Re: Spinosaurus/Lost World

[Robert.J.Meyerson@uwrf.edu (Rob Meyerson)]

Steve Tomporowski writes;

>Has anybody every given any consideration to the balancing mechanisms (inner 
>ear, etc) that dinosaurs possessed?  Especially in relationship to bird, 
>reptiles, etc?  Reason:  My wife picked up one of the 'Lost World' dinosaur 
>toys, specifically Spinosaurus.  I thought the reproduction was pretty nice 
>(note: the lower jaw even had teeth only on the forward half, and compared 
>to sketches by G. Paul, it seems to be a juvenile), but the sucker is hard 
>to stand up!  The tail did do some of the balancing act, but there must have 
>been more than that.....

Consider the difference between a motorcycle and an automobile: the motorcycle 
has contact with the ground at two places, while the car has contact with the 
ground in four places.  In design tests, it has been shown that these "contact 
points" are crutial to the vehicles stability, and the more the merrier (the 
idealized vehicle is a "flying saucer" shape with six to eight wheels placed 
along the perimeter [these tests were demonstrated in _Beyond 2000_, on The 
Discovery Channel]).  So, when the car is moving, or is stationary, it takes no 
energy to keep the car from tipping over; for the motorcycle, the rider needs 
to 
make constant/subtle changes in his/her position to keep the motorcycle on it's 
wheels (or use a kickstand).

A bipedal animal is like the motorcycle, where constant changes are required to 
keep one's balance.  Try placing a free-standing toy soldier (one without the 
little plastic base) on it's feet.  This is not easy, as the slightest motion 
knocks the figure over.  Yet, real people have no difficulty staying on their 
feet.  This is because our sense of balance knows if we are about to fall over, 
and will correct our position to keep us upright.

So, it can be expected that a toy theropod will not be able to stay on it's 
feet 
very easily; at least, not without cheating a little, and using the tail as a 
brace.


Rob Meyerson
Orphan Vertebrate Paleontologist

***
The most exciting phrase to hear in science, the one that heralds new 
discoveries, is not "Eureka!" (I found it!) but "That's 
funny ..." 
-- Isaac Asimov