Re: How are columbiformes (doves and pigeons) related to psittaciformes?

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

Tim Williams (twilliams_alpha@hotmail.com) wrote:

<The Mayr (2000) paper quoted by Mickey also repeats Mayr's previous 
objections to referring the parrot-like beak fragment from the Lance 
Formation to the Psittacidae. This would mean that the strikingly 
parrot-like characters in the Late Cretaceous lower jaw fragment (e.g.,
K-shaped neurovascular canal, very concave symphysis) would be the result
of convergence. (Or the specimen was reworked, although I don't want to
pooh-pooh the stratigraphical work of the folks who unearthed the
specimen).>

  What ARE Mayr's objections to this specimen? I am HOPING this isn't
based solely on the stratigraphic location....

  I've gone over this specimen thanks to Clarke and Stidham, and for some
reason, I can't find a reason why it's NOT a psittacid or even
psittaciform jaw bone. Even if it were reworked from Paleocene or Eocene
sediments, and barring the "jarring" idea of such a long lineage prior to
the "un-parrot-like" psittaciforms from Messel of more advanced
crown-group parrots, this would still be an incredible find. Supposed
caenagnathid synapomorphies are found in crown parrots as well, and this
does not absolve the avian features of the jaw that caenagnathids lack but
the Lance jaw possesses.

  Cheers,

=====
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.

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


        
                
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