Re: Running T. rex

["David Marjanovic" <David.Marjanovic@gmx.at>]

> >    I've just heard Olivier Rieppel say on the radio  that Sue was unable
> >to run, that ?she could only walk. How come?   Have I listened correctly,
> >is ?she 13,5 m  long?   Thanks in advance for answers.  :-)
>
> I just asked Olivier about this, and he responded with "I was on the
radio?
> When?"

Not live, of course. Austrian radio, so Ö1, probably, today, just before I
wrote.

> But to answer your question - a lot of it depends on what you mean by
> "run."  Work by Matt Carrano, John Hutchinson, and others suggests that
> suspensory locomotion (i.e. running in such a way that both feet are off
> the ground at the same time at some point in the gait) would have been
> unlikely.  If we define "run" that way, then T. rex may not have been a
> runner.

He didn't say "run", he said convolutely "couldn't run at such speeds that
it would have been necessary that both legs were at any time simultanously
off the ground" (not a literal quote, he was speaking German).

Why is this considered unlikely?