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A NEW REF, SOME TETRAPODS, AND CLADISTICS & PT



NEW REF
First of all, here is a new ref that I haven't seen on the list yet:

Chinsamy, A, Martin, L D, and Dodson, P.  1998.  Bone microstructure of the
diving bird _Hesperornis_ and the volant _Ichthyornis_ from the Niobrara Chalk
of western Kansas.  Cretaceous Research 19:225-235.

They come to the conclusion based on bone microstructure that these two birds
had a more advanced physiology than _Patagopteryx_ and enantiornithines.

TETRAPODA
I don't get this discussion at all.....  Tetrapoda has never had any sort of
coloquial usage like Reptilia.  There has never been a lable "tetrapod" that
excluded stuff like snakes or birds because they don't have feet.  In
elementary textbooks when they introduce the term tetrapod, they show a
picture of a snake without fail.

CLADISTICS AND PT
Jonathon Woolf wrote:
<<c), as you point out, is the cladistic one, and the cladists can have it
for all I care.  Any definition that says _Seymouria_ isn't a tetrapod has no
rational basis as far as I can tell..>>

To which Jon Wagner responded:
<<We've been through "rationality" and taxonomy before. Please check
the archieves under "Arctometarsalia".>>

Which caused Jonathon Woolf to answer with:
<<So we have, and you're still wrong. Without some reason applied to it, any
"classification method" is simply a recipe for manufacturing meaningless
collections of random syllables.>>

Alas, I do not wish to further this "discussion," but I feel we need to remind
everyone of a few things:
1) scientific names are just labels and needn't tell you ANYTHING 
"a rose by any other name would smell as sweet..."
2) there is no reason to have 'reason' applied to it, as long as everyone
agrees to what something means, then that is what it means

<<Since reason is something that's noticeably lacking in the way many alleged
experts in the field apply cladistics, the method itself is effectively
worthless.>>

SAYS WHO!?  You have continually claimed that cladistics is worthless without
any proof.  HOW is cladistics useless?  The application of cladistics is
almost universally accepted and used by everyone in any field of biology.

Cladistics is not the same as phylogenetic taxonomy.  Cladistics is filling
out matrices, chugging them through a computer and coming up with a tree etc
etc.  Phylogentic Taxonomy is the application of formal names with unambiguous
definitions to clades.

<<_Homo sapiens_ is supposed to be a thinking animal -- so why not think
instead of mindlessly following the rules?>>

No one is mindlessly following anything.  These rules are subject to change,
but are agreed upon by most everyone.  Try to keep the ad hominem to a
minimum.

Wagner:
<<The idea behind crown clades (at least in part) was to restrict taxa
based on extant animals to the most recent common ancestor of all extant
froms and all of its descendants. The purpose was to "clean house".>>

Woolf:
<<If membership in a group can't be diagnosed, the group is effectively
useless -- and in a number of cases there is no known way to distinguish
members
of a crown-based clade from their immediate ancestors.>>

Yes, that is probably true of their IMMEDIATE ancestors, but most of the time,
you can distinguish whether or not they fall within a clade or are outside of
it.

<<There is a long, long string of fossil forms from the latest Triassic up
through the mid Cretaceous that look mammalian in every detail -- but can't be
called mammals because they date from before the last common ancestor of
Monotremata and Theria.>>

SO WHAT?  Why does this make crown-clades useless?  The farther you get away
from the crown-clade the less mammal-like these things are.  You could extend
this outgroup lumping out enough to make Eubacteria mammals.  You make a
definition and stick with it.  Stop whining about how nearly mammal-like non-
mammals are.  

_Marasuchus_ and _Psuedolagosuchus_ are close to dinosaurs, but aren't, but I
don't see Novas, Sereno or Arcucci whining to change the definition of
Dinosauria to let them in because they are really dinosaur-like.  You don't
see them saying that cladistics and PT are useless because _Marasuchus_ or
_Psuedolagosuchus_ is dino-like, but not a dinosaur...

These are the rules, if you don't like them use your brand of reasoning and
make new ones and publish them.  If they catch on, they catch on, if they
don't, then use these ones because these are the ones that everyone uses.

Peter Buchholz
Tetanurae@aol.com

Bacerial poop