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Re: "Oxygen Helped Mammals Grow, Study Finds"
" Hengst and others (1993, 1996) demonstrated that a large long necked
sauropod suchas the Tithonian
_Apatosaurus_ required an oxygen content in
the atmosphere of about 35% to function at any level above a very slow
slower than the rates deducted from trackways.
Hengst et al. showed nothing except their capability for impressive
oversight. They assumed a lizard-style lung or something. They didn't even
mention the possibility of a bird-type lung! I'm sure even a crocodilian
lung (cross-current gas exchange, ventilation by moving the liver) would
have given less reality-free results (if we ignore for a minute the absence
of gastralia and pubic mobility in sauropods).
Our measured levels of [B]arremian and Aptian oxygen are 28%
and 29% respectively. It thus is not very surprising that our only
surviving Aptian sauropods are both small, and short-necked, clearly
adaptations to these low Early Cretaceous oxygen levels.
Long live *Sauroposeidon*...
THE LATE CRETACEOUS DINOSAUR RADIATION
Was there such a thing...?
" WHY DID DINOSAURS AND NOT MAMMALS GO EXTINCT?
Hengst has shown that Dinosaurs could not venilate their lungs as
as Birds or Mammals (Hengst et al '93, '96).
By means of at least spiral reasoning, yes.
* Mammals and Birds only require 7 breaths to completely
replace the air in their lungs.
I'd bet money that birds require fewer than mammals! Birds have smaller
lungs and larger tidal volume.
Barremian 130 mya 28%
Aptian 115 mya 29%
Cenomanian 95 mya 35%
Turonian 88 mya 33%
Judith River Formation 75 mya 35%
Basal Hell Creek 70 mya 35%
Hell Creek (Maastrictian) 68 mya 35%
Top-most Hell Creek 65.2 mya 31%
AFTER K/T Boundary 65 mya 29%
Is there so much Cretaceous and Paleocene amber???
Interesting how the authors use "secular" -- apparently for "long-term".
Latin saeculum = "century" or "era". The religious sense is derived from the
meaning "not eternal".