Re: The heart of a Brachiosaurus

[John Bois <jbois@umd5.umd.edu>]

I don't know the answer to your question.  But here are some things to
think about.  Much depends upon whether or not the animal raised its head
directly above its body, or whether it browsed closer to the ground.  In
the first case one would expect high blood pressure or some fantastic
adaptation (eg., 7 neck hearts) to get the blood all the way up.  I
believe brain tissues (for example) in all creatures are equally prone to
bursting (as in strokes).  Therefore, if excessive pressure was needed to
pump blood up then one would expect an excessively high rate of strokes. 
We have no way of knowing whether or not this occurred.  I wonder if 
giraffes experience more of these difficulties?

Either way, moving blood around a huge body was just one of the
physiological problems to be solved by these gigantic creatures.  Indeed,
one could argue, as I have, that being big was a rather pathological
condition.

 On Tue, 24 Nov 1998
GGreyOwl@aol.com wrote:

> Hi, everyone. I'm a new subscriber to the list with an important question ( at
> least it's important to my dinosaur-loving 9-year old [I think he wants to be
> a cardiologist!]). 
> 
> Julian wants to know how big was the heart of a Brachiosaurus. It must have
> been huge to pump blood all the way up to its head. And/or was its blood
> pressure really high? Does anybody have any thoughts, theories, or pertinent
> facts on this vascular question?
> 
> Thanks.
>