Re: _T. rex_ strikes ( was Ceratopsian frills)

[stevet@shelby.net (Stephen Throop)]

Stan Friesen wrote:

> > I think the physics of a wolf's attack make a larger size undesirable.
> 
> If it did then they would *be* larger.

We agree.... I think?

> 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.  

>  >  Still, I would have expected scavengers to look more agile and have
>  > more menacing arms.
> 
> Actually, most scavengers are rather odd looking.  The largest
> scavengers I know of now are the brown hyena (*not* the larger spotted
> hyena, which hunts), and the two species of condor.  Neither is what
> I would call particularly agile.

I think condors eat by checking out a lot of opportunities, not by
chasing off land animals.  I would expect a hyena to be a lot more agile
than a 40-foot biped.

> Also, for its size _T. rex_ looks *incredibly* agile - it is about
> as gracile (slender) as it is possible for a 5 ton animal to be.

Maybe "agile" isn't the word I want, but it's the only one I can think
of.  I mean the ability to change motion abruptly.  For example, tall
basketball stars are fast and coordinated, but short players have become
stars because they can make more sudden moves.  I call that agility. 

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

A tall, slender runner may have the efficiency to excel in marathons,
but a shorter, stockier runner may be a faster sprinter.

Among 5 ton animals, I'd expect _Triceratops_, with its short, muscular
legs, to be much better at quick moves and short sprints than _T rex_. 

Thanks for your remarks.

Stephen Throop