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Re: *Archaeopteryx* Is Not A Penguin



I wrote:

<<...to alter the ability of passivity?>>

  James Cunningham (jrccea@bellsouth.net) wrote:

<I'm sorry, I don't know what that means. Would you elaborate
please?>

  The ease through which an animal moves through its medium. The
more viscuous, for instance, the less passivity that animal will
have, unless it alters is body form -- penguins have greater
passivity because they're body shape is bullet like in aspect,
and this morphology is mimicked in the body of other aquatic
birds and mammals, such as whales and dolphins, and
hesperornithiforms.

<Again, I'm not sure that I understand. Are you saying that
penguins are descended from flighted birds that had a lower
aspect ratio? If so, I don't know - phylogeny isn't my thing.>

  Penguins pertain to the restricted group Spheniscii, which I
beleive stems from within the Tubinares, parallel to
procellariiforms (tube-nosed birds). By all phylogenies, the
ancestor of the penguin must have been flighted. In answer to
David's state, yes, they also bear remiges [brachial], but
apparently not retrices [caudal] feathers, but the retrices are
very short and stiff, and act to control the tension of the
trailing edge. To my knowledge. I've not examined penguin
biology too much, but should, as I've usually been concentrated
more of my recent avian studies on skeletal morphology and
cranial mechanics in tetrapods.


=====
Jaime A. Headden

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

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