ceratopsian gaits

["Bonnie Blackwell, x 3332" <bonn@qcvaxa.acc.qc.edu>]

I have a comment and a question on this debate:
1.  Didn't someone recently find a ceratopsian with much better preservation
that showed the only way to reconstruct the limb was with an erect posture
and no bowleggedness?  I seem to recall that from discussions last spring
or summer.

2.  I was recently at the AMNH with a friend whom I toured through the 
dino halls.  We looked long and hard at both the ceratopsian mounts and 
the others that still maintain the old bowlegged stance.  Several things
became very obvious to me:
a.  Most of the bones in all the displays show evidence that indicate the
articular surfaces were severely weathered prior to fossilization, esp.
the Apatosaurus.  This means that it is much more difficult to interpret
the correct positioning for the joints because the articular surface is
lacking in lenticular bone.  Some of the bones look like they may have lost
as much as 25-75% of the cancellous bone in the epiphysis.  
Lacking the cartelage between joints also makes it more difficult,
esp. for knees, wrists, and ankles. 

b.  My friend commented that he did not see how these animals could sleep
unless they were able to lock their knees like most ungulates can do.
This is something that I have never heard anyone discuss in reference
to the stance controversy.  But to me it suddenly made perfect sense.
If you have a large animal that weighs more than a few hundred pounds,
sleeping on the ground is not a good plan, esp. with T. rex around to 
hunt you down.  Therefore, it makes sense to lock your knees and sleep
standing up.  I would then argue that maybe all the herbivorous dinosaurs
likely had that option.  

I know that Martin Lockley had something at the Purgatory River site
that he thought was a resting "trace" - a small puddle shaped
depression maybe 2 m in diameter and 15-20 cm deep (it's been
8 years since i saw it), but there was no way to infer that it
was a sauropod resting spot, and would have been more suitable
for a much smaller animal like a theropod.  

Therefore, 2 more questions:
3.  Does anyone know of any other resting traces?  Are any large enough
to be matchable with any large herbivorous dino?
4.  Does anyone know of any sources that discuss dino sleeping 
behaviour?  Would locked knees and elbows be a physical possibility for
any dinosaurs?
thanx
b

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Bonnie Blackwell,                               bonn@qcvaxa.acc.qc.edu
Dept of Geology,                                (718) 997-3332
Queens College, City University of New York,    fax:  997-3349
Flushing, NY 11367-1597