Re: Sauropod Energetics (Peristaltic pumps for arteries?)

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

Guy Leahy wrote

<< If Kent's reconstructions are correct, the neutral head position  
in Brachiosaurus would have been 6-7 m above ground, similar to the  
estimated head/ground distance in indricotheres.  Although it may be  
coincidence, it's interesting to note the heart/head distance in  
indricotheres is similar to large giraffes.  Perhaps a heart/head  
distance of ~2 m represents a physiological constraint for mammalian  
cardiovascular systems to supply blood to the brain? >>

Dr. Hanns-Christian Gunga kindly estimated for me the position of the  
heart within the thoracic cavity of Brachiosaurus, which indeed would  
result in about 2-2.5 m vertical separation, based on a reconstructed  
ONP derived from the Janensch illustrations of the fossil vertebrae.

(ONP = Osteological Neutral Pose, i.e. undeflected posture of the  
axial skeleton)