Re: Dinosauricon Phylogeny: in progress

[Mike Taylor <mike@indexdata.com>]

> Date: Thu, 22 May 2003 11:37:31 -0700 (PDT)
> From: "T. Michael Keesey" <mightyodinn@yahoo.com>
> 
> Any corrections or suggestions are welcome, on- or off-list.

I hope that when this goes into the live site, it will be presented in
the form of the very useful ASCII-cladogram format that the old
Dinosauricon introduced?  Much easier to make sense of than the
intented bullet-lists.  (For your April Fool joke, you could have
claimed that you were going to use the Kinman System :-)

> Date: Thu, 22 May 2003 14:20:04 -0700 (PDT)
> From: "T. Michael Keesey" <mightyodinn@yahoo.com>
>
> > --Apatosaurinae
> >       |--Eobrontosaurus
> >       `--+--Apatosaurus
> >           `--Brontosaurus
> > 
> > What supports _Brontosaurus_ being a separate species?
> 
> You mean genus?
> I am provisionally (note that word!) using special stem-based
> definitions for all genera:
> (x is a species.)
> Genus(x) = Clade(x <- all other species used as internal specifiers
> for genera)
> 
> Thus, _Brontosaurus_ would be Clade(_excelsus_ <- all other type
> species of genera [including _ajax_]). The only way to invalidate it
> would be to show that _excelsus_ is a synonym of a type species of
> an older genus (_Apatosaurus ajax_???), or that it is ancestral to
> another type species.

Eh, but hang on, what's your definition of a "type species"?  Because
whatever you choose as being a type species induces a genus-clade
under your provisional "genus" concept.  It seems to me that you could
just has well have chosen to say "_excelsus_ is not a type species,
therefore we have no genus Brontosaurus".

In other words, your answer to Nick's quesiton "What supports
_Brontosaurus_ being a separate [genus]?" could have been "Nothing
supports it, I've just decided that's how I want it to be".

What am I missing?

 _/|_    _______________________________________________________________
/o ) \/  Mike Taylor  <mike@indexdata.com>  http://www.miketaylor.org.uk
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