Re: CROCODYLOMORPH ENDOTHERMY

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

On Thu, 25 Jan 1996 Dinogeorge@aol.com wrote:

> In a message dated 96-01-24 21:46:31 EST, pharrinj@PLU.edu (Nicholas J.
> Pharris) writes:
> 
> >Thank you both for the info, but has any work been done re: histology (or 
> >anything else) to find out at what point in their evolution crocs 
> >returned to ectothermy?  What sort of temperature control do they maintain?
> 
> "Returned to ectothermy"? As far as I know, all crurotarsan thecodontians
> were always ectotherms. But with four-chambered hearts.

According to Bakker, erythrosuchids and some other early thecodontians, at 
least, had low P/P ratios and plexiform bone (two features I continue to 
belive indicate endothermy).

Early crocs were also long-limbed, even partly bipedal.

I'm not convinced that an ectotherm would need a four-chambered heart.

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