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: Wednesday, December 05, 2001 5:19 PM
Subject: Re: Dinosaurs, Size, and Land Area


> ----------
> >From: John Bois <jbois@umd5.umd.edu>
> >Subject: RE: Dinosaurs, Size, and Land Area
> >Date: Thu, 6 Dec 2001 6:12 AM
>
> > On Wed, 5 Dec 2001 HPB1956@aol.com wrote:
> >
> >> "Dinosaur populations may have consisted mostly of posthatchling
juveniles
> ..."
> >
> > One would think that crocs would be worth looking at here.  My
> > understanding is that little crocs areculled fairly quickly.  meanwhile,
> > large crocs are immune from predation and once in that size range, exist
> > for a long time enabling a swelling of adult population.  Numbers,
anyone?
>
> I'd say crocs are what Greg Paul used for his dinosaur population
'models'.
> 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?  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?  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?

~R.



>
> ---------------------------
> Dr Steven Salisbury
> Palaeontology and Geology, Queensland Museum
> PO Box 3300, South Brisbane, Q 4101, Australia
>
> email: steve_salisbury@bigpond.com
> phone: +61 0407788660
>
> http://www.Qmuseum.qld.gov.au/organisation/sections/PalaeontologyGeology/