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Re: Dinosauricon Phylogeny: in progress



T. Mike Keesey wrote:
... as I said in my original post, _Ornithopoda_ isn't done yet.
Since basal _Ornithopoda_ have not been the subject of many analyses, I will
probably simplify the structure (big polytomies), as with basal
_Sauropodomorpha_.


[snip]

See original post.


Oops. :-(

> --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.



So in otherwords, you're going to split up genera, as opposed to lumping them, does this mean that North American ornithomimids will be polygeneric, as opposed to be lumped into _Ornithomimus_?


> Why are _Neovenator_ and _Acrocanthosaurus_ not carcharodontosaurines or
> allosaurines?

It seemed to me word was still out on which side they belonged to.


Is it? I thought that _Neovenator_ has always been considered a carcharodontosaurine.


> Why is _Stenonychosaurus_ a separate taxon from _Troodon_?

I think there's been DML discussion on this, but it could be argued that
_Troodon_, being a tooth taxon, should be considered dubious. Dubious taxa are
simply shown as _incertae sedis_, since the designation of _nomen dubium_ is a
little subjective (or, at best, prone to change) for my tastes. (Well, so is
_incertae sedis_ -- but I kind of need that one.)



So you regard the other material as _Stenonychosaurus_?


Nick Gardner

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