Re: Dinosaur Taxonomy (was Re: Re: dinosaur flatware)

[pharrinj@PLU.edu]

On Mon, 15 Jan 1996, Stan Friesen wrote:

> From: pharrinj@PLU.edu
> ither
>  > 
>  > But how can you classify the (hypothetical) common ancestor of 
>  > Herrerasauria and Theropoda in either group?  If you use a typological 
>  > classification, you cannot place it in the Herrerasauria, for instance, 
>  > because it necessarily lacks the defining characteristics of that group.
> 
> Not if the defining characters of Herrerasauria do not include any
> uniquely derived characters found only in the known herrerasaurs.

If that is the case, then no taxon Herrerasauria should ever be 
diagnosed, and the points discussed here become moot.

> 
> [Actually, I am not convinced that the known hererasaurs *do* form
> a monophyletic group - especially if one includes Eoraptor].

I totally agree about _Eoraptor_. It's too primitive to be a true 
herrerasaur.  I put it near the base of the Sarcodinosauria (_Eo._ + 
Herrerasauria + Theropoda).  It looks, too, like it's probably not very 
far removed from the Phytodinosaur ancestor.

> 
> swf@elsegundoca.attgis.com            sarima@netcom.com
> 
> The peace of God be with you.
> 

    Nick