Re: Spinosaur Variation

[smithjb@sas.upenn.edu (Joshua Smith)]

Jaime A. Headden wrote:
> 
> I wrote: (Jaime first)
> 
> <<The rarity of fossils other than teeth in Africa for
> these critters would suggests a relative low density
> population any given area. Gadoufaoua was certainly
> more populous spinosaur-wise than Baharija (Egypt) or
> the Tafilalt and Kem Kem (Morocco), yet we have only
> one good specimen. Very wet, temperate, very like the
> southern US in summer at its more agreeable times. The
> north was both cooler and more forested, being able to
> support giant titanosaurs as well as bigger spinosaurs
> and carnosaurs/abelisaurs/whateverosaurs. This
> suggests a less radiating role in the function of the
> sail.>>
> 
> 
> Josh Smith replied, putting his granite gavel down
> hard on the table:

JOSH (second): Granite gavel.  Nice one.  I rather like that.
> 

>JOSH (first):   
        First:  Considering that the records at the Egyptian
> Geological Survey in Cairo only record three German
> expeditions that went to Bahariya (the Oasis, where
> the type locality of the formation crops out) and that
> only one of them was actually focused entirely on the
> Bahariya Formation itself, and considering that most
> of the data regarding these German expeditions failed
> to survive the 1940s, and considering that there are
> no active dinosaur paleontologists in Egypt today and
> considering that no one (almost--see forthcoming
> posting) has played in Bahariya in 50 years, I don't
> really think we should be making claims about the
> theropod population density of the paleo western
> desert.>
> 
> JAIME (second):  It was my understanding that the Baharija was spread
> out over the Egyptian, Tunisian, and Algerian Tethyan
> coast in the Berr to Apt-Alb. Fossils ascribed to
> Spinosaurus are strewn across much either
> contemporaneous or above- or lowere-lying strata, but
> I did not realized that the Baharija was best confined
> to the type locality. My appologies.

JOSH (second):  I don't think that I was as harsh as granite gaveling, 
but whatever.  Appologies not necessary.  The point that I was making 
(beating up on, whatever) was that fossils are only ascribed to 
spinosaurs right now and nothing is currently known about Bahariya 
anymore, so we don't have any idea about what the theropod population 
density of Bahariya is.  You specifically mentioned Egypt, and what I 
said about the Bahariya in Egypt is correct.  We don't have enough data 
to make any comparisons about theropod density within the Cenomanian of 
Egypt in comparision to anywhere.  That is all.


>JOSH (First): 
> <Second: What is the deal with everyone running around
> saying that the western desert was cool and forested?
> What little paleoclimatic data exists for that area
> (and it isn't bloody much, folks) is highly 
> speculative at best. I didn't see a lot of stuff that
> I would call data to supported cool, temperate
> forests.>
> 
> JAIME (Second):  For my part, it was from my understanding that the
> Tegama Group, Cameroonian formations I forget the
> names (or name) of, and the Kem Kem and Tafilalt were
> mudstones and siltstones, with fauna depicting a very
> estuarine and partially lacustrine environment,
> coupled with the estimated mean temperature of the
> region and its equatorial location at the time period,
> that it was similar to the Lousianan, east Texan,
> Alabaman to Floridian environments. I read these, in
> Sereno et al. (1994, 1996, 1998), Russell (1996), and
> Taquet (1998), and thus fell to my perceptions that
> Everglades and Okavango Delta were not too far from
> what these places may have been like. When I said
> "temperate ... forested" I did not clarify my meaning,
> and confused the term "temperate": "equitorial" or
> "semi-equitorial" (compared to today) are better terms
> and are what I was thinking of, and forested as in
> broad stands of trees, not like conifer forests of
> Canada, Europe, and America. The Moroccan habitats
> would have to have some great forests or such to
> support the *Aegyptosaurus* that tromped around out
> there.

        JOSH (Second):  My point was not an attack at you but a criticism 
of the paleotemperature estimates for these areas, which I think are 
crap, regardless of what Sereno and Russell have cited.  As for the 
forests, again, there are not a lot of data to suggest one sort of major
macrofloral assemblage or another.

        Sometimes it seems as though Holtz and I could just resubmit old 
messages.  Our main points are generally the same.  Mine: where the hell 
are the data to support that conclusion?  Tom's: Will you all bloody well 
wait until the damn thing is published already?!

Does that help at all, Jaime?

-Josh


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Josh Smith
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