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Re: Ceratopsian gait
On 03/22/98 20:31:16 you wrote:
>
>
>I have heard a few people use this argument to totally discredit Johnson and
>Ostrom. This may
be going to far. The experiment that Johnson and Ostrom came up with was to
make models of the
shoulder and forelimb bones, and articulate them from there. Pl
>ease note that they ran their experiment using ONLY these bones (the rib cage
>never entered the
equasion). How they articulate the shoulder on the rib cage is irrelevant to
their results.
However, I do agree that they placed the limbs to high on the rib
> cage.
>
It was a good test, but one that I think was carried out the wrong way. The
only way, IMHO, to
find he range of movement of the arm is to have the foot planted on the ground
at the width of
the Tetrapodosaurus front foot. Then move the body forward and aft, that way
the total forward
walking movement would be known of the leg. The way Johnson and Ostrom did it
was to just move
the humerus with the ulna, radius and foot dangleing. I brought this up in my
Dinosaur World
article.
Tracy