Re: Spinosaurus sail

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

Waylon Rowley (whte_rbt_obj@yahoo.com) wrote:

<The fact that we have at least 3 juvenile/subadult spinosaurid
specimens is, at least to me, suspicious. Is there any
possibility that the lack of fused neurocentral sutures is
merely an adaptation these animals may have evolved to cope with
lateral/anteroposterior stresses placed on the neural spines?>

  This works for only *Spinosaurus*: both *Baryonyx* and
*Suchomimus* possess fused neurocentral sutures for enough
vertebrae to suggest that they, like most tetrapods, have
vertebrae that fused from the neck back, but also the tail
forward, leaving the back and sacrum to fused last. One sees
this in most of the specimens if one looks closely enough.

  It is curious that the majority of spinosaurid material is
subadult. Means in an ecology, if we even thought that
collection biases were minimal, that 1) adult animals were
really, really big and 2) they were very, very rare.

=====
Jaime A. Headden

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

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