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RE: T rex brooding



Thank you, Allan. :-).  It makes one wonder if tyrannosaurs might have had a
life style anything like modern predators with definite dimorphism, such as
the hyena?  

On the subject of huge, predatory dinosaurs: a fellow "dinophyle" here
recently mentioned a "mount" of a giganotosaurus somewhere here in the
states.  Perhaps Philadelphia? I wasn't aware that sufficient specimens had
been recovered for anything like a reasonable mount of this animal.

Dwight 

        -----Original Message-----
        From:   Allan Edels [SMTP:edels@email.msn.com]
        Sent:   Thursday, August 20, 1998 9:50 PM
        To:     dinosaur@usc.edu
        Subject:        Re: T rex brooding


        Dwight:

            I don't know if dimorphism is an *accepted* fact in
tyrannosaurs.
        However, I have been working my way thru the 1996 DinoFest
International
        publication (printed this year for DinoFest here in Phila.).  Neal
Larson
        (BHI) has a paper which lists all the _T. rex_ specimens (21 at the
time)
        and he sees definite sexual dimorphism.  There are robust specimens
with
        relatively smooth skulls (those that have skulls) - these are
presumed
        female.  Males are presumed gracile and have rugose skulls.  And he
has one
        presumed male specimen ("STAN") that shows an additional caudal
chevron
        immediately behind the sacral vertebrae - as in crocodiles (the
first caudal
        chevron - used for penile retraction).  He surmises that female _T.
rexes_
        will not have that chevron - not yet tested.  There is also a paper
by Ralph
        Chapman, Dave Weishampel, Gene Hunt, and Diego Rasskin-Gutman that
        summarizes Neal's findings on _T. rex_ and others' on other
dinosaurs
        ("Sexual Dimorphism in Dinosaurs" - I looked it up).

            Allan Edels


        -----Original Message-----
        From: Stewart, Dwight <Dwight.Stewart@VLSI.com>
        To: 'edels@email.msn.com' <edels@email.msn.com>; dinosaur@usc.edu
        <dinosaur@usc.edu>
        Date: Wednesday, August 19, 1998 4:56 PM
        Subject: RE: T rex brooding


        SNIP
        >IS
        >dimorphism an accepted fact in tyrannosaurs?  I'm NOT disputing it,
I was
        >just wondering how much scientific evidence there is for it?
        >
        > Dwight