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New Sauropod Analysis



A welcome change-of-pace:
Jeffrey A. Wilson, 2002. Sauropod dinosaur phylogeny:
critique and cladistic analysis. Zoological Journal
[London] 136(2):215-275
Jeffrey's 1999 dissertation, together with Matt
Bonnan's 2001 dissertation on sauropod locomotion,
Wilson/Sereno 1998, and  the array of
computer-generated animated "morphs" of sauropods, are
pushing the door of insight further open. Jeffrey in
both dissertation and the analysis published with Paul
Sereno, and now in this seminal analysis, has
presented a data matrix based, cladistic exegesis of
sauropod relationships using 234 characters. In the
process, Jeffrey's previous, cogent critiques of Mr
Upchurch's often convuluted analyses of sauropods are
upheld, and the interesting insights of Calvo/Salgado
1995 and Salgado/Coria/Calvo 1997 are elucidated.
Jeffrey's result: a paradigm of 234 applicable
characters of 27 genera. In Neosauropoda, one has
Macronaria (the "titanosaurs", largely known through
appendicular specimens) and Diplodocoidea (better
known through skulls and vertebrae). "Euhelopodidae"
is dismantled, at long last.
On a purely historical note, "Cetiosaurus" is
indeterminate scrap, and one wonders why the name
persists in one UK museum with a partial skeleton on
display. Perhaps -- like "Creosaurus" and
"Brontosaurus" embraced by Barneyologists who claim as
original ideas energetically advocated by the
now-forgotten Percy Lowe -- it is time for a summit
conference, as it were. I read with fascination
Gregory Paul's long analytical note on the Czerkas
compendium, and his pertinent remarks re: "academics"
and the "rads without official credentials". All of us
have to pay our rent and utilities, enabling one to
choose how to study organismal dinosaurology (even
"paleontology" is an oxymoron: dinosaurs survive, are
in need of constant study [and, yes, conservation and
protection from hominids])...paleontology as an
academic discipline is need of revitalization and
support (there are no longer  "Department[s] of
Paleontology" at any North American university). It is
possible to rigorously study taxa without linking
oneself to academic prisons -- and, because the data
is accessible with a little effort (university science
libraries, internet discussion groups, self-discipline
in extrapolating the data), the solution is:
self-publishing. I am not familiar with the actual
methodology of Stephen and Sylvia's "peer review"
process -- quite frankly, I don't care because I have
no reason to question their honesty and love of
dinosaurs;long before Bill Stout began publishing
scrap-books, Sylvia Czerkas demonstrated what an
enthusiastic observor of animals Charles R. Knight was
(regardless of the numerous errors of morphological
postures). At any rate: they (like George Olshevsky's
fine publications of genera lists [when will he
publish a volume listing all avian taxa, the ~ 9000
species existing? It could be done, using R.B. Sharpe,
existing data bases, AOU/BOU checklists, Peters, et
al.]), demonstrate that publishing one's own projects
is, in the end, the most parsimonious avenue.
But, I ramble in my musings re: Gregory Paul's
important manifesto of 12 September. I believe that
cladistic analyses are important, that phylogenetic
systematics provides one with the tools of sorting
through the labyrinths. Thomas Holtz's theropod
analyses, those of Jeffrey Wilson on sauropods, the
work of S.C. Bennett on pterosaurs (I am a heretic: I
believe pterosaurs and dinosaurs are sister taxa),
Gerald Mayr's work on the skulls and skeletons of
flying theropods of the Eocene (breath-taking, to say
the least), Allen Brush's analyses of feather
evolution, Jim Farlow's wryly humorous work on
smelling theropods...all are important analytical
tools, as are the Czerkas's work on the flying
troodontids/dromaeosaurs. 
