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Re: Physiological Adaptations of the Dinosauria (long)
to: "Rob Gay"
from: Waylon D. Rowley
Allow me to interject for a moment here:
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.
Unless you know something that I don't, the specimens of D. wetherilli
were preserved *without* crests, and they used D. breedorum (which does have
crests) to fill in the gaps in our knowledge on D. wetherilli's crest
morphology. Check out this link:
Since I lack any knowledge of D. breedorums crest height, length, and width,
I opted for ?D. sinensis for which I have seen pictures of at least.
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.
In that case, we need to know whether this "separate bone" has foramina for
the superior nasal artery.
This is a hypothetical _Eucoelophysis_ that you speak of, right? Because
_E. baldwini_ wasn't similarly-sized.
I'm talking about an E. baldwini that has been scaled up to ?D. sinensis
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.
Good point. Unfortunately, I simply don't have the money nor equipment to do
a study like this....so i'm going to leave it to the hands of more
prestigious paleontologists (assuming they'd want to test my hypothesis in
the first place.)
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