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Re: energy wasteful terramegathermy (hooray) vs energy efficient gigantothermy (boo hiss)



A technical glitch prevented this from going straight to the list -- MPR

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Date: Fri, 4 May 2001 08:21:29 -0400
From: Graydon <graydon@spitfire.velocet.net>
To: dinosaur@usc.ed
Subject: Re: energy wasteful terramegathermy  (hooray) vs energy efficient 
gigantothermy (boo hiss)]

On Fri, May 04, 2001 at 03:31:42AM -0400, archosaur@usa.net scripsit:
> Unless, of course, dinosaurs do represent these bradymetabolic/aerobic
> reptiles. Since no animal in the history of the planet, has ever gotten as
> large as the animals that came out of the Mesozoic, it makes for a highly
> debateable proposition (e.g. if mammalian metabolism is really required to
> reach sauropod sizes then how come the largest mammals we know of, barely hit
> mid sauropod size throughout their "dominance" of the planet?).

Structural limitations, there as side effects of being small for 120
Myears; no lumbar ribs, no cervical ribs, no pneumatic bones, no
option for neck-and-tail balance beam back structures, reliance on
jaws for mechanical food processing; there's enough differences in the
body plan to argue that sauropods are something of a special case,
preserving options not surviving in the mammal genome.

That the largest mammals are about the size of the largest
non-sauropds strikes me as the more interesting comparison, there;
sauropod morphology has something to do with the size they reached.

- -- 
                           graydon@dsl.ca
               To maintain the end is to uphold the means.
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