[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

Re: Enigmosauria



Mickey Mortimer (Mickey_Mortimer111@msn.com) wrote:

<You used Caudipteridae here- http://dml.cmnh.org/2002May/msg00026.html
http://dml.cmnh.org/2001May/msg00513.html In any case, if you chose to
ignore Enigmosauria based on the moratorium, with the above exceptions
being mistakes, I wouldn't fault you.  But you said yourself there is more
reason than that...>

  I have used Caudipteridae because it is a formally, fully validly
diagnosed and determined "Family" taxon covered by the ICZN. It doesn't
require a definition. I also consider this taxon to be equal to
*Caudipteryx* until another taxon is closer to *Caudipteryx* than to any
other established "genus." In the times that I have used it, it has
usually followed the previous authors or discussors using it (in the
examples above, Greg Paul and Ken Kinman, respectively). There was at one
point a considered use (based on the ICZN) but I have a tendency to use a
lot of taxa (e.g., *Oviraptor*) that have not been phylogenetically
defined ... since I consider all species equal (as Mickey should well
know), this is not inconsistent. I tend to take taxa defined for the sake
of a defined node with a grain of salt, and do not currently use
Caudipteridae, not even on my website, where I do discuss *Caudipteryx*.

<Yes, for those people unable to comprehend the concept of a clade being
labeled in a cladogram, Enigmosauria's meaning would remain completely
ambiguous. Luckily, the cladogram shows us two taxa are included
(Therizinosauria, Oviraptorosauria) and many others excluded
(Eumaniraptora, Troodontidae, Compsognathidae, Ornithomimosauria,
Tyrannosauridae, etc.).  THIS is it's usage.>

  You would define that as a stem-defined node? That was your usage? Or
maybe the first part of that sentence, a node defined on oviraptorosaurs
and therizinosauroids? Or perhaps it's a stem including one of those two
and excluding all other taxa on the cladogram but for its sister-group?
Which of these definitions is the unambiguous intent present in the
figure?

<It's not a very specific usage, but it's a usage nonetheless.>

  The keyword here is "ambiguous," though Mickey uses "not very specific,"
but then, that's the point, and Mickey is repeating what I said in the
last post of this thread. If it's ambiguous, its usage cannot be made
applicable when using other taxa. Say, maybe *Incisivosaurus* (or perhaps
*Protarchaeopteryx* in deferrence to Senter et al. [in press] or Mortimer
[here on the list]) is the sister group to BOTH therizinosauroids and
oviraptorosaurs ... how would this relate on that cladogram? If you can
explain how the figure explains use of the name as a definition in an
unambiguous way, I would like to hear it.

<Anyone shown the cladogram, even who hasn't been online, would see it's a
group that includes therizinosauroids and oviraptorosaurs.>

  This doesn't matter. You are trying to make an argument about how it
DOES relate to them, but not HOW, and the HOW is what is required to make
the use of the given name unambiguous. As I would have hoped to have shown
above, there is little if any unambiguity.

<As I argued here http://dml.cmnh.org/2003Jun/msg00371.html , many other
clade names have equally ambiguous usage, yet are not rejected by you or
others.  Using my example on that page, Charadriiformes.  Is it
stem-based? Node-based?  A crown group?  A total group?  We don't know,
it's not defined anywhere.  All we have are lists of included taxa, much
as the cladogram shows two taxa are included in Enigmosauria.>

  I beleive various authors have supported that all standard orders of
modern birds be treated as either crowns or as stems from all other
standard orders of living birds. It is not MY place to use this, or allow
myself to be inpeached for the use of the word, since it's use has been
firmly established by wrote for over two hundred years, even though its
applicability as a stem or crown is also ambiguous. It however, has gone
under proper naming conditions, not just in a figure, and as you may (or
may not) remember, I was involved in the discussion regarding
*Enantiornis* being named in a figure, and the debate over THAT was quite
heavy. As a genus and species, it's situation was quite affirmed, not so
the given name, which without any other published use or referrence is,
ONCE again, ambiguous. Charadriiformes, though while mildly less
ambiguous, needs a definition. I do not reject this. I beleive, however,
that Sibley and Alqvist have suggested some definitions for most avian
groups, but cannot recall them off the top of my head.

<Paul made up his own subtly different equivalents for Theropoda,
Tetanurae, Maniraptora and Pygostylia, and efffectively ignored those
older names.>

  Paul did not use his names to approximate those, though he did reject
using them, as his names applied to clades that were entirely different
and may resolve to moments in history that are NOT contingent on those
names. As those names have been node or stem-defined, and Paul's
apomorphy-based, they do reflect entirely different effects on a
cladogram, especially if, say, Averostra (which does not reflect
Tetanurae, but a more basal clade including *Dilophosaurus*) is found to
demonstrate a different content. The new SVP abstracts suggest that if
*Procompsognathus* is NOT a dinosaur, but a more basal
ornithodiran/avemetatarsalian, then it does indeed show that Pauls'
Avepoda includes Theropoda ... and as perhaps all basal dinosaurs where
effectively three-toed without use of the hallux on the ground, then his
name also includes Dinosauria. So, Paul is not a good example of renaming.
As for Sereno, note that every new definition will get more refined, and
since there are no rules FOR definitions ANYWHERE, anything goes; from
these, the best can be selected, or a new one coined, to reflect whoever
gets to "decide" which definition will be used ... any at all.

