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Re: Ceratosauria vs. Neotheropoda?

On Sat, Nov 21, 2009 at 7:50 PM, Tim Williams <tijawi@yahoo.com> wrote:
> I know Thecodontia is an extreme example; but I can see paraphyletic groups 
> being misused and abused by people who (whether by accident or design) equate 
> evolutionary 'grades' with clades, and come up with all sorts of spurious 
> phylogenetic hypotheses and conclusions as a result. ÂEven Paul (2008) is 
> somewhat guilty of this, in comparing the evolution of 'iguanodonts' (a 
> grade) with that of hadrosaurids (a clade), as if the two groups represent 
> separate halves of a whole (Hadrosauriformes), rather than one being a subset 
> of the other.

This could potentially be ameliorated by having a different
orthographic standard for them. At least one type of paraphyletic
group has potential here: the stem group including all non-X pan-X can
be written "stem-X" (where X is a crown clade).

T. Michael Keesey
Technical Consultant and Developer, Internet Technologies
Glendale, California