Gregory Paul asks many to "Readjust your minds to the
new reality". I understand his frustration...as well
as his excitement over the fact that new, beautiful
skeletons of feathered dinosaurs are emerging. (Gerald
Mayr sent me a photograph of the psittacosaur with the
feathery structures on its tail, and I could only
think that feathers are an evolutionary novelty, to
borrow from E. Mayr, adapted for specific uses not
necessarily seen in other taxa.) As Gregory Paul
notes, and I would concur, macroevolutionary processes
are nonuniform (or nonlinear, if one prefers), not
neat-and-tidy. We are speaking of the Mesozoic: a far
more complex explosion and radiation of divergence
than some would realize, with insects, flowering
plants, dinosaurs, pterosaurs, et al. interrelated in
a web of ecological adaptation pressures and genomic
metamorphoses. Some dinosaurs ran up trees and learned
to fly, some ran down trees and learned to fly, some
flew and then became non-fliers.
My idea for a summit is not meant as humour. I believe
that phylogenetic systematics (be it Gregory Paul and
the Czerkas team, or Thomas Holtz et al. on the "other
side") needs to be free of the switch-blades of anger.
I agree with Gregory that an analysis is possible
without cladistics, but I believe that careful work
and analysis, supplemented with rigorous cladistic
data matrices (cf. Thomas Holtz's 2000 paper on
theropod phylogeny)is equally important. I further
believe (perhaps naively) that "the massive reversals
inevitably associated with flight loss in birds so
basal they are still basically dinosaurian in form",
as Gregory Paul writes, ARE analyzable by cladistic
methodologies. However, I equally and strongly concur
with Gregory Paul that, in the 1980s, there existed
the evidence that many theropods were secondarily
flightless taxa (which means the osteology retained
observable "traces" of flying grandparents, so to
speak). The flying dinosaurs were dissimilar to other
flying dinosaurs and flying pterosaurs, and yet...they
flew. And yet. Cladistics is a tool not the goal.
Which is why I believe that Gregory's observation
about the state-of-flux existing re: the relationships
of the emerging fliers/nonfliers is to be considered:
the "degree of mosaic evolution, convergence,
parallelism is so massive...that we simply do not have
a system that can restore the relationships....The
only solution is more transitional forms".
We do, indeed, have a system, Gregory, and Thomas
Holtz's 2000 phylogeny is a demonstration of how known
specimens can be analyzed without prejudgments.
Binary/multistate characters are unordered; facial
pneumatic structures are analyzable; and PAUP 3.1.1
with heuristic search options are usable. Thomas Holtz
clearly noted that "Branch-and-Bound and Exhaustive
search methods would require prohibitively long run
times given current computer calculation speeds".
(Livezey and Zusi are developing analyses of living
dinosaurs using osteology and soft-part anatomy, with
pre-K/T theropods as more successively removed
outgroups). The solution: networking several
high-speed computers together, with Branch-and-Bound
and Exhaustive search methods, and entering the
characters of the emerging taxa as they become known.
Cryptovalans, sinornithosaurs, Jeholornis,
Scanoriopteryx, etc. etc. are animals whose character
states are known variably and can be analyzed. (And
there's the fascinating work of Ken Dial which may
hold some of the behavioural "keys" to "seeing" how
these early feathered dinosaurs managed to survive.)
The result? I believe that the characters's
relationships would become clearer (or, perhaps, raise
further questions re: taxa predicated upon poorly
preserved specimens). 
And so. I am interested in least maximum parsimony
analyses of these emerging taxa, and asking why so
many became secondarily flightless, and so on.
That Gregory Paul has made significant contributions
is not the point, nor are disagreements with Czerkas's
elucidations. My point, Gregory, is that we are
looking at the same dinosaurs, with different methods,
or overlapping methods. The wings of different taxa
are not, as Matt Bonnan has stressed, homologous
(epigenetics > morphologies > ecomorphologies), but
they are wings. And Stephen Czerkas may argue that
dromaeosaurs are not dinosaurs (I would disagree). But
I would agree that flying dinosaurs emerged from
different clades, for different reasons.
I am reminded of two statements:
And so, they are ever returning to us, the dead. W.G.
Sebald 1996.
For me, memory evokes the theatre. For what is a
performance if not a fragment of memory in the process
of being born? It lives only for an instant in
eternity, a powerful human appeal to the beauty of an
existence that is nevertheless inevitably committed to
the ugliness and decreptitude of death. Elie Wiesel 2002.

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