Re: ONP

["Kent A. Stevens" <kent@cs.uoregon.edu>]

Osteological Neutral Pose (n) A geometrically-defined neutral state  
of deflection, esp. for intervertebral articulations.  A neck (or  
trunk) in ONP would exhibit the characteristic curve along the axial  
skeleton due to the osteology, and define the zero state for flexion  
(e.g. dorsiflexion would be positive, ventriflexion negative relative  
to that zero point).  The degree to which ONP approximates the  
habitual rest pose of a vertebrae is not yet clear for extant, let  
alone extinct, vertebrates, but ONP appears to correspond to the  
alert-yet-inactive posture for the vast majority of vertebrates.   It  
works for chickens, horses, giraffes, and many others.  Note that  
claims to the contrary need to be supported by carefully establishing  
the ONP for a given taxon's vertebral column, then comparing its  
intrinsic curvature to the curve assumed by the vertebral column when  
the behaving animal is in an apparently alert, resting pose (which  
might require a bit of radiography).   Please see discussions in the  
publications (especially the two sauropod book chapters) on my  
website for geometric details.

http://www.cs.uoregon.edu/~kent/DinoMorph.html

Enjoy!

Kent




On Jan 19, 2006, at 12:03 PM, Jean-Michel Benoit wrote:

> Hello, honored fellow listmembers
> I must apologize if it's been explained before, but I've lost the  
> first post
> about ONP and, as the archives keep no readable trace of it (message
> truncature stuff), I wonder what it means..
> Cheers,
> Jean-Michel