[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

Re: "Oxygen Helped Mammals Grow, Study Finds"

"    Hengst and others (1993, 1996) demonstrated that a large long necked
sauropod suchas the Tithonian


and/or Kimmeridgian...

_Apatosaurus_ required an oxygen content in
the atmosphere of about 35% to function at any level above a very slow walk,
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 easily
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".