Re: Ornithomimid beaks

[Graydon <graydon@dsl.ca>]

On Sat, Sep 01, 2001 at 02:45:32PM +0000, Marilyn Wegweiser scripsit:
> <SNIP>
> >How many times did beaks evolve?
> 
> Many, many times. Look at the Mollusca for example. There are many with 
> beaks. A beak is a polyphyletic derivision.

Teach me to ask an unqualified question. :]

I meant to ask, 'in theropods, how many times did beaks evolve?'; it's
obvious that there are many beaked things (squid, turtles,
dicynodonts...) and it's obvious that there have been beaks more than
once in the dinosauria (ornithsichians and aves), but so far as I know
it's *not* obvious how many times beaks came up in theropods, or whether
they're a synomorphy for the clade that has Aves in it, or if some
*type* of beak is.

Probably not enough fossil evidence one way or another, alas.

-- 
                           graydon@dsl.ca
               To maintain the end is to uphold the means.