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1) David, please contact me! Who are you working with in Mexico? Marisol
Montanello has access to my Master's Thesis, which has details on the specimen
Lehman and I are working on from Big Bend. If you are nowhere near her, we can
work out some way for you to have a look at my thesis. We DEFINITELY need to
get you a copy of Horner's 1992 monograph on Prosaurolophus. I would very much
like to hear from you, and I would be happy to help in any way I can.
2) As Tracy pointed out, our little Big Bend Kritosaurus looks a lot like
Kritosaurus (= Gryposaurus) latidens in the nose. I have deliberately avoided
the Mexican material, as it is likely comparable to Big Bend material (although
after speaking with Rene Hernandez at the meeting, I have a few doubts). Our
little guy is probably from lower in the equivalent section than most of the
Mexican material (as well as all of the other BBNP material), and he does not
show up in the better known, C. mariscalensis-bearing units above.
3) the Kritosaurus situation is still a little hazy in the literature,
primarily due to a lack of synthesis. Since The Dinosauria, at least, it has
been customary to regard Kritosaurus as a nomen dubium because it "lacked" the
nasals (many of us knew that nasals were present, but no one has really looked
at them). Horner, in 1992, described new material that certainly pertains to
the species, and that puts such nomenclatural issues to rest. Lucas tried to
dispute this, but Sullivan (or is it Willamson? my bad) laid that firmly to
rest in the Dinos of New Mexico volume, and actually went so far as to
strengthen the assocation of the new material with the type.
As it stands, Kritosaurus navajovius is unquestionably valid (as those who
visited my poster know, I am of the opinion that it never should have been
questioned... bloody nasocentric taxonomy!). Whether or not you consider
species notabilis and latidens (oh, yeah, and the likely
nondistinct "incurivmanus") to belong to Kritosaurus or not depends on two
Phylogeny: Horner opined that Kritosaurus navajovius is actually CLOSER to
Saurolophus osborni than is Prosaurolophus maximus, in which case the species
listed above and Navajovius would not form a monophyletic group. He thus
advocated retaining Gryposaurus for the others. This is sound reasoning, and is
supportable IF you accept his phylogeny. I have data, which I shall be
presenting in a published forum in the not-too-distant future, that supports
rejection of this hypothesis. There is even a small amount of data to support
placement of navajovius WITHIN the species currently ascribed to Gryposaurus.
Preference: So then, there is the question of "what is a genus?" I
personally don't give a flying fishhead. For me, there is NO value in retaining
a monospecific genus within, or sister to, an almost identical genus. I sink
Gryposaurus into Kritosaurus, and I refuse to apologize for doing so. They are
pretty much the same thing, with navajovius being an "extreme" notabilis, the
same way Saurolophus osborni is an "extreme" "Prosaurolophus" maximus.
Short question, long answer, old story.
Hope all this helps,