Re: lung capacity

[Dann Pigdon <dannj@alphalink.com.au>]

GSP1954@aol.com wrote:
> 
> As I discuss in DA, lung volume is not a reliable indicator of aerobic
> capacity because reptiles have very large lungs (they are so inefficient 
> because
> they are so simple) while birds have small lungs (they are super efficient
> because of complexity and air sac ventilation).

Indeed. Diving animals can further complicate the issue. Aquatic
varanids can have quite complex, convoluted lungs, as compared to the
simple bag-like organs in other varanid species. Perhaps it is the
internal surface area of the lungs, rather than absolute volume, that is
a better indicator of aerobic capacity.

Also, lung capacity doesn't necesarily indicate metabolic level. Aquatic
varanids don't have higher metabolic rates than their landlubber
cousins. They can just go longer between breaths.

-- 
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Dann Pigdon                   Australian Dinosaurs:
GIS / Archaeologist         http://www.geocities.com/dannsdinosaurs
Melbourne, Australia        http://www.alphalink.com.au/~dannj/
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