re: T. rex

[Stan Friesen <swf@tdat.ElSegundoCA.NCR.COM>]

 > I am impressed by studies suggesting T. rex ...`
 > had insufficient femoral bone mass to
 > sustain running speed (e.g. R. M. Alexander, "How dinosaurs ran" in
 > Scientific American, --I'll dig up the date and page if anyone's
 interested).

I am.

 > If this is correct, then its unlikely they were (at least) pursuit
 > predators.  Given that ceratopsians _could_ gallop by the same
 analysis,
 > as could hadrosaurs, T. rex must have been either an ambush predator
 > or a scavenger.  THe latter seems more parsimonious to me, given the
 > size (and smell?) of the beasts.
 >
What large terrestrial scavengers do you know of?
I know of none.  I know of some large *aerial* scavengers,
the condors), but no really large non-flying terrestrial
scavengers.  The largest land animal I know of that is primarily
a scavenger is one of the smaller species of hyena.  (The large
hyena you usually see in documentaries is as much a hunter as
the lion, or more so).

I do not believe that it is *possible* for a non-flying land
animal to be a scavenger at the size of T. rex and its relatives.

Also, scavenging does not explain the *strength* of the arms.
If the arms were small and *weak* that would be one thing,
but they are not.


I would like to see the bone mass studies verified before I
drew any radical conclusions from them.  But ambush hunting
is certainly a possibility.  [Though some tyrannosaurs *were*
fast runners, as they had the leg proportions of runners].


swf@elsegundoca.ncr.com         sarima@netcom.com

The peace of God be with you.