<At this point, it's a matter of convincing others your ideas for a name
are right. If they follow you, congratulations, if they don't, it's your
risk for using taxonomy others don't and confusing people down the line.>

  If my ideas for a name are not followed, that's their fault. If I choose
a name and define it, and the people who choose to ignore my name choose
their own, and define it by the same token, they practice an hypocrisy: by
renaming my definition, they contradict the rules they follow in naming
theirs, and this is usually where the Principle of Priority [adapted from
the ICBN/ICZN] steps in.

<That's fine.  Others use (a very accommodating version of the) Phylocode
as the basis, and thus prefer definitional priority over chronological
priority.  Others define names in ways that blatantly contradict Phylocode
rules.> 

  As we have both argued against, and agree on mutually.

<The same things can all be said about virtually any 'order' of birds. 
Tell me how Charadriiformes is different than Enigmosauria in ways related
to its lack of definition.>

  Historical use and the work on referring to it a basic anatomical
paradigm, as has been done for more names than people defining names have
done. This implies that apart from the crown or stem uses noted above, it
can also be treated as an apomorphy-based named based on a suite of
apomorphies (a suggestion I posted to PhyloCode a while back that has NOT
been considered) rather than just one feature. In this case,
Charadriiformes has a distinct "life" that the given name has NOT, except
outside publication.

<If anything, Charadriiformes is more useless, since it's had multiple
combinations of content over the years.  It's included pigeons,
sandgrouse, cranes, rails, herons, bustards, and all sorts of other birds
since Garrod named it in 1873.>

  I agree with part of this: most names used in Aves and Mammalia are
largely useless by the same token. One thing it's been used as has been a
"shorebird" wastebasket, but since the last two decades, the content has
not been changed as drastically as spoken of by Mickey, as it should be
plain from recent genetic studies using both nuclear and mitochondrial
DNA.

<That's right.  It's all a cooperative, subjective, contradictory mishmash
of ideas and concepts at this point.>

  But that's the point. "Cooperative." This gives this nomenclature,
formally accepted, diagnosed, and "ranked" for centuries, validity. It
also suggests its definition. Charadriiformes was originally "defined" but
its included content, and has been "defined" by each approach to include
or exclude taxa. It was NOT named in a figure, and it has NOT been argued
to have been established UPON a figure.

<But now we have this debacle created by Naish et al. second guessing
themselves and mistakenly leaving it in, which has made the whole field
uneasy about naming it.>

  Naish et al. did not second-guess themselves, as it was a recommendation
made in review. The point of the paper was NOT to name taxa without a
thourough discussion of the taxa involved and a phylogenetic analysis to
support it, so they removed the name. Note that while there ARE a lot of
analyses that purport to find them, some are ambiguous, or some where
designed to find those phylogenies with little outgroup support for other
taxa, or support for other relationships without so much of "ovi + segno"
supporting characters as it should have. As for the "whole field" being
uneasy, this has not been the case, and Naish et al. have deferred the
case to those suited to the study of the group in specific and its
nomenclature. This should be more of the flavor of nomenclators, rather
than trying to name clades they think should be named, but performing
parsimony and other studies to test their theories, and only THEN name
based on such support.

  Incidentally, in the new SVP abstracts, Kirkland et al. and/or Zanno et
al. suggest that *Thecocoelurus* is a therizinosauroid ... which is rather
interesting as Naish/Naish et al. previous analysis of the material has
leaned more toward the oviraptorosaur identity, though the published
analysis placed it in an unresolved position regard either
therizinosauroid, or oviraptorosaur, as a trichotomy.

<And it's ridiculous.  Look at how many names Sereno publishes that work
in FAR less topologies than Enigmosauria would (assuming a rational
definition like : Oviraptor philoceratops, Enigmosaurus mongoliensis <-
Tyrannosaurus rex, Ornithomimus velox, Troodon formosus, Deinonychus
antirrhopus, Vultur gryphon).  Someone just needs the guts to get it over
with.>

  If anyone missed it, I have explained this is in the works. To quote Tom
Holtz, "Wait for the paper."

  Cheers,

=====
Jaime A. Headden

  Little steps are often the hardest to take.  We are too used to making leaps 
in the face of adversity, that a simple skip is so hard to do.  We should all 
learn to walk soft, walk small, see the world around us rather than zoom by it.

"Innocent, unbiased observation is a myth." --- P.B. Medawar (1969)


                
_______________________________
Do you Yahoo!?
Declare Yourself - Register online to vote today!
http://vote.yahoo.com