CLADISTICS AND PALEONTOLOGIST(S) OF THE CENTURY

[Tetanurae <Tetanurae@aol.com>]

SCROLL DOWN IF YOU HATE CLADISTICS

Jonathon Woolf wrote:
 <<Very good.  That's my exact question.  Unfortunately, you haven't given a
good
 answer yet.  No matter what alternatives, evasions, exceptions, riders, and
other
 1040-grade complexities you introduce, you cannot get away from the fact that
 ultimately, organisms are classified based on physical characteristics,>>

This is surprising to you?  Did you think that cladist told people they had
some magical way of deciphering the relationhsips of organisms?  Of course
not, they use characters to decipher the relationships.  Here is an
explanation on how to construct a cladogram in three easy steps that I give to
my non-scientist friends:
1) construct a spread sheet with species on the Y axis and character numbers
on the X axis
2) examine specimens to determine the proper character state for each of the
species and fill out the spreadsheet
3) plug the data into cladistic analysis program that will make trees based on
the statistically most likely distribution of characters

Not much to it....

That is completely different from naming clades, which is obviously what you
are bungling up with.  Clades are defined on ancestory because they are stable
as opposed exclusive membership based.  No matter how the topology changes, at
least some part of the classification stays intact.

I believe your original gripe had to do with nothing more than the fact that
Arctometatarsalia - named after the arctometatarsus - was a bad name since the
arctometatarsus evolved more than once.  So what?  Bird-like feet have evolved
at least three times, yet we keep the name Ornithopoda.  Even within
Ornithopoda, only hadrosauroids, dryosaurids and Gaspirnirsaura have even
remotely bird-like feet and the vast majority retain the primitive dinosaurian
pattern, yet we keep that name....  Not all ceratopians have horns, not all
pachycephalosaurs had markedly thick skulls....  I could go on, but I won't
because I pray you see the point...

 <<Question: how does one tell if a given organism meets this definition?  If
you
 answered, "by analyzing its characteristics," go to the head of the class.
All
 useful taxonomic definitions are ultimately character-based.>>

You are confusing diagnosis with definition.  Arctometatarsalia is DEFINED as
"Ornithomimus and all animals that share a more recent common ancestor with
Ornithomimus than with modern birds."  It is DIAGNOSED however by the
arctometatarsus (which, in fact, differs quite substantially from other forms
of arctometatarsaly), D-cross section premax teeth etc etc..

 <<Irrelevant to my original point: if the characteristic for which the taxon
was named
 is not a synapomorphy for ALL species within the taxon, the name is
inconsistent
 with the facts.>>

Ornithopoda again, Ceratopia again, Pachycephalosauria again, Phytosauria
again....
 
 <<Technically, no.  But if the definition is goofed to the extent that the
clade has
 no useful meaning, both name and clade should be dropped from the literature
and
 declared passe.>>

The clade has a perfectly useful meaning: "Ornithomimus and all animals that
share a more recent common ancestor with Ornithomimus than modern birds"  Just
because some members might not have the charactter that the clade was named
for doesn't mean that the name is obsolete.  The plain fact is that most if
not all currently recognized members of Arctometatarsalia have a very
distinctive arcometatarsus that is different from other forms of the
arctometatarsus.
 
 <<Nah, if I'd wanted to give that impression I'd have said "it's cladistics,
it's not
 supposed to make sense."  At the moment, as far as I can tell what I said is
 entirely correct: you and other hardcore cladists don't care if what you do
makes
 any rational sense.>>

It makes perfect rational sense.  If you would put aside the arogence for one
second and took the time to actually figure out what the hell you were talking
about, perhaps something could be done that was remotely useful.

 <<Claiming that characteristics don't matter when defining taxa
 is prima facie irrational -- with most organisms and all fossil organisms,
 characteristics are the only things we can use for definition of taxa.>>

Again, you are misunderstanding diagnosis with definition, whch reiterates my
previous point about having the slightest inkling of a clue about what you
were talking about.

AND NOW FOR SOMETHING COMPLETELY DIFFERENT:

Paleontologist of the century.  Since I know almost nothing about paleontology
outside of vert paleo, and even then if they are not involved in archosaurs, I
tend to get distracted....  But, here I shall wax philosophical...  Some
people want to chose Paul Sereno or Tom Holtz, and although the'r contribution
has been substantial, the fact that they got their phd's in 87 and 94
respectively, would make me think that they'd do the bulk of their work in the
upcoming century.  I do not think that Bob Bakker would be a good choice
because although he has popularized paleontology and has wacky ideas and has
forced a lot of people to reinterpret things, he almost never publishes and
when he does it is in a journal that no one can get ahold of.

I believe hands down, it would have to be Al Romer for his numerous
contributions to the vert literature that are still in use as we speak.
However, as for dino paleontologists I would have to say Franz Nopsca simply
because he was cool and queer and prolific, Jack McIntosh because he is one of
the most interesting and lively people I have ever had the pleasure of meeting
and makes paleonttology alive to me, and finally Peter Galton not only because
he did a lot of ornithischian work, but because he is tremendously prolific
and his work will stand the test of time.

Peter Buchholz
Tetanurae@aol.com

I'm takin some Eric Roberts home in a doggie bag, anyone else want some?