Re: _T. rex_ strikes ( was Ceratopsian frills)

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

From: stevet@shelby.net (Stephen Throop)

 > > Note there was, once upon a time, a much larger species of wolf,
 > > _Canis dirus_, which became extinct some time ago (in human terms).
 > > It is known in great numbers from the La Brea Tar Pits. This shows
 > > that when conditions favor a larger size, a larger wolf could exist.
 > 
 > I don't know what it weighed, what its proportions were, or what it
 > ate.  I think the encyclopedia gave its length at 6 feet and the length
 > of a big modern wolf at 5, excluding tails.  I described it as "not
 > dramatically bigger."  That seemed vague enough to disguise my
 > ignorance.  

Having been to the Paige Museum (at Rancho La Brea), I would estimate
the dire wolf at about twice the mass of the modern wolf.  It still
looks disappointingly small for a "giant", I'll admit.

If I remember rightly, the dire wolf and moden wolf coexisted for a
time, so they had to have been ecologically distinguished somehow.
How, I do not know.

 > I think condors eat by checking out a lot of opportunities, not by
 > chasing off land animals.

True.  This is something they can do as long range *gliders*. A
ground animal could not manage this kind of selectivity.

 >  I would expect a hyena to be a lot more agile than a 40-foot biped.

True.  However one of my points is that the *larger* hyena is an active
predator.  It is the *smaller* hyena species that is primarily a
scavenger.  In short, the evidence seems to be that large size
ground living scavengers are not effective.

[The scavenging brown hyena is actually about the size of a small
wolf, at the largest; the predatory spotted (laughing) hyena is
much larger than a wolf, and indeed approaches a leopard in size] 

 > A giraffe is slender, but it seems too tall for sudden moves.

Not a good comparison to a theropod.  A tyrannosaur's proportions
are those of a "fast" runner, a giraffe is not particularly designed
for running.

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

The peace of God be with you.