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Re: respiratory turbinates
In message <199609111623.LAA17785@juliet.ucs.indiana.edu>,
>This information may be from an article published in Science (v. 273, 30
>August, 1996, p. 1204-1207), by J. A. Ruben, W. J. Hillenius, N. R.
>Geist, A. Leitch, T. D. Jones, P. J. Curie, J. R. Horner, and G. Espe
>III, entitled The Metabolic Status of Some Late Cretaceous Dinosaurs.
>They examined the nasal regions of Nanotyrannus, Ornithomimus,
>Dromaeosaurus, and Hypacrosaurus, looking for evidence of, or room for,
>respiratory turbinates, as are found in more than 99% of living birds and
>mammals. They concluded that the dinosaurs examined did not have room
>for such structures [...]
>The authors suggested that presence or absence of respiratory turbinates
>may be used to assess the metabolic status of extinct vertebrates.
>Respiratory turbinates and otherwise enlarged nasal passages are believed
>to be associated with elevated lung ventilation rates, and, by extension,
>with high routine metabolic rates.
I'm fine so far, I merely note that association does not imply
>Their absence implies that metabolic and lung ventilation rates were
>sufficiently low that evaporative water and heat loss was not a
And I can imagine that turbinates might increase evaporative area and
therefore heat loss. But I can't make out how they would help to
conserve water. Or am I misunderstanding the above, and also Fastovsky
and Weishampel's little textbook which seems to say the same thing?
I guess that any hypotheses about other dinosaurian ways of getting rid
of heat must remain untestable speculation? Or can anybody make a
Dr Richard Keatinge,
fan of fast dinosaurs
am fanylion gofal mamolaeth gorau yng Nghymru / for details of best maternity
care in Wales