX
> Great Britain
> 

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