Sauropod Ancestors

[Amado Narvaez <anarvaez@umd5.umd.edu>]

Before I become too guilty of perpetuating a misconception in regard to 
prosauropod/sauropod relations, can someone clarify for me how conclusive 
the evidence is that the prosauropods were NOT ancestors of the 
sauropods? It seemed natural that prosauropods of the Triassic would 
evolve into the sauropods of the Jurassic, but most of my texts indicate 
that that was not likely the case. Are there any Triassic or early 
Jurassic contenders for direct ancestors of the sauropods? 

(Note to those who have been following the dinosaur songs I've posted. I 
will probably have to revise one verse of the Plateosaurus song depending 
on responses to this question.)

Thanks.

----- Amado Narvaez
      anarvaez@umd5.umd.edu