Re: Triassic Sauropods

["Matthew Bonnan" <mbonnan@hotmail.com>]

I had written:

<< well-developed femoral condyles which is a
 condition we only observe in titanosaurian postcrania >>

To which Dinogeorge responds:

"Isanosaurus has well-developed femoral condyles. How is this feature
titanosaurian?"

Right; I was just being hasty.  What I should have said was well-developed 
and DISTINCTLY SEPARATED condyles.  Distinct how?  Distinctly separated by a 
large and U-shaped space between the lateral and medial condyles of the 
femur in anterior view.  The medial condyle is actually higher than the 
lateral condyle (see Wilson and Carrano, 1999; or Borsuk-Bialynicka, 1977).  
Furthermore, titanosaurian femora have a distinct lateral bulge (lesser 
trochanter) and femoral shafts that are deflected medially (Wilson and 
Sereno, 1998; Wilson and Carrano, 1999).  A good example of this is seen in 
the photographic plates of Opisthoscoelicaudia in Borsuk-Bialynicka (1977).

You don't see this morphology in other sauropods, hence my suspicions about 
the titanosauriform affinities of the Bothriospondylus femur.

Matt Bonnan
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