Re: The Torso Tilt and Stiff Tails .-- Function in Locomotion

[JAMES ARONIS <Apollo@MLink.net>]

In regards to these anatomical modifications, would bipedal dinosaurs be
considered more efficient runners than ratites, or less? Does the tail lend to
superior balance, or do these compensations you mentioned that evolved due to
the atrophied tail? My main concern in this particular topic regards the
ultimate speed possibly reached by the ornithomimid dinosaurs. It has always
been an area of interest to me.

Thanks.

"Demetrios M. Vital" wrote:

> Ostriches have to sacrifice most of their femur for balance to compensate
> for the lack of a tail.  The muscle structure as well has changed,
> especialyl with the lack of the huge caudofemoralis.  Thus I have read that
> ostriches are not as good counterparts to dinosaurs as often perceived.
> Also, ostriches walk only on the distal ends of their phalanges, whereas
> dinos didn't have this tip-toe stance.  And if you knew all of that, sorry
> for taking up your time :)
>
> But, like I said, the caudofemoralis changes a lot of things, and I
> envision the tail shifting laterally over to the side of the leg touching
> the ground, and then back, with each step.  So not only does musculature
> cause it to shift left and right, it shifts for balance.
>
> Hope this helps,
>
> Demetrios
>
> On 16 Jul 2001, Buckaroobwana@aol.com wrote:
> > Greetings all,
> >        Just out of curiosity, what would happen to the long tails of
> > theropods while walking? Whenever I visit a zoo, I make it a point to
> observe
> >
> > the ostriches walking. I imagine theropods walking in a similar manner,
> but
> > what the tail would do puzzles me. Would it remain in a fixed position?,
> or
> > would leg muscle action cause it to move back and forth?
> >
>
> >
> >  Thanks,
> >
>
> >
> >              Brian Buck
> >