T. rex vision

[Crpntr@ix.netcom.com (Kenneth Carpenter)]

At the risk of getting myself in more hot water (brave or death wish):

Mickey Rowe wrote:
> I think the thing that concerned me the most about "Jurassic
>Park" (the movie) was the descriptions of Tyrannosaurus' hunting
>strategy.  In the book, Alan Grant formulated the hypothesis that
>Tyrannosaurus couldn't see stationary objects *AFTER* it didn't eat
>him as he stood motionless against its nose.  In the movie, Alan Grant
>claimed that T. rex vision was "based on motion" while he was still at
>the dig site.

while Larry Smith wrote:
>At the risk of re-igniting the Jurassic Park idiocies thread, one of
>the nasty things that film did was forget to explain the importance
>of amphibian DNA lousing up the dinosaurs - that the dinosaurs of
>Jurassic Park were as much art and reconstruction as any plaster
>model.  While I despise Crichton for many reasons, he _did_ make the
>point that most of the dinosaurs in Jurassic Park were hobbled with
>visual cortexes appropriate to frogs and not dinosaurs, because they
>never found visual cortex DNA - even the herbivours had the problem,
>a fairly major one for something whose food does not normally move
>in the first place.  Spielberg picked up on the visual stuff without
>the explanation and built it into the movie, and, as Mickey points
>out, it has become a part of the public perception of t-rex ...

>t-rex vision problems is just bad research and poor script writing.  

Permit me to say I disagree with you both.  Many years ago as an 
undergraduate, I kept a large bullsnake in my office (yeah, I was a 
lowly undergraduate with a office bigger than most graduate students 
had so I could keep animals).  I would feed her (she lacked the bulging 
cloaca of the male) mice from the pet store.  I had noticed that, while 
flicking her tongue to locate the prey, she would also jerk her head in 
the direction of motion.  I got a personal experience with this when one 
of the mice I was going to feed was dead.  I dropped the mouse in her 
cage anyway, and she went into her scent detection mode.  She seemed to 
have trouble finding the mouse, so I reached down to pick the mouse up 
by the tail.  Even before I reached the tail, she lunged and bit me 
having detected motion.  Realizing her mistake (taste, feel, etc.) she 
immediately let go and raced into her box.  I picked the mouse up by the 
tail and waved it a good foot from the opening of the box.  She poked 
her head out cautiously, flickering her tongue.  She approached within 
six inches and lunged garbbing the mouse this time.  Clearly, she did 
rely upon motion to locate prey.
   That the motion of prey is important to predators is demonstrated by 
new born fawns or baby ground birds who sit motionless if danger lurks. 
 Thus, I do not have problem with the untestable speculation that T. rex 
used motion in hunting.  I consider it possible, probable and even maybe 
(your choise of CYA terms).  I do have problem with the rex not being 
able to smell Grant from a foot away.  Afterall, the olfactory lobes of 
a T. rex endocast are big.