[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]
Re: Coelurus (and the "food fight")
Ken Kinman (firstname.lastname@example.org) wrote:
<Coelurosauria is not destabilizing, and I know the content of
Coelurosauria can be very destabilizing looking back twenty
years. Until 1994, no paper formally took Tyrannosauridae out of
Carnosauria (then an absolute mess) and put it into
Coelurosauria; other taxa have been included for no other reason
than they were small. Coelurosauria, among dinosaurs in general,
has had one of the most confusing histories, in itself, than any
other group except possibly Carnosauria. I wouldn't think you'd
want to use _any_ "formal" name less inclusive than Dinosauria.
<So I will continue to use the informal term coelurosaur. But
when you say maniraptoriform or maniraptor, I have to guess
whether you are following Sereno (who includes the
tyrannosauroids) or not (not to mention compsognathids and a
quite a few genera).>
When I use these terms, and I'm fairly certain Mickey does
this the same way, as does a great number of folk, including Tom
Holtz, Tim Williams, Mike Keesey, etc. I use them by their
proferred definition. So that when I said outside, I meant
outside. A node is defined as a group containing the most recent
common ancestor of at least two descendants, the point at which
they converge ancestrally being the "node." When something is
not a descendant of that ancestor, it is outside the node.
<It would be far less confusing and more concise (in terms of
content) just to say "coelurosaurs minus blah, blah, blah" (or
draw a cladogram, which I convert to a coding sequence), so I
will no longer use either maniraptoran or maniraptoriform.>
When one says "coelurosaurs minus blah, blah, blah" one can
simply say Coelurosauria, with the recognition that somewhere,
someone defined this group as (Neornithes <-- *Allosaurus*). So
that all taxa closer to birds than to *Allosaurus* are
coelurosaurs. Coelurosaurs minus compsognathids, *Deltadromeus,*
or *Dryptosaurus* are possible... But the definition does not
include them, and no where in the manual for phylogeny does it
say that once a content is established, this must stay with the
name. Content is fluid as knowledge increases ... if anything,
the differences between Holtz, Sereno, and as Mickey points out
[I was wrong, I'm blushing abashedly], Forster et al., Sues, Xu
et al., should show us where the problem taxa are. The stable
arrangement is what gets qualified in the phylogenetic
nomenclature and taxonomy, and this is what gets done.
<You are slicing up the tree into too many *formal* pieces, and
as Benton has noted, it going to just get messier and messier.>
No one is slicing the tree up. There is no tree. There are
those who feel that a certain arrangement might be more true
than another, and provide language for referring to this. For
those who work with arthropods, ungulates, mollusks, or
reptiles, there is a specialist's need to further define groups
beyond Arthropoda etc. Benton has added his fair share of taxa
with definitions, as well, so he's contributed to this so-called
"mess," beleive it or not. Eureptilia, Avemetatarsalia, etc.
don't confuse the issue? One analysis that comes along to
disrupt a beautiful little world does not mean that the system
has to be dropped.
<I not saying Linnean classification doesn't have it problems,
buyt at least it was a palatable stew of sorts.>
You prefer typology over ancestry-based arrangements?
<Soon we will either have "mush" or one faction of "cooks" will
have to try to oust the other group of cooks, and we will have
one big food fight that could paralyze the nomenclatural
restaurant for years.>
No one says you have to use Holtz' pots. You choose to ignore
some names, fine. The arrangement can stick. You ignore that,
and you begin to shoehorn typology into PT. Then we have more
than cooks in the kitchen, its the farriers, and the tailors...
Jaime A. Headden
Where the Wind Comes Sweeping Down the Pampas!!!!
Do You Yahoo!?
Get personalized email addresses from Yahoo! Mail - only $35
a year! http://personal.mail.yahoo.com/