Semi-aquatic dinos and one other question

["Demetrios M. Vital" <vita0015@umn.edu>]

Howdy,

There were a few emails onlist recently mentioning semi-aquatic dinos,
Bakker's unrevealed dinos, for instance, and semi-aquatic nodosaurs.  I am
wondering about semi-aquatic pachycephalosaurs.  Wouldn't the barrel-shaped
body and expansive gut give some added buoyancy?  Either way, I was hoping
to get some observations from more educated members of this list about that
idea.

And the other question: I was reconstructing a Stygimoloch spinifer ("was"
because I am done with it), but I never learned about marginocephalian
lips/cheeks, or the lack thereof.  I put cheeks on my S. spinifer, because
that has been the status quo for some time now.  However, I am wondering
whether they had lips or cheeks or not.  Can anyone help answer that, or
direct me to sources that can?

Thanks in advance!

-Demetrios Vital