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Rant (was RE: Details on SVP 2002 Part 2)

> From: Dinogeorge@aol.com [mailto:Dinogeorge@aol.com]
> In a message dated 10/16/02 1:10:37 AM Pacific Daylight Time,
> Mickey_Mortimer111@msn.com writes:
> << A phylogenetic analysis of 149 characters was performed, producing the
>  following tree-
>  |--Dryptosaurus
>  `--+--Alabama taxon
>     `--+--New Mexico taxon
>        `--+--+--Gorgosaurus
>           |  `--Albertosaurus
>           `--+--Utah taxon
>              `--+--+--Daspletosaurus
>                 |  `--MOR 590
>                 `--+--Tyrannosaurus bataar
>                    `--Tyrannosaurus rex >>
> My genericometer tells me that these new taxa are simply more species of
> Albertosaurus, and may even be just individual variants of existing
> Albertosaurus taxa. And there are so many gross differences between
> Tyrannosaurus and Tarbosaurus that I just can't believe this analysis has
> been done correctly. Look at the skulls in top view once in a
> while instead
> of laterally! Count the teeth! And how did Dryptosaurus get in
> there? There's
> not enough material known for Dryptosaurus to say anything
> significant about
> it. How could anyone get 149 characters out of that junkpile?
> Cladistics, bah.

Okay, folks have been telling me all meeting about how I don't blow my cool
when dealing with posts on the list.  Folks, please note the time: I am now
blowing my cool on this list.  I am doing so here because unlike several
recent cases of newbies, George has been around long enough to know better.

George, you have NEVER SEEN the three new taxa: how can you *POSSIBLY* have
an informed opinion on them?

Carr has logged as many hours on tyrannosaurid specimens as just about
anyone alive: not pictures, not drawings, not casts, but *specimens*.

Given that Currie, and me, and Carr, and Brochu, and Carpenter, and Paul
*ALL* agree based on direct observations of specimens that Tarbosaurus and
Tyrannosaurus are closer to each other than they are to other tyrannosaurid
taxa (except perhaps for Daspletosaurus, which may or may not be within the
node joining these two), doesn't that give you some clue that PERHAPS this
analysis was done correctly?

Yes, they are different animals.  Duh.  Yes, they have different tooth
counts.  Duh.  No one has synonymized rex and bataar yet; they merely
recognize that rex and bataar are most likely closer to each other than they
are to the albertosaur-grade forms.

No one says one can score 149 characters *from Dryptosaurus*.  That you seem
to think they could suggests to me that after all these years you still have
yet to try to learn the technique, how it deals with missing data, etc.

There is vastly more material for Dryptosaurus than there is for fairy tale
tree-dwelling ancestors for every major branch of Dinosauria.  That
Dryptosaurus does share a handful (three or four) characters uniquely with
classic tyrannosaurids which are not observed in other theropods is now
documented by Carr (although Currie and I also made similar, although not
the same particular, observations).  Is it definitely a tyrannosauroid:
surely not.  Is it most likely a tyrannosauroid based on current
information: that is what the analyses are saying.

Coda the First: Lest people think otherwise, I do not "dogmatically" accept
Carr's phylogeny.   I think he might well be correct, but I haven't seen the
full detailed version (esp. with regards to the New Mexico and Utah taxa).
What I have seen, though, shows that it is a major scientific work.  Yes,
the results differ somewhat from my own, and from the work of others, but
that is okay.

Coda the Second: Lest people think otherwise, I actually think George has a
lot of good ideas and observations.  I am merely (over?) reacting to his
response to a description of research which he did not see.  George has been
aware of dinosaur research for a long time now, and has added important
taxonomic contributions.  However, BECAUSE he has been aware of the work for
this long, he should know better by now that one should wait and see the
specimens (heck, even a figure in this case) before making judgement.

(And if you are going to play the gross morphology game, then the Utah taxon
would make a better new Daspletosaurus than an Albertosaurus!).


                Thomas R. Holtz, Jr.
                Vertebrate Paleontologist
Department of Geology           Director, Earth, Life & Time Program
University of Maryland          College Park Scholars
                College Park, MD  20742
Phone:  301-405-4084    Email:  tholtz@geol.umd.edu
Fax (Geol):  301-314-9661       Fax (CPS-ELT): 301-405-0796