Synapsid-diapsid split. Falsifiable?

["Larry Febo" <larryf@capital.net>]

OK Dr. Holtz. I`m looking for negative evidence here. The only thing I come
up with is some kind of comparison with the anapsida as an intermediate
link. If diapsids did occur later, from anapsid ancestors, then there has to
be a closer link between them and the anapsids than between them and
synapsids. The only thing I can think of would be  a DNA comparison. Surely
someone has performed this already, no? If so, is it admissable evidence???
Maybe some other physiological comparisons can be made as well.