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Re: Sauropod Self Defense



don ohmes writes:
 > Have any estimates been made of how long a sauropod could hold it's
 > head in the proposed vertical posture?

Hi, Don.  Mechnically, and all other factors being equal, it is
_easier_ to hold a long object vertiically than horizontally.  If you
doubt me, pick up a broom in one hand and hold it out horizontally.
How long can you hold it for before your muscles give out?  Now try
the same thing holiding it vertically -- you can hold it pretty much
forever.

So you'd think that sauropods could hold their necks upright much more
easily than out horizontally, right?  Yet we have good reason to think
that at least some sauropods did indeed hold their necks horizontal
most of the time.  So they must have had special adaptations enabled
them to do so.  Did they also, then, have special adaptations to
enabled them to hold their necks vertically for extended periods?  At
the moment, we just don't know.  To find out, it's going to take
someone to look into the anatomy in a lot more detail than anyone's
done yet.

As an experiment, I tried using my own body to verify that holding an
extremity horizontally is more demanding than holding it vertically:
simply, I stood up with one arm straight up in the air and the other
straight out, and waited to see how much more quickly the horizontal
arm crumpled.  To my surprise, they seemed to tire pretty much equally
quickly ... although as I'd stupidly forgotten to set myself up with
something to read while I waited, I got bored before reaching a firm
result.  I can only conclude that my arms are better built to stick
out horizontally than vertically.  That's not surprising given the
kinds of things that humans do with their arms, so it also shouldn't
surprising if sauropod osteology and correlated soft tissue was
optimised for ... whatever the heck their habitual posture was.

 _/|_    ___________________________________________________________________
/o ) \/  Mike Taylor    <mike@indexdata.com>    http://www.miketaylor.org.uk
)_v__/\  "If you lie to the compiler, it will get its revenge" --
         Henry Spencer.