Re: Archosaur Origins...was:MESENOSAURUS ERRATA

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

I wrote:

<< I should not have made such a generality.... however, I can pretty much 
assure you that there
are very few people who would conceivably confuse a titanosaur with a turkey. 
They are also
separated by a great deal of phyletic distance. Besides, you haven't answered 
my question. >>

George Olshevsky (Dinogeorge@aol.com) wrote:

<By the same token, they're not likely to confuse a turkey with an eagle, 
either. What's happening
here is that >you< are the one making the aesthetic judgment, when you want to 
keep dinosaurs from
being classified as birds despite the fact that they're more closely related to 
modern birds than
they are to any other extant animals. The idea of Apatosaurus as a giant, 
four-legged bird may
seem strange at first, but after a while you get used to it. Just as the idea 
of a hummingbird as
a small, flying dinosaur takes some getting used to.>

The point here is that birds _are_ dinosaurs. Escaping this is impossible. This 
is an event
horizon for one of the biggest singularities in paleontology, similar to the 
mammal line. Basing
groups on only living membership, regardless of the fossil diversity or the 
sense of priority,
which George should be aware of given his DGL. What I and others note is that 
redefining the group
of archosaurs as Aves and then applying the term "bird" to this, both of which 
George has
suggested doing, is based on a judgement of "hat seems right", and that's an 
aesthetic statement.
The idea of *Apatosaurus* as a four-legged bird is not just wrong, it defies 
the definition of
bird, both aesthetic and historically actual. George is welcome to use another 
term, but the
concept of a "bird" has been set in stone for many thousands of years as 
feathery, winged and
warmblooded. These animals descended through cold-blooded, featherless, and 
unwinged animals, some
which were quadrupedal, and this is an evolutionary tract. "Bird" remains 
unchanged. I thus do not
see this as informing the public as much as trying to ram a variable and an 
aesthetic concept down
the public's throat.

George also wrote:

<I see nothing contradictory in the system I outlined. What could be simpler? 
If it's more closely
related to modern birds than to any other animals, why not call it a bird (or, 
if you like, bird
sensu lato)?>

  Because the terms Dinosauria and Ornithosuchia and Avemetatarsalia, etc., 
have priority. Their
structure is defined. I see no reason to opt for a more inclusive Aves based on 
modern birds, when
other terms are available. What I see is the reluctance [forgive me if I'm 
wrong] to calling birds
dinosaurs, again based on an aesthetic concept of dinosaurs as traditional 
"reptiles", perhaps.
This only means working on the Reptilia group.... Linnaean definitions should 
be forgiven and
dropped from the annals of biology and taxonomy unless as an historical 
footnote, which I'm afraid
may be the delegation of an otherwise brilliant man. He worked in the system he 
"beleived" in, his
focus just didn't include evolution, and the sad truth is, he was wrong.

  Forgive me for being harsh,

=====
Jaime A. Headden

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

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