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Re: Family Nemegtosauridae



In a message dated 4/9/99 2:45:12 AM EST, A.Yates@zoo.latrobe.edu.au writes:

<< It has almost certainly
 evolved on multiple independant occasions. There are at least three,
 probably six such instances in sauropod phylogeny. They include the
 euhelopodids (which becomes two instances if the family is not monophyletic
 and Euhelopus is a somphospondyl), advanced diplodocimorphs and
 Camarasaurus. Phuwiangosaurus becomes the fifth if it is correctly placed as
 a basal titanosaur and Op. is of cousre the sixth if it is a derived
 titanosaurid. >>

Try to imagine sauropod phylogeny with neural-spine bifurcation as occurring 
>just once<, but in several stages, starting with the anterior dorsals and 
posterior cervicals, and then progressing up the neck and down the back. Much 
more straightforward.