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Re: birds and avians again



George Olshevsky (Dinogeorge@aol.com) wrote:

<Whales look more like fish than they look like horses. Do we then classify 
whales within Pisces
instead of Mammalia?>

  I can personally tell you that I've never confused a whale with a fish. They 
have, on the
outside visually, flubbery flesh, nostrils for breathing air, an extrusionary 
organ for copulation
in males [penis], and they suckle their young (I have watched whale calves 
suckle). These indicate
an intrinstic mammalian appearance.

  By similar token, pterosaurs and birds were once regulated to a single clade 
exclusive of other
reptiles (incl. dinosaurs) called Dracones, based solely on their similar 
adaptations to flight.


  I am curious, however, George, why you use Pisces? By your definitons, it is 
polyphyletic, not a
viable stem-clade, as all bony fish (Osteichthes) includes tetrapodomorphans, 
and thus, most
un-fish like vertebrates. The most inclusive clade comprising bony fish is 
Actinopterygii,
excluding dipnoans and tetrapods (Choanata, I believe). Pisces has not been 
used as a formal group
I beleive, for a century or so...


=====
Jaime A. Headden

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

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