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Re: non-avian "reptiles"




Jaime:
I do recognize a clade Dinosauria informally (at the end of my reptile classification---see below). I also recognize a clade Synapsida informally (at the beginning of my reptile classification----see below).
Note: The coding symbol _a_ shows that a group has a sister group within the previous group, and in a classification of Therapsiformes you would have another marker for mammals after the therapsid family they are most closely related to. This allows cladistic nesting and "semi"-paraphyletic groups to coexist in a single classification.
--------Ken Kinman
CLASS REPTILEA
1 Pelycosauriformes
_a_ Therapsiformes
_a_ {{Class Mammalea}}
2 Mesosauriformes
.
.
.
9 Saurischiformes
_a_ {{Class Avea}}
10 Ornithischiformes
*******************************************************
From: "Jaime A. Headden" <qilongia@yahoo.com>
Reply-To: qilongia@yahoo.com
To: dinosaur@usc.edu
CC: kinman@hotmail.com
Subject: Re: non-avian "reptiles"
Date: Wed, 2 Aug 2000 13:42:28 -0700 (PDT)

Ken Kinman wrote:

<It is certainly desirable to maintain "well-known"
classifications if they are correct, but that is not
one of my main priorities.>

  You had previously argued for maintaining some
historic perspective in classification (Reptilia;
distinction of Aves); why not extend this perspective
to all groups? I can answer this in one way for at
least some groups. Whatever the assumed relationship
of two fossil taxa, there will always be an upsetting
perspective, at some point in scientific time.

  It would be interesting why you say it is not your
priority to maintain well-known classifications, since
certainly Linnean taxonomy is so widely known it has
been taught in some grade schools, pick up a bio text
for High [Secondary] School or College in the States,
read the Brittanica or Americana, so, and they follow
this. Go international, and in at least German,
Spanish, English, Portiguese, Italian, and
French-speaking countries, they'll teach the same
thing. So quoting "well-known" would be a misuse of
data; and really, it evinces your personal perspective
of a generality (this is not a qualification of your
position, the term itself is a generality no matter
who or how you use it).

<For me the best classifications have what might be
called "heuristic value", and the cladistic
maximization of predictivity is only part of that.
Pure cladifications eventually suffer from some
combination of complexity, instability, confusion,
lack of utility, and certainly no way to reflect>
anagenetic information (divergence).>

  Pfff. Neither does Linnean. There is only a "I think
this feature meight be more telling as to phylogeny
and diversity than that" (as if a keeled sternum has
more phylogenetic information than a single-headed
quadrate) and this is not scientific. Cladistic
analysis uses computer algorhythyms to find best-fit
scenarios; the human elements is left to only the pick
and choose with characters, and this is testable by
repeating or changing the characters. If you think
they ran the character wrong, or shouldn't've used it
for whatever intrinsic value you place on the feature,
weighted or not, run it yourself, your way, and
compare results. Or, in other words, don't knock it
'til you try it.

<Cladists are fond of quoting Darwin wanting to base
classification on phylogeny, but he also advocated
reflecting divergence in classifications as well.>

  Science is about the science, not the people who did
it. Unless there is an abject partialism in the
statements or experiments, you should leave whose
quote is being used over whose else's, or which of
one's quotes is being preferred over another. Simply,
sometimes, a person can be wrong, and in one phrase,
be right (or apt) and wrong (off the mark).

<A mammal order will never equal an insect order, and
there is no reason that they need to be.>

  You just unarbitrarily weighted consideration of two
branches of life. Mammals and insects are two
different groups, and in most aspects of their
biology, insects have far more anatomical diversity
than mammals, with less hard-tissue effects on their
anatomy, being so small, they can diversify the shapes
of their chiton exoskeleton far more variedly than
flesh or hair does, etc....

<And I certainly would never removed Chiroptera from
Mammalia just because they fly. They can't match birds
in any measure of diversity that I am aware of, much
less geological range.>

  Pardon? What features do you use to quantify avian
diversity from other reptiles? Or for that matter,
compare to chiropterans, and you will find much the
same features concerning flight. Don't want to use
flight as the scale, but integument? Compare to
diversity of scale form and structure within Selachii
(anatomically similar to teeth) or just a single
"order" of "fish" like Perciformes.

<Although I am an eclectist, I have found a way to
nest groups without all the disadvantages of strict
cladifications.>

  I would disagree with your use of "nest" since
Linnean taxonomy as you have presented obviates
nesting (nodes, inclusions obviating exclusions),
where taking birds from within dinosaurs (or turtles
from within previous analyses of reptiles* and
diapsids*) is the exact opposite.

<Unfortunately when you try to explain this to either
traditional eclecticists or traditional cladists, both
sides think I'm "caving in" too much to the other
side.>

  I would also disagree with splitting scientists into
traditional anythings. This is unscientific, and
individuals can alter (and should, given new evidence
obviating a position) their positions quite easily.
Here on the list, the movement from non-saurischian
therizinosauroids to coelurosaurian therizinosauroids
happened quite dramatically (you can peruse the
archives for the extensive discussions on this
matter), but still there were several participants who
stated that presented evidence was too strong for them
to negate the position.

* vernacular

---------

  I would like to ask you if you could quantify (aside
from generalizing "diversity") the reasons you have
presented as existing for removing Aves from
Dinosauria, and also not even recognizing Dinosauria
as a clade.

=====
Jaime "James" A. Headden

  Dinosaurs are horrible, terrible creatures! Even the
  fluffy ones, the snuggle-up-at-night-with ones. You think
  they're fun and sweet, but watch out for that stray tail
  spike! Down, gaston, down, boy! No, not on top of Momma!

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