Re: paraphyletic Dromaeosauridae (Variraptor)

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

  One of the interesting things about *Variraptor* is that the
cervicodorsals are highly reminiscent of those of *Achillobator* (and
apparently *Utahraptor*), and as Mickey pointed out, they also resemble
the cervicodorsals of segnosaurs and oviraptorosaurs and *Avimimus*,
indicating the form of the vertebrae are plesiomorphic. The form of the
bones are not found in *Velociraptor*, *Deinonychus*, or the fluffy IVPP
specimen fluttering around on the http://www.AMNH.org website, and as such
it is not a stretch to consider the form to be plesiomorphic within
Maniraptora. This may indicate that the larger forms were outside the
"typical" Dromaeosauridae. The more basal forms appear to have been the
most avian in form, and that the derived dromaeosaurids were the least
avian. This seems ever more poignant with the analysis of Xu et al., 2000,
where the phylogeny can be adapted to suit this explanation:

  --+--*Microraptor*
    `--+--*Sinornithosaurus*
       `--+--+--*Velociraptor*
          |  |   `-?-"Ichabod"
          |  |--*Deinonychus*
          |  `--*Saurornitholestes*
          |-?-*Pyroraptor*
          `--*Dromaeosaurus*

  *Pyroraptor* may actually be a valid velociraptorine, but
*Dromaeosaurus* appears to be one of the most derived, rather than basal,
dromaeosaurids. I doubt we'll be done with these. Two more taxa are coming
from Laurasia based on unique skulls for the most part, and they may
resolve problems, or creat new ones. Nonetheless, funny animals.

=====
Jaime A. Headden

  Little steps are often the hardest to take.  We are too used to making leaps 
in the face of adversity, that a simple skip is so hard to do.  We should all 
learn to walk soft, walk small, see the world around us rather than zoom by it.

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