re:tucking

["Cunningham, Betty" <bcunning@nssi.com>]

     >a really interesting posting, but you failed to consider the lack or 
     >presence of  a tail acting as a counter balance.  how does that fit 
     >into your theory? b
     
     The only surviving species that walk bipedally today and have tails 
     (functioning tails, not vestigal stubs) are the monkeys and lemurs.  
     They generally hold their tails vertical from the ground while 
     bipedal, but throw them backwards to counterbalance leaning forwards 
     (returning to quadroped stance, for example)
     
     Since the majority of bipedal dinosaurs have tendons to insure 
     rigidity in their tails, the major weight of the tail would tend to 
     follow the body weight.  The more flexible ends of the tail would have 
     to act as a counterweight to the body.  This would be IN COMBINATION 
     with any arm movement, not excluded from it.  We are merely talking 
     about weight shifts at BOTH ends of a see-saw, or teeter-totter, the 
     back legs being the fulcrum..  The more mass at the end of the tail, 
     the less the arms would need to move to correct weight shifts.  The 
     less weight at the end of the tail, the more the arms would have to 
     move.
       
     Thus:
     
     small-but-long-tailed bipedal dinosaurs would have less arm movements 
     (in general) than small-but-stumpy-tailed bipedal dinosaurs, but the 
     movements would still be there. IMHO
     
     Betty Cunningham(Flyinggoat@aol.com)
     (bcunning@nssi.com)
     -who's trying to think of a stumpy-tailed bipedal dinosaur-