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Re: re:Dinosaur Hunting techniques



 bcunning@nssi.com (Betty Cunningham) wrote:

<<  You don't mention that lions tend to have multiple animals bringing 
     down larger prey, not just attacking one-on-one.  This seems to be 
     determined mostly on how hungry the pride is when the prey is brought 
     down.  So a baby gazelle may be brought down one-on-one, but an adult 
     gazelle/wildebeast/zebra may be brought down by several individuals.  
     How does this affect your theory? >>

Granted lions tend to hunt in groups.  However, that does not preclude the
occasional lone hunter from trying his/her luck.  My statements regarding the
hunting strategies of lions refer to such occasions.

<< Didn't you know that they race cheetahs like 
     greyhounds in Egypt and other Arabian countries>>

No, I didn't.  However, racing cheetahs does not necessarily involve studying
their acceleration abilities.  Milton Hildebrand has done some wonderful
studies involving cheetah _speeds_, for example, but nothing much on
_accelerations_.  Lions, on the other hand, have been studied for their
acceleration abilities, using force-generated-by-hind-limbs and mass
calculations.

<<  Why, in your discussions of the physiology of the animals, lions, 
     cheetahs, and T rexs, do you consider lions, being a very robust 
     animal, like cheetahs, and not like T rex, also a very robust animal.>>

Well, because lions are more like cheetahs then they are like tyrannosaurs.
 However, I believe (although this may not have come across in my posting)
that tyrannosaurs were more like lions than cheetahs in their pursuit
strategies.

 << T rexs certainly aren't gracile in any way.  Cheetahs are very 
     gracile.  They have flexible spines so that in the full gallop their 
     spines ripple like a trampoline.  I don't picture T rex's spine doing 
     anything so undignified during a run.  I can see (perhaps) something 
     smaller and more elegant of form like Veloceraptor or Deinonychus 
     developing along  the lines of a speedster like the cheetah, but not 
     ol' brick T rex.  He's built like a truck, not a Ferrari.  Perhaps 
     even Allosaurus fragilus might be considered to be a speedier design, 
     but T rex? >>

There's a very good reason why you don't picture tyrannosaur spines rippling:
 tyrannosaurs are bipeds!  The elastic spine of quadrupedal cursors helps to
store energy, allowing for a much increased stride when the spine is
straightened (which occurs when the animal pushes off with its hind feet).
 Theropod dinosaurs, being obligate bipeds, have no need for (and indeed,
could not use) such an energy-storing mechanism.  This is not to say that
they might not have had other mechanisms - perhaps thick elastic foot pads.
 However, I seriously doubt that any bipedal runner could match a
similar-sized quadruped for speed.  I have never been able to outrun any dog!

<< (and what with all the fused tendons along most therapods' tails,  you 
     don't see the completely supple spine like in a cheetah, anyways.  
     Therapods spines seem to have been reinforced to prevent exactly that 
     kind of movement.)>>

Again, the two animals operate differently.  I apologize if I gave the
impression that tyrannosaurs were likely the fastest runners of their day.  I
merely wished to convey the idea that they may have been quite capable of
running down prey at "high" speeds.  How high depends on how fast their prey
ran!

Hope this clarifies some points.

Derek Smith