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RE: Diplodocid duck-and-cover techniques



Naturally, I like that theory too!  

The use of the tail as an impact weapon is very problematic - the bones are
too delicate.  The last 2 meteres of the tail weighed about 3 kg - not much
mass if you are going to use it against a predator big enough to actually be
a problem to a diplodocid.  The bones are fine and delicate and would not
have withstood an impact.  The joint surfaces are exposed and thus would be
involved in an impact - unlike dinosaurs with tail clubs where the club has
evolved to keep joint surfaces away from an impact.

Finally, it is not clear why adults would need any defense mechanism other
than their size and the use of their legs (including the forelimbs that had
a large thumspike).  What defense mechanism do elephants have?  None other
than bulk, but it works for them.

The sonic boom from the whip cracking could have been used to scare
predators, but more likely it was used as part of a mating ritual.  We don't
expect elk, moose, peacock or other animals use their extreme antlers or
plumage for defense - it is for a far more important effect - sexual
selection.  Diplodocid tails are probably another example.  

At any rate this was all in our paper in Paleobiology, and also covered in
many popular sources, including Discover, NY Times etc.  I won't repeat it
all here.

Nathan

> -----Original Message-----
> From: Edels [mailto:edels@email.msn.com]
> Sent: Friday, July 28, 2000 10:20 PM
> To: dinosaur@usc.edu
> Subject: RE: Diplodocid duck-and-cover techniques
> 
> 
> Ah, how soon they forget...
> 
> I kinda like Nathan Myhrvold and Phil Currie's theory that 
> sauropods could
> "snap" their tails at supersonic speeds, creating a sound 
> level of 200+
> decibels.  This would most likely cause pain to predators.  
> (Maybe).  :-)
> 
> Also, it might be difficult for sauropods to stop the side to 
> side motion
> when they were moving.
> 
> Allan Edels
>