RE: kritosaurus?

[jonathan.r.wagner@mail.utexas.edu]

Responses:

     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 
factors:
     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,

    Wagner