RE: Warm-Blooded debate

["Douglas W. Lewis" <dwlewis@rmii.com>]

-----Original Message-----
From:   Jeffrey Martz [SMTP:martz@holly.ColoState.EDU]
Sent:   Monday, June 16, 1997 10:58 AM
To:     Eric A Campbell
Cc:     gsraptor@arkansas.net; dinosaur@usc.edu
Subject:        Re: Warm-Blooded debate


> They couldn't do this as ecotherms! Take the Komodo Dragon, for example.
> It can run fast, as it has to, but it will sometimes pause in the middle
> of a chase to catch it's breath. I severely doubt that a T. Rex would
> have survived as a predator if it stopped in the middle of a chase.

     Komodo dragons seem to be getting by without starving
to death.  Keep in mind if you are an ectotherm, you may not have as
much energy for an extended chase as an endotherm, but at the same time
you don't need to eat as much anyway so you get to have a few more
unsuccessful chases.  Also keep in mind that if ALL dinosaurs were
ectotherms, the theropods and herbivorous dinosaurs would have the same
physiological limitations. 

> don't think that the 15-inch claw found on the _Utahraptor_'s foot would
> be of much use if it was a scavenger. A slow ecothermic scavenger.

I'll put in something here. Utahraptor,15-inch claw or not,would need a lot of 
energy to bring down a dino larger than it. Whether there was two of'em or not. 
So I think that that would point more towards them being endothermic(correct me 
on my terms if I'm mis-using them). But it could also be that they wouldn't be 
very active in between hunts. But then again why would they have been designed 
to be so agile? Not to mention being equiped(spelling?) to take down something 
a lot larger than it. 
     For that matter,why were all dinosaurs designed to be agile? If we take a 
look at modern day ectotherms,they're not designed to be very agile at all. 
Then why were dinosaurs designed to be more agile than modern day ectotherms if 
they themselves were ectotherms? 
       From what I've seen,their design alone points to them being endotherms. 
Such as,their legs all being underneath their bodies,only mammals have their 
legs this way. And as we all know,mammals are endotherms. All present 
ectotherms on the other hand,do not have their legs underneath their bodies. 
This too would imply that dinosaurs were endothermic. 
     I personally do not see any evidence that dinosaurs were ectothermic.

Caleb
http://www.geocities.com/Area51/Vault/6619/index.html