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Re: Apatosaurus: Follow up



I have alot of the relevant refs available as pdfs if
you need them, including Wilson, 1999, but also
Wedel's slight alterations. I don't have upchurch et
al's 2004 monograph though.

Denver.


--- Mike Taylor <mike@miketaylor.org.uk> wrote:

> > Date: Mon, 11 Jul 2005 08:57:49 -0700 (PDT)
> > From: Mike Limonite <taradosgon@yahoo.com>
> > 
> > While searching the web for a a site that would
> give me the correct
> > names for the different parts of a sauropods
> vertebrae I came across
> > DML posts from 2004 which had mentioned alot of
> the material that
> > was in my post making mine for the most part
> redundant (and looking
> > back at the Gilmore Monograph some of the
> information I gave was
> > incorrect). However, I still have a couple
> questions.
> 
> Hi, Mike, nice to see some sauropod discussion
> on-list.  Regarding the
> name so the laminae, the definitive paper is Wilson
> 1999, which
> established the system that's been used all but
> universally since
> then:
> 
>       Wilson, Jeffrey A.  1999.  A nomenclature for
> vertebral
>       laminae in sauropods and other saurischian
> dinosaurs.  Journal
>       of Vertebrate Palaeontology 19(4): 639-653.
> 
> Not to steal Wilson's thunder, but the system is
> actually
> astonishingly simple, once you get over the long
> names.  (Which is
> really the point of the system, and the reason it's
> caught on.)  Each
> lamina is just named after the two things it joins. 
> Spine up on top,
> centrum down below, pre- and post-zygs at the front
> and back, and
> diapophysis and parapophysis sticking out the sides.
>  So if you have a
> lamina joining (say) the prezyg and the diapophysis,
> it's a
> prezygadiapophyseal lamina (or PRDL for short).  If
> you have a lamine
> below the postzyg (i.e. connecting it with the
> centrum), it's a
> centropostzygapophyseal lamina (CPOL).  And so on. 
> Anything that
> doesn't fit into that scheme is just labelled and
> "acessory lamina"
> and swept under the carpet :-)
> 
> Second thing: if you're interested in detailed
> _Apatosaurus_
> morphology and species-identity issues, then you
> _must_ get the new
> Upchurch et al. 2005 monograph, which is state of
> the art on that
> taxon.  It's a marvellous piece of work in every
> way: ferociously
> detailed, meticulously referenced and (not least)
> beautifully
> illustrated:
> 
>       Upchurch, Paul, Yukimitsu Tomida, and Paul M.
> Barrett.  2004.
>       A new specimen of _Apatosaurus ajax_ (Sauropoda:
> Diplodocidae)
>       from the Morrison Formation (Upper Jurassic) of
> Wyoming, USA.
>       National Science Museum Monographs No.26.  Tokyo. 
> ISSN
>       1342-9574
> 
> > Also the significance of anterior projections on
> the cervical ribs
> > of _Apatosaurus_ specimens in classifying them has
> been undermined.
> 
> "Undermined" as in "wiped out"  :-)
> 
> > However, the anterior projections seen on _A.
> excelsus_ and _A.
> > ajax_ cervicals would offer a different muscle
> attachment point than
> > the ventral processes seen in _A. louisae_ and
> some _A. ajax_ and
> > _A. excelsus_ cervicals, unless anterior
> projections grow from these
> > ventral processes as the animal grows wouldn't _A.
>  louisae_ have a
> > completely different muscle structure than CM 563?
>  Which would also
> > mean that CM 563 and YPM 1980, even being of the
> same species
> > (_A. excesus_) had noticeable differences in
> cervical muscles?
> 
> That seems extremely unlikely, as the presence and
> absence of anterior
> projections from the cervical ribs seems to vary
> along all sorts of
> axes, e.g. ontogenetic or even along the neck of an
> individual.  More
> likely, the muscle attachment sites are homologous
> in all cases; just
> very hard to spot :-)
> 
>  _/|_ 
>
___________________________________________________________________
> /o ) \/  Mike Taylor  <mike@miketaylor.org.uk> 
> http://www.miketaylor.org.uk
> )_v__/\  "One hour of life, crowded to the full with
> glorious action,
>        and filled with noble risks, is worth whole years
> of those mean
>        observances of paltry decorum" -- Sir Walter
> Scott.
> 
> --
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> 



        
        
                
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