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

Re: Sauropod Energetics (Peristaltic pump)



Richard:

I've posted several times before about the possibilities of higher O2 levels, and some of the ramifications. [I'll dig up the postings, which have references, if needed].

I won't repeat it all here, except to say that some currently suspect studies on gases preserved in amber indicated that the O2 level was as high as 35%, nearly double our current level, and just under a theoretical maximum for our atmosphere (It is _suspected_ that higher concentrations would lead to spontaneous combustion of the atmosphere).

The studies indicated that the O2 levels varied up and down over the last 230 my. [The amber gases seemed to have such GREAT data].

Amber, unfortunately, apparently does leak some gases, in unknown and unequal rates (over millions of years!); so that the actual O2 level is very difficult to determine. Newer tests involving natural Carbon sequestration rates (in oceanic sediments) may help us determine the true levels of O2, but I don't know how far these tests have come in the last 2 years.

Some things that might be helped by increased O2 levels: The extreme sizes of many dinosaurs (especially sauropods) would be easier to support in higher O2 - the muscles would work better with the additional O2 (allowing them to carry more weight per pound of muscle); and, as you suggest, the blood that did reach the brain would have more O2, to allow better functioning when (IF!) the head was raised much above the 2.5 meter distance from the heart.

The blood pressure would not need to be as high to maintain sufficient O2 to the brain. [Some workers have suggested that the largest sauropods may have lived (conservatively) up to 150 years, and some have speculated as much as 1200 years! These ages would be somewhat easier to achieve with lower BP].

Hope this helps,

Allan Edels


From: "Richard W. Travsky" <rtravsky@uwyo.edu>
Reply-To: rtravsky@uwyo.edu
To: dinosaur@usc.edu
Subject: Re: Sauropod Energetics (Peristaltic pump)
Date: Tue, 31 Jan 2006 09:23:15 -0700 (MST)

On Thu, 26 Jan 2006, Sim Koning wrote:
Would some sauropods need to maintain blood flow in order to raise their
heads long enough to take a mouthful? Surely if a diplodocid (or other
species that maintained horizontal necks most of the time) was able to
seal off the blood supply out of the neck for a few seconds to prevent
blood from draining away from the brain, then a few moments of no blood
flow to that tiny brain wouldn't be so critical?

It would mean they couldn't raise their heads for any length of time
(barring other unknown blood flow mechanisms), but it wouldn't make
quick forays into higher elevations entirely impossible.

That's Bakker's hypothesis, but I don't know how long even a small brain could function without a constant oxygen supply. It would mean that these

Would higher oxygen levels compensate?

[...]