Re: Physiological Adaptations of the Dinosauria (long)

["Rob Gay" <rob_redwing@hotmail.com>]

Allow me to interject for a moment here:
> Because (to my knowledge) ?D. sinensis has the largest nasolacrimal
crest among coelophysoids (with the possible exception of D. wetherilli)<
> From what I have seen (pictures and drawings) of _D. sinensis_, the crests 
are apx. the same size as that of _D. wetherilli_ (a little bigger, but 
negligible). However, they appear to be much thicker than _D. wetherilli_, 
and I would think that you would want thin vanes if you were going to be 
using this structure as a radiator. But if we were going to discuss crest 
vs. total skull size, I would think that _Syntarsus kayentakatae_ would have 
the largest proprtional crest, being apx. 40% of the length and 21% of the 
height of the skull, plus having an antobrital fenestra almost as long and 
twice as tall. And, this is almost contra your argument, but most 
coelophysoids have >huge< antorbital fenestrae, covering in some cases 
almost 45% of the length of the skull.

> which when acting as a radiator panel for the superior nasal artery,<
In coelophysoids that had crests, most of the crest was composed of the 
lacrimal, or even a seprate bone, as posited by Welles (1984), so 
positioning might be questionable for this function.

> would give it a higher condensation rate than, say, a similarly-sized E. 
> baldwini.<
This is a hypothetical _Eucoelophysis_ that you speak of, right? Because _E. 
baldwini_ wasn't similarly-sized.

> If you took a measurement of the istopic ratio for the crest itself and the 
> base of the antorbital fossa, it should indicate how much heat was being 
> lost, and whether condensation was really possible in this animal.<
I don't follow here. Both of the areas mentioned here are what you propose 
for heat exchangers, so you have no neutral ground. You'd also need to take 
a sample from some place like the illium or the scapula to see if there was 
a difference.
Peace,
Rob

Student of Geology
Northern Arizona University
P.O. Box 20840
Flagstaff, Az. 86011
AIM: TarryAGoat
"A _Coelophysis_ with feathers?"

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