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Re: Mongolian dinosaur inspires religion in grad student



At 04:42 PM 10/2/96 -0500, Tom Holtz wrote (quoting me) wrote:

>Actually, by rules of Linnean taxonomy, the superfamily would be
>"Ornithomimoidea" (Ornithomim- + -oidea).

        I hate this darned keyboard.  I do find it impressive that I
apparently misspelled this twice.  I plead weary fingers.  I have spent the
entire day cutting out crystal forms, thirty of which I found out yesterday
are due tomorrow...

>>course, in the phylogeny I presented, this taxon recieves his name
>>Bullatosauria.

>Bullatosauria is the node-based taxon joining Troodon (or Stenonychosaurus,
>as soon as a second distinct troodontid with the same tooth form is found in
>the Judith River... :-() and Ornithomimus.

        And in the phylogeny I presented, Tyrannosauroidea was closer to
Ornithomimus than to Troodon, and therefore, the clade (Tyrannosauroidea,
Ornithomimoidea, Troodontidae) was  covered by "Bullatosauria".
        Uh, were you joking about the stenonychosaur?  I don't read smiley
well...

>>        I am still unclear on how to handle the apparent "synonomy" of a
>>stem-based clade and a node-based clade...
>
>These will not be synonyms unless they use the same name.

        Sorry, I cannot remember the terms...  I was thinking of... is it
_subjective synonyms_ that include the same taxa?  Anyway, thanks for the
clarification!

>>        Note that, in the above, I assume Ornithomimoidea to be "all animals
>>more closely related to Ornithomimus than to Troodon or Tyrannosaurus."
>>Presently, this gives Ornithomimisauria: "all animals more closely related
>>to Ornithomimus than they are to Troodon",
>
>I like this one, which I use informally (until I formally define it
>somewhere...)

        It equally could apply to Ornithomimisauria, or you could specify
the superfamily as a node between, I don't know, say Garudamimus and
Ornithomimus or something.  I hope this doesn't happen.  I would be
interested to hear someone's justification for a taxon higher than a
superfamily for this clade.

>>or "the most recent common ancestor of Tyrannosaurus and
>>Ornithomimus and all of it's decendants."

>This I don't like.

        I was just misusing taxonomy.  If I can find whomever it was who
coined it (Barsbold?  Osmolska?), I think I'll apologize.  I can't help it,
I think it might help to name this clade.  I guess exapting (getting my
dime's worth) a previously used term is bad form (Holtz 1996).  Back to the
drawing board...

>>        But of course!  The D-shaped premax teeth of Pelicanomimus are
>>probably what keeps making the ornithomims come out as sister to the
>>tyrannosaurs!

>Have you coded the maxillary and dentary tooth form yet?

        To the best of my ability, I believe so.  Falls under:
        Extreme tooth density
        Teeth with a basal constriction

        I don't see what you're getting at quite yet.  I think that the
program is interpreting most of the tooth characters as Bullatosaur (sensu
Wagner, sorry again :) plesiomorphies.  It is possible that part of the
problem is that Holtz 1994 is still not fully integrated into the dataset
(and Russel et Dong 1993 is waiting...), because I left my great big
character map at home in Virginia.
        Like I said, work in progress...  :)

>As has been said before:  Homoplasy! Thy name is "Theropod"!

        It is possible that a modern "evolutionary taxonomy" of the
Coelurosauria migt more properly represent my current read on their phylogeny:
        Fuzzy-Class     Coelurosauria
                Infra-micro-order       Maniraptora
                Infra-micro-order       Oviraptorsauria
                Infra-micro-order       Arctometarsali
                
        We're all one big happy trichotomy!

        Wagner
+-------------******ONCE AGAIN, NOTE NEW E-MAIL ADRESS******---------------+
| Jonathan R. Wagner                    "You can clade if you want to,     |
| Department of Geosciences              You can leave your friends behind |
| Texas Tech University                  Because your friends don't clade  |
| Lubbock, TX 79409                               and if they don't clade, |
|       *** wagner@ttu.edu ***           Then they're no friends of mine." |
|           Web Page:  http://faraday.clas.virginia.edu/~jrw6f             |
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