Re: BAD vs. BADD (was: Re: Most popular/common dinosaur misconceptions)

[Tim Williams <twilliams_alpha@hotmail.com>]

Jaime Headden wrote:

> > I?m afraid I don?t quite get what you are saying here. Why is it okay to 
> > call
> > a bird a dinosaur, but it?s not okay to call a snake a lizard? Especially 
> > when
> > you seem to be in agreement with Pianka & Vitt on just that, further down 
> > in
> > the post.
>
>   A lizard, unfortunately, entails the idea of a sprawling legged animal. 
> Although it is technically correct to refer to snakes as "legless lizards",

This is something Mike Keesey is pounding away at (very articulately too), 
but there is a distinction between vernacular and phylogenetic usage.  Sure, 
there's an overlap - such as 'dinosaur'.  As well as being applied by 
non-scientists to almost any extinct animal, the word 'dinosaur' is also 
used as a metaphor for any outdated concept ("this machine is a dinosaur!").

But trying to let the vernacular usage of a term direct the 
scientific/phylogenetic usage is letting the tail wag the dog.  Birds are 
dinosaurs, and the rest are non-avian dinosaurs.  The bats-are-mammals 
analogy is perfectly suited to the phylogenetic concept of 
birds-are-dinosaurs.  There is no distinction between "evolved from" and 
"evolved within" (contra Jura/Jason).  Phylogeny only recognizes 
relationships by descent.

Cheers

Tim