Re: 4-CHAMBERED ECTOTHERM

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

On Fri, 26 Jan 1996, D.W.Naish wrote:

> > Four-chambered heart first, endothermy later. (Note that no extant 
> > endotherms
> > have three-chambered hearts, but one group of extant ectotherms--crocs--has
> > four-chambered hearts.)
> 
> _Heterocephalus glaber_, the naked mole rat, was shown in 1993 to be a truly
> *ectothermic* mammal. It too has a 4-chambered heart. 
> 

And it also evolved from endothermic ancestors.  

Note:  don't even think 
about using this to show that ectothermic dinosaurs could have evolved 
from endothermic ancestors.  No dinosaur was aquatic like a croc, and 
certainly no dinosaur (especially a sauropod, for whom the theory has 
been most often advanced) lived in a burrow in the tropics!

> 
> DARREN NAISH
> 
> 

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