Re: Another anatomy question

["Jaime A. Headden" <qilongia@yahoo.com>]

  For clarification's sake to something Ray Stanford wrote, the neural arch is 
every part of the
vertebra that is not the centra, and includes the neural pedicels and all 
apophyses (neurapophyis
[neural spine], diapophyses, parapophyses, and zygapophyses, and in birds, the 
hypoapophysis).

David Marjanovic (david.marjanovic@gmx.at) wrote:

<<Because of the reference to the centra lying "...deep within the body...", I 
suspect David may
have really meant to say neural SPINES, instead of neural arches.>>

<Thanks, but I am speaking of the... AFAIK they're called the pedicels of the 
neural arches. It
looks like the centra have sunk into the trunk, or the entire upper and middle 
parts of the neural
arches, with the ribs, have been pulled dorsally.>

  This is more of a matter of the pedicels becoming taller, and the transverse 
processes becoming
dorsally deflected, causing the rib articulations to be more dorsally 
positioned relative to other
ornithischian (even ceratopsian) or sauropod dorsals. This space is used 
internally to house the
kidneys, caudal/dorsal extent of the lungs, and internal musculature. Check 
your comparative
anatomy, David. Stegosaur ribs are broader at the base, then the shafts deflect 
ventrally. This
abrupt shift in form of the ribs, I believe, do not have an explanation.


=====
Jaime A. Headden

  Aaaaaaaaaaaaaaaaaaaahhhhhhhhhhhhhhhhhhr-gen-ti-na
  Where the Wind Comes Sweeping Down the Pampas!!!!

__________________________________________________
Do You Yahoo!?
Listen to your Yahoo! Mail messages from any phone.
http://phone.yahoo.com