Re: forelimb posture

["Allan Edels" <edels@email.msn.com>]

Scott, et al:

    My post was based on personal observation of several ceratopsian mounts,
some of which I know from long association.  In addition, I refered to
Dodson and Farlow's paper in the DinoFest International Symposium (of
1996) - published 1998.  In the paper, they discussed the 'slight-sprawl',
and they conferred with Greg Paul on several of his objections, which they
seem to have eliminated or reduced - at least to their satisfaction (No word
on whether GSP agreed with their assessments).

    My assumption, not having attended the SVP in NYC (or asking Peter or
Jim directly), is that Peter was unwilling to debate anything about the
postures of sauropods and stegosaurs without direct examination of the
specific structures involved (such as the flange on the humerus, etc.), in
comparison to the ceratopsians.  Perhaps he has done so since.

    My impression is that the 'slight-sprawl' would have the humerus about
20-30 degrees off of perpendicular (to the ground), with the radius and ulna
angling back nearly as much - but slightly less than the upper forelimb.

    Hope this info helps, perhaps Jim Farlow can elaborate.  (If he can be
caught before the SVP meeting year) :-).

        Allan Edels

-----Original Message-----
From: Scott A Hartman <ottscay@uwyo.edu>
To: Allan Edels <edels@email.msn.com>
Cc: PATG@vax2.concordia.ca <PATG@vax2.concordia.ca>; dinosaur@usc.edu
<dinosaur@usc.edu>
Date: Friday, September 25, 1998 9:10 PM
Subject: Re: forelimb posture


>Before this discussion goes much further, how do you define "minor
>sprawl"?  "Semi sprawling" is the posture adopted by alligators during
>their high walk.  Ceratopsians certainly did not do that.  On the other
>hand, they also didn't have columnar limbs that
>were as stock straight as graviportal sauropods or elephants.
>     Who on the list attended Farlow and Dodson's talk on ceratopsian limb
>posture at SVP in NY?  Correct me if memory fails, but I believe that
>Farlow's exact words towards the conclusion of the talk were: "When we
>began this project, I thought the trackways could be reconciled with a
>semi-sprawling gait.  Well, as you've seen, if yoy play around with the
>numbers, you can get an animal that is thinking about being
>semi-sprawled."  After this, GSP pointed out that the anatomical features
>that were cited as being incompatible with an upright ceratopsian posture
>could be found in sauropods and stegosaurs, neither of which are thought
>to have had any trouble walking upright.  Farlow replied that he would
>defer that question to his coauthor, and asked Dr. Dodson if he'd like to
>answer it, to which he replied "No."
>     It sounded to me that within the realm of scientific debate, they
>were waving the proverbial white flag.  Did I miss something?
>
>Scott Hartman
>