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Re: birds and/or/with dino's

Mike Keesey <keesey@gmail.com> wrote:

> Under the "phytodinosaur" hypothesis, Saurischia would
> become a
> heterodefinitional synonym of Theropoda. 

Wouldn't Saurischia have priority over Theropoda, given that Saurischia was 
named first?  In the event that sauropodomorphs are closer to ornithischians, 
Saurischia would quash Theropoda - if we let priority alone decide.

This is why I think it's important to frame definitions such that certain names 
are abolished if the clades they denote change radically in content.  In a 
situation where Saurischia is limited only to theropods, then there's not much 
point keeping the name Saurischia at all, IMHO.  We don't want Saurischia 
excluding sauropods, any more than we want sauropods ending up inside 
Ornithischia.  The addition of negative specifiers would preclude both 

> Or do you mean that they were considered paraphyletic, even
> though
> they later turned out to be polyphyletic?

Yep, they were originally envisaged as "ancestral stock" groups (stem-groups).

> You mean total groups, no? (Stem-Cetacea roughly
> corresponds to
> Archaeoceti.) Interesting idea.

Yep, my mistake.  I meant to say Cete would include both stem- and 
crown-Cetacea (Cete = pan-Cetacea), and Paraxonia would include both stem- and 
crown-Artiodactyla (Paraxonia = pan-Artiodactyla).  Either of these clades 
might also come to include mesonychians as well.

> Homerdefinitional cinnamons!