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Spinosaur Variation

Jaime A. Headden wrote:
>   Aside from the sail-back variation in various
> spinosaurs, with Bary being the wimp of the group and
> Spino the most flamboyant theropod _ever_, the fact
> that a more southerly spinosaur should have a shorter
> sail than a more northerly one should have something
> to say on the radiator/billboard debate. Spinosaurs
> typically really wouldn't need to display in threat,
> being the biggest around. 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. Of
> course, Sucho was still not full-grown, like Bary, so
> we do not really know the full development of the
> sails.
        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.

        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.  

Josh Smith
University of Pennsylvania
Department of Earth and Environmental Science
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