Re: Dinosaur Were Endotherms

["Matthew Troutman" <m_troutman@hotmail.com>]

>I have defended this all my life. And I'd go an step further: any erect
>posture, compulsory biped should be an endotherm.It implies sustained
>activity.

    Don't get me wrong, I was a supporter of the endothermic hypothesis, 
but the most recent research has shown me its more likely otherwise. 
Anyway, yes dinosaurs do show an erect posture that implies high levels 
of activity. But that is the only thing that it proves; high activity. 
Ectotherms have the ability to have high activity levels. At present I 
think that the phrase " quasi-ectotherm " applies to dinosaurs since 
they show some features of endotherms but lack some of the more derived 
refinements.

>Forget about turbinates. This is the only real, living proof (there are 
NO
>compulsory cold-blooded fully erect bipeds living today) that ALL 
dinosaurs
>had their own kind of endothermy and ALL dinosaurs descended from 
bipedal
>animals, most probably arboreal and in different stages of becoming
>airborne, that already had changed metabolism in their way up and down 
the
>trees.

    Snakes, *Draco*, some monitors, chameleons, and many other 
ectotherms did not change to a higher metabolism even when they are 
arboreal. At present, RTs are the best evidence that we have for the 
metabolism of dinosaurs, and the lack of them says that they are most 
likely ectotherms or quasi-ectotherms. Until they are found, the 
evidence suggests ectothermy.

I don't like the idea that dinosaurs were ectotherms, but until more 
evidence is found, I must go with the ectothermy side.

MattTroutman

______________________________________________________
Get Your Private, Free Email at http://www.hotmail.com