Consider this, however: Of all the large theropods (_Carcharodontosaurus_,
_Giganotosaurus_, _Allosaurus_, etc.) _T. rex_ seems to be the one with the
MOST massive thighs and hips. This would imply, at least as far as I can
see, that _T. rex_ could move faster than those others, because their legs
and hip structure would not allow for nearly the same amount of muscle mass
(or percentage of those muscles versus total body mass). True, on an
absolute flat-out race between the 3 dinos I mentioned above and _T. rex_,
_Allosaurus_ MIGHT win because of the lower overall body mass. _T. rex_
would come in second. I would be interested to see if John would analyze
_Allosaurus_'s speed range as well, to see if my surmise is correct.
Concerning some of Dann's points below:
Another use of _T. rex_'s massive legs could be to hold down his prey, much
like modern birds of prey do. Jack Horner, in one of his many statements
about the poor hunting skills of _T. rex_, said "Maybe he hid behind a rock
and jumped out and kicked over a _Triceratops_!". Ha-Ha, Jack - maybe
that's exactly what he (_T. rex_) did do! Then, he held the animal down
(with those legs), and bit into its back and neck to kill it.
I've also thought that maybe the huge legs on _T. rex_ would make it much
easier for the animal to raise itself up from a "prone" position to stand.
(I put quotes around prone, because I think the animal couldn't lie down
completely - probably rested on the pubis, which I think would have been
very padded).