RE: SAUROPOD QUESTIONS

["Stewart, Dwight" <Dwight.Stewart@VLSI.com>]

        -----Original Message-----
        From:   GSP1954@aol.com [SMTP:GSP1954@aol.com]
        Sent:   Thursday, November 05, 1998 10:11 PM
        To:     dinosaur@usc.edu
        Subject:        SAUROPOD QUESTIONS

        Two questions. Does anyone know if there has been a paper that
discusses A)
        the increase in hours spent each day feeding by large mammalian
herbivores,
        with B) the conclusion that sauropods were too big to feed
themselves within
        24 hours if they had a mammalian energy budget? 

        Second. Has Tony Fiorillo published a paper on sauropod tooth
microwear since
        1991? 

        GSPaul


        I know I read a recent paper on potential sauropod endothermia, but
can't locate the reference right now.  I believe it was in Scientific
American.  There's also an old argument that sauropods heads were too small
to feed their huge bodies whether they were endothermic or not. :-)  Yet,
obviously they did.  I think a lot of this depends on how rich was the
available nutrition in the plants that they fed on and how well equipped
were they to extract that nutrition?  If sauropods follow the model of
modern, plant eating animals; their digestive system was probably designed
to extract 
        Nearly every available ounce of nutrition from their food, this
might mean:
1)      A VERY long intestional tract
2)      Multiple stomachs
3)      Gastrolithes
4)      The ability to chew cud, etc.

I once read that ~ 60% of the calories we take in is used to maintain our
endothermic condition.  This sounded high to me, but a physician told me the
same thing about a year ago.  But that much caloric expenditure wouldn't be
necessary to an enormous animal like many sauropods.  The ratio of their
greatly increased bulk to their exposed surface area would aid in
maintaining a stable temperature.  I know that "gigantothermia" has caught a
lot of "heat" (sorry about the pun)
Lately, but the physics of it make sense.  Dr. Horner thinks Tyrannosaurus
rex changed metabolic strategy after it neared its adult size; perhaps
switching from a form of endothermia to gigantothermia.
Might not sauropods (many of whom grew to several times the size of a
Tyrannosaurus rex) have employed the same strategy.  

I know I'm not really answering your question, but I'll try to find the
article I mentioned.
         
        Dwight