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Re: Quo vadis, T. rex? [long]

On Thu, 8 Feb 1996, Jeffrey Martz wrote:

> > But do you see where I'm coming from?  The way I see it, birds *can't* be 
> > "derived enough" to "warrant being called something different", just as 
> > neither I nor any of my descendants can ever not be a mammal and a 
> > primate.  A bird can't change itself enough to erase who its ancestors 
> > were, or what its closest relatives are.  
> > In my book, the purpose of 
> > taxonomy is to illustrate what is related to what.  You can't do that if 
> > you go around ripping groups out of their proper places in the tree of 
> > life and pretending that they've become something else.  
>      We've become something other than crossopterygian 
> fish.  

We're not "fish" (an unscientific term for vertebrates that live in the 
water and breathe with gills), but you'd better believe we're 
crossopterygians!  (Actually, I prefer to crossopterygians + tetrapods as 
Sarcoscelidea.  The "Crossopterygia" would then be dismantled as a 
formal taxon and listed as "basal sarcoscelideans.")

> Taxonomy is useful in showing how things are related, but also in 
> how they differ which is why we call things by different names.  

Yes, they acquire a new name, but they don't lose the old one. The 
distinctiveness of birds is recognized by the fact that they have their 
own taxon, the Aves, but it is unnecessary and silly to try to emphasize 
the point by trying to say that they are not dinosaurs.

> This 
> does not alter phylogenetic relationships, only makes thing a little more 
> convenient.  We can use the different termss "birds" and "dinosaurs" while 
> recognizing at the same time that the first group is still descended from the 
> second.     

OK.  Use "dinosaurs" as a non-technical short-hand for non-avian members of 
the Dinosauria.  Just don't forget that in scientific terms, they're still 
memebers of the Dinosauria.

> LN Jeff

Nick Pharris
Pacific Lutheran University
Tacoma, WA 98447

"If you can't convince them, confuse them." -- Harry S Truman