Re: Dinosaurs, Size, and Land Area

["Rob Schenck" <rs7286@albany.edu>]

----- Original Message -----
From: "Steve Salisbury" <steve_salisbury@bigpond.com>
To: "Dinolist" <dinosaur@usc.edu>
Sent: Thursday, December 06, 2001 1:22 AM
Subject: Re: Dinosaurs, Size, and Land Area


>
> ----------
> >From: "Rob Schenck" <rs7286@albany.edu>
> >To: "The Dinosaur Mailing List" <dinosaur@usc.edu>
> >Subject: Re: Dinosaurs, Size, and Land Area
> >Date: Thu, 6 Dec 2001 2:43 PM
>
> >> Most croc populations are often segregated into various size cohorts,
the
> >> most prevalent separation being between juveniles and larger males.
The
> >> ranges of nesting females and juveniles frequently overlap.  The main
> >> factor
> >> contributing to dispersal appears to be agonistic interactions between
> >> adults and growing juveniles; large crocs will often prey on
> >> intermediate-sized animals and hatchlings.  As a result of this
agonistic
> >> behaviour, intermediate-sized animals are often excluded from areas
they
> >> were able to occupy when they were smaller, and take refuge in
> > >non-breeding areas known as 'stockyards'.
> >>
> >> Steve
> >>
> >
> > what is it that keeps the stockyard animals from agressively defending
> > territory?
>
> Size and perhaps, dare I say it, intelligence.
>
> >It seems like the meek ones are forced into places that are not
> > claimed by agressive ones, the stockyards.  Where does the meekness come
> > from tho, is it a behavioural trait related to their size, meaning are
the
> > intermediate ones cowed into not being agressive, or are they non
agressors
> > to begin with?
>
> It's just a size thing.  Even if intermediate size crocs were more
> aggressive towards larger ones, I don't think it would make much
difference.
> A decrease in meekness corelates well with an increase in size.  Even the
> most agressive big male would've done it's time in a stockyard.
>

perhaps i misunderstand this phenomena.  Are the crocs waiting in the
stockyards to grow and become big enough to defend thier own private
territory, or are they in the stockyards because they are "fully grown"
(with the understanding that croc growth never fully stops but rather
approaches a limit) and are just not big enough to defend or win challenges.

are the large ones defending territory by being big; and by virtue of being
so big they go relatively unchallenged,  or by being agressive;  where being
little and agressive with someone who is big and agressive leads to
undesirable result.

> >this might be interesting because it leads me to ask, what
> > with dinosaurs being so large, is it possible that the same things
making
> > some large types agressive also affecting their appearance?  Could
> > individuals that are seperated into two species actual be "morphs" of
> > "agression dimorphism"? I'm not suggesting that this is the case for
estant
> > "crocs" of course, it should be apparent that it is not.  However, if
this
> > nascent idea is correct, it would dictate that larger crocodiles are
more
> > agressive right of the bat, and that they demonstrate some degree of
> > difference in appearance from less agressive smaller ones, at least
> > differences not related to size.  Is this ludicris or no?
>
> Um . . . not quite sure what you're getting at.
>

i am saying if larger crocs are more agressive (within their own species),
is it probable that the same holds true for dinosaurs?  And -if- it holds
true for dinosaurs, is it probable that they, having extreme size, might
also have extreme size differences, and therefore also extreme differences
in aggression.  And further, -if- this is probable, then can it be tested by
examining physical/anatomical/morphological differences between size
classes, and looking for factors that are unrelated to larger size itself,
such as if the larger croc is twice as big, but its dermal scutes are more
than twice as big or high, then this might be realted to whatever is causing
that agression, (such as higher levels of testosterone or whatever).  This
of course is meaningless if larger crocs are infact not more aggressive, and
are simply not chalenged by intermediate sized crocs.  Thats what i meant by
"agression" dimorphism", i though the analogy to sexual dimorphism was more
apparent than it is.  Of course this whole idea is rather silly, but, as i
said in the begining, at least i find it interesting, and thought it woudl
be worth a shot posting.


~R.