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Re: Spinosaurs as what?



Hello all
for a non-specialist, what is the time span of all these ages? And if no
other _Spinosaurus_ material has been found yet, it doesn't mean that it
will not be found in the future, I mean in another location (like Niger or
Morocco)
And, yes, can we get rid of this stupid racist idiot? I thought he and his
kin were extinct.
Cheers,
Jean-Michel

----- Original Message -----
From: "Mickey Mortimer" <Mickey_Mortimer111@msn.com>
To: <dinosaur@usc.edu>
Sent: Saturday, February 26, 2005 9:58 PM
Subject: Re: Spinosaurs as what?


> T. Michael Keesey wrote:
>
> >_Ouranosaurus_ was already mentioned, and _Rebbachisaurus_ had long
> >vertebral spines as well: three dinosaurs from distinct lineages
> >(_Spinosaurus_ a theropod, _Ouranosaurus_ and ornithischian,
> >_Rebbachisaurus_ a sauropodomorph) with the same trait, all living at
> >the same time and in the same place. Coincidence? Not likely.
>
> Actually, very likely in my mind.  For one thing, the taxa were NOT
> contemporaneous.  Spinosaurus is from the Cenomanian Baharija Formation of
> Egypt, Rebbachisaurus is from the Albian Tegana Formation of Morocco, and
> Ouranosaurus is from the Aptian Elrhaz Formation of Niger.  Elrhaz
> spinosaurids and rebbachisaurids are Suchomimus and Nigersaurus,
> respectively, neither of which have very high neural spines.  The Baharija
> has large theropod dorsals (Bahariasaurus?, Deltadromeus?) without tall
> neural spines.  And even if they were contemporaneous, I can't think of an
> ecosystem today where a few unrelated taxa (but not other taxa which are
> more closely related to one of the taxa in question) all evolve a trait
for
> a common purpose.
>
> Mickey Mortimer
> Undergraduate, Earth and Space Sciences
> University of Washington
> The Theropod Database - http://students.washington.edu/eoraptor/Home.html
>