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An Upper Campanian or Lower Maastrichtian age variable is given based on
correlated stratigraphy with the Judithian in North America. Stated this before.
Saurolophus may just as easily occur in the Campanian as easily as
*Velociraptor* crosses the Cenomanian-Campanian boundary, if the Djadokhtan
correlates are affected. As for the tyrannosaur levels, you would have to prove
the two levels permitted contemporary interchange, whereas the Nemegt does
appear to have a more basal tyrannosaur, hadrosaur assemblage. Correlated to
phylogeny, the "tarbosaurs" would be more basal than the "tyrannosauruses."
*Tarbosaurus* itself has been linked to the Horseshoe Canyon *Daspletosaurus* by
Currie (2003), and in this, would appear to have a more basal Maastrichtian
corrollary than would be afforded otherwise. This would suggest the Horseshoe
Canyon is closer in taxa and probably correllation than is the Hell Creek or
Lancian, and that the Judithian fauna correlates (including mammals and lizards)
would imply a Campanian-Maastrichtian age, rather than middle or upper
Jaime A. Headden
Little steps are often the hardest to take. We are too used to making leaps in
the face of adversity, that a simple skip is so hard to do. We should all learn
to walk soft, walk small, see the world around us rather than zoom by it.
"Innocent, unbiased observation is a myth." --- P.B. Medawar (1969)