Neutral (i.e. semi-supinated or non-pronated) hands and quadrupedalism

[Himmapaan]

In a word, yes. 

(Though it wouldn't yet be 'supinated', as that means the palms facing upwards. Yes, I'm afraid I really am hung up on this.  )

[amargasaurus cazaui]

In a word, yes. 

(Though it wouldn't yet be 'supinated', as that means the palms facing upwards. Yes, I'm afraid I really am hung up on this.  )

Thanks for explaining it for me. I am uncertain wether to leave the hands pronated or to adjust them to a neutral position, but am leaning more daily to altering it so the hands display a semi supinated conditon. If I can alter the way they are attached to allow it to be adjustable that would be my first choice.
You stated radius or largest bone over ulna or smaller bone, as I understand it.This should be easy enough to change on the mount, although it would be more permanent unless I can figure out something simpler

[amargasaurus cazaui]

As I get closer to taking the effort and work to redo the hands of the Psittacosaurus, I realize there is a lingering question in my mind which I am certain either Himmapaan or Horridus, or perhaps Gryph can help with here. As the mount was created the hands are completely pronated. I would like to move them to what is considered a more natural postition which Niroot was kind enough to explain would need to be done at the elbows rather than the wrists. My remaining question is...would the hands be totally netural or facing one another then? Or slightly angled towards the up as well as inwards, or angled downwards and in? Thoughts? I am not certain what is the correct angle for the dinosaur. If he were indeed able to come down on all four feet, I wonder if the hands would be completely neutral or more angled upwards as well as in?

[Himmapaan]

The forearms themselves (and consequently the hands) ought to be completely neutral, palms facing each other. But if you wanted, you can actually angle out the elbows so that the angle of the hands as parallel to the ground can vary slightly. If that makes any sense at all...

[DinoToyForum]

Just a reference for some of the terminology used in this thread: 



'Soup'-inated, as if serving soup.
Pro-nated, as if a pro basket ball player.
You've got to have a system. 

[amargasaurus cazaui]

Just a reference for some of the terminology used in this thread: 



'Soup'-inated, as if serving soup.
Pro-nated, as if a pro basket ball player.
You've got to have a system. 

I like that chart, it simplifies alot of the questions I have asked. I smiled at the word choice you used as well because in writing an article from the dinosaur's point of view, I was writing about this particular issue, and had the dinosaur state.....
"Wait...I am a plant eater...nothing I have should be soup-a-nated, and I honestly prefer being salad-ated. I don't really even like croutons."

[wings]

@ amargasaurus cazaui
Not sure whether you've read this before but I think this article ( http://download.bioon.com.cn/view/upload/month_1004/20100401_c53c480957da4b866ebd7P3kLPbdcisi.attach.pdf ) explains the reasoning of hand/arm rotation on advance ceratopsians quite well which in turn would probably apply to quite a number of archosaurs also.

[amargasaurus cazaui]

@ amargasaurus cazaui
Not sure whether you've read this before but I think this article ( http://download.bioon.com.cn/view/upload/month_1004/20100401_c53c480957da4b866ebd7P3kLPbdcisi.attach.pdf ) explains the reasoning of hand/arm rotation on advance ceratopsians quite well which in turn would probably apply to quite a number of archosaurs also.

That one takes some slow reading and careful thinking, to grasp. Still the argument being made, based on an articulated find is hard to dispute. I am enjoying reading these, welcome to the forum and thanks

[wings]

Perhaps it is easier to grasp the idea from this podcast ( http://ia600708.us.archive.org/13/items/AlongTheBackbone-Episode7HandsDownOrWhyVelciraptorCouldNotOpen/ATB-Episode7-Bonnan.mp3 ).