Re: "armoured" spinosaurs (and Stromer's numbers)

["Jaime A. Headden" <qilongia@yahoo.com>]

Brett Booth (brettbooth@worldnet.att.net) wrote:

<I ... believe that the Spinosaur sail is actually the sail of an old
Oranosaurus. The sails are just too similar to me, and until a Spinosaur
skull with back and sail elements are found I'm not a believer.>

  Gross anatomy does not support this. Centra in *Spinosaurus* dorsals are
opisthocoelous, and only in the last two or one vertebrae do they become
platycoelous. Iguanodontian dorsals are, for the most part, between
platycoelous and amphiplatyan, as in *Ouranosaurus*. The centra are also
spool-shaped in spinosaurs, but much more attenuated ventrally in
iguanodonts, looking almost tear-shaped in section across the middle of
the vertebra. Slight pleurocoelous depressions are present in anterior
vertebrae as well, lacking in nearly every ornithischian (I'd say every,
but I'm not counting my chickens before they're hatched; plus, I haven't
done a conclusive survey). The neural arches are also, for the most part, 
different in the extent of infradiapophyseal laminae, and the depth of the
pockets between them. Overall shape of the spines differ slightly in the
general parallel-ness of the cranial and caudal spinal margins, lack of
paired pre- and postspinal laminae, and lack of the basal cranial--caudal
expansion (which may have been the true epaxial muscular anchor in
*Spinosaurus*), not the distal end, as seen in *Ouranosaurus*, but not
*Spinosaurus aegyptiacus* 1912-VIII.

  BTW, what is the proper designation for the specimen allocation for
Stromer's Münich specimens? The München material being destroyed, was it
actaully allocated to a "proper" museum collection, and does this musuem
or repository have an abbreviation or can one be formed to suit the
numbers given them? As I understand it, they are field numbers (date and
located specimen) rather than repository catalogue numbers. However, as
the only numbers by which we have for them, they are the cited numbers. I
can't recall if published cites for the numbers include abbreviations or
just the Münich museum's lable followed by the numbers assigned. Much help
will be appreciated.

<Suchomimus and Baryonyx have elongated nueral spines but they seem to be
over the hips. I think a Spinosaur with a large sail over the back and
long arms and skull would be a little too front heavy.>

  They said that for *Tyrannosaurus*, too. However, basal tetanurines have
longer tails, and would have been as suited to balancing. Presuming a
fat-storage as some favor would only add weight and make the animal much
more heavier. However, the skull is very narrow and I do not beleive the
skull was any heavier or more topple-likely than *Allosaurus* and it's
longish neck compared to somthing like *Tyrannosaurus* and its huge skull
(though lighter relative to volume than *Allosaurus*' was, apparently.

=====
Jaime A. Headden

  Little steps are often the hardest to take.  We are too used to making leaps 
in the face of adversity, that a simple skip is so hard to do.  We should all 
learn to walk soft, walk small, see the world around us rather than zoom by it.

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