Re: New in JVP

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

Jim Cunningham (jrccea@bellsouth.net) wrote:

<If from an adult Qsp, a 14 inch CV5 would equate roughly to a 4.35 foot neck
and a span of 14.2 feet, more or less. a 14 inch CV6 would equate roughly to a
5.04 foot neck and a span of 16.45 feet more or less.>

  I've read the paper, now. Henderson and Peterson write (pg. 192):

  "BMR P2002.2 resembles a putative fifth cervical of *Quetzalcoatlus* sp. from
   the Maastrichtian Javelina Formation in Texas (TMM 42180-2), although BMR
   P2002.2 possesses an apparently more robust hypapophyseal process (which
   restricted ventral deflection of the neck) at its anterior end. We do not
   attribute much importance to this difference, however, owing to the
   substantial deformation suffered by both specimens. However, BMR P2002.2 is
   relatively gracile by comparison with the Texas material. BMR P2002.2 is 348
   mm in length (exapophyses to caudal condoyle) whereas the cervical of
   *Quetzalcoatlus* sp. is 394 mm long. BMR P2002.2 is severely crushed
   transversely and at midlength is only 5 mm thick. The corresponding
   measurement of the dorsoventrally crushed TMM 42180-2 is 34 mm. The
   distortion complicates comparison, but assuming a near circular cross
section
   of both vertebrae, the diameter of the uncrushed Burpee Museum vertebra
would
   have been about 18.25 mm at midlength whereas that of TMM 42180-2 was about
   30.5 mm. The slenderness of BMR P2002.1 is also reflected by a transverse
   diameter across the prezygapophyses of 22.25 mm compared to an estimated
   width of &#8764;38 mm in the cervical of *Quetzalcoatlus* sp. (only one
   zygapophysis is preserved in the specimen, and the anterior end of the
   vertebra has been expanded transversely by crushing, preventing precise
   measurement of its width). A comparable disparity in width exists at the
   posterior ends of the specimens, but distortion precludes accurate
   measurements. It seems unlikely that the difference in width between the two
   vertebrae would have been eliminated by an increase in length of the BMR
   P2002.2 specimen to equal that of the fifth cervical of *Quetzalcoatlus*
sp."

  Thus Jim's surmise of generally a 5th cervical is borne out by the authors of
the paper. They state they studied the composite cervical series at the Texas
Memorial Museum, the same specimens Jim has, so it's no surprise there. The
crushing of the vertebra has collapsed the internal camarae so that only the
extremely thin walls of the bone define the width throughout most of the
vertebra.

  Cheers,

Jaime A. Headden
http://bitestuff.blogspot.com/

"Innocent, unbiased observation is a myth." --- P.B. Medawar (1969)

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